Soreq H


Full name : Soreq Hermona

First name : Hermona

Mail : The Hebrew University of Jerusalem\; Dept. of Biological Chemistry\; Edmond J. Safra Campus-Givat Ram\; Jerusalem 91904

Zip Code :

City :

Country : Israel

Email :

Phone : +97226585109

Fax :

Website : \/\/\/soreq\/home

Directory :

References (284)

Title : Ribosomal protein L24 mediates mammalian microRNA processing in an evolutionarily conserved manner - Tzur_2024_Cell.Mol.Life.Sci_81_55
Author(s) : Tzur Y , Dubnov S , Madrer N , Bar A , Nadorp B , Mishra N , Heppenstall P , Bennett ER , Greenberg DS , Winek K , Soreq H
Ref : Cell Mol Life Sciences , 81 :55 , 2024
Abstract : To investigate the mechanism(s) underlying the expression of primate-specific microRNAs (miRs), we sought DNA regulatory elements and proteins mediating expression of the primate-specific hsa-miR-608 (miR-608), which is located in the SEMA4G gene and facilitates the cholinergic blockade of inflammation by targeting acetylcholinesterase mRNA. 'Humanized' mice carrying pre-miR-608 flanked by 250 bases of endogenous sequences inserted into the murine Sema4g gene successfully expressed miR-608. Moreover, by flanking miR-608 by shortened fragments of its human genome region we identified an active independent promoter within the 150 nucleotides 5' to pre-miR-608, which elevated mature miR-608 levels by 100-fold in transfected mouse- and human-originated cells. This highlighted a regulatory role of the 5' flank as enabling miR-608 expression. Moreover, pull-down of the 150-base 5' sequence revealed its interaction with ribosomal protein L24 (RPL24), implicating an additional mechanism controlling miR-608 levels. Furthermore, RPL24 knockdown altered the expression of multiple miRs, and RPL24 immunoprecipitation indicated that up- or down-regulation of the mature miRs depended on whether their precursors bind RPL24 directly. Finally, further tests showed that RPL24 interacts directly with DDX5, a component of the large microprocessor complex, to inhibit miR processing. Our findings reveal that RPL24, which has previously been shown to play a role in miR processing in Arabidopsis thaliana, has a similar evolutionarily conserved function in miR biogenesis in mammals. We thus characterize a novel extra-ribosomal role of RPL24 in primate miR regulation.
ESTHER : Tzur_2024_Cell.Mol.Life.Sci_81_55
PubMedSearch : Tzur_2024_Cell.Mol.Life.Sci_81_55
PubMedID: 38261097

Title : Recent advances in cholinergic mechanisms as reactions to toxicity, stress, and neuroimmune insults - Kovarik_2023_J.Neurochem_17thISCM_
Author(s) : Kovarik Z , Moshitzky G , Macek Hrvat N , Soreq H
Ref : Journal of Neurochemistry , : , 2023
Abstract : This review presents recent studies of the chemical and molecular regulators of acetylcholine (ACh) signaling and the complexity of the small molecule and RNA regulators of those mechanisms that control cholinergic functioning in health and disease. The underlying structural, neurochemical, and transcriptomic concepts, including basic and translational research and clinical studies, shed new light on how these processes inter-change under acute states, age, sex, and COVID-19 infection; all of which modulate ACh-mediated processes and inflammation in women and men and under diverse stresses. The aspect of organophosphorus (OP) compound toxicity is discussed based on the view that despite numerous studies, acetylcholinesterase (AChE) is still a vulnerable target in OP poisoning because of a lack of efficient treatment and the limitations of oxime-assisted reactivation of inhibited AChE. The over-arching purpose of this review is thus to discuss mechanisms of cholinergic signaling dysfunction caused by OP pesticides, OP nerve agents, and anti-cholinergic medications; and to highlight new therapeutic strategies to combat both the acute and chronic effects of these chemicals on the cholinergic and neuroimmune systems. Furthermore, OP toxicity was examined in view of cholinesterase inhibition and beyond in order to highlight improved small molecules and RNA therapeutic strategies and assess their predicted pitfalls to reverse the acute toxicity and long-term deleterious effects of OPs.
ESTHER : Kovarik_2023_J.Neurochem_17thISCM_
PubMedSearch : Kovarik_2023_J.Neurochem_17thISCM_
PubMedID: 37429600

Title : Recent advances in cholinergic mechanisms: A preface for the ISCM2022 special issue - Kovarik_2023_J.Neurochem_17thISCM__
Author(s) : Kovarik Z , Soreq H
Ref : Journal of Neurochemistry , : , 2023
Abstract : This preface introduces the Journal of Neurochemistry special issue on Cholinergic Mechanisms that highlights the progress in the molecular, structural, neurochemical, pharmacological, toxicological, and clinical studies of the cholinergic system which underline its complexity and impact on health and disease. This issue comprises of (systematic) reviews and original articles, the majority of which have been presented at the 17th International Symposium on Cholinergic Mechanisms (ISCM2022) held in Dubrovnik, Croatia in May 2022. The symposium brought together leading "Cholinergikers" to shed new light on cholinergic transmission, ranging from the molecular to the clinical and cognitive mechanisms.
ESTHER : Kovarik_2023_J.Neurochem_17thISCM__
PubMedSearch : Kovarik_2023_J.Neurochem_17thISCM__
PubMedID: 38082541

Title : Novel single-nucleus transcriptomics unravels developmental and functionally controlled principles of mammalian neuromuscular junctions - Soreq_2023_J.Neurochem__
Author(s) : Soreq H
Ref : Journal of Neurochemistry , : , 2023
Abstract : Prof Ohno's team (Ohkawara et al. 2023, current issue) underscored the dynamic and functional features that co-shape the embryonic and early post-natal development of mammalian neuromuscular junctions (NMJs) using single-nucleus transcriptomics which provides specific insights into the activities of individually studied nuclei and their functional characteristics. Unlike other single-nucleus transcriptomics studies, which tend to be limited to single developmental time points, this article provides novel views of the complex developmental and regulatory dynamics and embryonic cell type origins underscoring the formation of functioning mammalian NMJs by combining this transcriptomic approach with interference tests in cultured C2C12 myotubes. This reveals intriguing novel links between the particular nicotinic acetylcholine receptor genes (nAChR) and regulator transcripts thereof and enables outlining the sequential development of functioning NMJs along embryogenesis and soon after delivery. Specifically, the timewise and cell type origins of the studied nuclei emerged as essential for NMJ neurogenesis and inter-cellular transfer of specific regulators has been indicated. Breaking the barriers between distinct research subdisciplines, this study opens new neurochemistry research directions that recombine developmental, regulatory, and functional transcriptomics in NMJ-including tissues. Moreover, these findings may facilitate tests of diverse pharmaceutical and therapeutic modulators of neuromuscular functioning in health and disease, assisting the translational research progress in treating devastating neuromuscular states such as in amyotrophic lateral sclerosis, myasthenia gravis or individuals poisoned occupationally or otherwise with anticholinesterase inhibitors.
ESTHER : Soreq_2023_J.Neurochem__
PubMedSearch : Soreq_2023_J.Neurochem__
PubMedID: 37942848

Title : Altered levels of variant cholinesterase transcripts contribute to the imbalanced cholinergic signaling in Alzheimer's and Parkinson's disease - Gok_2022_Front.Mol.Neurosci_15_941467
Author(s) : Gok M , Madrer N , Zorbaz T , Bennett ER , Greenberg D , Bennett DA , Soreq H
Ref : Front Mol Neurosci , 15 :941467 , 2022
Abstract : Acetylcholinesterase and butyrylcholinesterase (AChE and BChE) are involved in modulating cholinergic signaling, but their roles in Alzheimer's and Parkinson's diseases (AD and PD) remain unclear. We identified a higher frequency of the functionally impaired BCHE-K variant (rs1803274) in AD and PD compared to controls and lower than in the GTEx dataset of healthy individuals (n = 651); in comparison, the prevalence of the 5'-UTR (rs1126680) and intron 2 (rs55781031) single-nucleotide polymorphisms (SNPs) of BCHE and ACHE's 3'-UTR (rs17228616) which disrupt AChE mRNA targeting by miR-608 remained unchanged. qPCR validations confirmed lower levels of the dominant splice variant encoding the "synaptic" membrane-bound ACHE-S in human post-mortem superior temporal gyrus samples from AD and in substantia nigra (but not amygdala) samples from PD patients (n = 79, n = 67) compared to controls, potentially reflecting region-specific loss of cholinergic neurons. In contradistinction, the non-dominant "readthrough" AChE-R mRNA variant encoding for soluble AChE was elevated (p < 0.05) in the AD superior temporal gyrus and the PD amygdala, but not in the neuron-deprived substantia nigra. Elevated levels of BChE (p < 0.001) were seen in AD superior temporal gyrus. Finally, all three ACHE splice variants, AChE-S, AChE-R, and N-extended AChE, were elevated in cholinergic-differentiated human neuroblastoma cells, with exposure to the oxidative stress agent paraquat strongly downregulating AChE-S and BChE, inverse to their upregulation under exposure to the antioxidant simvastatin. The multi-leveled changes in cholinesterase balance highlight the role of post-transcriptional regulation in neurodegeneration. (235).
ESTHER : Gok_2022_Front.Mol.Neurosci_15_941467
PubMedSearch : Gok_2022_Front.Mol.Neurosci_15_941467
PubMedID: 36117917

Title : Distinct CholinomiR Blood Cell Signature as a Potential Modulator of the Cholinergic System in Women with Fibromyalgia Syndrome - Erbacher_2022_Cells_11_
Author(s) : Erbacher C , Vaknine S , Moshitzky G , Lobentanzer S , Eisenberg L , Evdokimov D , Sommer C , Greenberg DS , Soreq H , Uceyler N
Ref : Cells , 11 : , 2022
Abstract : Fibromyalgia syndrome (FMS) is a heterogeneous chronic pain syndrome characterized by musculoskeletal pain and other key co-morbidities including fatigue and a depressed mood. FMS involves altered functioning of the central and peripheral nervous system (CNS, PNS) and immune system, but the specific molecular pathophysiology remains unclear. Anti-cholinergic treatment is effective in FMS patient subgroups, and cholinergic signaling is a strong modulator of CNS and PNS immune processes. Therefore, we used whole blood small RNA-sequencing of female FMS patients and healthy controls to profile microRNA regulators of cholinergic transcripts (CholinomiRs). We compared microRNA profiles with those from Parkinson's disease (PD) patients with pain as disease controls. We validated the sequencing results with quantitative real-time PCR (qRT-PCR) and identified cholinergic targets. Further, we measured serum cholinesterase activity in FMS patients and healthy controls. Small RNA-sequencing revealed FMS-specific changes in 19 CholinomiRs compared to healthy controls and PD patients. qRT-PCR validated miR-182-5p upregulation, distinguishing FMS patients from healthy controls. mRNA targets of CholinomiRs bone morphogenic protein receptor 2 and interleukin 6 signal transducer were downregulated. Serum acetylcholinesterase levels and cholinesterase activity in FMS patients were unchanged. Our findings identified an FMS-specific CholinomiR signature in whole blood, modulating immune-related gene expression.
ESTHER : Erbacher_2022_Cells_11_
PubMedSearch : Erbacher_2022_Cells_11_
PubMedID: 35455956

Title : Cholinergic blockade of neuroinflammation: from tissue to RNA regulators - Zorbaz_2022_Neuronal.Signal_6_NS20210035
Author(s) : Zorbaz T , Madrer N , Soreq H
Ref : Neuronal Signal , 6 :NS20210035 , 2022
Abstract : Inflammatory stimuli and consequent pro-inflammatory immune responses may facilitate neurodegeneration and threaten survival following pathogen infection or trauma, but potential controllers preventing these risks are incompletely understood. Here, we argue that small RNA regulators of acetylcholine (ACh) signaling, including microRNAs (miRs) and transfer RNA fragments (tRFs) may tilt the balance between innate and adaptive immunity, avoid chronic inflammation and prevent the neuroinflammation-mediated exacerbation of many neurological diseases. While the restrictive permeability of the blood-brain barrier (BBB) protects the brain from peripheral immune events, this barrier can be disrupted by inflammation and is weakened with age. The consequently dysregulated balance between pro- and anti-inflammatory processes may modify the immune activities of brain microglia, astrocytes, perivascular macrophages, oligodendrocytes and dendritic cells, leading to neuronal damage. Notably, the vagus nerve mediates the peripheral cholinergic anti-inflammatory reflex and underlines the consistent control of body-brain inflammation by pro-inflammatory cytokines, which affect cholinergic functions; therefore, the disruption of this reflex can exacerbate cognitive impairments such as attention deficits and delirium. RNA regulators can contribute to re-balancing the cholinergic network and avoiding its chronic deterioration, and their activities may differ between men and women and/or wear off with age. This can lead to hypersensitivity of aged patients to inflammation and higher risks of neuroinflammation-driven cholinergic impairments such as delirium and dementia following COVID-19 infection. The age- and sex-driven differences in post-transcriptional RNA regulators of cholinergic elements may hence indicate new personalized therapeutic options for neuroinflammatory diseases.
ESTHER : Zorbaz_2022_Neuronal.Signal_6_NS20210035
PubMedSearch : Zorbaz_2022_Neuronal.Signal_6_NS20210035
PubMedID: 35211331

Title : Regulators of cholinergic signaling in disorders of the central nervous system - Winek_2021_J.Neurochem__
Author(s) : Winek K , Soreq H , Meisel A
Ref : Journal of Neurochemistry , : , 2021
Abstract : Cholinergic signaling is crucial in cognitive processes and degenerating cholinergic projections are a pathological hallmark in dementia. Use of cholinesterase inhibitors is currently the main treatment option to alleviate symptoms of Alzheimer's disease and has been postulated as a therapeutic strategy in acute brain damage (stroke, traumatic brain injury). However, the benefits of this treatment are still not clear. Importantly, cholinergic receptors are expressed both by neurons and by astrocytes and microglia, and binding of acetylcholine to the alpha7 nicotinic receptor in glial cells results in anti-inflammatory response. Similarly, the brain fine-tunes the peripheral immune response over the cholinergic anti-inflammatory axis. All of these processes are of importance for the outcome of acute and chronic neurological disease. Here, we summarize the main findings about the role of cholinergic signaling in brain disorders and provide insights into the complexity of molecular regulators of cholinergic responses, such as microRNAs and transfer RNA fragments, both of which may fine-tune the orchestra of cholinergic mRNAs. The available data suggest that these small non-coding RNA regulators may include promising biomarkers for predicting disease course and assessing treatment responses and might also serve as drug targets to attenuate signaling cascades during overwhelming inflammation and to ameliorate regenerative capacities of neuroinflammation.
ESTHER : Winek_2021_J.Neurochem__
PubMedSearch : Winek_2021_J.Neurochem__
PubMedID: 33638173

Title : Cortical VIP(+) \/ChAT(+) interneurons: From genetics to function - Dudai_2021_J.Neurochem_158_1320
Author(s) : Dudai A , Yayon N , Soreq H , London M
Ref : Journal of Neurochemistry , 158 :1320 , 2021
Abstract : One of the urgent tasks of neuroscience is to understand how neuronal circuits operate, what makes them fail, and how to repair them when needed. Achieving this goal requires identifying the principal circuitry elements and their interactions with one another. However, what constitutes 'an atom' of a neuronal circuit, a neuronal type, is a complex question. In this review we focus on a class of cortical neurons that are exclusively identified by the expression of vasoactive intestinal polypeptide (VIP) and choline acetyltransferase (ChAT). The genetic profile of these VIP(+) /ChAT(+) interneurons suggests that they can release both gamma-aminobutyric acid (GABA) and acetylcholine (ACh). This hints to a specific potential role in the cortical circuitry. Yet the VIP(+) /ChAT(+) interneurons are sparse (a mere 0.5% of the cortical neurons), which raises questions about their potential to significantly affect the circuit function. In view of recent developments in genetic techniques that allow for direct manipulation of these neurons, we provide a thorough and updated picture of the properties of the VIP(+) /ChAT(+) interneurons. We discuss their genetic profile, their physiological and structural properties, and their input-output mapping in sensory cortices and the medial prefrontal cortex (mPFC). Then, we examine possible amplification mechanisms for mediating their function in the cortical microcircuit. Finally, we discuss directions for further exploration of the VIP(+) /ChAT(+) population, focusing on its function during behavioral tasks as compared to the VIP(+) /ChAT(-) population.
ESTHER : Dudai_2021_J.Neurochem_158_1320
PubMedSearch : Dudai_2021_J.Neurochem_158_1320
PubMedID: 33301603

Title : Preface: Cholinergic mechanisms: This is the Preface for the special issue Cholinergic Mechanisms - Anglister_2021_J.Neurochem__
Author(s) : Anglister L , Silman I , Soreq H
Ref : Journal of Neurochemistry , : , 2021
Abstract : This special issue of the Journal of Neurochemistry, entitled "Cholinergic Mechanisms," presents 15 reviews and two original papers, which have been selected to cover the broad spectrum of topics and disciplines presented at the XVIth International Symposium on Cholinergic Mechanisms (ISCM-XVI), ranging from the molecular and the cellular to the clinical and the cognitive mechanisms of cholinergic transmission. The authors discuss recent developments in the field, for instance, the association of cholinergic transmission with a number of important neurological and neuromuscular diseases in the central and peripheral nervous systems.
ESTHER : Anglister_2021_J.Neurochem__
PubMedSearch : Anglister_2021_J.Neurochem__
PubMedID: 34458988

Title : Blood acetylcholinesterase activity is associated with increased 10 year all-cause mortality following coronary angiography - Shenhar-Tsarfaty_2020_Atherosclerosis_313_144
Author(s) : Shenhar-Tsarfaty S , Brzezinski RY , Waiskopf N , Finkelstein A , Halkin A , Berliner S , Rogowski O , Zeltser D , Shapira I , Laufer-Perl M , Shacham Y , Litmanowicz B , Banai S , Soreq H , Arbel Y
Ref : Atherosclerosis , 313 :144 , 2020
Abstract : BACKGROUND AND AIMS: Parasympathetic dysfunction is associated with increased risk for major adverse cardiovascular events (MACE). However, clinically validated biomarkers that reflect parasympathetic activity are not yet available. We sought to assess the ability of serum cholinesterase activity to predict long term survival in patients undergoing coronary angiography. METHODS: We prospectively followed 1002 consecutive patients undergoing clinically indicated coronary angiography (acute coronary syndrome or stable angina). We measured blood acetylcholinesterase (AChE) activity using the acetylcholine analog acetylthiocholine. Mortality rates were determined up to 10 years of follow-up. We divided our cohort into 3 groups with low, intermediate and high AChE activity by a Chi-square automatic interaction detection method (CHAID). RESULTS: Patients with lower than cutoff levels of AChE (<300 nmol/min/ml) had higher mortality rates over 10 years of follow-up, after adjusting for conventional risk factors, biomarkers, clinical indication, and use of medications (HR = 1.6, 95% CI 1.1-2.5, p = 0.02). Patients with intermediate levels of AChE (300-582 nmol/min/ml) were also at increased risk for death (HR = 1.4, 95% CI 1.1-1.9, p = 0.02). AChE was inversely correlated with C-reactive protein, troponin I, fibrinogen and neutrophil/lymphocyte ratio levels. CONCLUSIONS: Patients presenting for coronary angiography with low levels of serum AChE activity are at increased risk for death during long term follow-up.
ESTHER : Shenhar-Tsarfaty_2020_Atherosclerosis_313_144
PubMedSearch : Shenhar-Tsarfaty_2020_Atherosclerosis_313_144
PubMedID: 33049656

Title : Transfer RNA fragments replace microRNA regulators of the cholinergic poststroke immune blockade - Winek_2020_Proc.Natl.Acad.Sci.U.S.A_117_32606
Author(s) : Winek K , Lobentanzer S , Nadorp B , Dubnov S , Dames C , Jagdmann S , Moshitzky G , Hotter B , Meisel C , Greenberg DS , Shifman S , Klein J , Shenhar-Tsarfaty S , Meisel A , Soreq H
Ref : Proc Natl Acad Sci U S A , 117 :32606 , 2020
Abstract : Stroke is a leading cause of death and disability. Recovery depends on a delicate balance between inflammatory responses and immune suppression, tipping the scale between brain protection and susceptibility to infection. Peripheral cholinergic blockade of immune reactions fine-tunes this immune response, but its molecular regulators are unknown. Here, we report a regulatory shift in small RNA types in patient blood sequenced 2 d after ischemic stroke, comprising massive decreases of microRNA levels and concomitant increases of transfer RNA fragments (tRFs) targeting cholinergic transcripts. Electrophoresis-based size-selection followed by qRT-PCR validated the top six up-regulated tRFs in a separate cohort of stroke patients, and independent datasets of small and long RNA sequencing pinpointed immune cell subsets pivotal to these responses, implicating CD14(+) monocytes in the cholinergic inflammatory reflex. In-depth small RNA targeting analyses revealed the most-perturbed pathways following stroke and implied a structural dichotomy between microRNA and tRF target sets. Furthermore, lipopolysaccharide stimulation of murine RAW 264.7 cells and human CD14(+) monocytes up-regulated the top six stroke-perturbed tRFs, and overexpression of stroke-inducible tRF-22-WE8SPOX52 using a single-stranded RNA mimic induced down-regulation of immune regulator Z-DNA binding protein 1. In summary, we identified a "changing of the guards" between small RNA types that may systemically affect homeostasis in poststroke immune responses, and pinpointed multiple affected pathways, which opens new venues for establishing therapeutics and biomarkers at the protein and RNA level.
ESTHER : Winek_2020_Proc.Natl.Acad.Sci.U.S.A_117_32606
PubMedSearch : Winek_2020_Proc.Natl.Acad.Sci.U.S.A_117_32606
PubMedID: 33288717

Title : Central and peripheral anti-inflammatory effects of acetylcholinesterase inhibitors - Vaknine_2020_Neuropharmacol_168_108020
Author(s) : Vaknine S , Soreq H
Ref : Neuropharmacology , 168 :108020 , 2020
Abstract : Acetylcholinesterase (AChE) inhibitors modulate acetylcholine hydrolysis and hence play a key role in determining the cholinergic tone and in implementing its impact on the cholinergic blockade of inflammatory processes. Such inhibitors may include rapidly acting small molecule AChE-blocking drugs and poisonous anti-AChE insecticides or war agent inhibitors which penetrate both body and brain. Notably, traumatized patients may be hyper-sensitized to anti-AChEs due to their impaired cholinergic tone, higher levels of circulation pro-inflammatory cytokines and exacerbated peripheral inflammatory responses. Those largely depend on the innate-immune system yet reach the brain via vagus pathways and/or disrupted blood-brain-barrier. Other regulators of the neuro-inflammatory cascade are AChE-targeted microRNAs (miRs) and synthetic chemically protected oligonucleotide blockers thereof, whose size prevents direct brain penetrance. Nevertheless, these larger molecules may exert parallel albeit slower inflammatory regulating effects on brain and body tissues. Additionally, oligonucleotide aptamers interacting with innate immune Toll-Like Receptors (TLRs) may control inflammation through diverse routes and in different rates. Such aptamers may compete with the action of both small molecule inhibitors and AChE-inhibiting miRs in peripheral tissues including muscle and intestine. However, rapid adaptation processes, visualized in neuromuscular junctions enable murine survival under otherwise lethal anti-cholinesterase exposure; and both miR inhibitors and TLR-modulating aptamers may exert body-brain signals protecting experimental mice from acute inflammation. The complex variety of AChE inhibiting molecules identifies diverse body-brain communication pathways which may rapidly induce long-lasting central reactions to peripheral stressful and inflammatory insults in both mice and men.
ESTHER : Vaknine_2020_Neuropharmacol_168_108020
PubMedSearch : Vaknine_2020_Neuropharmacol_168_108020
PubMedID: 32143069

Title : Barrel cortex VIP\/ChAT interneurons suppress sensory responses in vivo - Dudai_2020_PLoS.Biol_18_e3000613
Author(s) : Dudai A , Yayon N , Lerner V , Tasaka GI , Deitcher Y , Gorfine K , Niederhoffer N , Mizrahi A , Soreq H , London M
Ref : PLoS Biol , 18 :e3000613 , 2020
Abstract : Cortical interneurons expressing vasoactive intestinal polypeptide (VIP) and choline acetyltransferase (ChAT) are sparsely distributed throughout the neocortex, constituting only 0.5% of its neuronal population. The co-expression of VIP and ChAT suggests that these VIP/ChAT interneurons (VChIs) can release both gamma-aminobutyric acid (GABA) and acetylcholine (ACh). In vitro physiological studies quantified the response properties and local connectivity patterns of the VChIs; however, the function of VChIs has not been explored in vivo. To study the role of VChIs in cortical network dynamics and their long-range connectivity pattern, we used in vivo electrophysiology and rabies virus tracing in the barrel cortex of mice. We found that VChIs have a low spontaneous spiking rate (approximately 1 spike/s) in the barrel cortex of anesthetized mice; nevertheless, they responded with higher fidelity to whisker stimulation than the neighboring layer 2/3 pyramidal neurons (Pyrs). Analysis of long-range inputs to VChIs with monosynaptic rabies virus tracing revealed that direct thalamic projections are a significant input source to these cells. Optogenetic activation of VChIs in the barrel cortex of awake mice suppresses the sensory responses of excitatory neurons in intermediate amplitudes of whisker deflections while increasing the evoked spike latency. The effect of VChI activation on the response was similar for both high-whisking (HW) and low-whisking (LW) conditions. Our findings demonstrate that, despite their sparsity, VChIs can effectively modulate sensory processing in the cortical microcircuit.
ESTHER : Dudai_2020_PLoS.Biol_18_e3000613
PubMedSearch : Dudai_2020_PLoS.Biol_18_e3000613
PubMedID: 32027647

Title : Modulation of hippocampal neuronal resilience during aging by the Hsp70\/Hsp90 co-chaperone STI1 - Lackie_2020_J.Neurochem_153_727
Author(s) : Lackie RE , Razzaq AR , Farhan SMK , Qiu LR , Moshitzky G , Beraldo FH , Lopes MH , Maciejewski A , Gros R , Fan J , Choy WY , Greenberg DS , Martins VR , Duennwald ML , Lerch JP , Soreq H , Prado VF , Prado MAM
Ref : Journal of Neurochemistry , 153 :727 , 2020
Abstract : Chaperone networks are dysregulated with aging, but whether compromised Hsp70/Hsp90 chaperone function disturbs neuronal resilience is unknown. Stress-inducible phosphoprotein 1 (STI1; STIP1; HOP) is a co-chaperone that simultaneously interacts with Hsp70 and Hsp90, but whose function in vivo remains poorly understood. We combined in-depth analysis of chaperone genes in human datasets, analysis of a neuronal cell line lacking STI1 and of a mouse line with a hypomorphic Stip1 allele to investigate the requirement for STI1 in aging. Our experiments revealed that dysfunctional STI1 activity compromised Hsp70/Hsp90 chaperone network and neuronal resilience. The levels of a set of Hsp90 co-chaperones and client proteins were selectively affected by reduced levels of STI1, suggesting that their stability depends on functional Hsp70/Hsp90 machinery. Analysis of human databases revealed a subset of co-chaperones, including STI1, whose loss of function is incompatible with life in mammals, albeit they are not essential in yeast. Importantly, mice expressing a hypomorphic STI1 allele presented spontaneous age-dependent hippocampal neurodegeneration and reduced hippocampal volume, with consequent spatial memory deficit. We suggest that impaired STI1 function compromises Hsp70/Hsp90 chaperone activity in mammals and can by itself cause age-dependent hippocampal neurodegeneration in mice. Cover Image for this issue: doi: 10.1111/jnc.14749.
ESTHER : Lackie_2020_J.Neurochem_153_727
PubMedSearch : Lackie_2020_J.Neurochem_153_727
PubMedID: 31562773

Title : Cholinergic Stress Signals Accompany MicroRNA-Associated Stereotypic Behavior and Glutamatergic Neuromodulation in the Prefrontal Cortex - Moshitzky_2020_Biomolecules_10_
Author(s) : Moshitzky G , Shoham S , Madrer N , Husain AM , Greenberg DS , Yirmiya R , Ben-Shaul Y , Soreq H
Ref : Biomolecules , 10 : , 2020
Abstract : Stereotypic behavior (SB) is common in emotional stress-involved psychiatric disorders and is often attributed to glutamatergic impairments, but the underlying molecular mechanisms are unknown. Given the neuro-modulatory role of acetylcholine, we sought behavioral-transcriptomic links in SB using TgR transgenic mice with impaired cholinergic transmission due to over-expression of the stress-inducible soluble 'readthrough' acetylcholinesterase-R splice variant AChE-R. TgR mice showed impaired organization of behavior, performance errors in a serial maze test, escape-like locomotion, intensified reaction to pilocarpine and reduced rearing in unfamiliar situations. Small-RNA sequencing revealed 36 differentially expressed (DE) microRNAs in TgR mice hippocampi, 8 of which target more than 5 cholinergic transcripts. Moreover, compared to FVB/N mice, TgR prefrontal cortices displayed individually variable changes in over 400 DE mRNA transcripts, primarily acetylcholine and glutamate-related. Furthermore, TgR brains presented c-fos over-expression in motor behavior-regulating brain regions and immune-labeled AChE-R excess in the basal ganglia, limbic brain nuclei and the brain stem, indicating a link with the observed behavioral phenotypes. Our findings demonstrate association of stress-induced SB to previously unknown microRNA-mediated perturbations of cholinergic/glutamatergic networks and underscore new therapeutic strategies for correcting stereotypic behaviors.
ESTHER : Moshitzky_2020_Biomolecules_10_
PubMedSearch : Moshitzky_2020_Biomolecules_10_
PubMedID: 32503154

Title : NEAT1 is overexpressed in Parkinson's disease substantia nigra and confers drug-inducible neuroprotection from oxidative stress - Simchovitz_2019_FASEB.J_33_11223
Author(s) : Simchovitz A , Hanan M , Niederhoffer N , Madrer N , Yayon N , Bennett ER , Greenberg DS , Kadener S , Soreq H
Ref : FASEB Journal , 33 :11223 , 2019
Abstract : Recent reports attribute numerous regulatory functions to the nuclear paraspeckle-forming long noncoding RNA, nuclear enriched assembly transcript 1 (NEAT1), but the implications of its involvement in Parkinson's disease (PD) remain controversial. To address this issue, we assessed NEAT1 expression levels and cell type patterns in the substantia nigra (SN) from 53 donors with and without PD, as well as in interference tissue culture tests followed by multiple in-house and web-available models of PD. PCR quantification identified elevated levels of NEAT1 expression in the PD SN compared with control brains, an elevation that was reproducible across a multitude of disease models. In situ RNA hybridization supported neuron-specific formation of NEAT1-based paraspeckles at the SN and demonstrated coincreases of NEAT1 and paraspeckles in cultured cells under paraquat (PQ)-induced oxidative stress. Furthermore, neuroprotective agents, including fenofibrate and simvastatin, induced NEAT1 up-regulation, whereas RNA interference-mediated depletion of NEAT1 exacerbated death of PQ-exposed cells in a leucine-rich repeat kinase 2-mediated manner. Our findings highlight a novel protective role for NEAT1 in PD and suggest a previously unknown mechanism for the neuroprotective traits of widely used preventive therapeutics.-Simchovitz, A., Hanan, M., Niederhoffer, N., Madrer, N., Yayon, N., Bennett, E. R., Greenberg, D. S., Kadener, S., Soreq, H. NEAT1 is overexpressed in Parkinson's disease substantia nigra and confers drug-inducible neuroprotection from oxidative stress.
ESTHER : Simchovitz_2019_FASEB.J_33_11223
PubMedSearch : Simchovitz_2019_FASEB.J_33_11223
PubMedID: 31311324

Title : Intensify3D: Normalizing signal intensity in large heterogenic image stacks - Yayon_2018_Sci.Rep_8_4311
Author(s) : Yayon N , Dudai A , Vrieler N , Amsalem O , London M , Soreq H
Ref : Sci Rep , 8 :4311 , 2018
Abstract : Three-dimensional structures in biological systems are routinely evaluated using large image stacks acquired from fluorescence microscopy; however, analysis of such data is muddled by variability in the signal across and between samples. Here, we present Intensify3D: a user-guided normalization algorithm tailored for overcoming common heterogeneities in large image stacks. We demonstrate the use of Intensify3D for analyzing cholinergic interneurons of adult murine brains in 2-Photon and Light-Sheet fluorescence microscopy, as well as of mammary gland and heart tissues. Beyond enhancement in 3D visualization in all samples tested, in 2-Photon in vivo images, this tool corrected errors in feature extraction of cortical interneurons; and in Light-Sheet microscopy, it enabled identification of individual cortical barrel fields and quantification of somata in cleared adult brains. Furthermore, Intensify3D enhanced the ability to separate signal from noise. Overall, the universal applicability of our method can facilitate detection and quantification of 3D structures and may add value to a wide range of imaging experiments.
ESTHER : Yayon_2018_Sci.Rep_8_4311
PubMedSearch : Yayon_2018_Sci.Rep_8_4311
PubMedID: 29523815

Title : Personalized genetics of the cholinergic blockade of neuroinflammation - Simchovitz_2017_J.Neurochem_142 Suppl 2_178
Author(s) : Simchovitz A , Heneka MT , Soreq H
Ref : Journal of Neurochemistry , 142 Suppl 2 :178 , 2017
Abstract : Acetylcholine signaling is essential for cognitive functioning and blocks inflammation. To maintain homeostasis, cholinergic signaling is subjected to multi-leveled and bidirectional regulation by both proteins and non-coding microRNAs ('CholinomiRs'). CholinomiRs coordinate the cognitive and inflammatory aspects of cholinergic signaling by targeting major cholinergic transcripts including the acetylcholine hydrolyzing enzyme acetylcholinesterase (AChE). Notably, AChE inhibitors are the only currently approved line of treatment for Alzheimer's disease patients. Since cholinergic signaling blocks neuroinflammation which is inherent to Alzheimer's disease, genomic changes modifying AChE's properties and its susceptibility to inhibitors and/or to CholinomiRs regulation may affect the levels and properties of inflammasome components such as NLRP3. This calls for genomic-based medicine approaches based on genotyping of both coding and non-coding single nucleotide polymorphisms (SNPs) in the genes involved in cholinergic signaling. An example is a SNP in a recognition element for the primate-specific microRNA-608 within the 3' untranslated region of the AChE transcript. Carriers of the minor allele of that SNP present massively elevated brain AChE levels, increased trait anxiety and inflammation, accompanied by perturbed CholinomiR-608 regulatory networks and elevated prefrontal activity under exposure to stressful insults. Several additional SNPs in the AChE and other cholinergic genes await further studies, and might likewise involve different CholinomiRs and pathways including those modulating the initiation and progression of neurodegenerative diseases. CholinomiRs regulation of the cholinergic system thus merits in-depth interrogation and is likely to lead to personalized medicine approaches for achieving better homeostasis in health and disease. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
ESTHER : Simchovitz_2017_J.Neurochem_142 Suppl 2_178
PubMedSearch : Simchovitz_2017_J.Neurochem_142 Suppl 2_178
PubMedID: 28326544

Title : Alexander George Karczmar (1917-2017) - Soreq_2017_J.Neurochem_143_609
Author(s) : Soreq H , Silman I
Ref : Journal of Neurochemistry , 143 :609 , 2017
Abstract : The neurochemistry community at large and the Advisory Board of The International Symposia on Cholinergic Mechanisms mourn the loss of Alexander George Karczmar, the elected Honorary President of these international symposia, who passed away peacefully in his Chicago home at the age of 100 on August 17, 2017. For many of us Alex was the essence of cholinergic signaling, and personified its versatile power to send messages between the brain and the peripheral tissues and organs, and to connect between body and soul.
ESTHER : Soreq_2017_J.Neurochem_143_609
PubMedSearch : Soreq_2017_J.Neurochem_143_609
PubMedID: 29027666

Title : Mutant alpha-Synuclein Overexpression Induces Stressless Pacemaking in Vagal Motoneurons at Risk in Parkinson's Disease - Lasser-Katz_2017_J.Neurosci_37_47
Author(s) : Lasser-Katz E , Simchovitz A , Chiu WH , Oertel WH , Sharon R , Soreq H , Roeper J , Goldberg JA
Ref : Journal of Neuroscience , 37 :47 , 2017
Abstract : alpha-Synuclein overexpression (ASOX) drives the formation of toxic aggregates in neurons vulnerable in Parkinson's disease (PD), including dopaminergic neurons of the substantia nigra (SN) and cholinergic neurons of the dorsal motor nucleus of the vagus (DMV). Just as these populations differ in when they exhibit alpha-synucleinopathies during PD pathogenesis, they could also differ in their physiological responses to ASOX. An ASOX-mediated hyperactivity of SN dopamine neurons, which was caused by oxidative dysfunction of Kv4.3 potassium channels, was recently identified in transgenic (A53T-SNCA) mice overexpressing mutated human alpha-synuclein. Noting that DMV neurons display extensive alpha-synucleinopathies earlier than SN dopamine neurons while exhibiting milder cell loss in PD, we aimed to define the electrophysiological properties of DMV neurons in A53T-SNCA mice. We found that DMV neurons maintain normal firing rates in response to ASOX. Moreover, Kv4.3 channels in DMV neurons exhibit no oxidative dysfunction in the A53T-SNCA mice, which could only be recapitulated in wild-type mice by glutathione dialysis. Two-photon imaging of redox-sensitive GFP corroborated the finding that mitochondrial oxidative stress was diminished in DMV neurons in the A53T-SNCA mice. This reduction in oxidative stress resulted from a transcriptional downregulation of voltage-activated (Cav) calcium channels in DMV neurons, which led to a reduction in activity-dependent calcium influx via Cav channels. Thus, ASOX induces a homeostatic remodeling with improved redox signaling in DMV neurons, which could explain the differential vulnerability of SN dopamine and DMV neurons in PD and could promote neuroprotective strategies that emulate endogenous homeostatic responses to ASOX (e.g., stressless pacemaking) in DMV neurons. SIGNIFICANCE STATEMENT: Overexpression of mutant alpha-synuclein causes Parkinson's disease, presumably by driving neurodegeneration in vulnerable neuronal target populations. However, the extent of alpha-synuclein pathology (e.g., Lewy bodies) is not directly related to the degree of neurodegeneration across various vulnerable neuronal populations. Here, we show that, in contrast to dopamine neurons in the substantia nigra, vagal motoneurons do not enhance their excitability and oxidative load in response to chronic mutant alpha-synuclein overexpression. Rather, by downregulating their voltage-activated calcium channels, vagal motoneurons acquire a stressless form of pacemaking that diminishes mitochondrial and cytosolic oxidative stress. Emulating this endogenous adaptive response to alpha-synuclein overexpression could lead to novel strategies to protect dopamine neurons and perhaps delay the onset of Parkinson's disease.
ESTHER : Lasser-Katz_2017_J.Neurosci_37_47
PubMedSearch : Lasser-Katz_2017_J.Neurosci_37_47
PubMedID: 28053029

Title : Dynamic changes in murine forebrain miR-211 expression associate with cholinergic imbalances and epileptiform activity - Bekenstein_2017_Proc.Natl.Acad.Sci.U.S.A_114_E4996
Author(s) : Bekenstein U , Mishra N , Milikovsky DZ , Hanin G , Zelig D , Sheintuch L , Berson A , Greenberg DS , Friedman A , Soreq H
Ref : Proc Natl Acad Sci U S A , 114 :E4996 , 2017
Abstract : Epilepsy is a common neurological disease, manifested in unprovoked recurrent seizures. Epileptogenesis may develop due to genetic or pharmacological origins or following injury, but it remains unclear how the unaffected brain escapes this susceptibility to seizures. Here, we report that dynamic changes in forebrain microRNA (miR)-211 in the mouse brain shift the threshold for spontaneous and pharmacologically induced seizures alongside changes in the cholinergic pathway genes, implicating this miR in the avoidance of seizures. We identified miR-211 as a putative attenuator of cholinergic-mediated seizures by intersecting forebrain miR profiles that were Argonaute precipitated, synaptic vesicle target enriched, or differentially expressed under pilocarpine-induced seizures, and validated TGFBR2 and the nicotinic antiinflammatory acetylcholine receptor nAChRa7 as murine and human miR-211 targets, respectively. To explore the link between miR-211 and epilepsy, we engineered dTg-211 mice with doxycycline-suppressible forebrain overexpression of miR-211. These mice reacted to doxycycline exposure by spontaneous electrocorticography-documented nonconvulsive seizures, accompanied by forebrain accumulation of the convulsive seizures mediating miR-134. RNA sequencing demonstrated in doxycycline-treated dTg-211 cortices overrepresentation of synaptic activity, Ca2+ transmembrane transport, TGFBR2 signaling, and cholinergic synapse pathways. Additionally, a cholinergic dysregulated mouse model overexpressing a miR refractory acetylcholinesterase-R splice variant showed a parallel propensity for convulsions, miR-211 decreases, and miR-134 elevation. Our findings demonstrate that in mice, dynamic miR-211 decreases induce hypersynchronization and nonconvulsive and convulsive seizures, accompanied by expression changes in cholinergic and TGFBR2 pathways as well as in miR-134. Realizing the importance of miR-211 dynamics opens new venues for translational diagnosis of and interference with epilepsy.
ESTHER : Bekenstein_2017_Proc.Natl.Acad.Sci.U.S.A_114_E4996
PubMedSearch : Bekenstein_2017_Proc.Natl.Acad.Sci.U.S.A_114_E4996
PubMedID: 28584127

Title : Cholinergic Surveillance over Hippocampal RNA Metabolism and Alzheimer's-Like Pathology - Kolisnyk_2017_Cereb.Cortex_27_3553
Author(s) : Kolisnyk B , Al-Onaizi M , Soreq L , Barbash S , Bekenstein U , Haberman N , Hanin G , Kish MT , Souza da Silva J , Fahnestock M , Ule J , Soreq H , Prado VF , Prado MAM
Ref : Cerebral Cortex , 27 :3553 , 2017
Abstract : The relationship between long-term cholinergic dysfunction and risk of developing dementia is poorly understood. Here we used mice with deletion of the vesicular acetylcholine transporter (VAChT) in the forebrain to model cholinergic abnormalities observed in dementia. Whole-genome RNA sequencing of hippocampal samples revealed that cholinergic failure causes changes in RNA metabolism. Remarkably, key transcripts related to Alzheimer's disease are affected. BACE1, for instance, shows abnormal splicing caused by decreased expression of the splicing regulator hnRNPA2/B1. Resulting BACE1 overexpression leads to increased APP processing and accumulation of soluble Abeta1-42. This is accompanied by age-related increases in GSK3 activation, tau hyperphosphorylation, caspase-3 activation, decreased synaptic markers, increased neuronal death, and deteriorating cognition. Pharmacological inhibition of GSK3 hyperactivation reversed deficits in synaptic markers and tau hyperphosphorylation induced by cholinergic dysfunction, indicating a key role for GSK3 in some of these pathological changes. Interestingly, in human brains there was a high correlation between decreased levels of VAChT and hnRNPA2/B1 levels with increased tau hyperphosphorylation. These results suggest that changes in RNA processing caused by cholinergic loss can facilitate Alzheimer's-like pathology in mice, providing a mechanism by which decreased cholinergic tone may increase risk of dementia.
ESTHER : Kolisnyk_2017_Cereb.Cortex_27_3553
PubMedSearch : Kolisnyk_2017_Cereb.Cortex_27_3553
PubMedID: 27312991

Title : Antisense miR-132 blockade via the AChE-R splice variant mitigates cortical inflammation - Mishra_2017_Sci.Rep_7_42755
Author(s) : Mishra N , Friedson L , Hanin G , Bekenstein U , Volovich M , Bennett ER , Greenberg DS , Soreq H
Ref : Sci Rep , 7 :42755 , 2017
Abstract : MicroRNA (miR)-132 brain-to-body messages suppress inflammation by targeting acetylcholinesterase (AChE), but the target specificity of 3'-AChE splice variants and the signaling pathways involved remain unknown. Using surface plasmon resonance (SPR), we identified preferential miR-132 targeting of soluble AChE-R over synaptic-bound AChE-S, potentiating miR-132-mediated brain and body cholinergic suppression of pro-inflammatory cytokines. Inversely, bacterial lipopolysaccharide (LPS) reduced multiple miR-132 targets, suppressed AChE-S more than AChE-R and elevated inflammatory hallmarks. Furthermore, blockade of peripheral miR-132 by chemically protected AM132 antisense oligonucleotide elevated muscle AChE-R 10-fold over AChE-S, and cortical miRNA-sequencing demonstrated inverse brain changes by AM132 and LPS in immune-related miRs and neurotransmission and cholinergic signaling pathways. In neuromuscular junctions, AM132 co-elevated the nicotinic acetylcholine receptor and AChE, re-balancing neurotransmission and reaching mild muscle incoordination. Our findings demonstrate preferential miR-132-induced modulation of AChE-R which ignites bidirectional brain and body anti-inflammatory regulation, underscoring splice-variant miR-132 specificity as a new complexity level in inflammatory surveillance.
ESTHER : Mishra_2017_Sci.Rep_7_42755
PubMedSearch : Mishra_2017_Sci.Rep_7_42755
PubMedID: 28209997

Title : Weakened cholinergic blockade of inflammation associates with diabetes-related depression - Shenhar-Tsarfaty_2016_Mol.Med_22_
Author(s) : Shenhar-Tsarfaty S , Shapira I , Toker S , Rogowski O , Berliner S , Ritov Y , Soreq H
Ref : Mol Med , 22 : , 2016
Abstract : Emerging evidence demonstrates association of depression with both immune malfunctioning and worsened course of diverse aging-related diseases, but there is no explanation for the pathway(s) controlling this dual association. Here, we report that in post-reproductive and evolutionarily 'blind' years, depression may weaken pathogen-host defense, compatible with the antagonistic pleiotropy hypothesis. In 15,532 healthy volunteers, depression scores associated with both inflammatory parameters and with increased circulation cholinesterase activities, implicating debilitated cholinergic blockade of inflammation as an underlying mechanism; furthermore, depression, inflammation and cholinesterase activities all increased with aging. In the entire cohort, combined increases in inflammation and the diabetic biomarker hemoglobin A1c associated with elevated depression. Moreover, metabolic syndrome patients with higher risk of diabetes showed increased cholinesterase levels and pulse values, and diabetics presented simultaneous increases in depression, inflammation and circulation cholinesterase activities, suggesting that cholinergic impairment precedes depression. Our findings indicate that dys-functioning cholinergic regulation weakens the otherwise protective link between depression and pathogen-host defense, with global implications for aging-related diseases.
ESTHER : Shenhar-Tsarfaty_2016_Mol.Med_22_
PubMedSearch : Shenhar-Tsarfaty_2016_Mol.Med_22_
PubMedID: 27257683

Title : Photocatalytic Reactive Oxygen Species Formation by Semiconductor-Metal Hybrid Nanoparticles. Toward Light-Induced Modulation of Biological Processes - Waiskopf_2016_Nano.Lett_16_4266
Author(s) : Waiskopf N , Ben-Shahar Y , Galchenko M , Carmel I , Moshitzky G , Soreq H , Banin U
Ref : Nano Lett , 16 :4266 , 2016
Abstract : Semiconductor-metal hybrid nanoparticles manifest efficient light-induced spatial charge separation at the semiconductor-metal interface, as demonstrated by their use for hydrogen generation via water splitting. Here, we pioneer a study of their functionality as efficient photocatalysts for the formation of reactive oxygen species. We observed enhanced photocatalytic activity forming hydrogen peroxide, superoxide, and hydroxyl radicals upon light excitation, which was significantly larger than that of the semiconductor nanocrystals, attributed to the charge separation and the catalytic function of the metal tip. We used this photocatalytic functionality for modulating the enzymatic activity of horseradish peroxidase as a model system, demonstrating the potential use of hybrid nanoparticles as active agents for controlling biological processes through illumination. The capability to produce reactive oxygen species by illumination on-demand enhances the available peroxidase-based tools for research and opens the path for studying biological processes at high spatiotemporal resolution, laying the foundation for developing novel therapeutic approaches.
ESTHER : Waiskopf_2016_Nano.Lett_16_4266
PubMedSearch : Waiskopf_2016_Nano.Lett_16_4266
PubMedID: 27224678

Title : Molecular Mechanisms Regulating LPS-Induced Inflammation in the Brain - Lykhmus_2016_Front.Mol.Neurosci_9_19
Author(s) : Lykhmus O , Mishra N , Koval L , Kalashnyk O , Gergalova G , Uspenska K , Komisarenko S , Soreq H , Skok MV
Ref : Front Mol Neurosci , 9 :19 , 2016
Abstract : Neuro-inflammation, one of the pathogenic causes of neurodegenerative diseases, is regulated through the cholinergic anti-inflammatory pathway via the alpha7 nicotinic acetylcholine receptor (alpha7 nAChR). We previously showed that either bacterial lipopolysaccharide (LPS) or immunization with the alpha7(1-208) nAChR fragment decrease alpha7 nAChRs density in the mouse brain, exacerbating chronic inflammation, beta-amyloid accumulation and episodic memory decline, which mimic the early stages of Alzheimer's disease (AD). To study the molecular mechanisms underlying the LPS and antibody effects in the brain, we employed an in vivo model of acute LPS-induced inflammation and an in vitro model of cultured glioblastoma U373 cells. Here, we report that LPS challenge decreased the levels of alpha7 nAChR RNA and protein and of acetylcholinesterase (AChE) RNA and activity in distinct mouse brain regions, sensitized brain mitochondria to the apoptogenic effect of Ca(2+) and modified brain microRNA profiles, including the cholinergic-regulatory CholinomiRs-132/212, in favor of anti-inflammatory and pro-apoptotic ones. Adding alpha7(1-208)-specific antibodies to the LPS challenge prevented elevation of both the anti-inflammatory and pro-apoptotic miRNAs while supporting the resistance of brain mitochondria to Ca(2+) and maintaining alpha7 nAChR/AChE decreases. In U373 cells, alpha7-specific antibodies and LPS both stimulated interleukin-6 production through the p38/Src-dependent pathway. Our findings demonstrate that acute LPS-induced inflammation induces the cholinergic anti-inflammatory pathway in the brain, that alpha7 nAChR down-regulation limits this pathway, and that alpha7-specific antibodies aggravate neuroinflammation by inducing the pro-inflammatory interleukin-6 and dampening anti-inflammatory miRNAs; however, these antibodies may protect brain mitochondria and decrease the levels of pro-apoptotic miRNAs, preventing LPS-induced neurodegeneration.
ESTHER : Lykhmus_2016_Front.Mol.Neurosci_9_19
PubMedSearch : Lykhmus_2016_Front.Mol.Neurosci_9_19
PubMedID: 27013966

Title : Cholinergic Regulation of hnRNPA2\/B1 Translation by M1 Muscarinic Receptors - Kolisnyk_2016_J.Neurosci_36_6287
Author(s) : Kolisnyk B , Al-Onaizi MA , Xu J , Parfitt GM , Ostapchenko VG , Hanin G , Soreq H , Prado MAM , Prado VF
Ref : Journal of Neuroscience , 36 :6287 , 2016
Abstract : Cholinergic vulnerability, characterized by loss of acetylcholine (ACh), is one of the hallmarks of Alzheimer's disease (AD). Previous work has suggested that decreased ACh activity in AD may contribute to pathological changes through global alterations in alternative splicing. This occurs, at least partially, via the regulation of the expression of a critical protein family in RNA processing, heterogeneous nuclear ribonucleoprotein (hnRNP) A/B proteins. These proteins regulate several steps of RNA metabolism, including alternative splicing, RNA trafficking, miRNA export, and gene expression, providing multilevel surveillance in RNA functions. To investigate the mechanism by which cholinergic tone regulates hnRNPA2/B1 expression, we used a combination of genetic mouse models and in vivo and in vitro techniques. Decreasing cholinergic tone reduced levels of hnRNPA2/B1, whereas increasing cholinergic signaling in vivo increased expression of hnRNPA2/B1. This effect was not due to decreased hnRNPA2/B1 mRNA expression, increased aggregation, or degradation of the protein, but rather to decreased mRNA translation by nonsense-mediated decay regulation of translation. Cell culture and knock-out mice experiments demonstrated that M1 muscarinic signaling is critical for cholinergic control of hnRNPA2/B1 protein levels. Our experiments suggest an intricate regulation of hnRNPA2/B1 levels by cholinergic activity that interferes with alternative splicing in targeted neurons mimicking deficits found in AD. SIGNIFICANCE STATEMENT: In Alzheimer's disease, degeneration of basal forebrain cholinergic neurons is an early event. These neurons communicate with target cells and regulate their long-term activity by poorly understood mechanisms. Recently, the splicing factor hnRNPA2/B, which is decreased in Alzheimer's disease, was implicated as a potential mediator of long-term cholinergic regulation. Here, we demonstrate a mechanism by which cholinergic signaling controls the translation of hnRNPA2/B1 mRNA by activation of M1 muscarinic type receptors. Loss of cholinergic activity can have profound effects in target cells by modulating hnRNPA2/B1 levels.
ESTHER : Kolisnyk_2016_J.Neurosci_36_6287
PubMedSearch : Kolisnyk_2016_J.Neurosci_36_6287
PubMedID: 27277805

Title : Intensified vmPFC surveillance over PTSS under perturbed microRNA-608\/AChE interaction - Lin_2016_Transl.Psychiatry_6_e801
Author(s) : Lin T , Simchovitz A , Shenhar-Tsarfaty S , Vaisvaser S , Admon R , Hanin G , Hanan M , Kliper E , Bar-Haim Y , Shomron N , Fernandez G , Lubin G , Fruchter E , Hendler T , Soreq H
Ref : Transl Psychiatry , 6 :e801 , 2016
Abstract : Trauma causes variable risk of posttraumatic stress symptoms (PTSS) owing to yet-unknown genome-neuronal interactions. Here, we report co-intensified amygdala and ventromedial prefrontal cortex (vmPFC) emotional responses that may overcome PTSS in individuals with the single-nucleotide polymorphism (SNP) rs17228616 in the acetylcholinesterase (AChE) gene. We have recently shown that in individuals with the minor rs17228616 allele, this SNP interrupts AChE suppression by microRNA (miRNA)-608, leading to cortical elevation of brain AChE and reduced cortisol and the miRNA-608 target GABAergic modulator CDC42, all stress-associated. To examine whether this SNP has effects on PTSS and threat-related brain circuits, we exposed 76 healthy Israel Defense Forces soldiers who experienced chronic military stress to a functional magnetic resonance imaging task of emotional and neutral visual stimuli. Minor allele individuals predictably reacted to emotional stimuli by hyperactivated amygdala, a hallmark of PTSS and a predisposing factor of posttraumatic stress disorder (PTSD). Despite this, minor allele individuals showed no difference in PTSS levels. Mediation analyses indicated that the potentiated amygdala reactivity in minor allele soldiers promoted enhanced vmPFC recruitment that was associated with their limited PTSS. Furthermore, we found interrelated expression levels of several miRNA-608 targets including CD44, CDC42 and interleukin 6 in human amygdala samples (N=7). Our findings suggest that miRNA-608/AChE interaction is involved in the threat circuitry and PTSS and support a model where greater vmPFC regulatory activity compensates for amygdala hyperactivation in minor allele individuals to neutralize their PTSS susceptibility.
ESTHER : Lin_2016_Transl.Psychiatry_6_e801
PubMedSearch : Lin_2016_Transl.Psychiatry_6_e801
PubMedID: 27138800

Title : Gut feeling: MicroRNA discriminators of the intestinal TLR9-cholinergic links - Nadorp_2015_Int.Immunopharmacol_29(1)_8
Author(s) : Nadorp B , Soreq H
Ref : Int Immunopharmacol , 29 :8 , 2015
Abstract : The intestinal tissue notably responds to stressful, cholinergic and innate immune signals by microRNA (miRNA) changes, but whether and how those miRNA regulators modify the intestinal cholinergic and innate immune pathways remained unexplored. Here, we report changes in several miRNA regulators of cholinesterases (ChEs) and correspondingly modified ChE activities in intestine, splenocytes and the circulation of mice exposed to both stress and canonical or alternative Toll-Like Receptor 9 (TLR9) oligonucleotide (ODN) aptamer activators or blockers. Stressful intraperitoneal injection of saline, the anti-inflammatory TLR9 agonist mEN101 aptamer or the inflammation-activating TLR9 aptamer ODN 1826 all increased the expression of the acetylcholinesterase (AChE)-targeting miR-132. In comparison, mEN101 but neither ODN 1826 nor saline injections elevated intestinal miR-129-5p, miR-186 and miR-200c, all predicted to target both AChE and the homologous enzyme butyrylcholinesterase (BChE). In cultured immune cells, BL-7040, the human counterpart of mEN101, reduced AChE activity reflecting inflammatory reactions in a manner preventable by the TLR9 blocking ODN 2088. Furthermore, the anti-inflammatory BL-7040 TLR9 aptamer caused reduction in nitric oxide and AChE activity in both murine splenocytes and human mononuclear cells at molar concentrations four orders of magnitude lower than ODN 1826. Our findings demonstrate differential reaction of cholinesterase-targeting miRNAs to distinct TLR9 challenges, indicating upstream miRNA co-regulation of the intestinal alternative NFkappaB pathway and cholinergic signaling. TLR9 aptamers may hence potentiate miRNA regulation that enhances cholinergic signaling and the resolution of inflammation, which opens new venues for manipulating bowel diseases.
ESTHER : Nadorp_2015_Int.Immunopharmacol_29(1)_8
PubMedSearch : Nadorp_2015_Int.Immunopharmacol_29(1)_8
PubMedID: 26003847

Title : Readthrough acetylcholinesterase (AChE-R) and regulated necrosis: pharmacological targets for the regulation of ovarian functions? - Blohberger_2015_Cell.Death.Dis_6_e1685
Author(s) : Blohberger J , Kunz L , Einwang D , Berg U , Berg D , Ojeda SR , Dissen GA , Frohlich T , Arnold GJ , Soreq H , Lara H , Mayerhofer A
Ref : Cell Death Dis , 6 :e1685 , 2015
Abstract : Proliferation, differentiation and death of ovarian cells ensure orderly functioning of the female gonad during the reproductive phase, which ultimately ends with menopause in women. These processes are regulated by several mechanisms, including local signaling via neurotransmitters. Previous studies showed that ovarian non-neuronal endocrine cells produce acetylcholine (ACh), which likely acts as a trophic factor within the ovarian follicle and the corpus luteum via muscarinic ACh receptors. How its actions are restricted was unknown. We identified enzymatically active acetylcholinesterase (AChE) in human ovarian follicular fluid as a product of human granulosa cells. AChE breaks down ACh and thereby attenuates its trophic functions. Blockage of AChE by huperzine A increased the trophic actions as seen in granulosa cells studies. Among ovarian AChE variants, the readthrough isoform AChE-R was identified, which has further, non-enzymatic roles. AChE-R was found in follicular fluid, granulosa and theca cells, as well as luteal cells, implying that such functions occur in vivo. A synthetic AChE-R peptide (ARP) was used to explore such actions and induced in primary, cultured human granulosa cells a caspase-independent form of cell death with a distinct balloon-like morphology and the release of lactate dehydrogenase. The RIPK1 inhibitor necrostatin-1 and the MLKL-blocker necrosulfonamide significantly reduced this form of cell death. Thus a novel non-enzymatic function of AChE-R is to stimulate RIPK1/MLKL-dependent regulated necrosis (necroptosis). The latter complements a cholinergic system in the ovary, which determines life and death of ovarian cells. Necroptosis likely occurs in the primate ovary, as granulosa and luteal cells were immunopositive for phospho-MLKL, and hence necroptosis may contribute to follicular atresia and luteolysis. The results suggest that interference with the enzymatic activities of AChE and/or interference with necroptosis may be novel approaches to influence ovarian functions.
ESTHER : Blohberger_2015_Cell.Death.Dis_6_e1685
PubMedSearch : Blohberger_2015_Cell.Death.Dis_6_e1685
PubMedID: 25766324

Title : Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R - Atsmon_2015_Toxicol.Appl.Pharmacol_287_202
Author(s) : Atsmon J , Brill-Almon E , Nadri-Shay C , Chertkoff R , Alon S , Shaikevich D , Volokhov I , Haim KY , Bartfeld D , Shulman A , Ruderfer I , Ben-Moshe T , Shilovitzky O , Soreq H , Shaaltiel Y
Ref : Toxicol Appl Pharmacol , 287 :202 , 2015
Abstract : PRX-105 is a plant-derived recombinant version of the human 'read-through' acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50nmol/kg PRX-105, 2min before being exposed to 1.33xLD50 and 1.5xLD50 of toxin and 10min after exposure to 1.5xLD50 survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t(1/2)) in mice was 994 (+/-173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t(1/2) in humans was substantially longer than in mice (average 26.7h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation.
ESTHER : Atsmon_2015_Toxicol.Appl.Pharmacol_287_202
PubMedSearch : Atsmon_2015_Toxicol.Appl.Pharmacol_287_202
PubMedID: 26051873

Title : Functional segregation of voltage-activated calcium channels in motoneurons of the dorsal motor nucleus of the vagus - Cooper_2015_J.Neurophysiol_114_1513
Author(s) : Cooper G , Lasser-Katz E , Simchovitz A , Sharon R , Soreq H , Surmeier DJ , Goldberg JA
Ref : Journal of Neurophysiology , 114 :1513 , 2015
Abstract : Calcium influx elevates mitochondrial oxidant stress (mOS) in dorsal motor nucleus of the vagus (DMV) neurons that are prone to Lewy body pathologies in presymptomatic Parkinson's disease (PD) patients. In experimental PD models, treatment with isradipine, the dihydropyridine with the highest affinity to Cav1.3 channels, prevents subthreshold calcium influx via Cav1.3 channels into midbrain dopamine neurons and protects them from mOS. In DMV neurons, isradipine is also effective in reducing mOS despite overwhelming evidence that subthreshold calcium influx is negligible compared with spike-triggered influx. To solve this conundrum we combined slice electrophysiology, two-photon laser scanning microscopy, mRNA profiling, and computational modeling. We find that the unusually depolarized subthreshold voltage trajectory of DMV neurons is positioned between the relatively hyperpolarized activation curve of Cav1.3 channels and that of other high-voltage activated (HVA) calcium channels, thus creating a functional segregation between Cav1.3 and HVA calcium channels. The HVA channels flux the bulk of calcium during spikes but can only influence pacemaking through their coupling to calcium-activated potassium currents. In contrast, Cav1.3 currents, which we show to be more than an order-of-magnitude smaller than the HVA calcium currents, are able to introduce sufficient inward current to speed up firing. However, Kv4 channels that are constitutively open in the subthreshold range guarantee slow pacemaking, despite the depolarizing action of Cav1.3 and other pacemaking currents. We propose that the efficacy of isradipine in preventing mOS in DMV neurons arises from its mixed effect on Cav1.3 channels and on HVA Cav1.2 channels.
ESTHER : Cooper_2015_J.Neurophysiol_114_1513
PubMedSearch : Cooper_2015_J.Neurophysiol_114_1513
PubMedID: 26156385

Title : Fear and C-reactive protein cosynergize annual pulse increases in healthy adults - Shenhar-Tsarfaty_2015_Proc.Natl.Acad.Sci.U.S.A_112_E467
Author(s) : Shenhar-Tsarfaty S , Yayon N , Waiskopf N , Shapira I , Toker S , Zaltser D , Berliner S , Ritov Y , Soreq H
Ref : Proc Natl Acad Sci U S A , 112 :E467 , 2015
Abstract : Recent international terror outbreaks notably involve long-term mental health risks to the exposed population, but whether physical health risks are also anticipated has remained unknown. Here, we report fear of terror-induced annual increases in resting heart rate (pulse), a notable risk factor of all-cause mortality. Partial least squares analysis based on 325 measured parameters successfully predicted annual pulse increases, inverse to the expected age-related pulse decline, in approximately 4.1% of a cohort of 17,380 apparently healthy active Israeli adults. Nonbiased hierarchical regression analysis among 27 of those parameters identified pertinent fear of terror combined with the inflammatory biomarker C-reactive protein as prominent coregulators of the observed annual pulse increases. In comparison, basal pulse primarily depended on general physiological parameters and reduced cholinergic control over anxiety and inflammation, together indicating that consistent exposure to terror threats ignites fear-induced exacerbation of preexisting neuro-immune risks of all-cause mortality.
ESTHER : Shenhar-Tsarfaty_2015_Proc.Natl.Acad.Sci.U.S.A_112_E467
PubMedSearch : Shenhar-Tsarfaty_2015_Proc.Natl.Acad.Sci.U.S.A_112_E467
PubMedID: 25535364

Title : Predicted overlapping microRNA regulators of acetylcholine packaging and degradation in neuroinflammation-related disorders - Nadorp_2014_Front.Mol.Neurosci_7_9
Author(s) : Nadorp B , Soreq H
Ref : Front Mol Neurosci , 7 :9 , 2014
Abstract : MicroRNAs (miRNAs) can notably control many targets each and regulate entire cellular pathways, but whether miRNAs can regulate complete neurotransmission processes is largely unknown. Here, we report that miRNAs with complementary sequence motifs to the key genes involved in acetylcholine (ACh) synthesis and/or packaging show massive overlap with those regulating ACh degradation. To address this topic, we first searched for miRNAs that could target the 3'-untranslated regions of the choline acetyltransferase (ChAT) gene that controls ACh synthesis; the vesicular ACh transporter (VAChT), encoded from an intron in the ChAT gene and the ACh hydrolyzing genes acetyl- and/or butyrylcholinesterase (AChE, BChE). Intriguingly, we found that many of the miRNAs targeting these genes are primate-specific, and that changes in their levels associate with inflammation, anxiety, brain damage, cardiac, neurodegenerative, or pain-related syndromes. To validate the in vivo relevance of this dual interaction, we selected the evolutionarily conserved miR-186, which targets both the stress-inducible soluble "readthrough" variant AChE-R and the major peripheral cholinesterase BChE. We exposed mice to predator scent stress and searched for potential associations between consequent changes in their miR-186, AChE-R, and BChE levels. Both intestinal miR-186 as well as BChE and AChE-R activities were conspicuously elevated 1 week post-exposure, highlighting the previously unknown involvement of miR-186 and BChE in psychological stress responses. Overlapping miRNA regulation emerges from our findings as a recently evolved surveillance mechanism over cholinergic neurotransmission in health and disease; and the corresponding miRNA details and disease relevance may serve as a useful resource for studying the molecular mechanisms underlying this surveillance.
ESTHER : Nadorp_2014_Front.Mol.Neurosci_7_9
PubMedSearch : Nadorp_2014_Front.Mol.Neurosci_7_9
PubMedID: 24574962

Title : Competing targets of microRNA-608 affect anxiety and hypertension - Hanin_2014_Hum.Mol.Genet_23_4569
Author(s) : Hanin G , Shenhar-Tsarfaty S , Yayon N , Hoe YY , Bennett ER , Sklan EH , Rao DC , Rankinen T , Bouchard C , Geifman-Shochat S , Shifman S , Greenberg DS , Soreq H
Ref : Hum Mol Genet , 23 :4569 , 2014
Abstract : MicroRNAs (miRNAs) can repress multiple targets, but how a single de-balanced interaction affects others remained unclear. We found that changing a single miRNA-target interaction can simultaneously affect multiple other miRNA-target interactions and modify physiological phenotype. We show that miR-608 targets acetylcholinesterase (AChE) and demonstrate weakened miR-608 interaction with the rs17228616 AChE allele having a single-nucleotide polymorphism (SNP) in the 3'-untranslated region (3'UTR). In cultured cells, this weakened interaction potentiated miR-608-mediated suppression of other targets, including CDC42 and interleukin-6 (IL6). Postmortem human cortices homozygote for the minor rs17228616 allele showed AChE elevation and CDC42/IL6 decreases compared with major allele homozygotes. Additionally, minor allele heterozygote and homozygote subjects showed reduced cortisol and elevated blood pressure, predicting risk of anxiety and hypertension. Parallel suppression of the conserved brain CDC42 activity by intracerebroventricular ML141 injection caused acute anxiety in mice. We demonstrate that SNPs in miRNA-binding regions could cause expanded downstream effects changing important biological pathways.
ESTHER : Hanin_2014_Hum.Mol.Genet_23_4569
PubMedSearch : Hanin_2014_Hum.Mol.Genet_23_4569
PubMedID: 24722204

Title : Decline in serum cholinesterase activities predicts 2-year major adverse cardiac events - Arbel_2014_Mol.Med_20_38
Author(s) : Arbel Y , Shenhar-Tsarfaty S , Waiskopf N , Finkelstein A , Halkin A , Revivo M , Berliner S , Herz I , Shapira I , Keren G , Soreq H , Banai S
Ref : Mol Med , 20 :38 , 2014
Abstract : Parasympathetic activity influences long-term outcome in patients with cardiovascular disease, but the underlying mechanism(s) linking parasympathetic activity and the occurrence of major adverse cardiovascular events (MACEs) are incompletely understood. The aim of this pilot study was to evaluate the association between serum cholinesterase activities as parasympathetic biomarkers and the risk for the occurrence of MACEs. Cholinergic status was determined by measuring the cumulative capacity of serum acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) to hydrolyze the AChE substrate acetylthiocholine. Cholinergic status was evaluated in randomly selected patients undergoing cardiac catheterization. The patients were divided into two groups of 100 patients in each group, with or without occurrence of MACEs during a follow-up period of 40 months. Cox regression models adjusted for potential clinical, metabolic and inflammatory confounders served to evaluate association with clinical outcome. We found that patients with MACE presented lower cholinergic status and AChE values at catheterization (1,127 +/- 422 and 359 +/- 153 nmol substrate hydrolyzed per minute per milliliter, respectively) than no-MACE patients (1,760 +/- 546 and 508 +/- 183 nmol substrate hydrolyzed per minute per milliliter, p < 0.001 and p < 0.001, respectively), whose levels were comparable to those of matched healthy controls (1,622 +/- 303 and 504 +/- 126 nmol substrate hydrolyzed per minute per milliliter, respectively). In a multivariate analysis, patients with AChE or total cholinergic status values below median showed conspicuously elevated risk for MACE (hazard ratio 1.85 [95% confidence interval [CI] 1.09-3.15, p = 0.02] and 2.21 [95% CI 1.22-4.00, p = 0.009]) compared with those above median, even after adjusting for potential confounders. We conclude that parasympathetic dysfunction expressed as reduced serum AChE and AChE activities in patients compared to healthy controls can together reflect impaired parasympathetic activity. This impairment predicts the risk of MACE up to 40 months in such patients. Monitoring these parasympathetic parameters might help in the risk stratification of patients with cardiovascular disease.
ESTHER : Arbel_2014_Mol.Med_20_38
PubMedSearch : Arbel_2014_Mol.Med_20_38
PubMedID: 24395570

Title : Cholinesterases as biomarkers for parasympathetic dysfunction and inflammation-related disease - Shenhar-Tsarfaty_2014_J.Mol.Neurosci_53_298
Author(s) : Shenhar-Tsarfaty S , Berliner S , Bornstein NM , Soreq H
Ref : Journal of Molecular Neuroscience , 53 :298 , 2014
Abstract : Accumulating evidence suggests parasympathetic dysfunction and elevated inflammation as underlying processes in multiple peripheral and neurological diseases. Acetylcholine, the main parasympathetic neurotransmitter and inflammation regulator, is hydrolyzed by the two closely homologous enzymes, acetylcholinesterase and butyrylcholinesterase (AChE and BChE, respectively), which are also expressed in the serum. Here, we consider the potential value of both enzymes as possible biomarkers in diseases associated with parasympathetic malfunctioning. We cover the modulations of cholinesterase activities in inflammation-related events as well as by cholinesterase-targeted microRNAs. We further discuss epigenetic control over cholinesterase gene expression and the impact of single-nucleotide polymorphisms on the corresponding physiological and pathological processes. In particular, we focus on measurements of circulation cholinesterases as a readily quantifiable readout for changes in the sympathetic/parasympathetic balance and the implications of changes in this readout in health and disease. Taken together, this cumulative know-how calls for expanding the use of cholinesterase activity measurements for both basic research and as a clinical assessment tool.
ESTHER : Shenhar-Tsarfaty_2014_J.Mol.Neurosci_53_298
PubMedSearch : Shenhar-Tsarfaty_2014_J.Mol.Neurosci_53_298
PubMedID: 24254221

Title : AChE and RACK1 Promote the Anti-Inflammatory Properties of Fluoxetine - Waiskopf_2014_J.Mol.Neurosci_53_306
Author(s) : Waiskopf N , Ofek K , Gilboa-Geffen A , Bekenstein U , Bahat A , Bennett ER , Podoly E , Livnah O , Hartmann G , Soreq H
Ref : Journal of Molecular Neuroscience , 53 :306 , 2014
Abstract : Selective serotonin reuptake inhibitors (SSRIs) show anti-inflammatory effects, suggesting a possible interaction with both Toll-like-receptor 4 (TLR4) responses and cholinergic signaling through as yet unclear molecular mechanism(s). Our results of structural modeling support the concept that the antidepressant fluoxetine physically interacts with the TLR4-myeloid differentiation factor-2 complex at the same site as bacterial lipopolysaccharide (LPS). We also demonstrate reduced LPS-induced pro-inflammatory interleukin-6 and tumor necrosis factor alpha in human peripheral blood mononuclear cells preincubated with fluoxetine. Furthermore, we show that fluoxetine intercepts the LPS-induced decreases in intracellular acetylcholinesterase (AChE-S) and that AChE-S interacts with the nuclear factor kappa B (NFkappaB)-activating intracellular receptor for activated C kinase 1 (RACK1). This interaction may prevent NFkappaB activation by residual RACK1 and its interacting protein kinase PKCbetaII. Our findings attribute the anti-inflammatory properties of SSRI to surface membrane interference with leukocyte TLR4 activation accompanied by intracellular limitation of pathogen-inducible changes in AChE-S, RACK1, and PKCbetaII.
ESTHER : Waiskopf_2014_J.Mol.Neurosci_53_306
PubMedSearch : Waiskopf_2014_J.Mol.Neurosci_53_306
PubMedID: 24258317

Title : Sustained Alzheimer's amyloid pathology in myeloid differentiation protein-88-deficient APPswe\/PS1 mice - Goll_2014_Neurodegener.Dis_13_58
Author(s) : Goll Y , Bekenstein U , Barbash S , Greenberg DS , Zangen R , Shoham S , Soreq H
Ref : Neurodegener Dis , 13 :58 , 2014
Abstract : BACKGROUND: Most Alzheimer's disease (AD) cases arise sporadically and may involve innate immune activation of microglial expressed Toll-like receptors regulated through the myeloid differentiation protein 88 (MyD88) pathway. OBJECTIVE: It was the aim of this study to test the innate immune involvement in AD pathology.
METHODS: We mated APPsw/PS1DeltaE9 mice with MyD88-deficient mice.
RESULTS: Progeny mice had similar levels of soluble amyloid-beta peptides, amyloid plaque density and neuroimmune staining patterns. However, double-transgenic mice did show a significantly reduced life expectancy. CONCLUSION: Our findings indicate that impaired innate immune responses may play a role in AD pathology.
ESTHER : Goll_2014_Neurodegener.Dis_13_58
PubMedSearch : Goll_2014_Neurodegener.Dis_13_58
PubMedID: 24192711

Title : Acetylcholinesterase activity in the cerebrospinal fluid of dogs with seizures - Chai_2013_Vet.J_198_292
Author(s) : Chai O , Sommer A , Zimmerman G , Soreq H , Friedman A , Bdolah-Abram T , Aroch I , Shamir MH
Ref : Vet J , 198 :292 , 2013
Abstract : Recent studies in animal models have focused on the role of cholinergic elements, mainly acetylcholinesterase (AChE) and the 'readthrough' acetylcholinesterase isoform (AChE-R), in seizures. A prospective double-masked study was conducted to assess the activity of AChE and AChE-R in cerebrospinal fluid (CSF) of 26 dogs post-seizure, 28 dogs with intervertebral disc disease (IVDD) and 16 healthy dogs. AChE was also measured in the serum in the post-seizure and IVDD groups. The results showed no significant differences in CSF AChE among the three groups. AChE-R was not detected in any dog and AChE in the serum was similar between groups. This preliminary study provides new information on AChE and AChE-R in the CSF and sera of dogs following naturally-occurring seizures.
ESTHER : Chai_2013_Vet.J_198_292
PubMedSearch : Chai_2013_Vet.J_198_292
PubMedID: 23988333

Title : Cholinergic involvement and manipulation approaches in multiple system disorders - Ofek_2013_Chem.Biol.Interact_203_113
Author(s) : Ofek K , Soreq H
Ref : Chemico-Biological Interactions , 203 :113 , 2013
Abstract : Within the autonomic system, acetylcholine signaling contributes simultaneously and interactively to cognitive, behavioral, muscle and immune functions. Therefore, manipulating cholinergic parameters such as the activities of the acetylcholine hydrolyzing enzymes in body fluids or the corresponding transcript levels in blood leukocytes can change the global status of the autonomic system in treated individuals. Specifically, cholinesterase activities are subject to rapid and effective changes. The enzyme activity baseline increases with age and body mass index and depends on gender and ethnic origin. Also, the corresponding DNA (for detecting mutations) and RNA (for measuring specific mRNA transcripts) of cholinergic genes present individual variability. In leukocytes, acetylcholine inhibits the production of pro-inflammatory cytokines, suggesting relevance of cholinergic parameters to both the basal levels and to disease-induced inflammation. Inversely, acetylcholine levels increase under various stress stimuli, inducing changes in autonomic system molecules (e.g., pro-inflammatory cytokines) which can penetrate the brain; therefore, manipulating these levels can also effect brain reactions, mainly of anxiety, depression and pain. Additionally, neurodegenerative diseases often involve exacerbated inflammation, depression and anxiety, providing a focus interest group for cholinergic manipulations. In Alzheimer's disease, the systemic cholinergic impairments reflect premature death of cholinergic neurons. The decline of cholinesterases in the serum of Parkinson's disease and post- stroke patients, discovery of the relevant microRNAs and the growing range of use of anticholinesterase medications all call for critical re-inspection of established and novel approaches for manipulating cholinergic parameters.
ESTHER : Ofek_2013_Chem.Biol.Interact_203_113
PubMedSearch : Ofek_2013_Chem.Biol.Interact_203_113
PubMedID: 22898318

Title : Forebrain deletion of the vesicular acetylcholine transporter results in deficits in executive function, metabolic, and RNA splicing abnormalities in the prefrontal cortex - Kolisnyk_2013_J.Neurosci_33_14908
Author(s) : Kolisnyk B , Al-Onaizi MA , Hirata PH , Guzman MS , Nikolova S , Barbash S , Soreq H , Bartha R , Prado MAM , Prado VF
Ref : Journal of Neuroscience , 33 :14908 , 2013
Abstract : One of the key brain regions in cognitive processing and executive function is the prefrontal cortex (PFC), which receives cholinergic input from basal forebrain cholinergic neurons. We evaluated the contribution of synaptically released acetylcholine (ACh) to executive function by genetically targeting the vesicular acetylcholine transporter (VAChT) in the mouse forebrain. Executive function was assessed using a pairwise visual discrimination paradigm and the 5-choice serial reaction time task (5-CSRT). In the pairwise test, VAChT-deficient mice were able to learn, but were impaired in reversal learning, suggesting that these mice present cognitive inflexibility. Interestingly, VAChT-targeted mice took longer to reach criteria in the 5-CSRT. Although their performance was indistinguishable from that of control mice during low attentional demand, increased attentional demand revealed striking deficits in VAChT-deleted mice. Galantamine, a cholinesterase inhibitor used in Alzheimer's disease, significantly improved the performance of control mice, but not of VAChT-deficient mice on the 5-CSRT. In vivo magnetic resonance spectroscopy showed altered levels of two neurochemical markers of neuronal function, taurine and lactate, suggesting altered PFC metabolism in VAChT-deficient mice. The PFC of these mice displayed a drastic reduction in the splicing factor heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1), whose cholinergic-mediated reduction was previously demonstrated in Alzheimer's disease. Consequently, several key hnRNPA2/B1 target transcripts involved in neuronal function present changes in alternative splicing in VAChT-deficient mice, including pyruvate kinase M, a key enzyme involved in lactate metabolism. We propose that VAChT-targeted mice can be used to model and to dissect the neurochemical basis of executive abnormalities.
ESTHER : Kolisnyk_2013_J.Neurosci_33_14908
PubMedSearch : Kolisnyk_2013_J.Neurosci_33_14908
PubMedID: 24027290

Title : Plasma acetylcholinesterase activity correlates with intracerebral beta-amyloid load - Alkalay_2013_Curr.Alzheimer.Res_10_48
Author(s) : Alkalay A , Rabinovici GD , Zimmerman G , Agarwal N , Kaufer D , Miller BL , Jagust WJ , Soreq H
Ref : Curr Alzheimer Res , 10 :48 , 2013
Abstract : BACKGROUND: Previous studies have demonstrated alterations in the peripheral cholinergic system in Alzheimer's disease (AD), though results have been inconsistent and not linked to in vivo biomarkers of pathology. We examined the relationship between amyloid-beta (Abeta) plaques and plasma cholinesterase activity in a heterogeneous dementia population.
METHODS: 29 participants with clinical AD and 35 with non-AD diagnoses underwent positron emission tomography (PET) with the amyloid ligand [11C] PIB and plasma measurements of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity. Multi-linear regression was used to evaluate the relationship between AChE or BChE activity and PIB binding (adjusted for age, sex, apolipoprotein E4 and vascular risk), applying voxel-wise and region of interest (ROI) approaches. AChE activity was further adjusted for cholinesterase inhibitor (ChE-I) use. Global amyloid load was measured using a PIB Index, representing mean tracer binding in frontal, parietal, lateral temporal and cingulate cortex.
RESULTS: AChE activity was correlated with PIB Index (beta=0.39, p < 0.001) and with regional PIB binding in frontal, temporal, parietal and occipital lobes, precuneus and posterior cingulate on both voxel-wise (p < 0.001 uncorrected) and ROI (beta=0.26-0.41, p < 0.005) analysis. Correlations remained significant after covarying clinical diagnosis (beta=0.42, p=0.001), and among participants naive to ChE-I (beta=0.51, p=0.005). No correlation was found between BChE activity and PIB. Among AD participants, disease severity was not correlated with AChE, BChE or PIB Index. CONCLUSION: AChE activity in plasma is correlated with brain Abeta load. Activation of the 'anti-inflammatory cholinergic pathway' may provide the link between Abeta plaques and peripheral cholinergic measures.
ESTHER : Alkalay_2013_Curr.Alzheimer.Res_10_48
PubMedSearch : Alkalay_2013_Curr.Alzheimer.Res_10_48
PubMedID: 23157337

Title : Hippocampal microRNA-132 mediates stress-inducible cognitive deficits through its acetylcholinesterase target - Shaltiel_2013_Brain.Struct.Funct_218_59
Author(s) : Shaltiel G , Hanan M , Wolf Y , Barbash S , Kovalev E , Shoham S , Soreq H
Ref : Brain Struct Funct , 218 :59 , 2013
Abstract : Diverse stress stimuli induce long-lasting cognitive deficits, but the underlying molecular mechanisms are still incompletely understood. Here, we report three different stress models demonstrating that stress-inducible increases in microRNA-132 (miR-132) and consequent decreases in its acetylcholinesterase (AChE) target are causally involved. In a mild model of predator scent-induced anxiety, we demonstrate long-lasting hippocampal elevation of miR-132, accompanied by and associated with reduced AChE activity. Using lentiviral-mediated suppression of "synaptic" AChE-S mRNA, we quantified footshock stress-inducible changes in miR-132 and AChE and its corresponding cognitive damages. Stressed mice showed long-lasting impairments in the Morris water maze. In contrast, pre-stress injected AChE-suppressing lentivirus, but not a control virus, reduced hippocampal levels of both miR-132 and AChE and maintained similar cognitive performance to that of naive, non-stressed mice. To dissociate between miR-132 and synaptic AChE-S as potential causes for stress-inducible cognitive deficits, we further used engineered TgR mice with enforced over-expression of the soluble "readthrough" AChE-R variant without the 3'-untranslated region binding site for miR-132. TgR mice displayed excess AChE-R in hippocampal neurons, enhanced c-fos labeling and correspondingly intensified reaction to the cholinergic agonist pilocarpine. They further showed excessive hippocampal expression of miR-132, accompanied by reduced host AChE-S mRNA and the GTPase activator p250GAP target of miR-132. At the behavioral level, TgR mice showed abnormal nocturnal locomotion patterns and serial maze mal-performance in spite of their reduced AChE-S levels. Our findings attribute stress-inducible cognitive impairments to cholinergic-mediated induction of miR-132 and consequently suppressed ACHE-S, opening venues for intercepting these miR-132-mediated damages.
ESTHER : Shaltiel_2013_Brain.Struct.Funct_218_59
PubMedSearch : Shaltiel_2013_Brain.Struct.Funct_218_59
PubMedID: 22246100

Title : Atherosclerosis and arteriosclerosis parameters in stroke patients associate with paraoxonase polymorphism and esterase activities - Shenhar-Tsarfaty_2013_Eur.J.Neurol_20_891
Author(s) : Shenhar-Tsarfaty S , Waiskopf N , Ofek K , Shopin L , Usher S , Berliner S , Shapira I , Bornstein NM , Ritov Y , Soreq H , Ben Assayag E
Ref : Eur Journal of Neurology , 20 :891 , 2013
Abstract : BACKGROUND AND PURPOSE: Polymorphic paraoxonase (PON1) variants can variably prevent low- and high-density lipoprotein oxidation, but their role in provoking atherosclerosis remained unclear. We addressed this issue by profiling PON1 polymorphisms and enzymatic activities, and assessing atherosclerosis and cerebral arteriosclerosis severity in post-stroke patients.
METHODS: Carotid artery intima-media-thickness (IMT), cerebral white matter lesions (WML), serum PON1 -108C/T, Q192R and L55M polymorphisms, and PON and acetylcholinesterase (AChE) enzyme activities were determined in 237 patients.
RESULTS: Genetic variation at the PON1 locus showed a strong influence on PON1 activity in ischaemic stroke patients, but lacked direct influence on IMT. Stroke patients with PON1 QQ192 or MM55 genotypes demonstrated lower PON and arylesterase activities at both Day 1 and 12 months post-stroke than patients with either RQ/RR192 or LM/LL55 genotypes (P < 0.001). Furthermore, patients with carotid atherosclerosis and/or cerebral arteriosclerosis expressed as IMT, carotid plaques and WML had lower 12 months PON1 activity than patients without (P = 0.02, P = 0.027 and P = 0.001, respectively), and PON and AChE hydrolysis rates were more tightly correlated in patients carrying the PON1 192R compared with the 192QQ allele, in a gene dose-dependent manner (P < 0.001). CONCLUSION: Our findings show inverse PON1 activity-carotid atherosclerosis and -cerebral arteriosclerosis association in stroke patients: the lower the PON1 activity the more progressed is the atherosclerotic process and the weaker is the association with AChE activity. Extending previous PON1 genetic studies in stroke populations, our study emphasizes the PON1 activity as a potential anti-atherogenic element and proposes involvement of cholinesterase activities in its effects.
ESTHER : Shenhar-Tsarfaty_2013_Eur.J.Neurol_20_891
PubMedSearch : Shenhar-Tsarfaty_2013_Eur.J.Neurol_20_891
PubMedID: 23305304

Title : Heterogeneous nuclear ribonucleoprotein A1 in health and neurodegenerative disease: from structural insights to post-transcriptional regulatory roles - Bekenstein_2013_Mol.Cell.Neurosci_56_436
Author(s) : Bekenstein U , Soreq H
Ref : Molecular & Cellular Neurosciences , 56 :436 , 2013
Abstract : Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a family of conserved nuclear proteins that associate with nascent RNA polymerase II transcripts to yield hnRNP particles, playing key roles in mRNA metabolism, DNA-related functions and microRNA biogenesis. HnRNPs accompany transcripts from stages of transcriptional regulation through splicing and post-transcriptional regulation, and are believed to affect the majority of expressed genes in mammals. Most hnRNP mRNA transcripts undergo alternative splicing and post-translational modifications, to yield a remarkable diversity of proteins with numerous functional elements that work in concert in their multiple functions. Therefore, mis-regulation of hnRNPs leads to different maladies. Here, we focus on the role of one of the best-known members of this protein family, hnRNP A1 in RNA metabolism, and address recent works that note its multileveled involvement in several neurodegenerative disorders. Initially discovered as a DNA binding protein, hnRNP A1 includes two RNA recognition motifs, and post-translational modifications of these and other regions in this multifunctional protein alter both its nuclear pore shuttling properties and its RNA interactions and affect transcription, mRNA splicing and microRNA biogenesis. HnRNP A1 plays several key roles in neuronal functioning and its depletion, either due to debilitated cholinergic neurotransmission or under autoimmune reactions causes drastic changes in RNA metabolism. Consequently, hnRNP A1 decline contributes to the severity of symptoms in several neurodegenerative diseases, including Alzheimer's disease (AD), spinal muscular atrophy (SMA), fronto-temporal lobar degeneration (FTLD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), hereditary spastic paraparesis (HSP) and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). At the translational level, these properties of hnRNP A1 led to massive research efforts aimed at developing RNA-targeted therapeutic tools such as splicing-modulating oligonucleotides with promising pharmaceutical potential. HnRNP A1 thus presents an intriguing example for the complexity and importance of heteronuclear ribonucleoproteins in health and disease. This article is part of a Special Issue entitled 'RNA and splicing regulation in neurodegeneration'.
ESTHER : Bekenstein_2013_Mol.Cell.Neurosci_56_436
PubMedSearch : Bekenstein_2013_Mol.Cell.Neurosci_56_436
PubMedID: 23247072

Title : Meta-analysis of genetic and environmental Parkinson's disease models reveals a common role of mitochondrial protection pathways - Soreq_2012_Neurobiol.Dis_45_1018
Author(s) : Soreq L , Ben-Shaul Y , Israel Z , Bergman H , Soreq H
Ref : Neurobiol Dis , 45 :1018 , 2012
Abstract : Both genetic and environmental factors trigger risks of and protection from Parkinson's disease, the second most common neurodegenerative syndrome, but possible inter-relationships between these risk and protection processes were not yet explored. By examining gene expression changes in the brains of mice under multiple treatments that increase or attenuate PD symptoms we detected underlying disease and protection-associated genes and pathways. In search for potential links between these different genes and pathways, we conducted meta-analysis on 131 brain region transcriptomes from mice over-expressing native or mutated alpha-synuclein (SNCA) with or without the protective HSP70 chaperone, or exposed to the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), with or without the protective acetylcholinesterase (AChE-R) variant. All these models showed shared risk-inducible and protection-suppressible transcript modifications. Self-organized map (SOM) classification revealed risk- and protection-associated alterations in nuclear and mitochondrial metal ion-regulated transcripts, respectively; Gene Ontology based analysis validated these pathways. To complement this approach, and identify potential outcome damages, we further searched for shared functional enrichments in the lists of genes detected in young SNCA mutant or in old SNCA mutants and MPTP-exposed mice. This post-hoc functional analysis identified early-onset changes in Parkinsonian, immune and alternative splicing pathways which shifted into late-onset or exposure-associated NFkB-mediated neuro-inflammation. Our study suggests metal ions-mediated cross-talk between nuclear and mitochondrial pathways by both environmental and genetic risk and protective factors involved in Parkinson's disease, which eventually culminates in neuro-inflammation. Together, these findings offer new insights and novel targets for therapeutic interference with the gene-environment interactions underlying sporadic PD.
ESTHER : Soreq_2012_Neurobiol.Dis_45_1018
PubMedSearch : Soreq_2012_Neurobiol.Dis_45_1018
PubMedID: 22198569

Title : Stress-induced epigenetic transcriptional memory of acetylcholinesterase by HDAC4 - Sailaja_2012_Proc.Natl.Acad.Sci.U.S.A_109_E3687
Author(s) : Sailaja BS , Cohen-Carmon D , Zimmerman G , Soreq H , Meshorer E
Ref : Proc Natl Acad Sci U S A , 109 :E3687 , 2012
Abstract : Stress induces long-lasting changes in neuronal gene expression and cholinergic neurotransmission, but the underlying mechanism(s) are incompletely understood. Here, we report that chromatin structure and histone modifications are causally involved in this transcriptional memory. Specifically, the AChE gene encoding the acetylcholine-hydrolyzing enzyme acetylcholinesterase is known to undergo long-lasting transcriptional and alternative splicing changes after stress. In mice subjected to stress, we identified two alternative 5' exons that were down-regulated after stress in the hippocampus, accompanied by reduced acetylation and elevated trimethylation of H3K9 at the corresponding promoter. These effects were reversed completely by daily administration of the histone deacetylase (HDAC) inhibitor sodium butyrate for 1 wk after stress. H3K9 hypoacetylation was associated with a selective, sodium butyrate-reversible promoter accumulation of HDAC4. Hippocampal suppression of HDAC4 in vivo completely abolished the long-lasting AChE-related and behavioral stress effects. Our findings demonstrate long-lasting stress-inducible changes in AChE's promoter choices, identify the chromatin changes that support this long-term transcriptional memory, and reveal HDAC4 as a mediator of these effects in the hippocampus.
ESTHER : Sailaja_2012_Proc.Natl.Acad.Sci.U.S.A_109_E3687
PubMedSearch : Sailaja_2012_Proc.Natl.Acad.Sci.U.S.A_109_E3687
PubMedID: 23236169

Title : Further developments with antisense treatment for myasthenia gravis - Sussman_2012_Ann.N.Y.Acad.Sci_1275_13
Author(s) : Sussman Jo , Argov Z , Wirguin Y , Apolski S , Milic-Rasic V , Soreq H
Ref : Annals of the New York Academy of Sciences , 1275 :13 , 2012
Abstract : We present further developments in the study of the antisense oligonucleotide EN101. Ongoing in vitro and in vivo studies demonstrate that EN101 is a TLR9-specific ligand that can suppress pro-inflammatory functions and shift nuclear factor kappa B (NF-kappaB) from the pro-inflammatory canonical pathway to the anti-inflammatory alternative pathway, which results in decreases acetylcholinesterase (AChE) activity. Preliminary results of a double-blinded phase II cross-over study compared 10, 20, and 40 mg EN101 administered to patients with myasthenia gravis. Patients were randomly assigned to one of three treatment groups in weeks 1, 3, and 5 and received their pretreatment dose of pyridostigmine in weeks 2 and 4. Thus far, all doses show a decrease in QMG scores, with a greater response to higher doses.
ESTHER : Sussman_2012_Ann.N.Y.Acad.Sci_1275_13
PubMedSearch : Sussman_2012_Ann.N.Y.Acad.Sci_1275_13
PubMedID: 23278572

Title : Nicotinic stimulation induces Tristetraprolin over-production and attenuates inflammation in muscle - Geyer_2012_Biochim.Biophys.Acta_1823_368
Author(s) : Geyer BC , Ben Ari S , Barbash S , Kilbourne J , Mor TS , Soreq H
Ref : Biochimica & Biophysica Acta , 1823 :368 , 2012
Abstract : Cholinergic signaling suppresses inflammation in blood and brain and attenuates apoptosis in other tissues, but whether it blocks inflammation in skeletal muscle under toxicant exposure, injuries and diseases remained unexplored. Here, we report nicotinic attenuation of inflammation and alteration of apoptotic protein expression pattern in murine muscle tissue and cultured myotubes, involving the RNA-binding protein, Tristetraprolin, and the anti-apoptotic protein, Mcl-1. In muscles and C2C12 myotubes, cholinergic excitation by exposure to nicotine or the organophosphorous pesticide, Paraoxon, induced Tristetraprolin overproduction while reducing pro-inflammatory transcripts such as IL-6, CXCL1 (KC) and CCL2 (MCP-1). Furthermore, nicotinic excitation under exposure to the bacterial endotoxin LPS attenuated over-expression of the CCL2 and suppressed the transcriptional activity of NF-kB and AP-1. Tristetraprolin was essential for this anti-inflammatory effect of nicotine in basal conditions. However, its knockdown also impaired the pro-inflammatory response to LPS. Finally, in vivo administration of Paraoxon or recombinant Acetylcholinesterase, leading respectively to either gain or loss of cholinergic signaling, modified muscle expression of key mRNA processing factors and several of their apoptosis-related targets. Specifically, cholinergic imbalances enhanced the kinase activators of the Serine-Arginine splicing kinases, Clk1 and Clk3. Moreover, Paraoxon raised the levels of the anti-apoptotic protein, Mcl-1, through a previously unrecognized polyadenylation site selection mechanism, producing longer, less stable Mcl-1 mRNA transcripts. Together, our findings demonstrate that in addition to activating muscle function, acetylcholine regulates muscle inflammation and cell survival, and point to Tristetraprolin and the choice of Mcl-1 mRNA polyadenylation sites as potential key players in muscle reactions to insults.
ESTHER : Geyer_2012_Biochim.Biophys.Acta_1823_368
PubMedSearch : Geyer_2012_Biochim.Biophys.Acta_1823_368
PubMedID: 22093924

Title : Similar cation channels mediate protection from cerebellar exitotoxicity by exercise and inheritance - Ben-Ari_2012_J.Cell.Mol.Med_16_555
Author(s) : Ben-Ari S , Ofek K , Barbash S , Meiri H , Kovalev E , Greenberg DS , Soreq H , Shoham S
Ref : J Cell Mol Med , 16 :555 , 2012
Abstract : Exercise and inherited factors both affect recovery from stroke and head injury, but the underlying mechanisms and interconnections between them are yet unknown. Here, we report that similar cation channels mediate the protective effect of exercise and specific genetic background in a kainate injection model of cerebellar stroke. Microinjection to the cerebellum of the glutamatergic agonist, kainate, creates glutamatergic excito\xE2\x80\x90toxicity characteristic of focal stroke, head injury or alcoholism. Inherited protection and prior exercise were both accompanied by higher cerebellar expression levels of the Kir6.1 ATP-dependent potassium channel in adjacent Bergmann glia, and voltage-gated KVbeta2 and cyclic nucleotide-gated cation HCN1 channels in basket cells. Sedentary FVB/N and exercised C57BL/6 mice both expressed higher levels of these cation channels compared to sedentary C57BL/6 mice, and were both found to be less sensitive to glutamate toxicity. Moreover, blocking ATP-dependent potassium channels with Glibenclamide enhanced kainate-induced cell death in cerebellar slices from the resilient sedentary FVB/N mice. Furthermore, exercise increased the number of acetylcholinesterase-positive fibres in the molecular layer, reduced cerebellar cytokine levels and suppressed serum acetylcholinesterase activity, suggesting anti-inflammatory protection by enhanced cholinergic signalling. Our findings demonstrate for the first time that routine exercise and specific genetic backgrounds confer protection from cerebellar glutamatergic damages by similar molecular mechanisms, including elevated expression of cation channels. In addition, our findings highlight the involvement of the cholinergic anti-inflammatory pathway in insult-inducible cerebellar processes. These mechanisms are likely to play similar roles in other brain regions and injuries as well, opening new venues for targeted research efforts.
ESTHER : Ben-Ari_2012_J.Cell.Mol.Med_16_555
PubMedSearch : Ben-Ari_2012_J.Cell.Mol.Med_16_555
PubMedID: 21507200

Title : Acetylcholinesterase: old questions and new developments -
Author(s) : Tsim KWK , Soreq H
Ref : Front Mol Neurosci , 5 :101 , 2012
PubMedID: 23316131

Title : Fluoxetine induces vasodilatation of cerebral arterioles by co-modulating NO\/muscarinic signalling - Ofek_2012_J.Cell.Mol.Med_16_2736
Author(s) : Ofek K , Schoknecht K , Melamed-Book N , Heinemann U , Friedman A , Soreq H
Ref : J Cell Mol Med , 16 :2736 , 2012
Abstract : Ischaemic stroke patients treated with Selective Serotonin Reuptake Inhibitors (SSRI) show improved motor, cognitive and executive functions, but the underlying mechanism(s) are incompletely understood. Here, we report that cerebral arterioles in the rat brain superfused with therapeutically effective doses of the SSRI fluoxetine showed consistent, dose-dependent vasodilatation (by 1.2 to 1.6-fold), suppressible by muscarinic and nitric oxide synthase (NOS) antagonists [atropine, NG-nitro-l-arginine methyl ester (l-NAME)] but resistant to nicotinic and serotoninergic antagonists (mecamylamine, methylsergide). Fluoxetine administered 10-30 min. following experimental vascular photo-thrombosis increased arterial diameter (1.3-1.6), inducing partial, but lasting reperfusion of the ischaemic brain. In brain endothelial b.End.3 cells, fluoxetine induced rapid muscarinic receptor-dependent increases in intracellular [Ca(2+) ] and promoted albumin- and eNOS-dependent nitric oxide (NO) production and HSP90 interaction. In vitro, fluoxetine suppressed recombinant human acetylcholinesterase (rhAChE) activity only in the presence of albumin. That fluoxetine induces vasodilatation of cerebral arterioles suggests co-promotion of endothelial muscarinic and nitric oxide signalling, facilitated by albumin-dependent inhibition of serum AChE.
ESTHER : Ofek_2012_J.Cell.Mol.Med_16_2736
PubMedSearch : Ofek_2012_J.Cell.Mol.Med_16_2736
PubMedID: 22697296

Title : Stressing hematopoiesis and immunity: an acetylcholinesterase window into nervous and immune system interactions - Gilboa-Geffen_2012_Front.Mol.Neurosci_5_30
Author(s) : Gilboa-Geffen A , Hartmann G , Soreq H
Ref : Front Mol Neurosci , 5 :30 , 2012
Abstract : Hematopoietic stem cells (HSCs) differentiate and generate all blood cell lineages while maintaining self-renewal ability throughout life. Systemic responses to stressful insults, either psychological or physical exert both stimulating and down-regulating effects on these dynamic members of the immune system. Stress-facilitated division and re-oriented differentiation of progenitor cells modifies hematopoietic cell type composition, while enhancing cytokine production and promoting inflammation. Inversely, stress-induced increases in the neurotransmitter acetylcholine (ACh) act to mitigate inflammatory response and regain homeostasis. This signaling process is terminated when ACh is hydrolyzed by acetylcholinesterase (AChE). Alternative splicing, which is stress-modified, changes the composition of AChE variants, modifying their terminal sequences, susceptibility for microRNA suppression, and sub-cellular localizations. Intriguingly, the effects of stress and AChE variants on hematopoietic development and inflammation in health and disease are both subject to small molecule as well as oligonucleotide-mediated manipulations in vitro and in vivo. The therapeutic agents can thus be targeted to the enzyme protein, its encoding mRNA transcripts, or the regulator microRNA-132, opening new venues for therapeutic interference with multiple nervous and immune system diseases.
ESTHER : Gilboa-Geffen_2012_Front.Mol.Neurosci_5_30
PubMedSearch : Gilboa-Geffen_2012_Front.Mol.Neurosci_5_30
PubMedID: 22448158

Title : Acetylcholinesterase loosens the brain's cholinergic anti-inflammatory response and promotes epileptogenesis - Gnatek_2012_Front.Mol.Neurosci_5_66
Author(s) : Gnatek Y , Zimmerman G , Goll Y , Najami N , Soreq H , Friedman A
Ref : Front Mol Neurosci , 5 :66 , 2012
Abstract : Recent studies show a key role of brain inflammation in epilepsy. However, the mechanisms controlling brain immune response are only partly understood. In the periphery, acetylcholine (ACh) release by the vagus nerve restrains inflammation by inhibiting the activation of leukocytes. Recent reports suggested a similar anti-inflammatory effect for ACh in the brain. Since brain cholinergic dysfunctions are documented in epileptic animals, we explored changes in brain cholinergic gene expression and associated immune response during pilocarpine-induced epileptogenesis. Levels of acetylcholinesterase (AChE) and inflammatory markers were measured using real-time RT-PCR, in-situ hybridization and immunostaining in wild type (WT) and transgenic mice over-expressing the "synaptic" splice variant AChE-S (TgS). One month following pilocarpine, mice were video-monitored for spontaneous seizures. To test directly the effect of ACh on the brain's innate immune response, cytokines expression levels were measured in acute brain slices treated with cholinergic agents. We report a robust up-regulation of AChE as early as 48 h following pilocarpine-induced status epilepticus (SE). AChE was expressed in hippocampal neurons, microglia, and endothelial cells but rarely in astrocytes. TgS mice overexpressing AChE showed constitutive increased microglial activation, elevated levels of pro-inflammatory cytokines 48 h after SE and accelerated epileptogenesis compared to their WT counterparts. Finally we show a direct, muscarine-receptor dependant, nicotine-receptor independent anti-inflammatory effect of ACh in brain slices maintained ex vivo. Our work demonstrates for the first time, that ACh directly suppresses brain innate immune response and that AChE up-regulation after SE is associated with enhanced immune response, facilitating the epileptogenic process. Our results highlight the cholinergic system as a potential new target for the prevention of seizures and epilepsy.
ESTHER : Gnatek_2012_Front.Mol.Neurosci_5_66
PubMedSearch : Gnatek_2012_Front.Mol.Neurosci_5_66
PubMedID: 22639569

Title : Cholinesterase-Targeting microRNAs Identified in silico Affect Specific Biological Processes - Hanin_2011_Front.Mol.Neurosci_4_28
Author(s) : Hanin G , Soreq H
Ref : Front Mol Neurosci , 4 :28 , 2011
Abstract : MicroRNAs (miRs) have emerged as important gene silencers affecting many target mRNAs. Here, we report the identification of 244 miRs that target the 3'-untranslated regions of different cholinesterase transcripts: 116 for butyrylcholinesterase (BChE), 47 for the synaptic acetylcholinesterase (AChE-S) splice variant, and 81 for the normally rare splice variant AChE-R. Of these, 11 and 6 miRs target both AChE-S and AChE-R, and AChE-R and BChE transcripts, respectively. BChE and AChE-S showed no overlapping miRs, attesting to their distinct modes of miR regulation. Generally, miRs can suppress a number of targets; thereby controlling an entire battery of functions. To evaluate the importance of the cholinesterase-targeted miRs in other specific biological processes we searched for their other experimentally validated target transcripts and analyzed the gene ontology enriched biological processes these transcripts are involved in. Interestingly, a number of the resulting categories are also related to cholinesterases. They include, for BChE, response to glucocorticoid stimulus, and for AChE, response to wounding and two child terms of neuron development: regulation of axonogenesis and regulation of dendrite morphogenesis. Importantly, all of the AChE-targeting miRs found to be related to these selected processes were directed against the normally rare AChE-R splice variant, with three of them, including the neurogenesis regulator miR-132, also directed against AChE-S. Our findings point at the AChE-R splice variant as particularly susceptible to miR regulation, highlight those biological functions of cholinesterases that are likely to be subject to miR post-transcriptional control, demonstrate the selectivity of miRs in regulating specific biological processes, and open new venues for targeted interference with these specific processes.
ESTHER : Hanin_2011_Front.Mol.Neurosci_4_28
PubMedSearch : Hanin_2011_Front.Mol.Neurosci_4_28
PubMedID: 22007158

Title : Cholinesterase modulations in patients with acute bacterial meningitis - Berg_2011_Scand.J.Clin.Lab.Invest_71_350
Author(s) : Berg RM , Ofek K , Qvist T , Tofteng F , Soreq H , Moller K
Ref : Scand J Clin Lab Invest , 71 :350 , 2011
Abstract : BACKGROUND: The circulating cholinesterases acetyl- and butyrylcholinesterase may be suppressed and subsequently released from the brain in acute bacterial meningitis. METHODS: We report serum activities of acetylcholinesterase and butyrylcholinesterase in paired arterial and jugular venous samples from seven patients with acute bacterial meningitis and eight healthy controls. Paraoxonase 1, which protects these enzymes from oxidative inactivation, was also measured. FINDINGS AND CONCLUSION: Acetyl- and butyrylcholinesterase activities were lower in patients, independently of changes in paraoxonase 1. Arterial and jugular venous enzyme activities were similar both in patients and controls, suggesting that no cerebral release was present.
ESTHER : Berg_2011_Scand.J.Clin.Lab.Invest_71_350
PubMedSearch : Berg_2011_Scand.J.Clin.Lab.Invest_71_350
PubMedID: 21303225

Title : Activation of the alternative NFkappaB pathway improves disease symptoms in a model of Sjogren's syndrome - Gilboa-Geffen_2011_PLoS.One_6_e28727
Author(s) : Gilboa-Geffen A , Wolf Y , Hanin G , Melamed-Book N , Pick M , Bennett ER , Greenberg DS , Lester S , Rischmueller M , Soreq H
Ref : PLoS ONE , 6 :e28727 , 2011
Abstract : The purpose of our study was to understand if Toll-like receptor 9 (TLR9) activation could contribute to the control of inflammation in Sjogren's syndrome. To this end, we manipulated TLR9 signaling in non-obese diabetic (NOD) and TLR9(-/-) mice using agonistic CpG oligonucleotide aptamers, TLR9 inhibitors, and the in-house oligonucleotide BL-7040. We then measured salivation, inflammatory response markers, and expression of proteins downstream to NF-kappaB activation pathways. Finally, we labeled proteins of interest in salivary gland biopsies from Sjogren's syndrome patients, compared to Sicca syndrome controls. We show that in NOD mice BL-7040 activates TLR9 to induce an alternative NF-kappaB activation mode resulting in increased salivation, elevated anti-inflammatory response in salivary glands, and reduced peripheral AChE activity. These effects were more prominent and also suppressible by TLR9 inhibitors in NOD mice, but TLR9(-/-) mice were resistant to the salivation-promoting effects of CpG oligonucleotides and BL-7040. Last, salivary glands from Sjogren's disease patients showed increased inflammatory and decreased anti-inflammatory biomarkers, in addition to decreased levels of alternative NF-kappaB pathway proteins. In summary, we have demonstrated that activation of TLR9 by BL-7040 leads to non-canonical activation of NF-kappaB, promoting salivary functioning and down-regulating inflammation. We propose that BL-7040 could be beneficial in treating Sjogren's syndrome and may be applicable to additional autoimmune syndromes.
ESTHER : Gilboa-Geffen_2011_PLoS.One_6_e28727
PubMedSearch : Gilboa-Geffen_2011_PLoS.One_6_e28727
PubMedID: 22174879

Title : Butyrylcholinesterase interactions with amylin may protect pancreatic cells in metabolic syndrome - Shenhar-Tsarfaty_2011_J.Cell.Mol.Med_15_1747
Author(s) : Shenhar-Tsarfaty S , Bruck T , Bennett ER , Bravman T , Aassayag EB , Waiskopf N , Rogowski O , Bornstein N , Berliner S , Soreq H
Ref : J Cell Mol Med , 15 :1747 , 2011
Abstract : The metabolic syndrome (MetS) is a risk factor for type 2 diabetes mellitus (T2DM). However, the mechanisms underlying the transition from MetS to T2DM are unknown. Our goal was to study the potential contribution of butyrylcholinesterase (BChE) to this process. We first determined the hydrolytic activity of BChE in serum from MetS, T2DM and healthy individuals. The 'Kalow' variant of BChE (BChE-K), which has been proposed to be a risk factor for T2DM, was genotyped in the last two groups. Our results show that in MetS patients serum BChE activity is elevated compared to T2DM patients and healthy controls (P < 0.001). The BChE-K genotype showed similar prevalence in T2DM and healthy individuals, excluding this genotype as a risk factor for T2DM. However, the activity differences remained unexplained. Previous results from our laboratory have shown BChE to attenuate the formation of beta-amyloid fibrils, and protect cultured neurons from their cytotoxicity. Therefore, we next studied the in vitro interactions between recombinant human butyrylcholinesterase and amylin by surface plasmon resonance, Thioflavine T fluorescence assay and cross-linking, and used cultured pancreatic beta cells to test protection by BChE from amylin cytotoxicity. We demonstrate that BChE interacts with amylin through its core domain and efficiently attenuates both amylin fibril and oligomer formation. Furthermore, application of BChE to cultured beta cells protects them from amylin cytotoxicity. Taken together, our results suggest that MetS-associated BChE increases could protect pancreatic beta-cells in vivo by decreasing the formation of toxic amylin oligomers.
ESTHER : Shenhar-Tsarfaty_2011_J.Cell.Mol.Med_15_1747
PubMedSearch : Shenhar-Tsarfaty_2011_J.Cell.Mol.Med_15_1747
PubMedID: 20807286

Title : Changes in brain MicroRNAs contribute to cholinergic stress reactions - Meerson_2010_J.Mol.Neurosci_40_47
Author(s) : Meerson A , Cacheaux L , Goosens KA , Sapolsky RM , Soreq H , Kaufer D
Ref : Journal of Molecular Neuroscience , 40 :47 , 2010
Abstract : Mental stress modifies both cholinergic neurotransmission and alternative splicing in the brain, via incompletely understood mechanisms. Here, we report that stress changes brain microRNA (miR) expression and that some of these stress-regulated miRs regulate alternative splicing. Acute and chronic immobilization stress differentially altered the expression of numerous miRs in two stress-responsive regions of the rat brain, the hippocampal CA1 region and the central nucleus of the amygdala. miR-134 and miR-183 levels both increased in the amygdala following acute stress, compared to unstressed controls. Chronic stress decreased miR-134 levels, whereas miR-183 remained unchanged in both the amygdala and CA1. Importantly, miR-134 and miR-183 share a common predicted mRNA target, encoding the splicing factor SC35. Stress was previously shown to upregulate SC35, which promotes the alternative splicing of acetylcholinesterase (AChE) from the synapse-associated isoform AChE-S to the, normally rare, soluble AChE-R protein. Knockdown of miR-183 expression increased SC35 protein levels in vitro, whereas overexpression of miR-183 reduced SC35 protein levels, suggesting a physiological role for miR-183 regulation under stress. We show stress-induced changes in miR-183 and miR-134 and suggest that, by regulating splicing factors and their targets, these changes modify both alternative splicing and cholinergic neurotransmission in the stressed brain.
ESTHER : Meerson_2010_J.Mol.Neurosci_40_47
PubMedSearch : Meerson_2010_J.Mol.Neurosci_40_47
PubMedID: 19711202

Title : Serum cholinesterase activities distinguish between stroke patients and controls and predict 12-month mortality - Ben Assayag_2010_Mol.Med_16_278
Author(s) : Ben Assayag E , Shenhar-Tsarfaty S , Ofek K , Soreq L , Bova I , Shopin L , Berg RM , Berliner S , Shapira I , Bornstein NM , Soreq H
Ref : Mol Med , 16 :278 , 2010
Abstract : To date there is no diagnostic biomarker for mild stroke, although elevation of inflammatory biomarkers has been reported at early stages. Previous studies implicated acetylcholinesterase (AChE) involvement in stroke, and circulating AChE activity reflects inflammatory response, since acetylcholine suppresses inflammation. Therefore, carriers of polymorphisms that modify cholinergic activity should be particularly susceptible to inflammatory damage. Our study sought diagnostic values of AChE and Cholinergic Status (CS, the total capacity for acetylcholine hydrolysis) in suspected stroke patients. For this purpose, serum cholinesterase activities, butyrylcholinesterase-K genotype and inflammatory biomarkers were determined in 264 ischemic stroke patients and matched controls during the acute phase. AChE activities were lower (P<0.001), and butyrylcholinesterase activities were higher in patients than in controls (P=0.004). When normalized to sampling time from stroke occurrence, both cholinergic parameters were correlated with multiple inflammatory biomarkers, including fibrinogen, interleukin-6 and C-reactive protein (r=0.713, r=0.607; r=0.421, r=0.341; r=0.276, r=0.255; respectively; all P values<0.001). Furthermore, very low AChE activities predicted subsequent nonsurvival (P=0.036). Also, carriers of the unstable butyrylcholinesterase-K variant were more abundant among patients than controls, and showed reduced activity (P<0.001). Importantly, a cholinergic score combining the two cholinesterase activities discriminated between 94.3% matched pairs of patients and controls, compared with only 75% for inflammatory measures. Our findings present the power of circulation cholinesterase measurements as useful early diagnostic tools for the occurrence of stroke. Importantly, these were considerably more distinctive than the inflammatory biomarkers, albeit closely associated with them, which may open new venues for stroke diagnosis and treatment.
ESTHER : Ben Assayag_2010_Mol.Med_16_278
PubMedSearch : Ben Assayag_2010_Mol.Med_16_278
PubMedID: 20464061

Title : Alanine-to-threonine substitutions and amyloid diseases: butyrylcholinesterase as a case study - Podoly_2010_Chem.Biol.Interact_187_64
Author(s) : Podoly E , Hanin G , Soreq H
Ref : Chemico-Biological Interactions , 187 :64 , 2010
Abstract : Alanine-to-threonine (A to T) substitutions caused by single nucleotide polymorphisms (SNPs) occur in diverse proteins, and in certain cases these substitutions induce self-aggregation into amyloid fibrils or aggregation in other amyloidogenic proteins. This is compatible with the inverse preferences of alanine to form helices and of threonine to support beta-sheet structures, which are crucial for amyloid fibrils formation. Our interest in these mutations was initiated by studying the potential effects of the A539T substitution in the butyrylcholinesterase BChE-K variant on amyloid fibrils formation in Alzheimer's disease. Other examples are, Parkinson's disease (PD), where A53T alpha-synuclein occurs in Lewy bodies and familial amyloid polyneuropathy (FAP), where an A25T substitution appears in transthyretin (TTR). In peripheral organs, an A34T substitution is found in the light chain immunoglobulin genes of patients with systemic amyloidosis and in familial hypercholesterolemia, an A370T substitution occurs in the LDLR regulator of cholesterol homeostasis. That such substitutions appear in proteins with important cellular functions suggests that they confer antagonistic pleiotropy, providing added value at an earlier age but causing damages and inducing amyloid diseases later on. This, in turn, may explain the evolutionary selection and preservation of these substitutions. The structural effect of residue substitutions and in particular A to T substitutions in amyloidogenic diseases thus merits further attention.
ESTHER : Podoly_2010_Chem.Biol.Interact_187_64
PubMedSearch : Podoly_2010_Chem.Biol.Interact_187_64
PubMedID: 20060816

Title : Acetylcholinesterase variants in Alzheimer's disease: from neuroprotection to programmed cell death - Greenberg_2010_Neurodegener.Dis_7_60
Author(s) : Greenberg DS , Toiber D , Berson A , Soreq H
Ref : Neurodegener Dis , 7 :60 , 2010
Abstract : BACKGROUND: In Alzheimer's disease (AD), cholinergic neurons are particularly vulnerable for as yet unclear reasons. Here, we report that modified composition, localization and properties of alternative splice variants encoding the acetylcholine-hydrolyzing enzyme acetylcholinesterase (AChE) may be variably involved in disease progression or in systemic efforts to attenuate its progression. OBJECTIVE: The purpose of this study was to explore the implications for AD of the cellular and biochemical properties of the various AChE proteins, differing in their N and C termini. METHODS: We have used cell transfection with genetically engineered vectors as well as microinjection to overexpress specific AChE variants and explore the consequences to cellular well-being and survival. Additionally, we employed highly purified recombinant AChE-R and AChE-S to explore putative interactions with the AD beta-amyloid peptide. RESULTS: Our findings demonstrate distinct, and in certain cases inverse cell fate outcome under enforced expression of the human N- and C-terminally modified AChE variants, all of which have similar enzymatic activities. CONCLUSION: The N-terminal extension in conjunction with the primary helical C-terminal peptide of 'tailed' AChE-S facilitates, whereas the shorter, naturally unfolded C-terminus of the stress-induced AChE-R variant attenuates Alzheimer's pathology.
ESTHER : Greenberg_2010_Neurodegener.Dis_7_60
PubMedSearch : Greenberg_2010_Neurodegener.Dis_7_60
PubMedID: 20173328

Title : Plant-derived human butyrylcholinesterase, but not an organophosphorous-compound hydrolyzing variant thereof, protects rodents against nerve agents - Geyer_2010_Proc.Natl.Acad.Sci.U.S.A_107_20251
Author(s) : Geyer BC , Kannan L , Garnaud PE , Broomfield CA , Cadieux CL , Cherni I , Hodgins SM , Kasten SA , Kelley K , Kilbourne J , Oliver ZP , Otto TC , Puffenberger I , Reeves TE , Robbins N, 2nd , Woods RR , Soreq H , Lenz DE , Cerasoli DM , Mor TS
Ref : Proc Natl Acad Sci U S A , 107 :20251 , 2010
Abstract : The concept of using cholinesterase bioscavengers for prophylaxis against organophosphorous nerve agents and pesticides has progressed from the bench to clinical trial. However, the supply of the native human proteins is either limited (e.g., plasma-derived butyrylcholinesterase and erythrocytic acetylcholinesterase) or nonexisting (synaptic acetylcholinesterase). Here we identify a unique form of recombinant human butyrylcholinesterase that mimics the native enzyme assembly into tetramers; this form provides extended effective pharmacokinetics that is significantly enhanced by polyethylene glycol conjugation. We further demonstrate that this enzyme (but not a G117H/E197Q organophosphorus acid anhydride hydrolase catalytic variant) can prevent morbidity and mortality associated with organophosphorous nerve agent and pesticide exposure of animal subjects of two model species.
ESTHER : Geyer_2010_Proc.Natl.Acad.Sci.U.S.A_107_20251
PubMedSearch : Geyer_2010_Proc.Natl.Acad.Sci.U.S.A_107_20251
PubMedID: 21059932

Title : Transgenic plants as a source for the bioscavenging enzyme, human butyrylcholinesterase - Geyer_2010_Plant.Biotechnol.J_8_873
Author(s) : Geyer BC , Kannan L , Cherni I , Woods RR , Soreq H , Mor TS
Ref : Plant Biotechnol J , 8 :873 , 2010
Abstract : Organophosphorous pesticides and nerve agents inhibit the enzyme acetylcholinesterase at neuronal synapses and in neuromuscular junctions. The resulting accumulation of acetylcholine overwhelms regulatory mechanisms, potentially leading to seizures and death from respiratory collapse. While current therapies are only capable of reducing mortality, elevation of the serum levels of the related enzyme butyrylcholinesterase (BChE) by application of the purified protein as a bioscavenger of organophosphorous compounds is effective in preventing all symptoms associated with poisoning by these toxins. However, BChE therapy requires large quantities of enzyme that can easily overwhelm current sources. Here, we report genetic optimization, cloning and high-level expression of human BChE in plants. Plant-derived BChE is shown to be biochemically similar to human plasma-derived BChE in terms of catalytic activity and inhibitor binding. We further demonstrate the ability of the plant-derived bioscavenger to protect animals against an organophosphorous pesticide challenge.
ESTHER : Geyer_2010_Plant.Biotechnol.J_8_873
PubMedSearch : Geyer_2010_Plant.Biotechnol.J_8_873
PubMedID: 20353404

Title : Engineering DYRK1A overdosage yields Down syndrome-characteristic cortical splicing aberrations - Toiber_2010_Neurobiol.Dis_40_348
Author(s) : Toiber D , Azkona G , Ben-Ari S , Toran N , Soreq H , Dierssen M
Ref : Neurobiol Dis , 40 :348 , 2010
Abstract : Down syndrome (DS) associates with impaired brain functions, but the underlying mechanism(s) are yet unclear. The "gene dosage" hypothesis predicts that in DS, overexpression of a single gene can impair multiple brain functions through a signal amplification effect due to impaired regulatory mechanism(s). Here, we report findings attributing to impairments in the splicing process such a regulatory role. We have used DS fetal brain samples in search for initial evidence and employed engineered mice with MMU16 partial trisomy (Ts65Dn) or direct excess of the splicing-associated nuclear kinase Dyrk1A, overdosed in DS for further analyses. We present specific albeit modest changes in the DS brain's splicing machinery with subsequently amplified effects in target transcripts; and we demonstrate that engineered excess of Dyrk1A can largely recapitulate these changes. Specifically, in both the fetal DS brains and the Dyrk1A overdose models, we found ample modestly modified splicing-associated transcripts which apparently induced secondary enhancement in exon inclusion of key synaptic transcripts. Thus, DS-reduced levels of the dominant-negative TRKBT1 transcript, but not other TRKB mRNA transcripts, were accompanied by corresponding decreases in BDNF. In addition, the DS brains and Dyrk1A overdosage models showed selective changes in the transcripts composition of neuroligin mRNAs as well as reductions in the "synaptic" acetylcholinesterase variant AChE-S mRNA and corresponding increases in the stress-inducible AChE-R mRNA variant, yielding key synaptic proteins with unusual features. In cotransfected cells, Dyrk1A overdosage caused parallel changes in the splicing pattern of an AChE mini-gene, suggesting that Dyrk1A overdosage is both essential and sufficient to induce the observed change in the composition of AChE mRNA variants. Furthermore, the Dyrk1A overdosage animal models showed pronounced changes in the structure of neuronal nuclear speckles, where splicing events take place and in SR proteins phosphorylation known to be required for the splicing process. Together, our findings demonstrate DS-like brain splicing machinery malfunctioning in Dyrk1A overexpressing mice. Since individual splicing choices may alter cell fate determination, axon guidance, and synaptogenesis, these findings suggest the retrieval of balanced splicing as a goal for DS therapeutic manipulations early in DS development.
ESTHER : Toiber_2010_Neurobiol.Dis_40_348
PubMedSearch : Toiber_2010_Neurobiol.Dis_40_348
PubMedID: 20600907

Title : Erythropoietin attenuates hyperoxia-induced oxidative stress in the developing rat brain - Sifringer_2010_Brain.Behav.Immun_24_792
Author(s) : Sifringer M , Brait D , Weichelt U , Zimmerman G , Endesfelder S , Brehmer F , von Haefen C , Friedman A , Soreq H , Bendix I , Gerstner B , Felderhoff-Mueser U
Ref : Brain Behavior & Immunity , 24 :792 , 2010
Abstract : Oxygen toxicity contributes to the pathogenesis of adverse neurological outcome in survivors of preterm birth in clinical studies. In infant rodent brains, hyperoxia triggers widespread apoptotic neurodegeneration, induces pro-inflammatory cytokines and inhibits growth factor signaling cascades. Since a tissue-protective effect has been observed for recombinant erythropoietin (rEpo), we hypothesized that rEpo would influence hyperoxia-induced oxidative stress in the developing rat brain. The aim of this study was to investigate the level of glutathione (reduced and oxidized), lipid peroxidation and the expression of heme oxygenase-1 (HO-1) and acetylcholinesterase (AChE) after hyperoxia and rEpo treatment. Six-day-old Wistar rats were exposed to 80% oxygen for 2-48 h and received 20,000 IU/kg rEpo intraperitoneally (i.p.). Sex-matched littermates kept under room air and injected with normal saline or rEpo served as controls. Treatment with rEpo significantly reduced hyperoxia-induced upregulation of oxidized glutathione (GSSG) and malondialdehyde, a product of lipid breakdown, whereas reduced glutathione (GSH) was upregulated by rEpo. In parallel, hyperoxia-treated immature rat brains revealed rEpo-suppressible upregulation of synaptic AChE-S as well as of the stress-inducible AChE-R variant, together predicting rEpo-protected cholinergic signaling and restrained inflammatory reactions. Furthermore, treatment with rEpo induced upregulation of HO-1 on mRNA, protein and activity level in the developing rat brain. Our results suggest that rEpo generates its protective effect against oxygen toxicity by a reduction of diverse oxidative stress parameters and by limiting the stressor-inducible changes in both HO-1 and cholinergic functions.
ESTHER : Sifringer_2010_Brain.Behav.Immun_24_792
PubMedSearch : Sifringer_2010_Brain.Behav.Immun_24_792
PubMedID: 19729061

Title : MicroRNA-132 potentiates cholinergic anti-inflammatory signaling by targeting acetylcholinesterase - Shaked_2009_Immunity_31_965
Author(s) : Shaked I , Meerson A , Wolf Y , Avni R , Greenberg D , Gilboa-Geffen A , Soreq H
Ref : Immunity , 31 :965 , 2009
Abstract : MicroRNAs (miRNAs) contribute to both neuronal and immune cell fate, but their involvement in intertissue communication remained unexplored. The brain, via vagal secretion of acetylcholine (ACh), suppresses peripheral inflammation by intercepting cytokine production; therefore, we predicted that microRNAs targeting acetylcholinesterase (AChE) can attenuate inflammation. Here, we report that inflammatory stimuli induced leukocyte overexpression of the AChE-targeting miR-132. Injected locked nucleic acid (LNA)-modified anti-miR-132 oligonucleotide depleted miR-132 amounts while elevating AChE in mouse circulation and tissues. In transfected cells, a mutated 3'UTR miR-132 binding site increased AChE mRNA expression, whereas cells infected with a lentivirus expressing pre-miR-132 showed suppressed AChE. Transgenic mice overexpressing 3'UTR null AChE showed excessive inflammatory mediators and impaired cholinergic anti-inflammatory regulation, in spite of substantial miR-132 upregulation in brain and bone marrow. Our findings identify the AChE mRNA-targeting miR-132 as a functional regulator of the brain-to-body resolution of inflammation, opening avenues for study and therapeutic manipulations of the neuro-immune dialog.
ESTHER : Shaked_2009_Immunity_31_965
PubMedSearch : Shaked_2009_Immunity_31_965
PubMedID: 20005135

Title : The butyrylcholinesterase K variant confers structurally derived risks for Alzheimer pathology - Podoly_2009_J.Biol.Chem_284_17170
Author(s) : Podoly E , Shalev DE , Shenhar-Tsarfaty S , Bennett ER , Ben Assayag E , Wilgus H , Livnah O , Soreq H
Ref : Journal of Biological Chemistry , 284 :17170 , 2009
Abstract : The K variant of butyrylcholinesterase (BChE-K, 20% incidence) is a long debated risk factor for Alzheimer disease (AD). The A539T substitution in BChE-K is located at the C terminus, which is essential both for BChE tetramerization and for its capacity to attenuate beta-amyloid (Abeta) fibril formation. Here, we report that BChE-K is inherently unstable as compared with the "usual" BChE (BChE-U), resulting in reduced hydrolytic activity and predicting prolonged acetylcholine maintenance and protection from AD. A synthetic peptide derived from the C terminus of BChE-K (BSP-K), which displayed impaired intermolecular interactions, was less potent in suppressing Abeta oligomerization than its BSP-U counterpart. Correspondingly, highly purified recombinant human rBChE-U monomers suppressed beta-amyloid fibril formation less effectively than dimers, which also protected cultured neuroblastoma cells from Abeta neurotoxicity. Dual activity structurally derived changes due to the A539T substitution can thus account for both neuroprotective characteristics caused by sustained acetylcholine levels and elevated AD risk due to inefficient interference with amyloidogenic processes.
ESTHER : Podoly_2009_J.Biol.Chem_284_17170
PubMedSearch : Podoly_2009_J.Biol.Chem_284_17170
PubMedID: 19383604

Title : Pro-apoptotic protein-protein interactions of the extended N-AChE terminus - Toiber_2009_J.Neural.Transm.(Vienna)_116_1435
Author(s) : Toiber D , Greenberg DS , Soreq H
Ref : J Neural Transm (Vienna) , 116 :1435 , 2009
Abstract : The N-terminally extended "synaptic" acetylcholinesterase variant N-AChE-S operates to promote apoptosis; however, the protein partners involved in this function remain unknown. Here, we report that when microinjected to fertilized mouse oocytes, N-AChE-S caused embryonic death as early as the zygotic stage. To identify the putative protein partners involved, we first tried yeast two hybrid screening, but this approach failed, probably because of the N-AChE-S-induced lethality. In contrast, sequence analysis and a corresponding peptide array revealed possible partners, which were validated by co-immunoprecipitation. These include the kinases GSK3, Aurora and GAK, the membrane integrin receptors, and the death receptor FAS. Each of these could potentially modulate N-AChE-S-induced apoptosis with possible therapeutic value for the treatment of Alzheimer's disease.
ESTHER : Toiber_2009_J.Neural.Transm.(Vienna)_116_1435
PubMedSearch : Toiber_2009_J.Neural.Transm.(Vienna)_116_1435
PubMedID: 19533292

Title : N-acetylcholinesterase-induced apoptosis in Alzheimer's disease - Toiber_2008_PLoS.One_3_e3108
Author(s) : Toiber D , Berson A , Greenberg D , Melamed-Book N , Diamant S , Soreq H
Ref : PLoS ONE , 3 :e3108 , 2008
Abstract : BACKGROUND: Alzheimer's disease (AD) involves loss of cholinergic neurons and Tau protein hyper-phosphorylation. Here, we report that overexpression of an N-terminally extended "synaptic" acetylcholinesterase variant, N-AChE-S is causally involved in both these phenomena. METHODOLOGY AND PRINCIPAL FINDINGS: In transfected primary brain cultures, N-AChE-S induced cell death, morphological impairments and caspase 3 activation. Rapid internalization of fluorescently labeled fasciculin-2 to N-AChE-S transfected cells indicated membranal localization. In cultured cell lines, N-AChE-S transfection activated the Tau kinase GSK3, induced Tau hyper-phosphorylation and caused apoptosis. N-AChE-S-induced cell death was suppressible by inhibiting GSK3 or caspases, by enforced overexpression of the anti-apoptotic Bcl2 proteins, or by AChE inhibition or silencing. Moreover, inherent N-AChE-S was upregulated by stressors inducing protein misfolding and calcium imbalances, both characteristic of AD; and in cortical tissues from AD patients, N-AChE-S overexpression coincides with Tau hyper-phosphorylation.
CONCLUSIONS: Together, these findings attribute an apoptogenic role to N-AChE-S and outline a potential value to AChE inhibitor therapeutics in early AD.
ESTHER : Toiber_2008_PLoS.One_3_e3108
PubMedSearch : Toiber_2008_PLoS.One_3_e3108
PubMedID: 18769671

Title : Introduction: cholinesterases, from molecular complexity to non-hydrolytic functions -
Author(s) : Soreq H
Ref : Febs J , 275 :603 , 2008
PubMedID: 18205835

Title : The role of the read through variant of acetylcholinesterase in anxiogenic effects of predator stress in mice - Adamec_2008_Behav.Brain.Res_189_180
Author(s) : Adamec R , Head D , Soreq H , Blundell J
Ref : Behavioural Brain Research , 189 :180 , 2008
Abstract : This study examined the role of the read through variant of acetylcholinesterase (AChE-R) in lasting changes in murine affective behavior produced by a brief predator stress. AChE-R is elevated by stress in limbic cholinergic circuits implicated in anxiogenic effects of predator stress. The expression of AChE-R was blocked with a systemically administered central acting antisense oligonucleotide for AChE-R (EN101). EN101 was injected at multiple points prior to and after a predator stress in male C57 mice. Seven days after the last injection, behavior was tested. Predator stress caused a significant increase in startle amplitude, which EN101 blocked. This effect was specific to EN101, as the negative control inactive form of EN101, INVEN101 was without effect on stress effects on startle. Neither EN101 nor INVEN101 altered the anxiogenic effects of predator stress on behavior in the elevated plus maze, and both drugs partially reduced stress suppression of time active in the hole board. In the light dark box test, INVEN101 exhibited a weak block of stress effects on behavior for reasons which are unclear. Taken together, findings support the view that multiple neural systems are responsible for the different changes in behavior produced by predator stress. Present findings also suggest a role for AChE-R in specific anxiogenic (hyperarousal) effects following predator stress. Since AChE-R manipulations took place starting 23 h prior to predator stress and continued 48 h after predator stress, further research is necessary to determine the role of AChE-R in initiation and/or consolidation of hyperarousal effects of predator stress.
ESTHER : Adamec_2008_Behav.Brain.Res_189_180
PubMedSearch : Adamec_2008_Behav.Brain.Res_189_180
PubMedID: 18243359

Title : Nicotine relieves anxiogenic-like behavior in mice that overexpress the read-through variant of acetylcholinesterase but not in wild-type mice - Salas_2008_Mol.Pharmacol_74_1641
Author(s) : Salas R , Main A , Gangitano DA , Zimmerman G , Ben-Ari S , Soreq H , De Biasi M
Ref : Molecular Pharmacology , 74 :1641 , 2008
Abstract : Stress increases vulnerability and causes relapse to drugs of abuse. The usually rare read-through variant of acetylcholinesterase (AChE-R) is causally involved in stress-related behaviors, and transgenic mice constitutively overexpressing AChE-R (TgR) show behaviors characteristic of chronic stress. We measured anxiety-like behavior on TgR and control mice under normal conditions and under long-term nicotine treatment. In addition, we measured epibatidine binding in the brain and transcription status in the striatum, using microarrays, in wild-type and TgR mice. TgR mice behaved as more anxious than controls, an effect normalized by long-term nicotine intake. In control mice, long-term nicotine augmented epibatidine binding in several areas of the brain, including the hippocampus and striatum. In TgR transgenics, long-term nicotine increased epibatidine binding in some areas but not in the hippocampus or the striatum. Because the striatum is involved in the mechanisms of drug addiction, we studied how the transgene affected striatal gene expression. Whole-genome DNA microarray showed that 23 transcripts were differentially expressed in TgR mouse striata, including 15 known genes, 7 of which are anxiety-related. Subsequent reverse-transcriptase polymerase chain reaction validated changes in 7 of those 15 genes, confirmed the increase trend in 5 more transcripts, and further revealed changes in 5 genes involved in cholinergic signaling. In summary, we found that nicotine acts as an anxiolytic in TgR mice but not in control mice and that continuously overexpressed AChE-R regulates striatal gene expression, modulating cholinergic signaling and stress-related pathways.
ESTHER : Salas_2008_Mol.Pharmacol_74_1641
PubMedSearch : Salas_2008_Mol.Pharmacol_74_1641
PubMedID: 18776044

Title : Transgenic inactivation of acetylcholinesterase impairs homeostasis in mouse hippocampal granule cells - Cohen_2008_Hippocampus_18_182
Author(s) : Cohen JE , Zimmerman G , Melamed-Book N , Friedman A , Dori A , Soreq H
Ref : Hippocampus , 18 :182 , 2008
Abstract : In the adult murine hippocampus, dentate gyrus (DG), neurogenesis and neural cell death are thought to affect learning and memory in incompletely understood mechanism(s). Because cholinergic neurotransmission influences both of these functions, we hypothesized that cholinergic signaling, affected by acetylcholinesterase (AChE) activity, expression level, and alternative splicing, may provide a link between these processes. To challenge this hypothesis, we compared DG neurogenesis in transgenic mice overexpressing engineered "synaptic" AChE-S, incapable of acetylcholine (ACh) hydrolysis (TgSin) with strain-matched controls. In control mice, we observed increasing AChE gene expression with progressing neurogenesis. This involved dividing DG neurons expressing proliferating cell nuclear antigen (PCNA) and Tuj1-positive committed neurons compared with neighboring cells. However, TgSin hippocampi with lower hydrolytic AChE activity showed more PCNA-labeled cells than controls. In contrast, TgS mice overexpressing catalytically active AChE-S, with higher than control levels of AChE hydrolytic activity, presented elevated cell labeling by both bromodeoxyuridine and caspase-3, reflecting facilitated survival of newly born neurons as well as increased neural apoptosis. In comparison, overexpression of the stress-induced "readthrough" AChE-R variant in TgR mice resulted in higher hydrolytic activities but unchanged neurogenesis and apoptosis parameters, while all strains presented similar granule cell layer areas, cell density, and neuron numbers. Importantly, this homeostasis was maintained at a cognitive cost: in the hippocampal-dependent socially transmitted food preference task, TgS and TgSin mice showed impaired acquisition and retention, respectively. Our findings suggest that replacement of AChE-S with AChE-R serves to maintain DG homeostasis and associated cognitive tasks, highlighting the role of cholinergic signaling in adult hippocampal neurogenesis and functioning.
ESTHER : Cohen_2008_Hippocampus_18_182
PubMedSearch : Cohen_2008_Hippocampus_18_182
PubMedID: 17960645

Title : Cytokines and cholinergic signals co-modulate surgical stress-induced changes in mood and memory - Shapira-Lichter_2008_Brain.Behav.Immun_22_388
Author(s) : Shapira-Lichter I , Beilin B , Ofek K , Bessler H , Gruberger M , Shavit Y , Seror D , Grinevich G , Posner E , Reichenberg A , Soreq H , Yirmiya R
Ref : Brain Behavior & Immunity , 22 :388 , 2008
Abstract : Inflammatory cytokines and the cholinergic system have been implicated in the effects of stressors on mood and memory; however, the underlying mechanisms involved and the potential interrelationships between these pathways remain unclear. To address these questions, we administered neuropsychological tests to 33 generally healthy surgery patients who donated blood samples several days prior to undergoing moderate surgery (baseline), on the morning of the surgery (i.e., a psychological stressor), and one day after surgery. Eighteen control subjects were similarly tested. Serum levels of inflammatory cytokines, acetylcholinesterase (AChE) activity, and the stressor-inducible AChE-R variant were measured. An elevation in anxiety levels, an increase in depressed mood, and a decline in declarative memory were observed on the morning of the surgery, prior to any medical intervention, and were exacerbated one day after surgery. The surgical stressor-induced elevated IL-1 beta levels, which contributed to the increased depressed mood and to the post-surgery increase in AChE-R expression. The latter increase, which was also predicted by pre-surgery AChE-R and post-surgery mood disturbances, was associated with exacerbated memory impairments induced by surgery. In addition, elevated levels of AChE-R on the morning of the surgery predicted the post-surgery elevation in IL-6 levels, which was associated with amelioration of the memory impairments induced by surgery. Taken together, these findings suggest that exposure to a surgical stressor induces a reciprocal up-regulation of AChE-R and pro-inflammatory cytokines, which are involved in regulating the surgery-induced mood and memory disturbances.
ESTHER : Shapira-Lichter_2008_Brain.Behav.Immun_22_388
PubMedSearch : Shapira-Lichter_2008_Brain.Behav.Immun_22_388
PubMedID: 17959355

Title : Changes in readthrough acetylcholinesterase expression modulate amyloid-beta pathology - Berson_2008_Brain_131_109
Author(s) : Berson A , Knobloch M , Hanan M , Diamant S , Sharoni M , Schuppli D , Geyer BC , Ravid R , Mor TS , Nitsch RM , Soreq H
Ref : Brain , 131 :109 , 2008
Abstract : Alzheimer's disease has long been known to involve cholinergic deficits, but the linkage between cholinergic gene expression and the Alzheimer's disease amyloid pathology has remained incompletely understood. One known link involves synaptic acetylcholinesterase (AChE-S), shown to accelerate amyloid fibrils formation. Here, we report that the 'Readthrough' AChE-R splice variant, which differs from AChE-S in its 26 C-terminal residues, inversely exerts neuroprotective effects from amyloid beta (Abeta) induced toxicity. In vitro, highly purified AChE-R dose-dependently suppressed the formation of insoluble Abeta oligomers and fibrils and abolished Abeta toxicity to cultured cells, competing with the prevalent AChE-S protein which facilitates these processes. In vivo, double transgenic APPsw/AChE-R mice showed lower plaque burden, fewer reactive astrocytes and less dendritic damage than single APPsw mice, inverse to reported acceleration of these features in double APPsw/AChE-S mice. In hippocampi from Alzheimer's disease patients (n = 10), dentate gyrus neurons showed significantly elevated AChE-R mRNA and reduced AChE-S mRNA. However, immunoblot analyses revealed drastic reductions in the levels of intact AChE-R protein, suggesting that its selective loss in the Alzheimer's disease brain exacerbates the Abeta-induced damages and revealing a previously unforeseen linkage between cholinergic and amyloidogenic events.
ESTHER : Berson_2008_Brain_131_109
PubMedSearch : Berson_2008_Brain_131_109
PubMedID: 18056160

Title : Acetylcholine-induced seizure-like activity and modified cholinergic gene expression in chronically epileptic rats - Zimmerman_2008_Eur.J.Neurosci_27_965
Author(s) : Zimmerman G , Njunting M , Ivens S , Tolner E , Behrens CJ , Gross M , Soreq H , Heinemann U , Friedman A
Ref : European Journal of Neuroscience , 27 :965 , 2008
Abstract : The entorhinal cortex (EC) plays an important role in temporal lobe epilepsy. Under normal conditions, the enriched cholinergic innervation of the EC modulates local synchronized oscillatory activity; however, its role in epilepsy is unknown. Enhanced neuronal activation has been shown to induce transcriptional changes of key cholinergic genes and thus alter cholinergic responses. To examine cholinergic modulations in epileptic tissue we studied molecular and electrophysiological cholinergic responses in the EC of chronically epileptic rats following exposure to pilocarpine or kainic acid. We confirmed that while the total activity of the acetylcholine (ACh)-hydrolysing enzyme, acetylcholinesterase (AChE) was not altered, epileptic rats showed alternative splicing of AChE pre-mRNA transcripts, accompanied by a shift from membrane-bound AChE tetramers to soluble monomers. This was associated with increased sensitivity to ACh application: thus, in control rats, ACh (10-100 microm) induced slow (< 1Hz), periodic events confined to the EC; however, in epileptic rats, ACh evoked seconds-long seizure-like events with initial appearance in the EC, and frequent propagation to neighbouring cortical regions. ACh-induced seizure-like events could be completely blocked by the non-specific muscarinic antagonist, atropine, and were partially blocked by the muscarinic-1 receptor antagonist, pirenzepine; but were not affected by the non-specific nicotinic antagonist, mecamylamine. Epileptic rats presented reduced transcript levels of muscarinic receptors with no evidence of mRNA editing or altered mRNA levels for nicotinic ACh receptors. Our findings suggest that altered cholinergic modulation may initiate seizure events in the epileptic temporal cortex.
ESTHER : Zimmerman_2008_Eur.J.Neurosci_27_965
PubMedSearch : Zimmerman_2008_Eur.J.Neurosci_27_965
PubMedID: 18333967

Title : Human recombinant butyrylcholinesterase purified from the milk of transgenic goats interacts with beta-amyloid fibrils and suppresses their formation in vitro - Podoly_2008_Neurodegener.Dis_5_232
Author(s) : Podoly E , Bruck T , Diamant S , Melamed-Book N , Weiss A , Huang Y , Livnah O , Langermann S , Wilgus H , Soreq H
Ref : Neurodegener Dis , 5 :232 , 2008
Abstract : BACKGROUND In Alzheimer's disease (AD), brain butyrylcholinesterase (BChE) co-localizes with beta-amyloid (Abeta) fibrils.
AIMS: In vitro testing of the significance of this phenomenon to AD progress.
METHODS: A thioflavine T (ThT) fluorogenic assay, photo-induced cross-linking and quantifiable electron microscopy served to compare the effect on Abeta fibril formation induced by highly purified recombinant human BChE (rBChE) produced in the milk of transgenic goats with that of serum-derived human BChE.
RESULTS: Both proteins at 1:50 and 1:25 ratios to Abeta dose-dependently prolonged the ThT lag time and reduced the apparent rate of Abeta fibril formation compared to Abeta alone. Photo-induced cross-linking tests showed that rBChE prolonged the persistence of amyloid dimers, trimers and tetramers in solution, whereas Abeta alone facilitated precipitation of such multimers from solution. Transmission electron microscopy showed that rBChE at 1:100 to Abeta prevented the formation of larger, over 150-nm-long, Abeta fibrils and reduced fibril branching compared to Abeta alone as quantified by macro programming of Image Pro Plus software.
CONCLUSION: Our findings demonstrate that rBChE interacts with Abeta fibrils and can attenuate their formation, extension and branching, suggesting further tests of rBChE, with unlimited supply and no associated health risks, as a therapeutic agent for delaying the formation of amyloid toxic oligomers in AD patients.
ESTHER : Podoly_2008_Neurodegener.Dis_5_232
PubMedSearch : Podoly_2008_Neurodegener.Dis_5_232
PubMedID: 18322399

Title : Identifying alternative hyper-splicing signatures in MG-thymoma by exon arrays - Soreq_2008_PLoS.ONE_3_e2392
Author(s) : Soreq L , Gilboa-Geffen A , Berrih-Aknin S , Lacoste P , Darvasi A , Soreq E , Bergman H , Soreq H
Ref : PLoS ONE , 3 :e2392 , 2008
Abstract : BACKGROUND The vast majority of human genes (>70%) are alternatively spliced. Although alternative pre-mRNA processing is modified in multiple tumors, alternative hyper-splicing signatures specific to particular tumor types are still lacking. Here, we report the use of Affymetrix Human Exon Arrays to spot hyper-splicing events characteristic of myasthenia gravis (MG)-thymoma, thymic tumors which develop in patients with MG and discriminate them from colon cancer changes.
METHODOLOGY/PRINCIPAL FINDINGS: We combined GO term to parent threshold-based and threshold-independent ad-hoc functional statistics with in-depth analysis of key modified transcripts to highlight various exon-specific changes. These denote alternative splicing in MG-thymoma tumors compared to healthy human thymus and to in-house and Affymetrix datasets from colon cancer and healthy tissues. By using both global and specific, term-to-parent Gene Ontology (GO) statistical comparisons, our functional integrative ad-hoc method allowed the detection of disease-relevant splicing events.
CONCLUSIONS/SIGNIFICANCE: Hyper-spliced transcripts spanned several categories, including the tumorogenic ERBB4 tyrosine kinase receptor and the connective tissue growth factor CTGF, as well as the immune function-related histocompatibility gene HLA-DRB1 and interleukin (IL)19, two muscle-specific collagens and one myosin heavy chain gene; intriguingly, a putative new exon was discovered in the MG-involved acetylcholinesterase ACHE gene. Corresponding changes in spliceosome composition were indicated by co-decreases in the splicing factors ASF/SF(2) and SC35. Parallel tumor-associated changes occurred in colon cancer as well, but the majority of the apparent hyper-splicing events were particular to MG-thymoma and could be validated by Fluorescent In-Situ Hybridization (FISH), Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and mass spectrometry (MS) followed by peptide sequencing. Our findings demonstrate a particular alternative hyper-splicing signature for transcripts over-expressed in MG-thymoma, supporting the hypothesis that alternative hyper-splicing contributes to shaping the biological functions of these and other specialized tumors and opening new venues for the development of diagnosis and treatment approaches.
ESTHER : Soreq_2008_PLoS.ONE_3_e2392
PubMedSearch : Soreq_2008_PLoS.ONE_3_e2392
PubMedID: 18545673

Title : Alternate AChE-R variants facilitate cellular metabolic activity and resistance to genotoxic stress through enolase and RACK1 interactions - Mor_2008_Chem.Biol.Interact_175_11
Author(s) : Mor I , Bruck T , Greenberg D , Berson A , Schreiber L , Grisaru D , Soreq H
Ref : Chemico-Biological Interactions , 175 :11 , 2008
Abstract : Tumorogenic transformation is a multifaceted cellular process involving combinatorial protein-protein interactions that modulate different cellular functions. Here, we report apparent involvement in two independent tumorogenic processes by distinct partner protein interactions of the stress-induced acetylcholinesterase AChE-R and N-AChE-R variants. Human testicular tumors showed elevated levels of N-terminally extended N-AChE-R compared with healthy tissue, indicating alternate promoter usage in the transformed cells. Two-hybrid screens demonstrate that the C-terminus common to both N-AChE-R and AChE-R interacts either with the glycolytic enzyme enolase or with the scaffold protein RACK1. In vitro, the AChE-R C-terminal peptide ARP elevated enolase's activity by 12%, suggesting physiological relevance for this interaction. Correspondingly, CHO cells expressing either human AChE-R or N-AChE-R but not AChE-S showed a 25% increase in cellular ATP levels, indicating metabolic significance for this upregulation of enolase activity. ATP levels could be reduced by AChE-targeted siRNA in CHO cells expressing AChE-R but not AChE-S, attributing this elevation to the AChE-R C-terminus. Additionally, transfected CHO cells expressing AChE-R but not N-AChE-R showed resistance to up to 60 microM of the common chemotherapeutic agent, cis-platinum, indicating AChE-R involvement in another molecular pathway. cis-Platinum elevates the expression of the apoptosis-regulator p53-like protein, p73, which is inactivated by interaction with the scaffold protein RACK1. In co-transfected cells, AChE-R competed with endogenous RACK1 for p73 interaction. Moreover, AChE-R-transfected CHO cells presented higher levels than control cells of the pro-apoptotic TAp73 as well as the anti-apoptotic dominant negative DeltaNp73 protein, leading to an overall decrease in the proportion of pro-apoptotic p73. Together, these findings are compatible with the hypothesis that in cancer cells, both AChE-R and N-AChE-R elevate cellular ATP levels and that AChE-R modifies p73 gene expression by facilitating two independent cellular pathways, thus conferring both a selective metabolic advantage and a genotoxic resistance.
ESTHER : Mor_2008_Chem.Biol.Interact_175_11
PubMedSearch : Mor_2008_Chem.Biol.Interact_175_11
PubMedID: 18572152

Title : Antisense treatment for myasthenia gravis: experience with monarsen - Sussman_2008_Ann.N.Y.Acad.Sci_1132_283
Author(s) : Sussman JD , Argov Z , McKee D , Hazum E , Brawer S , Soreq H
Ref : Annals of the New York Academy of Sciences , 1132 :283 , 2008
Abstract : Acetylcholinesterase pre-mRNA is susceptible to alternative splicing. Myasthenia gravis has been shown to be associated with the expression of the readthrough transcript (AChE-R), which, unlike the normal "synaptic" transcript (AChE-S) is not tethered to the post-synaptic membrane, but is a soluble monomer in the synaptic cleft. In rats with experimental autoimmune myasthenia gravis (EAMG), inhibition of production of AChE-R using antisense is associated with a significant reduction in synaptic expression of AChE-R mRNA and protein, with improved muscle strength and stamina and increased survival. Synaptic AChE does not appear to be significantly affected by the induction of EAMG or treatment with antisense to AChE-R. Monarsen (EN101) is a synthetic 20-base antisense oligodeoxynucleotide directed against the human AChE gene. It is modified to achieve stability for oral administration. Sixteen patients with seropositive myasthenia gravis who were responsive to pyridostigmine were withdrawn from it and treated with Monarsen. Fourteen patients experienced a clinically significant response. In some, the improvement was dramatic. Although the dose of pyridostigmine was not optimized before the study, the majority of responders achieved better Quantitative Myasthenia Gravis scores than on pyridostigmine. The response of an individual muscle group to Monarsen was related to the degree of deterioration following the withdrawal of pyridostigmine. Cholinergic side effects were conspicuous by their absence. Monarsen is now being investigated in a phase II study.
ESTHER : Sussman_2008_Ann.N.Y.Acad.Sci_1132_283
PubMedSearch : Sussman_2008_Ann.N.Y.Acad.Sci_1132_283
PubMedID: 18567879

Title : Stress-induced alternative splicing modulations in brain and periphery: acetylcholinesterase as a case study - Shaked_2008_Ann.N.Y.Acad.Sci_1148_269
Author(s) : Shaked I , Zimmerman G , Soreq H
Ref : Annals of the New York Academy of Sciences , 1148 :269 , 2008
Abstract : Mammalian stress responses present a case study for investigating alternative splicing reactions in general, and changes in acetylcholinesterase (AChE) gene expression in particular, under endangered homeostasis. Acetylcholine (ACh) is a major regulator of stress responses, which was recently found to function as an essential route by which neurons can "talk" to immune cells. Therefore, chemical, physical, or psychological insults to the brain might all be traced in peripheral immune cells, which serve as key determinants in the physiological reactions to stress. Stress-induced changes in the alternative splicing patterns of AChE pre-mRNA give this gene and its different protein products diverse stress responsive functions that are associated with both the enzymatic and noncatalytic properties of AChE variants. Transgenic manipulations of AChE gene expression uncovered previously nonperceived aspects of stress responses, including brain-to-blood as well as immune-to-neuronal communication. Herein we discuss the newly gained understanding achieved by using genomic manipulations of AChE gene expression as tools for approaching the alternative splicing features of mammalian stress responses.
ESTHER : Shaked_2008_Ann.N.Y.Acad.Sci_1148_269
PubMedSearch : Shaked_2008_Ann.N.Y.Acad.Sci_1148_269
PubMedID: 19120119

Title : Acetylcholinesterase-R increases germ cell apoptosis but enhances sperm motility - Mor_2008_J.Cell.Mol.Med_12_479
Author(s) : Mor I , Sklan EH , Podoly E , Pick M , Kirschner M , Yogev L , Bar-Sheshet Itach S , Schreiber L , Geyer B , Mor T , Grisaru D , Soreq H
Ref : J Cell Mol Med , 12 :479 , 2008
Abstract : Changes in protein subdomains through alternative splicing often modify protein-protein interactions, altering biological processes. A relevant example is that of the stress-induced up-regulation of the acetylcholinesterase (AChE-R) splice variant, a common response in various tissues. In germ cells of male transgenic TgR mice, AChE-R excess associates with reduced sperm differentiation and sperm counts. To explore the mechanism(s) by which AChE-R up-regulation affects spermatogenesis, we identified AChE-R's protein partners through a yeast two-hybrid screen. In meiotic spermatocytes from TgR mice, we detected AChE-R interaction with the scaffold protein RACK1 and elevated apoptosis. This correlated with reduced scavenging by RACK1 of the pro-apoptotic TAp73, an outcome compatible with the increased apoptosis. In contrast, at later stages in sperm development, AChE-R's interaction with the glycolytic enzyme enolase-alpha elevates enolase activity. In transfected cells, enforced AChE-R excess increased glucose uptake and adenosine tri-phosphate (ATP) levels. Correspondingly, TgR sperm cells display elevated ATP levels, mitochondrial hyperactivity and increased motility. In human donors' sperm, we found direct association of sperm motility with AChE-R expression. Interchanging interactions with RACK1 and enolase-alpha may hence enable AChE-R to affect both sperm differentiation and function by participating in independent cellular pathways.
ESTHER : Mor_2008_J.Cell.Mol.Med_12_479
PubMedSearch : Mor_2008_J.Cell.Mol.Med_12_479
PubMedID: 18194455

Title : A novel isoform of acetylcholinesterase exacerbates photoreceptors death after photic stress - Kehat_2007_Invest.Ophthalmol.Vis.Sci_48_1290
Author(s) : Kehat R , Zemel E , Cuenca N , Evron T , Toiber D , Loewenstein A , Soreq H , Perlman I
Ref : Invest Ophthalmol Vis Sci , 48 :1290 , 2007
Abstract : PURPOSE: To study the involvement of stress-induced acetylcholinesterase (AChE) expression in light-induced retinal damage in albino rats. METHODS: Adult albino rats were exposed for 24 hours to bright, damaging light. AChE expression was monitored by in situ hybridization, by histochemistry for AChE activity, and by immunocytochemistry. An orphan antisense agent (Monarsen; Ester Neurosciences, Ltd., Herzlia Pituach, Israel) was administered intraperitoneally to minimize light-induced AChE expression. The electroretinogram (ERG) was recorded to assess retinal function. RESULTS: Twenty-four-hour exposure to bright light caused severe reduction in the ERG responses and augmented expression of mRNA for the "read-through" variant of AChE (AChE-R) in photoreceptor inner segments (IS), bipolar cells, and ganglion cells. AChE activity increased in IS. The expressed AChE protein was a novel variant, characterized by an extended N terminus (N-AChE). Systemic administration of the orphan antisense agent, Monarsen, reduced the photic induction of mRNA for AChE-R, and of the N-AChE protein. Rats exposed to bright, damaging light and treated daily with Monarsen exhibited larger ERG responses, relatively thicker outer nuclear layer (ONL), and more ONL nuclei than did rats exposed to the same damaging light but treated daily with saline. CONCLUSIONS: The findings indicate that the photic-induced novel variant of AChE (N-AChE-R) may be causally involved with retinal light damage and suggest the use of RNA targeting for limiting such damage.
ESTHER : Kehat_2007_Invest.Ophthalmol.Vis.Sci_48_1290
PubMedSearch : Kehat_2007_Invest.Ophthalmol.Vis.Sci_48_1290
PubMedID: 17325175

Title : Acetylcholinesterase\/C terminal binding protein interactions modify Ikaros functions, causing T lymphopenia - Perry_2007_Leukemia_21_1472
Author(s) : Perry C , Pick M , Podoly E , Gilboa-Geffen A , Zimmerman G , Sklan EH , Ben-Shaul Y , Diamant S , Soreq H
Ref : Leukemia , 21 :1472 , 2007
Abstract : Hematological changes induced by various stress stimuli are accompanied by replacement of the primary acetylcholinesterase (AChE) 3' splice variant acetylcholinesterase-S (AChE-S) with the myelopoietic acetylcholinesterase-R (AChE-R) variant. To search for putative acetylcholinesterase-S interactions with hematopoietic pathways, we employed a yeast two-hybrid screen. The transcriptional co-repressor C-terminal binding protein (CtBP) was identified as a protein partner of the AChE-S C terminus. In erythroleukemic K562 cells, AChE-S displayed nuclear colocalization and physical interaction with CtBP. Furthermore, co-transfected AChE-S reduced the co-repressive effect of CtBP over the hematopoietic transcription factor, Ikaros. In transgenic mice, overexpressed human (h) AChE-S mRNA induced selective bone marrow upregulation of Ikaros while suppressing FOG, another transcriptional partner of CtBP. Transgenic bone marrow cells showed a correspondingly elevated potential for producing progenitor colonies, compared with controls, while peripheral blood showed increased erythrocyte counts as opposed to reduced platelets, granulocytes and T lymphocytes. AChE's 3' alternative splicing, and the corresponding changes in AChE-S/CtBP interactions, thus emerge as being actively involved in controlling hematopoiesis and the potential for modulating immune functions, supporting reports on malfunctioning immune reactions under impaired splice site selection.
ESTHER : Perry_2007_Leukemia_21_1472
PubMedSearch : Perry_2007_Leukemia_21_1472
PubMedID: 17476278

Title : Plant-derived human acetylcholinesterase-R provides protection from lethal organophosphate poisoning and its chronic aftermath - Evron_2007_FASEB.J_21_2961
Author(s) : Evron T , Geyer BC , Cherni I , Muralidharan M , Kilbourne J , Fletcher SP , Soreq H , Mor TS
Ref : FASEB Journal , 21 :2961 , 2007
Abstract : Therapeutically valuable proteins are often rare and/or unstable in their natural context, calling for production solutions in heterologous systems. A relevant example is that of the stress-induced, normally rare, and naturally unstable "read-through" human acetylcholinesterase variant, AChE-R. AChE-R shares its active site with the synaptic AChE-S variant, which is the target of poisonous organophosphate anticholinesterase insecticides such as the parathion metabolite paraoxon. Inherent AChE-R overproduction under organophosphate intoxication confers both short-term protection (as a bioscavenger) and long-term neuromuscular damages (as a regulator). Here we report the purification, characterization, and testing of human, endoplasmic reticulum-retained AChE-R(ER) produced from plant-optimized cDNA in Nicotiana benthamiana plants. AChE-R(ER) purified to homogeneity showed indistinguishable biochemical properties, with IC50 = 10(-7) M for the organophosphate paraoxon, similar to mammalian cell culture-derived AChE. In vivo titration showed dose-dependent protection by intravenously injected AChE-R(ER) of FVB/N male mice challenged with a lethal dose of paraoxon, with complete elimination of short-term clinical symptoms at near molar equivalence. By 10 days postexposure, AChE-R prophylaxis markedly limited postexposure increases in plasma murine AChE-R levels while minimizing the organophosphate-induced neuromuscular junction dismorphology. Our findings present plant-produced AChE-R(ER) as a bimodal agent, conferring both short- and long-term protection from organophosphate intoxication.
ESTHER : Evron_2007_FASEB.J_21_2961
PubMedSearch : Evron_2007_FASEB.J_21_2961
PubMedID: 17475919

Title : Impaired hippocampal plasticity and errors in cognitive performance in mice with maladaptive AChE splice site selection - Farchi_2007_Eur.J.Neurosci_25_87
Author(s) : Farchi N , Shoham S , Hochner B , Soreq H
Ref : European Journal of Neuroscience , 25 :87 , 2007
Abstract : Neuronal splice site selection events control multiple brain functions. Here, we report their involvement in stress-modulated hippocampal plasticity and errors of cognitive performance. Under stress, alternative splicing changes priority from synaptic acetylcholinesterase (AChE-S) to the normally rare, soluble and monomeric AChE-R variant, which facilitates hippocampal long-term potentiation (LTP) and intensifies fear-motivated learning. To explore the adaptive value of changes in AChE splicing, we compared hippocampal plasticity and errors of executive function in TgS and TgR transgenic mice overexpressing AChE-S or AChE-R, respectively. Hippocampal slices from TgS and TgR mice presented delayed and facilitated transition to LTP maintenance, respectively, compared with strain-matched FVB/N controls. TgS slices further showed failed recruitment of both the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate and N-methyl-D-aspartate components of LTP, refractory response to cholinergic enhancement and suppressed protein kinase C (PKC) levels. Stable LTP could, however, be rescued by phorbol ester priming, attributing the TgS deficits to disrupted signal transduction. In serial maze tests, TgS mice displayed more errors of conflict and executive function than did FVB/N controls, reflecting maladaptive performance under chronic AChE-S overexpression. In contrast, TgR mice displayed enhanced serial maze performance, suggesting that chronic AChE-R overexpression facilitates adaptive reactions. Our findings are compatible with the notion that changes in the alternative splicing of AChE pre-mRNA and consequent alterations in PKC signalling are causally involved in modulating hippocampal plasticity and cognitive performance.
ESTHER : Farchi_2007_Eur.J.Neurosci_25_87
PubMedSearch : Farchi_2007_Eur.J.Neurosci_25_87
PubMedID: 17241270

Title : Acetylcholinesterase activity in veterans of the first Gulf War - Concato_2007_J.Investig.Med_55_360
Author(s) : Concato J , Aslan M , Palmisano MM , Doebbeling CC , Peduzzi P , Ofek K , Soreq H , Doebbeling B
Ref : J Investig Med , 55 :360 , 2007
Abstract : BACKGROUND: Factors affecting acetylcholine-mediated neurotransmission have been proposed as possible explanations for physical and mental health symptoms among veterans of the 1990-1991 Gulf War. This study was designed to examine relationships of deployment to the Gulf, as well as symptoms after military service, with postdeployment activity of acetylcholinesterase (AChE) and related enzymes.
METHODS: The patient population included 488 veterans, originally from Iowa at enlistment, who served in the US military during August 1990 to July 1991. Demographic, military, and clinical characteristics were obtained from a population-based cohort study (in 1995-1996) and from a nested case-control study (in 1999-2002). Stored serum samples (from the 1999-2002 assessment) were analyzed for activity of AChE and related enzymes. These two data sources were merged, and multiple linear regression models estimated the association of deployment, stress (anxiety) or mood disorders, and symptoms compatible with Gulf War veterans' illnesses (GWVIs), with enzyme activity.
RESULTS: Seventy-four percent (n = 361) of veterans had been deployed to the Gulf. At the time of evaluation, 23% (n = 113) of participants reported anxiety and 15% (n = 71) reported mood disorders; 49% (n = 171 of 347 eligible veterans) had symptoms of GWVIs, and the median AChE activity was 839 units. AChE activity was similar for compared groups across all categories, including an adjusted difference of -27 units (p = .50) for deployed versus nondeployed veterans and 87 units (p = .13) for veterans with versus without symptoms of GWVIs.
CONCLUSIONS: Neither deployment to the Gulf nor symptoms compatible with GWVIs are associated with long-term serum AChE activity.
ESTHER : Concato_2007_J.Investig.Med_55_360
PubMedSearch : Concato_2007_J.Investig.Med_55_360
PubMedID: 18062897

Title : Adaptive changes in acetylcholinesterase gene expression as mediators of recovery from chemical and biological insults - Evron_2007_Toxicology_233_97
Author(s) : Evron T , Greenberg D , Mor TS , Soreq H
Ref : Toxicology , 233 :97 , 2007
Abstract : Both organophosphate (OP) exposure and bacterial infection notably induce short- and long-term cholinergic responses. These span the central and peripheral nervous system, neuromuscular pathway and hematopoietic cells and involve over-expression of the "readthrough" variant of acetylcholinesterase, AChE-R, and its naturally cleavable C-terminal peptide ARP. However, the causal involvement of these changes with post-exposure recovery as opposed to apoptotic events remained to be demonstrated. Here, we report the establishment of stably transfected cell lines expressing catalytically active human "synaptic" AChE-S or AChE-R which are fully viable and non-apoptotic. In addition, intraperitoneally injected synthetic mouse ARP (mARP) elevated serum AChE levels post-paraoxon exposure. Moreover, mARP treatment ameliorated post-exposure increases in corticosterone and decreases in AChE gene expression and facilitated earlier retrieval of motor activity following both paraoxon and lipopolysaccharide (LPS) exposures. Our findings suggest a potential physiological role for overproduction of AChE-R and the ARP peptide following exposure to both chemical warfare agents and bacterial LPS.
ESTHER : Evron_2007_Toxicology_233_97
PubMedSearch : Evron_2007_Toxicology_233_97
PubMedID: 17005312

Title : Cholinergic status modulations in human volunteers under acute inflammation - Ofek_2007_J.Mol.Med_85_1239
Author(s) : Ofek K , Krabbe KS , Evron T , Debecco M , Nielsen AR , Brunnsgaad H , Yirmiya R , Soreq H , Pedersen BK
Ref : J Mol Med , 85 :1239 , 2007
Abstract : Cholinergic Status, the total soluble circulation capacity for acetylcholine hydrolysis, was tested for putative involvement in individual variabilities of the recruitment of immune cells in response to endotoxin challenge. Young (average age 26) and elderly (average age 70) volunteers injected with either Escherichia coli endotoxin or saline on two different occasions were first designated Enhancers and Suppressors if they showed increase or decrease, respectively, in plasma acetylcholinesterase (AChE) activity 1.5 h after endotoxin administration compared to saline. Enhancers showed significant co-increases in plasma butyrylcholinesterase (BChE) and paraoxonase (PON1) activities, accompanied by rapid recovery of lymphocyte counts. Young Enhancers alone showed pronounced post-exposure increases in the pro-inflammatory cytokine interleukin-6 (IL-6), and upregulation of the normally rare, stress-induced AChE-R variant, suggesting age-associated exhaustion of the cholinergic effects on recruiting innate immune reactions to endotoxin challenge. Importantly, IL-6 injected to young volunteers or administered in vitro to primary mononuclear blood cells caused upregulation of AChE, but not BChE or PON1, excluding it from being the sole cause for this extended response. Interestingly, Suppressors but not Enhancers showed improved post-exposure working memory performance, indicating that limited cholinergic reactions may be beneficial for cognition. Our findings establish Cholinergic Status modulations as early facilitators and predictors of individual variabilities in the peripheral response to infection.
ESTHER : Ofek_2007_J.Mol.Med_85_1239
PubMedSearch : Ofek_2007_J.Mol.Med_85_1239
PubMedID: 17657467

Title : Peripheral Site Acetylcholinesterase Blockade Induces RACK1-Associated Neuronal Remodeling - Farchi_2007_Neurodegener.Dis_4_171
Author(s) : Farchi N , Ofek K , Podoly E , Dong H , Xiang YY , Diamant S , Livnah O , Li J , Hochner B , Lu WY , Soreq H
Ref : Neurodegener Dis , 4 :171 , 2007
Abstract : BACKGROUND: Peripheral anionic site (PAS) blockade of acetylcholinesterase (AChE) notably affects neuronal activity and cyto-architecture, however, the mechanism(s) involved are incompletely understood.
OBJECTIVE: We wished to specify the PAS extracellular effects on specific AChE mRNA splice variants, delineate the consequent cellular remodeling events, and explore the inhibitory effects on interchanging RACK1 interactions.
METHODS: We exposed rat hippocampal cultured neurons to BW284C51, the peripheral anionic site inhibitor of AChE, and to the non-selective AChE active site inhibitor, physostigmine for studying the neuronal remodeling of AChE mRNA expression and trafficking.
RESULTS: BW284C51 induced overexpression of both AChE splice variants, yet promoted neuritic translocation of the normally rare AChE-R, and retraction of AChE-S mRNA in an antisense-suppressible manner. BW284C51 further caused modest decreases in the expression of the scaffold protein RACK1 (receptor for activated protein kinase betaII), followed by drastic neurite retraction of both RACK1 and the AChE homologue neuroligin1, but not the tubulin-associated MAP2 protein. Accompanying BW284C51 effects involved decreases in the Fyn kinase and membrane insertion of the glutamate receptor NR2B variant and impaired glutamatergic activities of treated cells. Intriguingly, molecular modeling suggested that direct, non-catalytic competition with Fyn binding by the RACK1-interacting AChE-R variant may be involved.
CONCLUSIONS: Our findings highlight complex neuronal AChE-R/RACK1 interactions and are compatible with the hypothesis that peripheral site AChE inhibitors induce RACK1-mediated neuronal remodeling, promoting suppressed glutamatergic neurotransmission.
ESTHER : Farchi_2007_Neurodegener.Dis_4_171
PubMedSearch : Farchi_2007_Neurodegener.Dis_4_171
PubMedID: 17596712

Title : Readthrough acetylcholinesterase in inflammation-associated neuropathies - Dori_2007_Life.Sci_80_2369
Author(s) : Dori A , Ifergane G , Saar-Levy T , Bersudsky M , Mor I , Soreq H , Wirguin I
Ref : Life Sciences , 80 :2369 , 2007
Abstract : The cholinergic control over inflammatory reactions calls for deciphering the corresponding protein partners. An example is blood-nerve barrier disruption allowing penetration of inflammatory factors, which is notably involved in various neuropathies due to yet unknown molecular mechanism(s). In rats, lipopolysaccharide (LPS) administration followed by intra-neural (i.n.) saline injection inducing a focal blood-nerve disruption leads to systemic inflammatory reaction accompanied by transient conduction impairment in the sciatic nerve. Here, we provide evidence compatible with the hypothesis that ARP, the naturally cleavable C-terminal peptide of the stress-induced "readthrough" acetylcholinesterase variant (AChE-R), is causally involved in the emergence of this LPS-induced conduction impairment. Intra-neural injection to naive rats of conditioned medium from cultured splenocytes exposed to LPS in vitro (reactive splenocyte medium) induced a transient conduction impairment that was accompanied by facilitated accumulation of cleaved intra-neural ARP. Protein kinase C (PKC) betaII, known to interact with ARP, was significantly elevated in the LPS-exposed sciatic nerve preparations. Moreover, direct i.n. injection of synthetic ARP30, bearing the mouse AChE-R C-terminal sequence, similarly induced PKCbetaII expression and conduction impairment. The induction of neural conduction impairment by ARP, possibly through its interaction with PKCbetaII, suggests a role for AChE-R expression in inflammation-associated neuropathies.
ESTHER : Dori_2007_Life.Sci_80_2369
PubMedSearch : Dori_2007_Life.Sci_80_2369
PubMedID: 17379257

Title : Treatment of human myasthenia gravis with oral antisense suppression of acetylcholinesterase -
Author(s) : Argov Z , McKee D , Agus S , Brawer S , Shlomowitz N , Yoseph OB , Soreq H , Sussman JD
Ref : Neurology , 69 :699 , 2007
PubMedID: 17698793

Title : Translational control of recombinant human acetylcholinesterase accumulation in plants - Geyer_2007_BMC.Biotechnol_7_27
Author(s) : Geyer BC , Fletcher SP , Griffin TA , Lopker MJ , Soreq H , Mor TS
Ref : BMC Biotechnol , 7 :27 , 2007
Abstract : BACKGROUND: Codon usage differences are known to regulate the levels of gene expression in a species-specific manner, with the primary factors often cited to be mRNA processing and accumulation. We have challenged this conclusion by expressing the human acetylcholinesterase coding sequence in transgenic plants in its native GC-rich sequence and compared to a matched sequence with (dicotyledonous) plant-optimized codon usage and a lower GC content. RESULTS: We demonstrate a 5 to 10 fold increase in accumulation levels of the "synaptic" splice variant of human acetylcholinesterase in Nicotiana benthamiana plants expressing the optimized gene as compared to the native human sequence. Both transient expression assays and stable transformants demonstrated conspicuously increased accumulation levels. Importantly, we find that the increase is not a result of increased levels of acetylcholinesterase mRNA, but rather its facilitated translation, possibly due to the reduced energy required to unfold the sequence-optimized mRNA. CONCLUSION: Our findings demonstrate that codon usage differences may regulate gene expression at different levels and anticipate translational control of acetylcholinesterase gene expression in its native mammalian host as well.
ESTHER : Geyer_2007_BMC.Biotechnol_7_27
PubMedSearch : Geyer_2007_BMC.Biotechnol_7_27
PubMedID: 17537261

Title : The thymic theme of acetylcholinesterase splice variants in myasthenia gravis - Gilboa-Geffen_2007_Blood_109_4383
Author(s) : Gilboa-Geffen A , Lacoste PP , Soreq L , Cizeron-Clairac G , Le Panse R , Truffault F , Shaked I , Soreq H , Berrih-Aknin S
Ref : Blood , 109 :4383 , 2007
Abstract : Cholinergic signaling and acetylcholinesterase (AChE) influence immune response and inflammation. Autoimmune myasthenia gravis (MG) is mediated by antibodies to the acetylcholine receptor and current therapy is based on anti-AChE drugs. MG is associated with thymic hyperplasia, showing signs of inflammation. The objectives of this study were to analyze the involvement of AChE variants in thymic hyperplasia. We found lower hydrolytic activities in the MG thymus compared with adult controls, accompanied by translocation of AChE-R from the cytoplasm to the membrane and increased expression of the signaling protein kinase PKC-betaII. To explore possible causal association of AChE-R changes with thymic composition and function, we used an AChE-R transgenic model and showed smaller thymic medulla compared with strain-matched controls, indicating that AChE-R overexpression interferes with thymic differentiation mechanisms. Interestingly, AChE-R transgenic mice showed increased numbers of CD4(+)CD8(+) cells that were considerably more resistant in vitro to apoptosis than normal thymocytes, suggesting possibly altered positive selection. We further analyzed microarray data of MG thymic hyperplasia compared with healthy controls and found continuous and discrete changes in AChE-annotated GO categories. Together, these findings show that modified AChE gene expression and properties are causally involved in thymic function and development.
ESTHER : Gilboa-Geffen_2007_Blood_109_4383
PubMedSearch : Gilboa-Geffen_2007_Blood_109_4383
PubMedID: 17272501

Title : Virtues and woes of AChE alternative splicing in stress-related neuropathologies - Meshorer_2006_Trends.Neurosci_29_216
Author(s) : Meshorer E , Soreq H
Ref : Trends in Neurosciences , 29 :216 , 2006
Abstract : The ACh hydrolyzing enzyme acetylcholinesterase (AChE) is a combinatorial series of proteins with variant N and C termini generated from alternate promoter usage and 3' alternative splicing. Neuronal AChE variants show indistinguishable enzymatic activity yet differ in their expression, multimeric assembly and membrane-association patterns. Differentially induced under stress, they show distinct non-hydrolytic properties and interact with different protein partners. Recent findings suggest that transcriptional and post-transcriptional regulation of AChE pre-mRNA is a neuroprotection strategy but might involve long-term damage. Specifically, variant-specific causal involvement of AChE in the progression of both neurodegenerative diseases (e.g. Alzheimer's and Parkinson's diseases) and neuromuscular syndromes (e.g. myasthenia gravis) raises the possibility that future therapeutic drugs might target specific AChE variant(s) or the corresponding RNA transcripts.
ESTHER : Meshorer_2006_Trends.Neurosci_29_216
PubMedSearch : Meshorer_2006_Trends.Neurosci_29_216
PubMedID: 16516310

Title : Modulated splicing-associated gene expression in P19 cells expressing distinct acetylcholinesterase splice variants - Ben-Ari_2006_J.Neurochem_97 Suppl 1_24
Author(s) : Ben-Ari S , Toiber D , Sas AS , Soreq H , Ben-Shaul Y
Ref : Journal of Neurochemistry , 97 Suppl 1 :24 , 2006
Abstract : Alternative splicing configurations and acetylcholinesterase (AChE) gene expression are both modified in neurons under stress. However, it is unclear if these phenomena are functionally interrelated. Using a home-made spotted microarray focused on splicing-associated transcripts, we tested the effects of excess 3' splice variants of human AChE on splicing-related gene expression in semi-differentiated neuronal P19 cells. Of the tested transcripts, 17.3% and 20.2% showed modified expression levels (log2 of the ratio<-0.3 or>0.3) in transfected P19 cells overexpressing the stress-inducible AChE-R variant or the synaptic AChE-S protein, respectively. Multiple transcripts encoding serine-arginine rich (SR) and SR-related splicing regulators were suppressed in cells expressing either of these variants, whereas the gene groups including splicing-related helicases and transcripts involved in apoptosis displayed variant-specific changes. Our findings are compatible with the assumption that both neuronal overexpression and alternative splicing of pre-AChE mRNA may be causally involved in initiating global changes in neuronal alternative splicing, causing subsequent modifications in the expression patterns of numerous target genes.
ESTHER : Ben-Ari_2006_J.Neurochem_97 Suppl 1_24
PubMedSearch : Ben-Ari_2006_J.Neurochem_97 Suppl 1_24
PubMedID: 16635247

Title : Gene-environment interactions in sporadic Parkinson's disease - Benmoyal-Segal_2006_J.Neurochem_97_1740
Author(s) : Benmoyal-Segal L , Soreq H
Ref : Journal of Neurochemistry , 97 :1740 , 2006
Abstract : Much has been learned in recent years about the genetics of familial Parkinson's disease. However, far less is known about those malfunctioning genes which contribute to the emergence and/or progression of the vast majority of cases, the 'sporadic Parkinson's disease', which is the focus of our current review. Drastic differences in the reported prevalence of Parkinson's disease in different continents and countries suggest ethnic and/or environmental-associated multigenic contributions to this disease. Numerous association studies showing variable involvement of multiple tested genes in these distinct locations support this notion. Also, variable increases in the risk of Parkinson's disease due to exposure to agricultural insecticides indicate complex gene-environment interactions, especially when genes involved in protection from oxidative stress are explored. Further consideration of the brain regions damaged in Parkinson's disease points at the age-vulnerable cholinergic-dopaminergic balance as being involved in the emergence of sporadic Parkinson's disease in general and in the exposure-induced risks in particular. More specifically, the chromosome 7 ACHE/PON1 locus emerges as a key region controlling this sensitive balance, and animal model experiments are compatible with this concept. Future progress in the understanding of the genetics of sporadic Parkinson's disease depends on globally coordinated, multileveled studies of gene-environment interactions.
ESTHER : Benmoyal-Segal_2006_J.Neurochem_97_1740
PubMedSearch : Benmoyal-Segal_2006_J.Neurochem_97_1740
PubMedID: 16805780

Title : RACK1 has the nerve to act: structure meets function in the nervous system - Sklan_2006_Prog.Neurobiol_78_117
Author(s) : Sklan EH , Podoly E , Soreq H
Ref : Prog Neurobiol , 78 :117 , 2006
Abstract : The receptor for activated protein kinase C 1 (RACK1) is an intracellular adaptor protein. Accumulating evidence attributes to this member of the tryptophan-aspartate (WD) repeat family the role of regulating several major nervous system pathways. Structurally, RACK1 is a seven-bladed-beta-propeller, interacting with diverse proteins having distinct structural folds. When bound to the IP3 receptor, RACK1 regulates intracellular Ca2+ levels, potentially contributing to processes such as learning, memory and synaptic plasticity. By binding to the NMDA receptor, it dictates neuronal excitation and sensitivity to ethanol. When bound to the stress-induced acetylcholinesterase variant AChE-R, RACK1 is implicated in stress responses and behavior, compatible with reports of RACK1 modulations in brain ageing and in various neurodegenerative diseases. This review sheds new light on both the virtues and the variety of neuronal RACK1 interactions and their physiological consequences.
ESTHER : Sklan_2006_Prog.Neurobiol_78_117
PubMedSearch : Sklan_2006_Prog.Neurobiol_78_117
PubMedID: 16457939

Title : Acetylcholinesterase modulates stress-induced motor responses through catalytic and noncatalytic properties - Sklan_2006_Biol.Psychiatry_60_741
Author(s) : Sklan EH , Berson A , Birikh KR , Gutnick A , Shahar O , Shoham S , Soreq H
Ref : Biological Psychiatry , 60 :741 , 2006
Abstract : BACKGROUND Cholinergic neurotransmission notably participates in stress-induced motor responses. Here we report the contribution of alternative splicing of acetylcholinesterase (AChE) pre-mRNA to modulate these responses. More specifically, we induced stress-associated hypofunction of dopaminergic, mainly D2 dopamine receptor-mediated neurotransmission by haloperidol and explored stress induced hyperlocomotion and catalepsy, an extreme form of immobility, induced in mice with AChE deficiencies. METHODS: Conditional transgenic (Tet/AS) mice were created with tetracycline-induced antisense suppression of AChE gene expression. Locomotion and catalepsy times were measured in Tet/AS and strain-matched control mice, under open-field exposure threat and under home-cage safety. RESULTS: In vitro, NGF-treated PC12 cells failed to extend neurites upon Tet/AS suppression. In vivo, Tet/AS but not control mice showed stress-associated hippocampal deposits of heat-shock protein 70 and GRP78 (BiP), predicting posttranscriptional changes in neuronal reactions. Supporting this notion, their striatal cholinergic neurons demonstrated facilitated capacity for neurite extension, attributing these in vivo changes in neurite extension to network interactions. Tet/AS mice presented stress-induced hyperlocomotion. Moreover, the dopamine antagonist haloperidol induced longer catalepsy in threatened Tet/AS than in control mice. When returned to home-cage safety, Tet/AS mice showed retarded release from catalepsy.
CONCLUSIONS: Acetylcholinesterase modulates stress-induced motor responses and facilitates resumption of normal motor behavior following stress through both catalytic and noncatalytic features.
ESTHER : Sklan_2006_Biol.Psychiatry_60_741
PubMedSearch : Sklan_2006_Biol.Psychiatry_60_741
PubMedID: 16904653

Title : MicroRNA modulation of megakaryoblast fate involves cholinergic signaling - Guimaraes-Sternberg_2006_Leuk.Res_30_583
Author(s) : Guimaraes-Sternberg C , Meerson A , Shaked I , Soreq H
Ref : Leuk Res , 30 :583 , 2006
Abstract : MicroRNAs (miRNAs) are abundant small regulatory RNAs with multiple roles in cell fate determination. The processes regulating cellular miRNA levels are still unclear and experimental oligonucleotide tools to readily mimic their effects are not yet available. Here, we report that thapsigargin-induced intracellular Ca(++) release suppressed pre-miR-181a levels in human promegakaryotic Meg-01 cells, induced differentiation-associated nuclear endoreduplication and caspase-3 activation and replaced the acetylcholinesterase 3' splice variant AChE-S with AChE-R. AChE, PKC and PKA inhibitors all attenuated the pre-miR-181a decline and the induced differentiation. AChmiON, a synthetic 23-mer 2'-oxymethylated oligonucleotide mimicking the miR-181a sequence, blocked the calcium-induced differentiation while elevating cellular pre-miR-181a levels and inducing DNA fragmentation and cell death. Moreover, when added to RW 264.7 macrophages, AChmiON at 100 nM induced nitric oxide production with efficiency close to that of bacterial endotoxin, demonstrating physiologically relevant activities also in blood-born monocytes/macrophages. The stress-induced modulation of hematopoietic miR-181a levels through AChE, PKC and PKA cascade(s) suggests using miRNA mimics for diverting the fate of hematopoietic tumor cells towards differentiation and/or apoptosis.
ESTHER : Guimaraes-Sternberg_2006_Leuk.Res_30_583
PubMedSearch : Guimaraes-Sternberg_2006_Leuk.Res_30_583
PubMedID: 16249029

Title : ACHE gene expression in human brain tumors involves alternative splicing and CREB-induced proliferative signals -
Author(s) : Perry C , Soreq H
Ref : Isr Med Assoc J , 8 :364 , 2006
PubMedID: 16838434

Title : Stress-induced cholinergic signaling promotes inflammation-associated thrombopoiesis - Pick_2006_Blood_107_3397
Author(s) : Pick M , Perry C , Lapidot T , Guimaraes-Sternberg C , Naparstek E , Deutsch V , Soreq H
Ref : Blood , 107 :3397 , 2006
Abstract : To study the role of the stress-induced "readthrough" acetylcholinesterase splice variant, AChE-R, in thrombopoiesis, we used transgenic mice overexpressing human AChE-R (TgR). Increased AChE hydrolytic activity in the peripheral blood of TgR mice was associated with increased thrombopoietin levels and platelet counts. Bone marrow (BM) progenitor cells from TgR mice presented an elevated capacity to produce mixed (GEMM) and megakaryocyte (Mk) colonies, which showed intensified labeling of AChE-R and its interacting proteins RACK1 and PKC. When injected with bacterial lipopolysaccharide (LPS), parent strain FVB/N mice, but not TgR mice, showed reduced platelet counts. Therefore, we primed human CD34+ cells with the synthetic ARP26 peptide, derived from the cleavable C-terminus of AChE-R prior to transplantation, into sublethally irradiated NOD/SCID mice. Engraftment of human cells (both CD45+ and CD41+ Mk) was significantly increased in mice that received ARP26-primed CD34+ human cells versus mice that received fresh nonprimed CD34+ human cells. Moreover, ARP26 induced polyploidization and proplatelet shedding in human MEG-01 promegakaryotic cells, and human platelet engraftment increased following ex vivo expansion of ARP26-treated CD34+ cells as compared to cells expanded with thrombopoietin and stem cell factor. Our findings implicate AChE-R in thrombopoietic recovery, suggesting new therapeutic modalities for supporting platelet production.
ESTHER : Pick_2006_Blood_107_3397
PubMedSearch : Pick_2006_Blood_107_3397
PubMedID: 16380450

Title : Adaptive acetylcholinesterase splicing patterns attenuate 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinsonism in mice - Ben-Shaul_2006_Eur.J.Neurosci_23_2915
Author(s) : Ben-Shaul Y , Benmoyal-Segal L , Ben-Ari S , Bergman H , Soreq H
Ref : European Journal of Neuroscience , 23 :2915 , 2006
Abstract : Balanced dopaminergic cholinergic interactions are crucial for proper basal ganglia function. This is dramatically demonstrated by the worsening of Parkinson's disease symptoms following acetylcholinesterase (AChE) inhibition. Typically, in the brain, the synapse-anchored synaptic AChE (AChE-S) variant is prevalent whereas the soluble readthrough AChE (AChE-R) variant is induced in response to cholinesterase inhibition or stress. Because of the known functional differences between these variants and the fact that AChE-R expression is triggered by various stimuli that themselves are often associated with Parkinson's disease risk, we hypothesized that the splice shift to AChE-R plays a functional role in Parkinsonian progression. After establishing that Paraoxon-induced AChE inhibition indeed aggravates experimental Parkinsonism triggered by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in mice, we tested the roles of individual AChE variants by exposing transgenic mice overexpressing either the AChE-S or AChE-R variant to MPTP. Differential reductions of tyrosine hydroxylase levels in the striatum and substantia nigra indicated that transgenic AChE-R expression confers resistance as compared with the parent FVB/N strain. In contrast, AChE-S overexpression accelerated the MPTP-induced damage. Survival, behavioral measures and plasma corticosterone levels were also compatible with the extent of the dopaminergic damage. Our findings highlight the functional differences between individual AChE variants and indicate that a naturally occurring stress or AChE inhibitor-induced splicing shift can act to minimize dopaminergic cholinergic imbalances. We propose that inherited or acquired alternative splicing deficits could accelerate Parkinsonism and that, correspondingly, adaptive alternative splicing events may attenuate disease progression.
ESTHER : Ben-Shaul_2006_Eur.J.Neurosci_23_2915
PubMedSearch : Ben-Shaul_2006_Eur.J.Neurosci_23_2915
PubMedID: 16819980

Title : Butyrylcholinesterase attenuates amyloid fibril formation in vitro - Diamant_2006_Proc.Natl.Acad.Sci.U.S.A_103_8628
Author(s) : Diamant S , Podoly E , Friedler A , Ligumsky H , Livnah O , Soreq H
Ref : Proc Natl Acad Sci U S A , 103 :8628 , 2006
Abstract : In Alzheimer's disease, both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) colocalize with brain fibrils of amyloid-beta (Abeta) peptides, and synaptic AChE-S facilitates fibril formation by association with insoluble Abeta fibrils. Here, we report that human BChE and BSP41, a synthetic peptide derived from the BChE C terminus, inversely associate with the soluble Abeta conformers and delay the onset and decrease the rate of Abeta fibril formation in vitro, at a 1:100 BChE/Abeta molar ratio and in a dose-dependent manner. The corresponding AChE synthetic peptide (ASP)40 peptide, derived from the homologous C terminus of synaptic human (h)AChE-S, failed to significantly affect Abeta fibril formation, attributing the role of enhancing this process to an AChE domain other than the C terminus. Circular dichroism and molecular modeling confirmed that both ASP40 and BChE synthetic peptide (BSP)41 are amphipathic alpha-helices. However, ASP40 shows symmetric amphipathicity, whereas BSP41 presented an aromatic tryptophan residue in the polar side of the C terminus. That this aromatic residue is causally involved in the attenuating effect of BChE was further supported by mutagenesis experiments in which (W8R) BSP41 showed suppressed capacity to attenuate fibril formation. In Alzheimer's disease, BChE may have thus acquired an inverse role to that of AChE by adopting imperfect amphipathic characteristics of its C terminus.
ESTHER : Diamant_2006_Proc.Natl.Acad.Sci.U.S.A_103_8628
PubMedSearch : Diamant_2006_Proc.Natl.Acad.Sci.U.S.A_103_8628
PubMedID: 16731619

Title : Hydrolytic and nonenzymatic functions of acetylcholinesterase comodulate hemopoietic stress responses - Grisaru_2006_J.Immunol_176_27
Author(s) : Grisaru D , Pick M , Perry C , Sklan EH , Almog R , Goldberg I , Naparstek E , Lessing JB , Soreq H , Deutsch V
Ref : J Immunol , 176 :27 , 2006
Abstract : Glucocorticoid-initiated granulocytosis, excessive proliferation of granulocytes, persists after cortisol levels are lowered, suggesting the involvement of additional stress mediator(s). In this study, we report that the stress-induced acetylcholinesterase variant, AChE-R, and its cleavable, cell-penetrating C-terminal peptide, ARP, facilitate granulocytosis. In postdelivery patients, AChE-R-expressing granulocyte counts increased concomitantly with serum cortisol and AChE activity levels, yet persisted after cortisol had declined. Ex vivo, mononuclear cells of adult peripheral blood responded to synthetic ARP26 by overproduction of hemopoietically active proinflammatory cytokines (e.g., IL-6, IL-10, and TNF-alpha). Physiologically relevant ARP26)levels promoted AChE gene expression and induced the expansion of cultured CD34+ progenitors and granulocyte maturation more effectively than cortisol, suggesting autoregulatory prolongation of ARP effects. In vivo, transgenic mice overexpressing human AChE-R, unlike matched controls, showed enhanced expression of the myelopoietic transcription factor PU.1 and maintained a stable granulocytic state following bacterial LPS exposure. AChE-R accumulation and the consequent inflammatory consequences can thus modulate immune responses to stress stimuli.
ESTHER : Grisaru_2006_J.Immunol_176_27
PubMedSearch : Grisaru_2006_J.Immunol_176_27
PubMedID: 16365392

Title : Coding region paraoxonase polymorphisms dictate accentuated neuronal reactions in chronic, sub-threshold pesticide exposure - Browne_2006_Faseb.J_20_1733
Author(s) : Browne RO , Benmoyal-Segal L , Zumsteg D , David Y , Kofman O , Berger A , Soreq H , Friedman A
Ref : FASEB Journal , 20 :1733 , 2006
Abstract : Organophosphate pesticides (OPs), known inhibitors of acetylcholinesterase (AChE), are used extensively throughout the world. Recent studies have focused on the ACHE/PON1 locus as a determinant of inherited susceptibility to environmental OP exposure. To explore the relationship of the corresponding gene-environment interactions with brain activity, we integrated neurophysiologic, neuropsychological, biochemical, and genetic methods. Importantly, we found that subthreshold OP exposure leads to discernible physiological consequences that are significantly influenced by inherited factors. Cortical EEG analyses by LORETA revealed significantly decreased theta activity in the hippocampus, parahippocampal regions, and the cingulate cortex, as well as increased beta activity in the prefrontal cortex of exposed individuals-areas known to play a role in cholinergic-associated cognitive functions. Through neuropsychological testing, we identified an appreciable deficit in the visual recall in exposed individuals. Other neuropsychological tests revealed no significant differences between exposed and non-exposed individuals, attesting to the specificity of our findings. Biochemical analyses of blood samples revealed increases in paraoxonase and arylesterase activities and reduced serum acetylcholinesterase activity in chronically exposed individuals. Notably, specific paraoxonase genotypes were found to be associated with these exposure-related changes in blood enzyme activities and abnormal EEG patterns. Thus, gene-environment interactions involving the ACHE/PON1 locus may be causally involved in determining the physiological response to OP exposure.
ESTHER : Browne_2006_Faseb.J_20_1733
PubMedSearch : Browne_2006_Faseb.J_20_1733
PubMedID: 16807370

Title : Readthrough acetylcholinesterase: a multifaceted inducer of stress reactions - Zimmerman_2006_J.Mol.Neurosci_30_197
Author(s) : Zimmerman G , Soreq H
Ref : Journal of Molecular Neuroscience , 30 :197 , 2006
Abstract : Stress insults induce hyperexcitation of cholinergic circuits, both peripherally in the sympathetic pathway (Tracey, 2002) and at the central nervous system (CNS) (Sapolsky, 1996). This reaction can serve to ensure survival but might also entail a risk to the hyperactivated neurons. Consequent changes in the expression of a series of proteins related to acetylcholine (ACh) metabolism might protect the organism from the potentially detrimental effects of this increase in ACh. Of particular interest among these effects is the induction by alternative splicing of the alternative, usually rare, readthrough variant of acetylcholinesterase (AChE), AChE-R. AChE-R is one of the first proteins conveying the signal that the organism has entered a state of alert. Viewing AChER as a stress signal can therefore serve to answer the question "How do we expect a stress signal to operate"? This facilitates the generation of hypotheses regarding the triggering of such signals and the effects it exerts at the molecular, cellular, and physiological levels.
ESTHER : Zimmerman_2006_J.Mol.Neurosci_30_197
PubMedSearch : Zimmerman_2006_J.Mol.Neurosci_30_197
PubMedID: 17192675

Title : Termination and beyond: acetylcholinesterase as a modulator of synaptic transmission - Zimmerman_2006_Cell.Tissue.Res_326_655
Author(s) : Zimmerman G , Soreq H
Ref : Cell Tissue Research , 326 :655 , 2006
Abstract : Termination of synaptic transmission by neurotransmitter hydrolysis is a substantial characteristic of cholinergic synapses. This unique termination mechanism makes acetylcholinesterase (AChE), the enzyme in charge of executing acetylcholine breakdown, a key component of cholinergic signaling. AChE is now known to exist not as a single entity, but rather as a combinatorial complex of protein products. The diverse AChE molecular forms are generated by a single gene that produces over ten different transcripts by alternative splicing and alternative promoter choices. These transcripts are translated into six different protein subunits. Mature AChE proteins are found as soluble monomers, amphipatic dimers, or tetramers of these subunits and become associated to the cellular membrane by specialized anchoring molecules or members of other heteromeric structural components. A substantial increasing body of research indicates that AChE functions in the central nervous system go far beyond the termination of synaptic transmission. The non-enzymatic neuromodulatory functions of AChE affect neurite outgrowth and synaptogenesis and play a major role in memory formation and stress responses. The structural homology between AChE and cell adhesion proteins, together with the recently discovered protein partners of AChE, predict the future unraveling of the molecular pathways underlying these multileveled functions.
ESTHER : Zimmerman_2006_Cell.Tissue.Res_326_655
PubMedSearch : Zimmerman_2006_Cell.Tissue.Res_326_655
PubMedID: 16802134

Title : ARP, the cleavable C-terminal peptide of readthrough acetylcholinesterase, promotes neuronal development and plasticity - Dori_2006_J.Mol.Neurosci_28_247
Author(s) : Dori A , Soreq H
Ref : Journal of Molecular Neuroscience , 28 :247 , 2006
Abstract : The mammalian acetylcholinesterase (ACHE) gene gives rise to diverse enzymatically active proteins with three different carboxyl termini. In the brain, the normally rare readthrough AChE-R monomer accumulates under embryonic development and in adults following psychological stress, head injury, or exposure to AChEs. In the prenatal developing cortex, its unique C-terminal peptide ARP associates with radial glial fibers supporting neuronal migration. In contrast, the major synaptic AChE-S variant appears in the migrating neurons themselves. Moreover, antisense suppression of AChE-R attenuates neuronal migration, allowing increased proliferation of neuronal progenitors. In the adult brain, neuronal AChE-R is either secreted or accumulates intraneuronally, where it interacts through ARP with the scaffold protein RACK1 and activated PKC-betaII. This associates with increased PKC-betaII activity, which shuttles to submembranal clusters (e.g., in hyperactivated hippocampal neurons). Cleavage yields the AChE-R-specific C-terminal peptide, including immunopositive ARP. Importantly, intrahippocampal injection of synthetic ARP was followed by its efficient neuronal penetration and retrograde transport into cortical and basal nuclei neurons. Moreover, ARP-injected mice presented increased stress-induced contextual fear, inhibitable by antisense suppression of AChE-R mRNA. Together, our findings point at the cleavable ARP peptide as a key regulator of neuronal development and plasticity and suggest its use as a drug target and/or research and therapeutic tool.
ESTHER : Dori_2006_J.Mol.Neurosci_28_247
PubMedSearch : Dori_2006_J.Mol.Neurosci_28_247
PubMedID: 16691012

Title : RNA-targeted suppression of stress-induced allostasis in primate spinal cord neurons - Evron_2005_Neurodegener.Dis_2_16
Author(s) : Evron T , Moyal-Segal LB , Lamm N , Geffen A , Soreq H
Ref : Neurodegener Dis , 2 :16 , 2005
Abstract : Peripheral acetylcholine levels notably control the synthesis in macrophages of pro-inflammatory cytokines; however, it remains unclear whether this peripheral regulatory pathway affects central nervous system neurons. To explore the interrelationship between neuronal cholinergic homeostasis and peripheral inflammatory responses in primates, we used spinal cord sections from cynomolgus monkeys after 7 days oral or intravenous treatment with Monarsen oligonucleotide. Monarsen is an antisense oligonucleotide 3'-protected by 2'-oxymethylation, which was proved to induce selective destruction of the stress-induced acetylcholinesterase splice variant AChE-R mRNA. Handling stress predictably suppressed neuronal choline acetyl transferase (ChAT) and the vesicular acetylcholine transporter (VAChT) in all treated monkeys. In Monarsen-treated animals, we further observed suppression of stress-induced increases in plasma AChE activities. Corresponding decreases in AChE-R mRNA were seen in spinal cord neurons, associated with parallel decline patterns in the mRNA encoding for the splice factor SC35 (the levels of which co-increase with those of AChE-R) as well as in the neuronal pro-inflammatory interleukins IL-1beta and IL-6. The antisense effects showed direct dose dependence and were inversely associated with neuronal cell size. These findings suggest a causal association between neuronal cholinergic allostasis and inflammatory reactions in primates and support the peripheral use of RNA-targeted intervention with AChE-R accumulation for the management of both stress and inflammatory responses.
ESTHER : Evron_2005_Neurodegener.Dis_2_16
PubMedSearch : Evron_2005_Neurodegener.Dis_2_16
PubMedID: 16908999

Title : SC35 promotes sustainable stress-induced alternative splicing of neuronal acetylcholinesterase mRNA - Meshorer_2005_Mol.Psychiatry_10_985
Author(s) : Meshorer E , Bryk B , Toiber D , Cohen J , Podoly E , Dori A , Soreq H
Ref : Mol Psychiatry , 10 :985 , 2005
Abstract : Long-lasting alternative splicing of neuronal acetylcholinesterase (AChE) pre-mRNA occurs during neuronal development and following stress, altering synaptic properties. To explore the corresponding molecular events, we sought to identify mRNAs encoding for abundant splicing factors in the prefrontal cortex (PFC) following stress. Here we show elevated levels of the splicing factor SC35 in stressed as compared with naive mice. In cotransfections of COS-1 and HEK293 cells with an AChE minigene allowing 3' splice variations, SC35 facilitated a shift from the primary AChE-S to the stress-induced AChE-R variant, while ASF/SF2 caused the opposite effect. Transfection with chimeric constructs comprising of SC35 and ASF/SF2 RRM/RS domains identified the SC35 RRM as responsible for AChE mRNA's alternative splicing. In poststress PFC neurons, increased SC35 mRNA and protein levels coincided with selective increase in AChE-R mRNA. In the developing mouse embryo, cortical progenitor cells in the ventricular zone displayed transient SC35 elevation concomitant with dominance of AChE-R over AChE-S mRNA. Finally, transgenic mice overexpressing human AChE-R, but not those overexpressing AChE-S, showed significant elevation in neuronal SC35 levels, suggesting a reciprocal reinforcement process. Together, these findings point to an interactive relationship of SC35 with cholinergic signals in the long-lasting consequences of stress on nervous system plasticity and development.
ESTHER : Meshorer_2005_Mol.Psychiatry_10_985
PubMedSearch : Meshorer_2005_Mol.Psychiatry_10_985
PubMedID: 16116489

Title : Inherited and acquired interactions between ACHE and PON1 polymorphisms modulate plasma acetylcholinesterase and paraoxonase activities - Bryk_2005_J.Neurochem_92_1216
Author(s) : Bryk B , Benmoyal-Segal L , Podoly E , Livnah O , Eisenkraft A , Luria S , Cohen A , Yehezkelli Y , Hourvitz A , Soreq H
Ref : Journal of Neurochemistry , 92 :1216 , 2005
Abstract : The 5.5 Mb chromosome 7q21-22 ACHE/PON1 locus harbours the ACHE gene encoding the acetylcholine hydrolyzing, organophosphate (OP)-inhibitable acetylcholinesterase protein and the paraoxonase gene PON1, yielding the OP-hydrolyzing PON1 enzyme which also displays arylesterase activity. In search of inherited and acquired ACHE-PON1 interactions we genotyped seven polymorphic sites and determined the hydrolytic activities of the corresponding plasma enzymes and of the AChE-homologous butyrylcholinesetrase (BChE) in 157 healthy Israelis. AChE, arylesterase, BChE and paraoxonase activities in plasma displayed 5.4-, 6.5-, 7.2- and 15.5-fold variability, respectively, with genotype-specific differences between carriers of distinct compound polymorphisms. AChE, BChE and arylesterase but not paraoxonase activity increased with age, depending on leucine at PON1 position 55. In contrast, carriers of PON1 M55 displayed decreased arylesterase activity independent of the - 108 promoter polymorphism. Predicted structural consequences of the PON1 L55M substitution demonstrated spatial shifts in adjacent residues. Molecular modelling showed substrate interactions with the enzyme variants, explaining the changes in substrate specificity induced by the Q192R substitution. Intriguingly, PON1, but not BChE or arylesterase, activities displayed inverse association with AChE activity. Our findings demonstrate that polymorphism(s) in the adjacent PON1 and ACHE genes affect each other's expression, predicting for carriers of biochemically debilitating ACHE/PON1 polymorphisms adverse genome-environment interactions.
ESTHER : Bryk_2005_J.Neurochem_92_1216
PubMedSearch : Bryk_2005_J.Neurochem_92_1216
PubMedID: 15715671

Title : Purification of transgenic plant-derived recombinant human acetylcholinesterase-R - Geyer_2005_Chem.Biol.Interact_157-158_331
Author(s) : Geyer BC , Muralidharan M , Cherni I , Doran J , Fletcher SP , Evron T , Soreq H , Mor TS
Ref : Chemico-Biological Interactions , 157-158 :331 , 2005
Abstract : Nicotiana benthamiana plants were engineered to express a codon-optimized gene encoding the human acetylcholinesterase-R (AChE) isoform. The transgenic plants expressed the protein at >0.4% of total soluble protein, and the plant-produced enzyme was purified to homogeneity. Following lysis, procainamide affinity chromatography and anion-exchange chromatography, more than 400-fold purification was achieved and electrophoretic purity was obtained. This pure protein is kinetically indistinguishable from the only commercially available source of human acetylcholinesterase, which is produced in mammalian cell culture. Thus, we have demonstrated a model system for the production of acetylcholinesterase, which is not susceptible to the quantitative limitations or mammalian pathogens associated with purification from mammalian cell culture or human serum.
ESTHER : Geyer_2005_Chem.Biol.Interact_157-158_331
PubMedSearch : Geyer_2005_Chem.Biol.Interact_157-158_331
PubMedID: 16269140

Title : Chronic cholinergic imbalances promote brain diffusion and transport abnormalities - Meshorer_2005_Faseb.J_19_910
Author(s) : Meshorer E , Biton IE , Ben-Shaul Y , Ben-Ari S , Assaf Y , Soreq H , Cohen Y
Ref : FASEB Journal , 19 :910 , 2005
Abstract : Cholinergic imbalances occur after traumatic effects and in the initial stages of neurodegenerative diseases, but their long-lasting effects remained largely unexplained. To address this, we used TgS transgenic mice constitutively overexpressing synaptic acetylcholinesterase (AChE-S) and presenting a complex phenotype of progressive neurodeterioration. T1- and T2-weighted magnetic resonance (MR) brain images appeared similar. However, diffusion-weighted MRI showed decreased baseline water apparent diffusion coefficient in the brains of TgS animals. Furthermore, contrast-enhanced MRI after gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) injection demonstrated slower recovery of normal signals in the TgS brains than with controls. Perfusion MR imaging and difference T1 maps calculated from pre- postcontrast T1-weighted MR images indicated accumulation of more Gd-DTPA molecules in the TgS brains than in the parent strain, reflecting impaired blood-brain barrier (BBB) functioning in these transgenic mice. To explore the molecular mechanism(s) underlying these global phenotypes, we performed microarray analysis in the stress-controlling prefrontal cortex of TgS vs. strain-matched wild-type animals. Profound overexpression of numerous ion channels, transporters, and adhesion genes was confirmed by real time RT-PCR tests. Immunohistochemical and immunoblot analyses revealed corresponding increases in the level and cellular distributions of the chloride channel CLCN3 and the water channel AQP4, both of which contribute to BBB maintenance. Our study attributes to balanced cholinergic neurotransmission, a central role in the brain's maintenance of water diffusion and ion transport, and indicates that chronic impairments in this maintenance facilitate neurodeterioration through interference with BBB function.
ESTHER : Meshorer_2005_Faseb.J_19_910
PubMedSearch : Meshorer_2005_Faseb.J_19_910
PubMedID: 15923401

Title : Acetylcholinesterase inhibitors reduce brain and blood interleukin-1beta production - Pollak_2005_Ann.Neurol_57_741
Author(s) : Pollak Y , Gilboa A , Ben-Menachem O , Ben-Hur T , Soreq H , Yirmiya R
Ref : Annals of Neurology , 57 :741 , 2005
Abstract : Overproduction of interleukin-1 within the brain is associated with Alzheimer's disease and other neurological conditions. We report that peripheral administration of the acetylcholinesterase inhibitors tacrine, rivastigmine, neostigmine, or EN101 (an antisense oligonucleotide directed at acetylcholinesterase messenger RNA) to mice significantly attenuated the production of interleukin-1beta in the hippocampus and blood, concomitantly with the reduction in acetylcholinesterase activity. These findings demonstrate that cholinergic enhancement produces central and peripheral antiinflammatory effects and suggest a novel therapeutic mechanism for acetylcholinesterase inhibitors.
ESTHER : Pollak_2005_Ann.Neurol_57_741
PubMedSearch : Pollak_2005_Ann.Neurol_57_741
PubMedID: 15852394

Title : Characterizing pea acetylcholinesterase - Muralidharan_2005_Chem.Biol.Interact_157-158_406
Author(s) : Muralidharan M , Soreq H , Mor TS
Ref : Chemico-Biological Interactions , 157-158 :406 , 2005
Abstract : Although the best-defined role of acetylcholinesterase (AChE) is to terminate cholinergic transmission signals, the presence of the enzyme and its substrate is not limited to the metazoan nervous system. Here, we describe the presence of cholinesterase and its initial characterization in pea roots.
ESTHER : Muralidharan_2005_Chem.Biol.Interact_157-158_406
PubMedSearch : Muralidharan_2005_Chem.Biol.Interact_157-158_406
PubMedID: 16429548

Title : Acetylcholinesterase\/paraoxonase interactions increase the risk of insecticide-induced Parkinson's disease - Benmoyal-Segal_2005_FASEB.J_19_452
Author(s) : Benmoyal-Segal L , Vander T , Shifman S , Bryk B , Ebstein RP , Marcus EL , Stessman J , Darvasi A , Herishanu Y , Friedman A , Soreq H
Ref : FASEB Journal , 19 :452 , 2005
Abstract : Exposure to agricultural insecticides, together with yet incompletely understood predisposing genotype/phenotype elements, notably increase the risk of Parkinson's disease. Here, we report findings attributing the increased risk in an insecticide-exposed rural area in Israel to interacting debilitating polymorphisms in the ACHE/PON1 locus and corresponding expression variations. Polymorphisms that debilitate PON1 activity and cause impaired AChE overproduction under anticholinesterase exposure were strongly overrepresented in patients from agriculturally exposed areas, indicating that they confer risk of Parkinson's disease. Supporting this notion, serum AChE and PON1 activities were both selectively and significantly lower in patients than in healthy individuals and in carriers of the risky polymorphisms as compared with other Parkinsonian patients. Our findings suggest that inherited interactive weakness of AChE and PON1 expression increases the insecticide-induced occurrence of Parkinson's disease.
ESTHER : Benmoyal-Segal_2005_FASEB.J_19_452
PubMedSearch : Benmoyal-Segal_2005_FASEB.J_19_452
PubMedID: 15629887

Title : Memory deficits correlating with acetylcholinesterase splice shift and amyloid burden in doubly transgenic mice - Rees_2005_Curr.Alzheimer.Res_2_291
Author(s) : Rees TM , Berson A , Sklan EH , Younkin L , Younkin S , Brimijoin S , Soreq H
Ref : Curr Alzheimer Res , 2 :291 , 2005
Abstract : Current mouse models of Alzheimer's disease show brain pathology that correlates to a degree with memory impairment, but underlying molecular mechanisms remained unknown. Here we report studies with three lines of transgenic mice: animals that doubly express mutated human amyloid precursor protein (APPswe) and human acetylcholinesterase (hAChE); and animals transgenic for only the APPswe or the hAChE. Among these genotypes, variations were observed in expression of mRNA for presenilin-1, which was highest in singly transgenic hAChE mice, and the stress-inducible form of AChE, which was elevated when both transgenes were present. At the age of nine months, both double and single transgenic mice displayed working memory impairment in a radial arm water maze. However, as compared with mice expressing amyloid alone, the double transgenic animals exhibited more numerous plaques and greater amyloid burden in brain (both by histochemistry and by ELISA of amyloid protein). Moreover, the amyloid burden in double transgenics was tightly correlated with memory impairment as measured by total maze errors (r2= 0.78, p = .002). This correlation was markedly stronger than observed in mice with amyloid alone. These new findings support the notion of cholinergic-amyloid interrelationships and highlight the double transgenic mice as a promising alternative for testing Alzheimer's therapies.
ESTHER : Rees_2005_Curr.Alzheimer.Res_2_291
PubMedSearch : Rees_2005_Curr.Alzheimer.Res_2_291
PubMedID: 15974894

Title : Cellular stress reactions as putative cholinergic links in Alzheimer's disease - Toiber_2005_Neurochem.Res_30_909
Author(s) : Toiber D , Soreq H
Ref : Neurochem Res , 30 :909 , 2005
Abstract : Alzheimer's disease involves normal cellular aging and chronic cellular stress events, leading to interrelated changes in gene expression and subsequent neurodegeneration. Premature death of cholinergic neurons and the formation of amyloid fibrils separately initiated the cholinergic and amyloid hypotheses of Alzheimer's disease. Here, we present evidence to the fact that these two distinct phenomena both associate with specific changes in acetylcholinesterase (AChE) gene expression within cholinergic neurons. For example, calcium misregulation promotes aberrant transcription and pro-apoptotic events, as well as AChE-induced modifications in cellular signal cascades. These reciprocally intercept with AChE regulation at the Endoplasmic Reticulum, modifying AChE gene expression, folding and signaling. Altered AChE properties may reflect changes in the enzymatic and/or non-enzymatic features of the multiple AChE splice variants. Under chronic cellular stress, aberrant AChE regulation may thus facilitate apoptotic pathways, promoting plaque formation, cognitive impairments and degeneration of cholinergic nerve cells.
ESTHER : Toiber_2005_Neurochem.Res_30_909
PubMedSearch : Toiber_2005_Neurochem.Res_30_909
PubMedID: 16187225

Title : Muscarinic modulations of neuronal anticholinesterase responses - Salmon_2005_Chem.Biol.Interact_157-158_105
Author(s) : Salmon A , Erb C , Meshorer E , Ginzberg D , Adani Y , Rabinovitz I , Amitai G , Soreq H
Ref : Chemico-Biological Interactions , 157-158 :105 , 2005
Abstract : Anticholinesterases (antiChEs) are increasingly used for treating patients with neurodegenerative diseases, but the dependence of their effects on the integrity of cholinergic functions has not yet been analyzed at the molecular level. Here, we report that manipulation of muscarinic neurotransmission confers drastic changes on antiChE responses in the rat brain. In the brains of naive, un-stressed rats, the irreversible organophosphate antiChE, diisopropylfluorophosphonate (DFP) induced post-treatment accumulation of catalytically active G1 monomers of acetylcholinesterase (AChE). Pre-treatment with the selective M1 muscarinic antagonist, pirenzepine, but not the general muscarinic antagonist, scopolamine, attenuated this G1 increase. DFP-enhanced AChE gene expression was accompanied by diverted splicing from the primary AChE-S mRNA variant, encoding G4 synaptic membrane AChE-S tetramers, to "readthrough" AChE-R mRNA, which encodes soluble G1 monomers. Both the mRNA increase and the shifted splicing were long lasting (>24 h) and common to the parietal cortex and hippocampal CA1 and CA3 neurons. Importantly, the splicing shift was maximal under DFP alone, as compared with sham-injected rats, and virtually preventable by pre-treatment with pirenzepine. In contrast, induction of AChE transcription was less dependent on muscarinic function, resulting in AChE-S but not AChE-R increases. Our findings demonstrate distinct regulation of the enhanced transcription and the alternative splicing reactions to antiChE treatment and shed new light on the differential responses to antiChEs of demented patients with increasingly impaired cholinergic neurotransmission.
ESTHER : Salmon_2005_Chem.Biol.Interact_157-158_105
PubMedSearch : Salmon_2005_Chem.Biol.Interact_157-158_105
PubMedID: 16289123

Title : Functional manipulations of acetylcholinesterase splice variants highlight alternative splicing contributions to murine neocortical development - Dori_2005_Cereb.Cortex_15_419
Author(s) : Dori A , Cohen J , Silverman WF , Pollack Y , Soreq H
Ref : Cerebral Cortex , 15 :419 , 2005
Abstract : Proliferation and differentiation of mammalian central nervous system progenitor cells involve concertedly controlled transcriptional and alternative splicing modulations. Searching for the developmental implications of this programming, we manipulated specific acetylcholinesterase (AChE) splice variants in the embryonic mouse brain. In wild type mice, 'synaptic' AChE-S appeared in migrating neurons, whereas the C-terminus cleaved off the stress-induced AChE-R variant associated with migratory radial glial fibers. Antisense suppression of AChE-R reduced neuronal migration, allowing increased proliferation of progenitor cells. In contrast, transgenic overexpression of AChE-R was ineffective, whereas transgenic excess of enzymatically active AChE-S or inactive AChE-Sin suppressed progenitors proliferation alone or both proliferation and neuronal migration, respectively. Our findings attribute to alternative splicing events an interactive major role in neocortical development.
ESTHER : Dori_2005_Cereb.Cortex_15_419
PubMedSearch : Dori_2005_Cereb.Cortex_15_419
PubMedID: 15749986

Title : Poster (37) Multileveled regulation of acetylcholinesterase gene expression under impaired cholinergic homeostasis. -
Author(s) : Soreq H
Ref : In: Cholinesterases in the Second Millennium: Biomolecular and Pathological Aspects , (Inestrosa NC, Campos EO) P. Universidad Catolica de Chile-FONDAP Biomedicina :340 , 2004

Title : Acetylcholinesterase\/paraoxonase genotype and expression predict anxiety scores in Health, Risk Factors, Exercise Training, and Genetics study - Sklan_2004_Proc.Natl.Acad.Sci.U.S.A_101_5512
Author(s) : Sklan EH , Lowenthal A , Korner M , Ritov Y , Landers DM , Rankinen T , Bouchard C , Leon AS , Rice T , Rao DC , Wilmore JH , Skinner JS , Soreq H
Ref : Proc Natl Acad Sci U S A , 101 :5512 , 2004
Abstract : Anxiety involves complex, incompletely understood interactions of genomic, environmental, and experience-derived factors, and is currently being measured by psychological criteria. Here, we report previously nonperceived interrelationships between expression variations and nucleotide polymorphisms of the chromosome 7q21-22 acetylcholinesterase-paraoxonase 1 (ACHE-PON1) locus with the trait- and state-anxiety measures of 461 healthy subjects from the Health, Risk Factors, Exercise Training, and Genetics Family Study. The AChE protein controls the termination of the stress-enhanced acetylcholine signaling, whereas the PON protein displays peroxidase-like activity, thus protecting blood proteins from oxidative stress damages. Serum AChE and PON enzyme activities were both found to be affected by demographic parameters, and showed inverse, reciprocal associations with anxiety measures. Moreover, the transient scores of state anxiety and the susceptibility score of trait anxiety both appeared to be linked to enzyme activities. This finding supported the notion of corresponding gene expression relationships. Parallel polymorphisms in the ACHE and PON1 genes displayed apparent associations with both trait- and state-anxiety scores. Our findings indicate that a significant source of anxiety feelings involves inherited and acquired parameters of acetylcholine regulation that can be readily quantified, which can help explaining part of the human variance for state and trait anxiety.
ESTHER : Sklan_2004_Proc.Natl.Acad.Sci.U.S.A_101_5512
PubMedSearch : Sklan_2004_Proc.Natl.Acad.Sci.U.S.A_101_5512
PubMedID: 15060281

Title : Stress-induced alternative splicing of acetylcholinesterase results in enhanced fear memory and long-term potentiation - Nijholt_2004_Mol.Psychiatry_9_174
Author(s) : Nijholt I , Farchi N , Kye M , Sklan EH , Shoham S , Verbeure B , Owen D , Hochner B , Spiess J , Soreq H , Blank T
Ref : Mol Psychiatry , 9 :174 , 2004
Abstract : Stress insults intensify fear memory; however, the mechanism(s) facilitating this physiological response is still unclear. Here, we report the molecular, neurophysiological and behavioral findings attributing much of this effect to alternative splicing of the acetylcholinesterase (AChE) gene in hippocampal neurons. As a case study, we explored immobilization-stressed mice with intensified fear memory and enhanced long-term potentiation (LTP), in which alternative splicing was found to induce overproduction of neuronal 'readthrough' AChE-R (AChE-R). Selective downregulation of AChE-R mRNA and protein by antisense oligonucleotides abolished the stress-associated increase in AChE-R, the elevation of contextual fear and LTP in the hippocampal CA1 region. Reciprocally, we intrahippocampally injected a synthetic peptide representing the C-terminal sequence unique to AChE-R. The injected peptide, which has been earlier found to exhibit no enzymatic activity, was incorporated into cortical, hippocampal and basal nuclei neurons by endocytosis and retrograde transport and enhanced contextual fear. Compatible with this hypothesis, inherited AChE-R overexpression in transgenic mice resulted in perikaryal clusters enriched with PKCbetaII, accompanied by PKC-augmented LTP enhancement. Our findings demonstrate a primary role for stress-induced alternative splicing of the AChE gene to elevated contextual fear and synaptic plasticity, and attribute to the AChE-R splice variant a major role in this process.
ESTHER : Nijholt_2004_Mol.Psychiatry_9_174
PubMedSearch : Nijholt_2004_Mol.Psychiatry_9_174
PubMedID: 14581933

Title : Poster (58) Acetylcholinesterase promotes amyloid plaques in transgenic mouse brain. -
Author(s) : Brimijoin S , Rees TM , Soreq H , Younkin S
Ref : In: Cholinesterases in the Second Millennium: Biomolecular and Pathological Aspects , (Inestrosa NC, Campos EO) P. Universidad Catolica de Chile-FONDAP Biomedicina :352 , 2004

Title : Tissue distribution of cholinesterases and anticholinesterases in native and transgenic tomato plants - Fletcher_2004_Plant.Mol.Biol_55_33
Author(s) : Fletcher SP , Geyer BC , Smith A , Evron T , Joshi L , Soreq H , Mor TS
Ref : Plant Mol Biol , 55 :33 , 2004
Abstract : Acetylcholinesterase, a major component of the central and peripheral nervous systems, is ubiquitous among multicellular animals, where its main function is to terminate synaptic transmission by hydrolyzing the neurotransmitter, acetylcholine. However, previous reports describe cholinesterase activities in several plant species and we present data for its presence in tomato plants. Ectopic expression of a recombinant form of the human enzyme and the expression pattern of the transgene and the accumulation of its product in transgenic tomato plants are described. Levels of acetylcholinesterase activity in different tissues are closely effected by and can be separated from alpha-tomatine, an anticholinesterase steroidal glycoalkaloid. The recombinant enzyme can also be separated from the endogenous cholinesterase activity by its subcellular localization and distinct biochemical properties. Our results provide evidence for the co-existence in tomato plants of both acetylcholinesterase activity and a steroidal glycoalkaloid with anticholinesterase activity and suggest spatial mutual exclusivity of these antagonistic activities. Potential functions, including roles in plant-pathogen interactions are discussed.
ESTHER : Fletcher_2004_Plant.Mol.Biol_55_33
PubMedSearch : Fletcher_2004_Plant.Mol.Biol_55_33
PubMedID: 15604663

Title : Blood-cell-specific acetylcholinesterase splice variations under changing stimuli - Pick_2004_Int.J.Dev.Neurosci_22_523
Author(s) : Pick M , Flores-Flores C , Grisaru D , Shochat S , Deutsch V , Soreq H
Ref : Int J Developmental Neuroscience , 22 :523 , 2004
Abstract : Developmental and trauma-induced mechanism(s) that modify inflammation and immune responses in blood cells were recently found to be regulated by acetylcholine. Here, we report corresponding blood cell-specific changes in acetylcholinesterase splice variants. Plasmon resonance and flow cytometry using acetylcholinesterase variant-specific antibody probes, revealed a progressive increase in myeloid cell fractions expressing the apoptosis-related acetylcholinesterase-S variant from newborns to adult controls and post-delivery mothers. Hematopoietic cell fractions positive for the myeloproliferative acetylcholinesterase-R variant, were similarly high in post-partum blood, both intracellular and on the cell surface. Moreover, intracellular acetylcholinesterase-S protein amounts as reflected by fluorescence intensity measurements remained unchanged in myeloid cells from post-partum mothers as compared with matched controls. Unlike brain neurons, which over-express intracellular acetylcholinesterase-R under stress, lymphocytes from post-partum mothers presented increased surface acetylcholinesterase-S and pronounced decreases in both the expression and contents of surface acetylcholinesterase-R. Peripheral stimuli-induced modulations in acetylcholine regulation may hence reflect blood cell lineage-dependent acetylcholinesterase splice variations.
ESTHER : Pick_2004_Int.J.Dev.Neurosci_22_523
PubMedSearch : Pick_2004_Int.J.Dev.Neurosci_22_523
PubMedID: 15465282

Title : ?Readthrough? acetylcholinesterase and cholinergic neurotransmission. -
Author(s) : Shoham S , Kovalev E , Sklan E , Soreq H
Ref : Cholinergic Mechanisms, CRC Press :697 , 2004

Title : Combinatorial complexity of 5' alternative acetylcholinesterase transcripts and protein products - Meshorer_2004_J.Biol.Chem_279_29740
Author(s) : Meshorer E , Toiber D , Zurel D , Sahly I , Dori A , Cagnano E , Schreiber L , Grisaru D , Tronche F , Soreq H
Ref : Journal of Biological Chemistry , 279 :29740 , 2004
Abstract : To explore the scope and significance of alternate promoter usage and its putative inter-relationship to alternative splicing, we searched expression sequence tags for the 5' region of acetylcholinesterase (ACHE) genes. Three and five novel first exons were identified in human and mouse ACHE genes, respectively. Reverse transcription-PCR and in situ hybridization validated most of the predicted transcripts, and sequence analyses of the corresponding genomic DNA regions suggest evolutionarily conserved promoters for each of the novel exons identified. Distinct tissue specificity and stress-related expression patterns of these exons predict combinatorial complexity with known 3' alternative AChE mRNA transcripts. Unexpectedly one of the 5' exons encodes an extended N terminus in-frame with the known AChE sequence, extending the increased complexity to the protein level. The resultant membrane variant(s), designated N-AChE, is developmentally regulated in human brain neurons and blood mononuclear cells. Alternative promoter usage combined with alternative splicing may thus lead to stress-dependent combinatorial complexity of AChE mRNA transcripts and their protein products.
ESTHER : Meshorer_2004_J.Biol.Chem_279_29740
PubMedSearch : Meshorer_2004_J.Biol.Chem_279_29740
PubMedID: 15123727

Title : Interaction of readthrough acetylcholinesterase with the PKC scaffold protein Rackl facilitates antisense-suppressible contextual fear responses -
Author(s) : Sklan EH , Shoham S , Soreq H
Ref : In: Cholinesterases in the Second Millennium: Biomolecular and Pathological Aspects , (Inestrosa NC, Campos EO) P. Universidad Catolica de Chile-FONDAP Biomedicina :65 , 2004

Title : CREB regulates AChE-R-induced proliferation of human glioblastoma cells - Perry_2004_Neoplasia_6_279
Author(s) : Perry C , Sklan EH , Soreq H
Ref : Neoplasia , 6 :279 , 2004
Abstract : The cyclic adenosine monophosphate (AMP) response element-binding protein, CREB, often modulates stress responses. Here, we report that CREB suppresses the glioblastoma proliferative effect of the stress-induced acetylcholinesterase variant, AChE-R. In human U87MG glioblastoma cells, AChE-R formed a triple complex with protein kinase C (PKC) epsilon and the scaffold protein RACK1, enhanced PKCepsilon phosphorylation, and facilitated BrdU incorporation. Either overexpressed CREB, or antisense destruction of AChE-R mRNA, PKC, or protein kinase A (PKA) inhibitors-but not CREB combined with PKC inhibition suppressed-this proliferation, suggesting that CREB's repression of this process involves a PKC-mediated pathway, whereas impaired CREB regulation allows AChE-R-induced, PKA-mediated proliferation of glioblastoma tumors.
ESTHER : Perry_2004_Neoplasia_6_279
PubMedSearch : Perry_2004_Neoplasia_6_279
PubMedID: 15153340

Title : Organophosphate risk of leukemogenesis -
Author(s) : Perry C , Soreq H
Ref : Leuk Res , 28 :905 , 2004
PubMedID: 15234565

Title : From brain to blood: alternative splicing evidence for the cholinergic basis of Mammalian stress responses - Pick_2004_Ann.N.Y.Acad.Sci_1018_85
Author(s) : Pick M , Flores-Flores C , Soreq H
Ref : Annals of the New York Academy of Sciences , 1018 :85 , 2004
Abstract : Three principal features of mammalian stress responses are that they span peripheral and CNS changes, modify blood cell composition and activities, and cover inter-related alterations in a large number of gene products. The finely tuned spatiotemporal regulation of these multiple events suggests the hierarchic involvement of modulatory neurotransmitters and modified process(es) in the pathway of gene expression that together would enable widely diverse stress responses. We report evidence supporting the notion that acetylcholine (ACh) acts as a stress-response-regulating transmitter and that altered ACh levels are variously associated with changes in the alternative splicing of pre-mRNA transcripts in brain neurons and peripheral blood cells. We used acetylcholinesterase (AChE) gene expression as a case study and developed distinct probes for its alternative splice variants at the mRNA and protein levels. In laboratory animals and human-derived cells, we found stress-induced changes in the alternative splicing patterns of AChE pre-mRNA, which attributes to this gene and its different protein products diverse stress responsive functions that are associated with the enzymatic and noncatalytic properties of AChE. Together, these approaches provide a conceptually unified view of the studied pathways for controlling stress responses in brain and blood.
ESTHER : Pick_2004_Ann.N.Y.Acad.Sci_1018_85
PubMedSearch : Pick_2004_Ann.N.Y.Acad.Sci_1018_85
PubMedID: 15240356

Title : Long-lasting acetylcholinesterase splice variations in anticholinesterase-treated Alzheimer's disease patients - Darreh-Shori_2004_J.Neurochem_88_1102
Author(s) : Darreh-Shori T , Hellstrom-Lindahl E , Flores-Flores C , Guan ZZ , Soreq H , Nordberg A
Ref : Journal of Neurochemistry , 88 :1102 , 2004
Abstract : Protein levels of different acetylcholinesterase (AChE) splice variants were explored by a combination of immunoblot techniques, using two different antibodies, directed against the C-terminus of the AChE-R splice variant or the core domain common to all variants. Both AChE-R and AChE-S splice variants as well as several heavier AChE complexes were detected in brain homogenates from the parietal cortex of patients with or without Alzheimer's disease (AD) as well as the cerebrospinal fluid (CSF) of AD patients, compatible with the assumption that CSF AChEs might originate from CNS neurons. Long-term changes in the composition of CSF AChE variants were further pursued in AD patients treated with rivastigmine (n = 11) or tacrine (n = 17) in comparison to untreated AD patients (n = 5). In untreated patients, AChE-R was markedly reduced as compared with the baseline level (37%), whereas the medium size AChE-S complex was increased by 32%. Intriguingly, tacrine produced a general and profound up-regulation of all detected AChE variants (up to 117%), whereas rivastigmine treatment caused a mild and selective up-regulation of AChE-R ( approximately 10%, p < 0.05). Moreover, the change in the ratio of AChE-R to AChE-S (R/S-ratio) strongly and positively correlated with sustained cognition at 12 months (p < 0.0001). Thus, evaluation of changes in the composition of CSF AChE variants may yield important information referring to the therapeutic efficacy and/or development of drug tolerance in AD patients treated with anti-cholinesterases.
ESTHER : Darreh-Shori_2004_J.Neurochem_88_1102
PubMedSearch : Darreh-Shori_2004_J.Neurochem_88_1102
PubMedID: 15009666

Title : Excessive expression of acetylcholinesterase impairs glutamatergic synaptogenesis in hippocampal neurons - Dong_2004_J.Neurosci_24_8950
Author(s) : Dong H , Xiang YY , Farchi N , Ju W , Wu Y , Chen L , Wang Y , Hochner B , Yang B , Soreq H , Lu WY
Ref : Journal of Neuroscience , 24 :8950 , 2004
Abstract : Acetylcholinesterase (AChE) exerts noncatalytic activities on neural cell differentiation, adhesion, and neuritogenesis independently of its catalytic function. The noncatalytic functions of AChE have been attributed to its peripheral anionic site (PAS)-mediated protein-protein interactions. Structurally, AChE is highly homologous to the extracellular domain of neuroligin, a postsynaptic transmembrane molecule that interacts with presynaptic beta-neurexins, thus facilitating synaptic formation and maturation. Potential effects of AChE expression on synaptic transmission, however, remain unknown. Using electrophysiology, immunocytochemistry, and molecular biological approaches, this study investigated the role of AChE in the regulation of synaptic formation and functions. We found that AChE was highly expressed in cultured embryonic hippocampal neurons at early culture days, particularly in dendritic compartments including the growth cone. Subsequently, the expression level of AChE declined, whereas synaptic activity and synaptic proteins progressively increased. Chronic blockade of the PAS of AChE with specific inhibitors selectively impaired glutamatergic functions and excitatory synaptic structures independently of cholinergic activation, while inducing AChE overexpression. Moreover, the PAS blockade-induced glutamatergic impairments were associated with a depressed expression of beta-neurexins and an accumulation of other synaptic proteins, including neuroligins, and were mostly preventable by antisense suppression of AChE expression. Our findings demonstrate that interference with the nonenzymatic features of AChE alters AChE expression, which impairs excitatory synaptic structure and functions.
ESTHER : Dong_2004_J.Neurosci_24_8950
PubMedSearch : Dong_2004_J.Neurosci_24_8950
PubMedID: 15483114

Title : The role of readthrough acetylcholinesterase in the pathophysiology of myasthenia gravis - Brenner_2003_Faseb.J_17_214
Author(s) : Brenner T , Hamra-Amitay Y , Evron T , Boneva N , Seidman S , Soreq H
Ref : FASEB Journal , 17 :214 , 2003
Abstract : Alternative splicing induces, under abnormal cholinergic neurotransmission, overproduction of the rare "readthrough" acetylcholinesterase variant AChE-R. We explored the pathophysiological relevance of this phenomenon in patients with myasthenia gravis (MG) and rats with experimental autoimmune MG (EAMG), neuromuscular junction diseases with depleted acetylcholine receptors. In MG and EAMG, we detected serum AChE-R accumulation. In EAMG, we alleviated electromyographic abnormalities by nanomolar doses of EN101, an antisense oligonucleotide that selectively lowers AChE-R in blood and muscle yet leaves unaffected the synaptic variant AChE-S. Whereas animals treated with placebo or conventional anticholinesterases continued to deteriorate, a 4 wk daily oral administration of EN101 improved survival, neuromuscular strength and clinical status in moribund EAMG rats. The efficacy of targeting only one AChE splicing variant highlights potential advantages of mRNA-targeted therapeutics for chronic cholinergic malfunctioning.
ESTHER : Brenner_2003_Faseb.J_17_214
PubMedSearch : Brenner_2003_Faseb.J_17_214
PubMedID: 12554700

Title : Chronic acetylcholinesterase overexpression induces multilevelled aberrations in mouse neuromuscular physiology - Farchi_2003_J.Physiol_546_165
Author(s) : Farchi N , Soreq H , Hochner B
Ref : Journal de Physiologie , 546 :165 , 2003
Abstract : Chronic overexpression of the acetylcholine-hydrolysing enzyme acetylcholinesterase (AChE) is a notable consequence of exposure to anticholinesterase drugs or poisons. However, the physiological consequences for the resultant neuromuscular disfunction have not yet been carefully analysed. Here we report detailed dissection of the different components of neuromuscular function in transgenic mice previously shown to display motor fatigue and altered muscle morphology as a consequence of neuronal overexpression of AChE-S, the synaptic AChE variant. Transgenic diaphragm muscle presented exaggerated fatigue as a combined consequence of neurotransmission fading and muscle mechanical malfunctioning. In a tetanic stimulation protocol, transgenic muscles rapidly fatigued to a larger extent than wild-type muscles, when stimulated either directly or via the phrenic nerve. AChE overexpression involved moderate but significant aberrations of synaptic transmission with higher quantal content (measured at 0.2 mM Ca(2+), 2.3 mM Mg(2+)). Furthermore, treatment with the anti-cholinesterase physostigmine revealed a higher amplitude and half-decay time of the transgenic quantal postsynaptic response. Our observations imply that elevated levels of neuronal AChE-S are expected to cause muscle exhaustion due to a combination of modest, multilevelled aberrations in synaptic transmission, muscle function and morphology.
ESTHER : Farchi_2003_J.Physiol_546_165
PubMedSearch : Farchi_2003_J.Physiol_546_165
PubMedID: 12509486

Title : Endotoxin-induced changes in human working and declarative memory associate with cleavage of plasma readthrough acetylcholinesterase - Cohen_2003_J.Mol.Neurosci_21_199
Author(s) : Cohen O , Reichenberg A , Perry C , Ginzberg D , Pollmacher T , Soreq H , Yirmiya R
Ref : Journal of Molecular Neuroscience , 21 :199 , 2003
Abstract : Endotoxin stimulation of the immune system produces marked alterations in memory functioning. However, molecular links between this cognitive response and infection-responding neurotransmission pathways are still unknown. The cytokine and memory responses of volunteers injected with 0.8 ng/kg Salmonella endotoxin were compared with changes in plasma levels and integrity of the stress-induced acetylcholinesterase variant, AChE-R. Vascular endothelial cells were found to express AChE-R messenger RNA and protein both in healthy and inflamed human tissues. Plasma AChE activity was reduced after endotoxin treatment, but not placebo treatment, parallel to the decline in cortisol after the endotoxin-induced peak and inversely to the accumulation of a C-terminal immunopositive AChE-R peptide of 36 amino acid residues. AChE-R cleavage coincided with significant endotoxin-induced improvement in working memory and impairment in declarative memory. By 3 h posttreatment, working memory improvement was negatively correlated with AChE-R cleavage, which showed association to proinflammatory cytokine levels. By 9 h posttreatment, declarative memory impairment was negatively correlated with AChE-R cleavage and positively correlated with the suppressed AChE activity. Endotoxin-induced peripheral cholinergic stress responses are hence associated with greater impairment in declarative memory and lower improvement in working memory, pointing at AChE-R as a surrogate marker of psychoneuroimmunological stress.
ESTHER : Cohen_2003_J.Mol.Neurosci_21_199
PubMedSearch : Cohen_2003_J.Mol.Neurosci_21_199
PubMedID: 14645987

Title : Acetylcholinesterase promotes beta-amyloid plaques in cerebral cortex - Rees_2003_Neurobiol.Aging_24_777
Author(s) : Rees TM , Hammond PI , Soreq H , Younkin S , Brimijoin S
Ref : Neurobiology of Aging , 24 :777 , 2003
Abstract : Studies in vitro have suggested that acetylcholinesterase (AChE) may interact with beta-amyloid to promote deposition of amyloid plaques in the brain of patients with Alzheimer's disease. To test that hypothesis in vivo, we crossed Tg2576 mice, which express human amyloid precursor protein and develop plaques at 9 months, with transgenic mice expressing human AChE. The resulting F1 hybrids (FVB/N x [C57B6 x SJL/J]) expressed both transgenes in brain. By 6 months of age, their cerebral cortex showed authentic plaques that stained both by thioflavin S and by beta-amyloid 1-40 and 1-42 immunohistochemistry. The plaques also stained positively for other components including Cd11b, GFAP, and AChE. Plaque onset in the hybrids occurred 30-50% sooner than in the parental lines. Plaque numbers increased with age and plaques remained more numerous in the doubly transgenic animals at 9 and 12 months. Quantitative immunoassay via ELISA also showed an increase of total amyloid content in brain at 9-12 months. These histological and biochemical results support the conclusion that AChE may play a role in pathogenesis of Alzheimer's disease
ESTHER : Rees_2003_Neurobiol.Aging_24_777
PubMedSearch : Rees_2003_Neurobiol.Aging_24_777
PubMedID: 12927760

Title : Interaction of readthrough acetylcholinesterase with RACK1 and PKCbeta II correlates with intensified fear-induced conflict behavior - Birikh_2003_Proc.Natl.Acad.Sci.U.S.A_100_283
Author(s) : Birikh KR , Sklan EH , Shoham S , Soreq H
Ref : Proceedings of the National Academy of Sciences of the United States of America , 100 :283 , 2003
Abstract : Behavioral reactions to stress are altered in numerous psychiatric and neurodegenerative syndromes, but the corresponding molecular processes and signal transduction pathways are yet unknown. Here, we report that, in mice, the stress-induced splice variant of acetylcholinesterase, AChE-R, interacts intraneuronally with the scaffold protein RACK1 and through it, with its target, protein kinase CbetaII (PKCbetaII), which is known to be involved in fear conditioning. In stress-responsive brain regions of normal FVBN mice, the mild stress of i.p. injection increased AChE and PKCbetaII levels in a manner suppressible by antisense prevention of AChE-R accumulation. Injection stress also prolonged conflict between escape and hiding in the emergence into an open field test. Moreover, transgenic FVBN mice overexpressing AChE-R displayed prolonged delay to emerge into another field (fear-induced behavioral inhibition), associated with chronically intensified neuronal colabeling of RACK1 and PKCbetaII in stress-responsive brain regions. These findings are consistent with the hypothesis that stress-associated changes in cholinergic gene expression regulate neuronal PKCbetaII functioning, promoting fear-induced conflict behavior after stress.
ESTHER : Birikh_2003_Proc.Natl.Acad.Sci.U.S.A_100_283
PubMedSearch : Birikh_2003_Proc.Natl.Acad.Sci.U.S.A_100_283
PubMedID: 12509514

Title : Complex regulation of acetylcholinesterase gene expression in human brain tumors - Perry_2002_Oncogene_21_8428
Author(s) : Perry C , Sklan EH , Birikh KR , Shapira M , Trejo L , Eldor A , Soreq H
Ref : Oncogene , 21 :8428 , 2002
Abstract : To study the regulation of acetylcholinesterase (AChE) gene expression in human brain tumors, 3' splice variants of AChE mRNA and potentially relevant transcription factor mRNAs were labeled in primary astrocytomas and melanomas. AChE-S and AChE-R mRNA, as well as Runx1/AML1 mRNA accumulated in astrocytomas in correlation with tumor aggressiveness, but neither HNF3beta nor c-fos mRNA was observed in melanoma and astrocytomas. Immunohistochemistry demonstrated nuclear Runx1/AML1 and cellular AChE-S and AChE-R in melanomas, however, only AChE-S, and not the secreted AChE-R variant, was retained in astrocyte tumor cells. Runx1/AML1 revealed weak linkage with ACHE promoter sequences, yet enhanced ACHE gene expression in co-transfected COS1 cells. The p300 co-activator and the ACHE promoter's distal enhancer facilitated this effect, which was independent of much of the Runx1/AML1 trans-activation domain. Surprisingly, GASP, a fusion product of green fluorescence protein (GFP) and ASP(67), a peptide composed of the 67 C-terminal amino acid residues of AChE-S, localized to COS1 cell nuclei. However, GARP, the corresponding fusion product of GFP with a peptide having the 51 C-terminal residues of AChE-E or GFP alone, remained cytoplasmic. Runx1/AML1 exhibited improved nuclear retention in GASP-expressing COS1 cells, suggesting modulated nuclear localization processes. Together, these findings reveal brain tumor-specific regulation of both expression and cellular retention of variant ACHE gene products.
ESTHER : Perry_2002_Oncogene_21_8428
PubMedSearch : Perry_2002_Oncogene_21_8428
PubMedID: 12466963

Title : Sustained cholinesterase inhibition in AD patients receiving rivastigmine for 12 months - Darreh-Shori_2002_Neurology_59_563
Author(s) : Darreh-Shori T , Almkvist O , Guan ZZ , Garlind A , Strandberg B , Svensson AL , Soreq H , Hellstrom-Lindahl E , Nordberg A
Ref : Neurology , 59 :563 , 2002
Abstract : OBJECTIVE: To study the long-term dual inhibitory effects of rivastigmine on acetylcholinesterase (AChE) and butyrylcholinesterase (BCHE) in patients with AD.
METHODS: Eleven patients with mild AD received rivastigmine for 12 months. Cholinesterase (ChE) activities in the CSF and plasma were assessed colorimetrically. Immunoblot analysis was used to evaluate AChE isoforms. Neuropsychiatric tests were performed throughout the study.
RESULTS: At 12 months, the mean dose of rivastigmine was 8.6 mg/d and specific activities of ChE in the CSF were lower than baseline values (by 36% for AChE and 45% for BCHE), correlating with parallel reductions in the plasma (27% for AChE and 33% for BCHE). The reduction of specific activities in the CSF, but not in the plasma, appeared to be dependent on the dose and duration of treatment. Scores of some of the neuropsychological tests associated with memory and attention were correlated with both plasma and CSF AChE and BCHE inhibition for up to 6 months. Immunoblot analysis revealed up-regulation of the "read-through" AChE isoform (AChE-R), whereas levels of the synaptic isoform were unchanged.
CONCLUSIONS: Rivastigmine causes persistent inhibition of AChE and BCHE in CSF as well as plasma. The persistent CSF inhibition contrasts with earlier findings after long-term treatment by the reversible ChE inhibitor tacrine, which demonstrated increased AChE activity in the CSF but not in the blood. Rivastigmine's effects on the preferential up-regulation of the AChE-R isoform may have a favorable effect on disease stabilization.
ESTHER : Darreh-Shori_2002_Neurology_59_563
PubMedSearch : Darreh-Shori_2002_Neurology_59_563
PubMedID: 12196650

Title : Upregulation of neuronal nicotinic receptor subunits alpha4, beta2, and alpha7 in transgenic mice overexpressing human acetylcholinesterase - Svedberg_2002_J.Mol.Neurosci_18_211
Author(s) : Svedberg MM , Svensson AL , Johnson M , Lee M , Cohen O , Court J , Soreq H , Perry E , Nordberg A
Ref : Journal of Molecular Neuroscience , 18 :211 , 2002
Abstract : Neuronal nicotinic receptor binding sites as well as mRNA levels encoding for subunits alpha4, beta2, and alpha7 were analysed in 3-mo-old transgenic mice generated with a neuronal overexpression of human acetylcholinesterase and in age-matched controls. The acetylcholinesterase transgenic mice display progressive cognitive impairment in spatial learning and memory. We here report a significantly increased [3H]epibatidine and [125I]alphabungarotoxin binding in the cortex and the caudate putamen of these mice. Quantitativein situ hybridization showed significant upregulation of mRNA corresponding to the nicotinic receptor subunits alpha4, beta2, and alpha7 in various brain regions in the transgenic mice compared to nontransgenic controls. Our results suggest that disruption of balanced cholinergic transmission by constitutive overexpression of acetylcholinesterase is accompanied by variable upregulation of several nicotinic receptor subtypes, in particular these associated with cholinergic terminals participating in compensatory response.
ESTHER : Svedberg_2002_J.Mol.Neurosci_18_211
PubMedSearch : Svedberg_2002_J.Mol.Neurosci_18_211
PubMedID: 12059039

Title : Alternative splicing and neuritic mRNA translocation under long-term neuronal hypersensitivity - Meshorer_2002_Science_295_508
Author(s) : Meshorer E , Erb C , Gazit R , Pavlovsky L , Kaufer D , Friedman A , Glick D , Ben-Arie N , Soreq H
Ref : Science , 295 :508 , 2002
Abstract : To explore neuronal mechanisms underlying long-term consequences of stress we studied stress-induced changes in the neuritic translocation of acetylcholinesterase AChE splice variants Under normal conditions we found the synaptic AChE-S mRNA and protein in neurites Corticosterone anticholinesterases and forced swim each facilitated a rapid minutes yet long-lasting weeks shift from AChE-S to the normally rare AChE-R mRNA promoted AChE-R mRNA translocation into neurites and induced enzyme secretion Weeks after stress electrophysiological measurements in hippocampus slices displayed apparently normal evoked synaptic responses but extreme hypersensitivity to both anticholinesterases and atropine Our findings suggest that neuronal hypersensitivity under stress involves neuritic replacement of AChE-S with AChE-R
ESTHER : Meshorer_2002_Science_295_508
PubMedSearch : Meshorer_2002_Science_295_508
PubMedID: 11799248

Title : The stress-associated acetylcholinesterase variant AChE-R is expressed in human CD34(+) hematopoietic progenitors and its C-terminal peptide ARP promotes their proliferation - Deutsch_2002_Exp.Hematol_30_1153
Author(s) : Deutsch V , Pick M , Perry C , Grisaru D , Hemo Y , Golan-Hadari D , Grant A , Eldor A , Soreq H
Ref : Experimental Hematology , 30 :1153 , 2002
Abstract : Hematopoietic stress responses involve increases in leukocyte and platelet counts, implying the existence of stress responsive factors that modulate hematopoiesis. Acetylcholinesterase (AChE) is expressed in mammalian neurons and hematopoietic cells. In brain, it responds to stress by mRNA overexpression and alternative splicing, yielding the rare stress-associated "readthrough" AChE-R variant protein. This led us to explore the hematopoietic involvement of AChE-R and its cleavable C-terminal peptide ARP. MATERIALS AND METHODS: AChE mRNA variants were labeled in CD34(+) hematopoietic progenitor cells by in situ hybridization. ARP expression was detected by multicolor flow cytometry. Bromo-deoxyuracil incorporation and viable cell counts served to evaluate the proliferative effects of ARP and suppressive effects of the AChE antisense oligonucleotide AS1 on CD34(+) cells. RESULTS: The distal enhancer, proximal promoter, and first intron of the human AChE gene include consensus binding sites for hematopoietically active and stress-induced transcription factors. CD34(+) cells from human cord blood were found to express all three variant AChE mRNAs, having different intracellular distributions. ARP was found in 5 to 15% of adult peripheral blood, bone marrow, and fetal CD34(+) cells (both committed CD38(+) and uncommitted CD38(-)) and in acute myeloid leukemia blasts. Externally supplied ARP by itself facilitated the proliferation of CD34(+) cells in an antisense suppressible manner. When combined with early-acting cytokines, ARP enhanced survival and expansion of CD34(+) cells up to 28 days in culture.
CONCLUSIONS: Our findings support ARP, the C-terminal peptide of AChE-R, as a new hematopoietic growth factor that may promote the myelopoietic expansion and thrombopoiesis characteristic of stress and may be used to enhance the efficiency of ex vivo expansion for bone marrow transplantation.
ESTHER : Deutsch_2002_Exp.Hematol_30_1153
PubMedSearch : Deutsch_2002_Exp.Hematol_30_1153
PubMedID: 12384146

Title : Neuronal overexpression of 'readthrough' acetylcholinesterase is associated with antisense-suppressible behavioral impairments - Cohen_2002_Mol.Psychiatry_7_874
Author(s) : Cohen O , Erb C , Ginzberg D , Pollak Y , Seidman S , Shoham S , Yirmiya R , Soreq H
Ref : Mol Psychiatry , 7 :874 , 2002
Abstract : Molecular origin(s) of the diverse behavioral responses to anticholinesterases were explored in behaviorally impaired transgenic (Tg) FVB/N mice expressing synaptic human acetylcholinesterase (hAChE-S). Untreated hAChE-S Tg, unlike nave FVB/N mice, presented variably intense neuronal overexpression of the alternatively spliced, stress-induced mouse "readthrough" mAChE-R mRNA. Both strains displayed similar diurnal patterns of locomotor activity that were impaired 3 days after a day-to-night switch. However, hAChE-S Tg, but not FVB/N mice responded to the circadian switch with irregular, diverse bursts of increased locomotor activity. In social recognition tests, controls displayed short-term recognition, reflected by decreased exploration of a familiar, compared to a novel juvenile conspecific as well as inverse correlation between social recognition and cortical and hippocampal AChE specific activities. In contrast, transgenics presented poor recognition, retrievable by tetrahydroaminoacridine (tacrine, 1.5 mg kg(-1)). Tacrine's effect was short-lived (24 h) suppression of the abnormal social recognition pattern in transgenics. Efficacy of antisense treatment was directly correlated with AChE-R levels and the severity of the impaired phenotype, being most apparent in transgenics presenting highly abnormal pre-treatment behavior. These findings demonstrate that neuronal AChE-R overproduction is involved in various behavioral impairments and anticholinesterase responses, and point to the antisense strategy as a potential approach for re-establishing cholinergic balance.
ESTHER : Cohen_2002_Mol.Psychiatry_7_874
PubMedSearch : Cohen_2002_Mol.Psychiatry_7_874
PubMedID: 12232781

Title : Development of human antibody fragments directed towards synaptic acetylcholinesterase using a semi-synthetic phage display library - Flores-Flores_2002_J.Neural.Transm.Suppl_62_165
Author(s) : Flores-Flores C , Nissim A , Shochat S , Soreq H
Ref : J Neural Transm Suppl , 62 :165 , 2002
Abstract : Current Alzheimer's disease therapies suppress acetylcholine hydrolysis by inhibiting acetylcholinesterase (AChE) at cholinergic synapses. However, anticholinesterases promote alternative splicing changing the composition of brain AChE variants. To study this phenomenon we developed monoclonal antibodies to acetylcholinesterase synaptic peptide (ASP), a synthetic peptide with the C-terminal sequence unique to the human synaptic variant AChE-S. Screening of a phage display human antibody library allowed the isolation of single-chain Fv (scFv) antibodies that were highly specific for ASP, and displayed closely related third complementarity determining regions of the variable heavy chain domain (V(H)-CDR3). BIAcore analysis demonstrated dissociation constants at the micromolar range: 1.6 x 10(-6) and 2.0 x 10(-6) M for ASP and the complete AChE-S protein, respectively. The anti-ASP antibodies provide a novel tool for studying the synaptic AChE-S variant, the expression of which is altered in ageing and dementia.
ESTHER : Flores-Flores_2002_J.Neural.Transm.Suppl_62_165
PubMedSearch : Flores-Flores_2002_J.Neural.Transm.Suppl_62_165
PubMedID: 12456061

Title : Expression of recombinant human acetylcholinesterase in transgenic tomato plants - Mor_2001_Biotechnol.Bioeng_75_259
Author(s) : Mor TS , Sternfeld M , Soreq H , Arntzen CJ , Mason HS
Ref : Biotechnol Bioeng , 75 :259 , 2001
Abstract : Enzyme therapy for the prevention and treatment of organophosphate poisoning depends on the availability of large amounts of cholinesterases. Transgenic plants are being evaluated for their efficiency and cost-effectiveness as a system for the bioproduction of therapeutically valuable proteins. Here we report production of a recombinant isoform of human acetylcholinesterase in transgenic tomato plants. Active and stable acetylcholinesterase, which retains the kinetic characteristics of the human enzyme, accumulated in tomato plants. High levels of specific activity were registered in leaves (up to 25 nmol min(-1) mg protein(-1)) and fruits (up to 250 nmol min(-1) mg protein(-1)).
ESTHER : Mor_2001_Biotechnol.Bioeng_75_259
PubMedSearch : Mor_2001_Biotechnol.Bioeng_75_259
PubMedID: 11590598

Title : Complex host cell responses to antisense suppression of ACHE gene expression - Galyam_2001_Antisense.Nucleic.Acid.Drug.Dev_11_51
Author(s) : Galyam N , Grisaru D , Grifman M , Melamed-Book N , Eckstein F , Seidman S , Eldor A , Soreq H
Ref : Antisense Nucleic Acid Drug Dev , 11 :51 , 2001
Abstract : 3'-End-capped, 20-mer antisense oligodeoxynucleotides (AS-ODN) protected with 2'-O-methyl (Me) or phosphorothioate (PS) substitutions were targeted to acetylcholinesterase (AChE) mRNA and studied in PC12 cells. Me-modified AS-ODN suppressed AChE activity up to 50% at concentrations of 0.02-100 nM. PS-ODN was effective at 1-100 nM. Both AS-ODN displayed progressively decreased efficacy above 10 nM. In situ hybridization and confocal microscopy demonstrated dose-dependent decreases, then increases, in AChE mRNA. Moreover, labeling at nuclear foci suggested facilitated transcription or stabilization of AChE mRNA or both under AS-ODN. Intracellular concentrations of biotinylated oligonucleotide equaled those of target mRNA at extracellular concentrations of 0.02 nM yet increased only 6-fold at 1 microM ODN. Above 50 nM, sequence-independent swelling of cellular, but not nuclear, volume was observed. Our findings demonstrate suppressed AChE expression using extremely low concentrations of AS-ODN and attribute reduced efficacy at higher concentrations to complex host cell feedback responses.
ESTHER : Galyam_2001_Antisense.Nucleic.Acid.Drug.Dev_11_51
PubMedSearch : Galyam_2001_Antisense.Nucleic.Acid.Drug.Dev_11_51
PubMedID: 11258621

Title : Frequent blood-brain barrier disruption in the human cerebral cortex - Tomkins_2001_Cell.Mol.Neurobiol_21_675
Author(s) : Tomkins O , Kaufer D , Korn A , Shelef I , Golan H , Reichenthal E , Soreq H , Friedman A
Ref : Cellular Molecular Neurobiology , 21 :675 , 2001
Abstract : 1. The blood-brain barrier (BBB) protects the brain from circulating xenobiotic agents. The pathophysiology, time span, spatial pattern, and pathophysiological consequences of BBB disruptions are not known. 2. Here, we report the quantification of BBB disruption by measuring enhancement levels in computerized tomography brain images. 3. Pathological diffuse enhancement associated with elevated albumin levels in the cerebrospinal fluid (CSF) was observed in the cerebral cortex of 28 out of 43 patients, but not in controls. Four patients displayed weeks-long focal BBB impairment. In 19 other patients, BBB disruption was significantly associated with elevated blood pressure, body temperature, serum cortisol, and stress-associated CSF 'readthrough" acetylcholinesterase. Multielectrode electroencephalography revealed enhanced slow-wave activities in areas of focal BBB disruption. Thus, quantification of BBB disruption using minimally invasive procedures, demonstrated correlations with molecular, clinical, and physiological stress-associated indices. 4. These sequelae accompany a wide range of neurological disorders, suggesting that persistent, detrimental BBB disruption is considerably more frequent than previously assumed.
ESTHER : Tomkins_2001_Cell.Mol.Neurobiol_21_675
PubMedSearch : Tomkins_2001_Cell.Mol.Neurobiol_21_675
PubMedID: 12043841

Title : Changes in neuronal acetylcholinesterase gene expression and division of labor in honey bee colonies - Shapira_2001_J.Mol.Neurosci_17_1
Author(s) : Shapira M , Thompson CK , Soreq H , Robinson GE
Ref : Journal of Molecular Neuroscience , 17 :1 , 2001
Abstract : Division of labor in honey bee colonies is highlighted by adult bees making a transition at 2-3 wk of age from working in the hive to foraging for nectar and pollen outside. This behavioral development involves acquisition of new tasks that may require advanced learning capabilities. Because acetylcholinesterase (AChE) hydrolyzes acetylcholine, a major neurotransmitter associated with learning in the insect brain, we searched for changes in AChE expression in the brain during bee behavioral development. Biochemical aspects of the AChE protein were similar in foragers and "nurse" bees that work in the hive tending brood. However, catalytic AChE activity was significantly lower in foragers. Cloning of bee AChE cDNA enabled mRNA analysis, which demonstrated that the forager-related decrease in AChE activity was associated with decreased AChE mRNA levels. This was particularly apparent in the mushroom bodies, a brain region known to be involved with olfactory and visual learning and memory. In addition, treatment with the AChE-inhibitor metrifonate improved performance in an olfactory-learning assay. These findings demonstrate long-term, naturally occurring developmental downregulation of AChE gene expression in the bee brain, and suggest that this genomic plasticity can contribute to facilitated learning capabilities in forager bees.
ESTHER : Shapira_2001_J.Mol.Neurosci_17_1
PubMedSearch : Shapira_2001_J.Mol.Neurosci_17_1
PubMedID: 11665858
Gene_locus related to this paper: apime-ACHE , apime-a0a087zxf6

Title : Acetylcholinesterase--new roles for an old actor - Soreq_2001_Nat.Rev.Neurosci_2_294
Author(s) : Soreq H , Seidman S
Ref : Nat Rev Neurosci , 2 :294 , 2001
Abstract : The discovery of the first neurotransmitter--acetylcholine--was soon followed by the discovery of its hydrolysing enzyme, acetylcholinesterase. The role of acetylcholinesterase in terminating acetylcholine-mediated neurotransmission made it the focus of intense research for much of the past century. But the complexity of acetylcholinesterase gene regulation and recent evidence for some of the long-suspected 'non-classical' actions of this enzyme have more recently driven a profound revolution in acetylcholinesterase research. Although our understanding of the additional roles of acetylcholinesterase is incomplete, the time is ripe to summarize the evidence on a remarkable diversity of acetylcholinesterase functions.
ESTHER : Soreq_2001_Nat.Rev.Neurosci_2_294
PubMedSearch : Soreq_2001_Nat.Rev.Neurosci_2_294
PubMedID: 11283752

Title : Genomic dissection reveals locus response to stress for mammalian acetylcholinesterase - Grant_2001_Cell.Mol.Neurobiol_21_783
Author(s) : Grant AD , Shapira M , Soreq H
Ref : Cellular Molecular Neurobiology , 21 :783 , 2001
Abstract : The mammalian acetylcholinesterase (ACHE) locus was investigated using computational predictive methods and experiments of reverse transcription polymerase chain reaction (RT-PCR). Computational analysis identified two genes downstream to ACHE, an inversely oriented arsenite resistance gene homologue (ARS), and a novel previously unidentified gene (PIX), co-oriented with ACHE. Experimental evidence shows coregulation of murine ACHE and ARS following confined swim, indicating coordinated locus response to stress, that is possibly mediated by altered cholinergic neurotransmission.
ESTHER : Grant_2001_Cell.Mol.Neurobiol_21_783
PubMedSearch : Grant_2001_Cell.Mol.Neurobiol_21_783
PubMedID: 12043848

Title : Compensatory mechanisms enhance hippocampal acetylcholine release in transgenic mice expressing human acetylcholinesterase - Erb_2001_J.Neurochem_77_638
Author(s) : Erb C , Troost J , Kopf S , Schmitt U , Loffelholz K , Soreq H , Klein J
Ref : Journal of Neurochemistry , 77 :638 , 2001
Abstract : Central cholinergic neurotransmission was studied in learning-impaired transgenic mice expressing human acetylcholinesterase (hAChE-Tg). Total catalytic activity of AChE was approximately twofold higher in synaptosomes from hippocampus, striatum and cortex of hAChE-Tg mice as compared with controls (FVB/N mice). Extracellular acetylcholine (ACh) levels in the hippocampus, monitored by microdialysis in the absence or presence of 10(-8)-10(-3) M neostigmine in the perfusion fluid, were indistinguishable in freely moving control and hAChE-Tg mice. Muscarinic receptor functions were unchanged as indicated by similar effects of scopolamine on ACh release and of carbachol on inositol phosphate formation. However, when the mice were anaesthetized with halothane (0.8 vol. %), hippocampal ACh reached significantly lower levels in AChE-Tg mice as compared with controls. Also, the high-affinity choline uptake (HACU) in hippocampal synaptosomes from awake hAChE-Tg mice was accelerated but was reduced by halothane anaesthesia. Moreover, hAChE-Tg mice displayed increased motor activity in novel but not in familiar environment and presented reduced anxiety in the elevated plus-maze test. Systemic application of a low dose of physostigmine (100 microgram/kg i.p.) normalized all of the enhanced parameters in hAChE-Tg mice: spontaneous motor activity, hippocampal ACh efflux and hippocampal HACU, attributing these parameters to the hypocholinergic state due to excessive AChE activity. We conclude that, in hAChE-Tg mice, hippocampal ACh release is up-regulated in response to external stimuli thereby facilitating cholinergic neurotransmission. Such compensatory phenomena most likely play important roles in counteracting functional deficits in mammals with central cholinergic dysfunctions.
ESTHER : Erb_2001_J.Neurochem_77_638
PubMedSearch : Erb_2001_J.Neurochem_77_638
PubMedID: 11299326

Title : Modified testicular expression of stress-associated readthrough acetylcholinesterase predicts male infertility - Mor_2001_Faseb.J_15_2039
Author(s) : Mor I , Grisaru D , Titelbaum L , Evron T , Richler C , Wahrman J , Sternfeld M , Yogev L , Meiri N , Seidman S , Soreq H
Ref : FASEB Journal , 15 :2039 , 2001
Abstract : Male infertility is often attributed to stress. However, the protein or proteins that mediate stress-related infertility are not yet known. Overexpression of the "readthrough" variant of acetylcholinesterase (AChE-R) is involved in the cellular stress response in a variety of mammalian tissues. Here, we report testicular overexpression of AChE-R in heads, but not tails, of postmeiotic spermatozoa from mice subjected to a transient psychological stress compared with age-matched control mice. Transgenic mice overexpressing AChE-R displayed reduced sperm counts, decreased seminal gland weight, and impaired sperm motility compared with age-matched nontransgenic controls. AChE-R was prominent in meiotic phase spermatocytes and in tails, but not heads, of testicular spermatozoa from AChE-R transgenic mice. Head-localized AChE-R was characteristic of human sperm from fertile donors. In contrast, sperm head AChE-R staining was conspicuously reduced in samples from human couples for whom the cause of infertility could not be determined, similar to the pattern found in transgenic mice. These findings indicate AChE-R involvement in impaired sperm quality, which suggests that it is a molecular marker for stress-related infertility.
ESTHER : Mor_2001_Faseb.J_15_2039
PubMedSearch : Mor_2001_Faseb.J_15_2039
PubMedID: 11511515

Title : A transcription-activating polymorphism in the ACHE promoter associated with acute sensitivity to anti-acetylcholinesterases - Shapira_2000_Hum.Mol.Genet_9_1273
Author(s) : Shapira M , Tur-Kaspa I , Bosgraaf L , Livni N , Grant AD , Grisaru D , Korner M , Ebstein RP , Soreq H
Ref : Hum Mol Genet , 9 :1273 , 2000
Abstract : Hypersensitivity to acetylcholinesterase inhibitors (anti-AChEs) causes severe nervous system symptoms under low dose exposure. In search of direct genetic origin(s) for this sensitivity, we studied six regions in the extended 22 kb promoter of the ACHE gene in individuals who presented adverse responses to anti-AChEs and in randomly chosen controls. Two contiguous mutations, a T-->A substitution, disrupting a putative glucocorticoid response element, and a 4-bp deletion, abolishing one of two adjacent HNF3 binding sites, were identified 17 kb upstream of the transcription start site. Allele frequencies for these mutations were 0.006 and 0.012, respectively, in 333 individuals of various ethnic origins, with a strong linkage between the deletion and the biochemically neutral H322N mutation in the coding region of ACHE. Heterozygous carriers of the deletion included a proband who presented with acute hypersensitivity to the anti-AChE pyridostigmine and another with unexplained excessive vomiting during a fourth pregnancy following three spontaneous abortions. Electromobility shift assays, transfection studies and measurements of AChE levels in immortalized lymphocytes as well as in peripheral blood from both carriers and non-carriers, revealed functional relevance for this mutation both in vitro and in vivo and showed it to increase AChE expression, probably by alleviating competition between the two hepatocyte nuclear factor 3 binding sites. Moreover, AChE-overexpressing transgenic mice, unlike normal FVB/N mice, displayed anti-AChE hypersensitivity and failed to transcriptionally induce AChE production following exposure to anti-AChEs. Our findings point to promoter polymorphism(s) in the ACHE gene as the dominant susceptibility factor(s) for adverse responses to exposure or to treatment with anti-AChEs.
ESTHER : Shapira_2000_Hum.Mol.Genet_9_1273
PubMedSearch : Shapira_2000_Hum.Mol.Genet_9_1273
PubMedID: 10814709
Gene_locus related to this paper: human-ACHE

Title : Anti-sense approach to anticholinesterase therapeutics - Soreq_2000_Isr.Med.Assoc.J_2_81
Author(s) : Soreq H , Seidman S
Ref : Isr Med Assoc J , 2 :81 , 2000
Abstract : The acetylcholine-hydrolyzing enzyme, acetylcholinesterase, is the molecular target of approved drugs for Alzheimer's disease and myasthenia gravis. However, recent data implicate AChE splicing variants in the etiology of complex diseases such as AD and MG. Despite the large arsenal of anti-AChE drugs, therapeutic inhibitors are primarily targeted towards an active site shared by all variants. In contrast, anti-sense oligonucleotides attack unique mRNA sequences rather than tertiary protein structures. AS-ODNs thus offer a means to target gene expression in a highly discriminative manner using very low concentrations of drug. In light of the likely role(s) of specific AChE variants in various diseases affecting cholinergic neurotransmission, the potential contribution that anti-sense technology can make towards improved approaches to anti-AChE therapeutics deserves serious attention.
ESTHER : Soreq_2000_Isr.Med.Assoc.J_2_81
PubMedSearch : Soreq_2000_Isr.Med.Assoc.J_2_81
PubMedID: 10909423

Title : Excess read-through acetylcholinesterase attenuates but the synaptic variant intensifies neurodeterioration correlates - Sternfeld_2000_Proc.Natl.Acad.Sci.U.S.A_97_8647
Author(s) : Sternfeld M , Shoham S , Klein O , Flores-Flores C , Evron T , Idelson GH , Kitsberg D , Patrick JW , Soreq H
Ref : Proc Natl Acad Sci U S A , 97 :8647 , 2000
Abstract : Acute stress increases the risk for neurodegeneration, but the molecular signals regulating the shift from transient stress responses to progressive disease are not yet known. The "read-through" variant of acetylcholinesterase (AChE-R) accumulates in the mammalian brain under acute stress. Therefore, markers of neurodeterioration were examined in transgenic mice overexpressing either AChE-R or the "synaptic" AChE variant, AChE-S. Several observations demonstrate that excess AChE-R attenuates, whereas AChE-S intensifies, neurodeterioration. In the somatosensory cortex, AChE-S transgenics, but not AChE-R or control FVB/N mice, displayed a high density of curled neuronal processes indicative of hyperexcitation. In the hippocampus, AChE-S and control mice, but not AChE-R transgenics, presented progressive accumulation of clustered, heat shock protein 70-immunopositive neuronal fragments and displayed a high incidence of reactive astrocytes. Our findings suggest that AChE-R serves as a modulator that may play a role in preventing the shift from transient, acute stress to progressive neurological disease.
ESTHER : Sternfeld_2000_Proc.Natl.Acad.Sci.U.S.A_97_8647
PubMedSearch : Sternfeld_2000_Proc.Natl.Acad.Sci.U.S.A_97_8647
PubMedID: 10890884

Title : Nicotinic receptor subtypes in human brain ageing, Alzheimer and Lewy body diseases - Perry_2000_Eur.J.Pharmacol_393_215
Author(s) : Perry E , Martin-Ruiz C , Lee M , Griffiths M , Johnson M , Piggott M , Haroutunian V , Buxbaum JD , Nasland J , Davis K , Gotti C , Clementi F , Tzartos SJ , Cohen O , Soreq H , Jaros E , Perry R , Ballard C , McKeith I , Court J
Ref : European Journal of Pharmacology , 393 :215 , 2000
Abstract : Human brain ageing is associated with reductions in a variety of nicotinic receptors subtypes, whereas changes in age-related disorders including Alzheimer's disease or Parkinson's disease are more selective. In Alzheimer's disease, in the cortex there is a selective loss of the alpha4 (but not alpha3 or 7) subunit immunoreactivity and of nicotine or epibatidine binding but not alpha-bungarotoxin binding. Epibatidine binding is inversely correlated with clinical dementia ratings and with the level of Abeta1-42, but not related to plaque or tangle densities. In contrast, alpha-bungarotoxin binding is positively correlated with plaque densities in the entorhinal cortex. In human temporal cortex loss of acetylcholinesterase catalytic activity is positively correlated with decreased epibatidine binding and in a transgenic mouse model over expressing acetylcholinesterase, epibatidine binding is elevated. In Parkinson's disease, loss of striatal nicotine binding appears to occur early but is not associated with a loss of alpha4 subunit immunoreactivity. Tobacco use in normal elderly individuals is associated with increased alpha4 immunoreactivity in the cortex and lower densities of amyloid-beta plaques, and with greater numbers of dopaminergic neurons in the substantia nigra pars compacta. These findings indicate an early involvement of the alpha4 subunit in beta-amyloidosis but not in nigro-striatal dopaminergic degeneration.
ESTHER : Perry_2000_Eur.J.Pharmacol_393_215
PubMedSearch : Perry_2000_Eur.J.Pharmacol_393_215
PubMedID: 10771016

Title : Antisense prevention of neuronal damages following head injury in mice - Shohami_2000_J.Mol.Med.(Berl)_78_228
Author(s) : Shohami E , Kaufer D , Chen Y , Seidman S , Cohen O , Ginzberg D , Melamed-Book N , Yirmiya R , Soreq H
Ref : J Mol Med (Berl) , 78 :228 , 2000
Abstract : Closed head injury (CHI) is an important cause of death among young adults and a prominent risk factor for nonfamilial Alzheimer's disease. Emergency intervention following CHI should therefore strive to improve survival, promote recovery, and prevent delayed neuropathologies. We employed high-resolution nonradioactive in situ hybridization to determine whether a single intracerebro-ventricular injection of 500 ng 2'-O-methyl RNA-capped antisense oligonucleotide (AS-ODN) against acetylcholinesterase (AChE) mRNA blocks overexpression of the stress-related readthrough AChE (AChE-R) mRNA splicing variant in head-injured mice. Silver-based Golgi staining revealed pronounced dendrite outgrowth in somatosensory cortex of traumatized mice 14 days postinjury that was associated with sites of AChE-R mRNA overexpression and suppressed by anti-AChE AS-ODNs. Furthermore, antisense treatment reduced the number of dead CA3 hippocampal neurons in injured mice, and facilitated neurological recovery as determined by performance in tests of neuromotor coordination. In trauma-sensitive transgenic mice overproducing AChE, antisense treatment reduced mortality from 50% to 20%, similar to that displayed by head-injured control mice. These findings demonstrate the potential of antisense therapeutics in treating acute injury, and suggest antisense prevention of AChE-R overproduction to mitigate the detrimental consequences of various traumatic brain insults.
ESTHER : Shohami_2000_J.Mol.Med.(Berl)_78_228
PubMedSearch : Shohami_2000_J.Mol.Med.(Berl)_78_228
PubMedID: 10933585

Title : Genomic and transcriptional characterization of the human ACHE locus: complex involvement with acquired and inherited diseases - Shapira_2000_Isr.Med.Assoc.J_2_470
Author(s) : Shapira M , Grant A , Korner M , Soreq H
Ref : Isr Med Assoc J , 2 :470 , 2000
Abstract : BACKGROUND: Abnormal levels of the acetylcholinesterase enzyme or aberrations involving the long arm of chromosome 7, harboring the ACHE gene at 7q22, occur in various diseases such as Alzheimer's, Parkinson's, and leukemias. However, the cause(s) of these abnormalities are still unknown. OBJECTIVE: To search for the genomic elements and transcriptional processes controlling ACHE gene expression and the plausible stability of its locus, by isolating, sequencing and characterizing the human (h)ACHE locus and its mRNA products.
METHODS: Three clones containing the ACHE gene were isolated from a human chromosome 7 cosmid library. Two of these clones were thereafter sequenced and searched for repetitive elements, open reading frames and corresponding expressed sequence tags. Reverse transcription-polymerase chain reaction was employed to further explore these findings.
RESULTS: The locus harboring the G,C-rich ACHE gene was found to be exceptionally rich in Alu repeats. It includes an additional, inversely oriented gene (ARS), tentatively associated with arsenite resistance. EST clones corresponding to both genes were found in cDNA libraries from 11 different human tissue sources, with ARS expressed in 10 additional tissues. Co-regulation of brain ACHE and ARS was suggested from their mutually increased expression following acute psychological stress.
CONCLUSIONS: The abundance of Alu retrotransposones may predispose the ACHE locus to chromosomal rearrangements. Additionally, coordinated transcriptional regulation is implied from the joint ARS-AChE expression in stress insult responses. Disease-related changes in AChE may therefore reflect locus-specific regulation mechanisms affecting multiple tissues.
ESTHER : Shapira_2000_Isr.Med.Assoc.J_2_470
PubMedSearch : Shapira_2000_Isr.Med.Assoc.J_2_470
PubMedID: 10897240

Title : Synaptogenesis and myopathy under acetylcholinesterase overexpression - Lev-Lehman_2000_J.Mol.Neurosci_14_93
Author(s) : Lev-Lehman E , Evron T , Broide RS , Meshorer E , Ariel I , Seidman S , Soreq H
Ref : Journal of Molecular Neuroscience , 14 :93 , 2000
Abstract : Environmental, congenital, and acquired immunological insults perturbing neuromuscular junction (NMJ) activity may induce a variety of debilitating neuromuscular pathologies. However, the molecular elements linking NMJ dysfunction to long-term myopathies are unknown. Here, we report dramatically elevated levels of mRNA encoding c-Fos and the "readthrough" (R) variant of acetylcholinesterase (AChE) in muscles of transgenic mice overexpressing synaptic (S) AChE in motoneurons and in control mice treated with the irreversible cholinesterase inhibitor diisopropylfluorophosphonate (DFP). Tongue muscles from DFP-treated and AChE-S transgenic mice displayed exaggerated neurite branching and disorganized, wasting fibers. Moreover, diaphragm muscles from both transgenic and DFP-treated mice exhibited NMJ proliferation. 2'-O-methyl-protected antisense oligonucleotides targeted to AChE mRNA suppressed feedback upregulation of AChE and ameliorated DFP-induced NMJ proliferation. Our findings demonstrate common transcriptional responses to cholinergic NMJ stress of diverse origin, and implicate deregulated AChE expression in excessive neurite outgrowth, uncontrolled synaptogenesis, and myopathology.
ESTHER : Lev-Lehman_2000_J.Mol.Neurosci_14_93
PubMedSearch : Lev-Lehman_2000_J.Mol.Neurosci_14_93
PubMedID: 10854041

Title : Human osteogenesis involves differentiation-dependent increases in the morphogenically active 3' alternative splicing variant of acetylcholinesterase - Grisaru_1999_Mol.Cell.Biol_19_788
Author(s) : Grisaru D , Lev-Lehman E , Shapira M , Chaikin E , Lessing JB , Eldor A , Eckstein F , Soreq H
Ref : Molecular & Cellular Biology , 19 :788 , 1999
Abstract : The extended human acetylcholinesterase (AChE) promoter contains many binding sites for osteogenic factors, including 1,25-(OH)2 vitamin D3 and 17beta-estradiol. In differentiating osteosarcoma Saos-2 cells, both of these factors enhanced transcription of the AChE mRNA variant 3' terminated with exon 6 (E6-AChE mRNA), which encodes the catalytically and morphogenically active E6-AChE isoform. In contrast, antisense oligodeoxynucleotide suppression of E6-AChE mRNA expression increased Saos-2 proliferation in a dose- and sequence-dependent manner. The antisense mechanism of action was most likely mediated by mRNA destruction or translational arrest, as cytochemical staining revealed reduction in AChE gene expression. In vivo, we found that E6-AChE mRNA levels rose following midgestation in normally differentiating, postproliferative fetal chondrocytes but not in the osteogenically impaired chondrocytes of dwarf fetuses with thanatophoric dysplasia. Taken together, these findings suggest morphogenic involvement of E6-AChE in the proliferation-differentiation balance characteristic of human osteogenesis.
ESTHER : Grisaru_1999_Mol.Cell.Biol_19_788
PubMedSearch : Grisaru_1999_Mol.Cell.Biol_19_788
PubMedID: 9858601

Title : Anticholinesterases induce multigenic transcriptional feedback response suppressing cholinergic neurotransmission - Kaufer_1999_Chem.Biol.Interact_119-120_349
Author(s) : Kaufer D , Friedman A , Seidman S , Soreq H
Ref : Chemico-Biological Interactions , 119-120 :349 , 1999
Abstract : Cholinesterase inhibitors (anti-ChEs) include a wide range of therapeutic, agricultural and warfare agents all aimed to inhibit the catalytic activity of the acetylcholine (ACh) hydrolysing enzyme acetylcholinesterase (AChE). In addition to promoting immediate excitation of cholinergic neurotransmission through transient elevation of synaptic ACh levels, anti-ChEs exposure is associated with long-term effects reminiscent of post-traumatic stress disorder. This suggested that exposure to anti-ChEs leads to persistent changes in brain proteins and called for exploring the mechanism(s) through which such changes could occur. For this purpose, we established an in vitro system of perfused, sagittal mouse brain slices which sustains authentic transcriptional responses for over 10 h and enables the study of gene regulation under controlled exposure to anti-ChEs. Slices were exposed to either organophosphate or cabamate anti-ChEs, both of which induced within 10 min excessive overexpression of the mRNA encoding the immediate early response transcription factor c-Fos. Twenty minutes later we noted 8-fold increases over control levels in AChE mRNA, accompanied by a 3-fold decrease in the mRNAs encoding for the ACh synthesizing enzyme choline acetyltransferase (ChAT) and the vesicular ACh transporter (VAChT). No changes were detected in synaptophysin mRNA levels. These modulations in gene expression paralleled those taking place under in vivo exposure. Of particular concern is the possibility that feedback processes leading to elevated levels of brain AChE may be similarly associated with low-level exposure to common organophosphorous anti-cholinesterases, and lead to long-term deleterious changes in cognitive functions.
ESTHER : Kaufer_1999_Chem.Biol.Interact_119-120_349
PubMedSearch : Kaufer_1999_Chem.Biol.Interact_119-120_349
PubMedID: 10421471

Title : Tracking cholinergic pathways from psychological and chemical stressors to variable neurodeterioration paradigms - Kaufer_1999_Curr.Opin.Neurol_12_739
Author(s) : Kaufer D , Soreq H
Ref : Curr Opin Neurol , 12 :739 , 1999
Abstract : Cholinergic hyperexcitation can be induced by both acute psychological stress and exposure to acetylcholinesterase inhibitors. Both factors are known risk factors for delayed neurodeterioration processes such as Alzheimer's disease and Parkinson's disease. Recent publications on the involvement of cholinergic pathways in these and other neurodeterioration syndromes are reviewed.
ESTHER : Kaufer_1999_Curr.Opin.Neurol_12_739
PubMedSearch : Kaufer_1999_Curr.Opin.Neurol_12_739
PubMedID: 10676758

Title : Structural roles of acetylcholinesterase variants in biology and pathology - Grisaru_1999_Eur.J.Biochem_264_672
Author(s) : Grisaru D , Sternfeld M , Eldor A , Glick D , Soreq H
Ref : European Journal of Biochemistry , 264 :672 , 1999
Abstract : Apart from its catalytic function in hydrolyzing acetylcholine, acetylcholinesterase (AChE) affects cell proliferation, differentiation and responses to various insults, including stress. These responses are at least in part specific to the three C-terminal variants of AChE which are produced by alternative splicing of the single ACHE gene. 'Synaptic' AChE-S constitutes the principal multimeric enzyme in brain and muscle; soluble, monomeric 'readthrough' AChE-R appears in embryonic and tumor cells and is induced under psychological, chemical and physical stress; and glypiated dimers of erythrocytic AChE-E associate with red blood cell membranes. We postulate that the homology of AChE to the cell adhesion proteins, gliotactin, glutactin and the neurexins, which have more established functions in nervous system development, is the basis of its morphogenic functions. Competition between AChE variants and their homologs on interactions with the corresponding protein partners would inevitably modify cellular signaling. This can explain why AChE-S exerts process extension from cultured amphibian, avian and mammalian glia and neurons in a manner that is C-terminus-dependent, refractory to several active site inhibitors and, in certain cases, redundant to the function of AChE-like proteins. Structural functions of AChE variants can explain their proliferative and developmental roles in blood, bone, retinal and neuronal cells. Moreover, the association of AChE excess with amyloid plaques in the degenerating human brain and with progressive cognitive and neuromotor deficiencies observed in AChE-transgenic animal models most likely reflects the combined contributions of catalytic and structural roles.
ESTHER : Grisaru_1999_Eur.J.Biochem_264_672
PubMedSearch : Grisaru_1999_Eur.J.Biochem_264_672
PubMedID: 10491113

Title : Human erythrocyte but not brain acetylcholinesterase hydrolyses heroin to morphine - Salmon_1999_Clin.Exp.Pharmacol.Physiol_26_596
Author(s) : Salmon AY , Goren Z , Avissar Y , Soreq H
Ref : Clinical & Experimental Pharmacology & Physiology , 26 :596 , 1999
Abstract : 1. In human blood, heroin is rapidly hydrolysed by sequential deacylation of two ester bonds to yield first 6-monoacetylmorphine (6-MAM), then morphine. 2. Serum butyrylcholinesterase (BCHE) hydrolyses heroin to 6-MAM with a catalytic efficiency of 4.5/min per mumol/L, but does not proceed to produce morphine. 3. In vitro, human erythrocyte acetylcholinesterase (AChE) hydrolyses heroin to 6-MAM, with a catalytic efficiency of 0.5/min per mumol/L under first-order kinetics. Moreover, erythrocyte AChE, but not BCHE is capable of further hydrolysing 6-MAM to morphine, albeit at a considerably slower rate. 4. Both hydrolysis steps by erythrocyte AChE were totally blocked by the selective AChE inhibitor BW284c51 but were not blocked by the BCHE-specific inhibitor, iso-OMPA (tetraisopropylpyrophosphoramide). 5. The brain synaptic form of AChE, which differs from the erythrocyte enzyme in its C-terminus, was incapable of hydrolysing heroin. 6. Heroin suppressed substrate hydrolysis by antibody-immobilized erythrocyte but not by brain AChE. 7. These findings reveal a new metabolic role for erythrocyte AChE, the biological function of which is as yet unexplained, and demonstrate distinct biochemical properties for the two AChE variants, which were previously considered catalytically indistinguishable.
ESTHER : Salmon_1999_Clin.Exp.Pharmacol.Physiol_26_596
PubMedSearch : Salmon_1999_Clin.Exp.Pharmacol.Physiol_26_596
PubMedID: 10474772

Title : Manipulations of ACHE gene expression suggest non-catalytic involvement of acetylcholinesterase in the functioning of mammalian photoreceptors but not in retinal degeneration - Broide_1999_Brain.Res.Mol.Brain.Res_71_137
Author(s) : Broide RS , Grifman M , Loewenstein A , Grisaru D , Timberg R , Stone J , Shani M , Patrick JW , Soreq H
Ref : Brain Research Mol Brain Res , 71 :137 , 1999
Abstract : To explore role(s) of acetylcholinesterase (AChE) in functioning and diseased photoreceptors, we studied normal (rd/+) and degenerating (rd/rd) murine retinas. All retinal neurons, expressed AChEmRNA throughout fetal development. AChE and c-Fos mRNAs peaked at post-natal days 10-12, when apoptosis of rd/rd photoreceptors begins. Moreover, c-Fos and AChEmRNA were co-overexpressed in rd/rd mice producing transgenic human (h), and host (m) AChE, but not in rd/+ mice. However, mAChE overexpression also occurred in transgenics expressing human serum albumin. Drastic variations in AChE catalytic activity were ineffective during development. Neither transgenic excess nor diisopropylfluorophosphonate (DFP) inhibition (80%) affected the rd phenotype; nor did DFP exposure induce photoreceptor degeneration or affect other key cholinergic proteins in rd/+ mice, unlike reports of adult mice and despite massive induction under DFP of c-Fos70 years). Therefore, the extreme retinal sensitivity to AChE modulation may reflect non-catalytic function(s) of AChE in adult photoreceptors. These findings exclude AChE as causing the rd phenotype, suggest that its primary function(s) in mammalian retinal development are non-catalytic ones and indicate special role(s) for the AChE protein in adult photoreceptors.
ESTHER : Broide_1999_Brain.Res.Mol.Brain.Res_71_137
PubMedSearch : Broide_1999_Brain.Res.Mol.Brain.Res_71_137
PubMedID: 10521568

Title : In vivo and in vitro resistance to multiple anticholinesterases in Xenopus laevis tadpoles - Shapira_1998_Toxicol.Lett_103_205
Author(s) : Shapira M , Seidman S , Livni N , Soreq H
Ref : Toxicol Lett , 103 :205 , 1998
Abstract : Natural and man-made anticholinesterases comprise a significant share of the Xenobiotic poisons to which many living organisms are exposed. To evaluate the potential correlation between the resistance of acetylcholinesterase (AChE) to such toxic agents and the systemic toxicity they confer, we characterized the sensitivity of AChE from Xenopus laevis tadpoles to inhibitors, examined the susceptibility of such tadpoles to poisoning by various anticholinesterases and tested the inhibitor sensitivities of recombinant human AChE produced in these amphibian embryos from microinjected DNA. Our findings reveal exceptionally high resistance of Xenopus AChE to carbamate, organophosphate and quaternary anticholinesterases. In spite of the effective in vivo penetrance to Xenopus tadpole tissues of paraoxon, the poisonous metabolite of the pro-insecticide parathion, the amphibian embryos displayed impressive resistance to this organophosphorous agent. The species specificity of this phenomenon was clearly displayed in Xenopus tadpoles expressing recombinant human AChE, which was far more sensitive than the frog enzyme to in vivo paraoxon inhibition. Our findings demonstrate a clear correlation between AChE susceptibility to enzymatic inhibition and the systemic toxicity of anticholinesterases and raise a serious concern regarding the use of Xenopus tadpoles for developmental toxicology tests of anticholinesterases.
ESTHER : Shapira_1998_Toxicol.Lett_103_205
PubMedSearch : Shapira_1998_Toxicol.Lett_103_205
PubMedID: 10022255

Title : Transgenic acetylcholinesterase induces enlargement of murine neuromuscular junctions but leaves spinal cord synapses intact - Andres_1998_Neurochem.Int_32_449
Author(s) : Andres C , Seidman S , Beeri R , Timberg R , Soreq H
Ref : Neurochem Int , 32 :449 , 1998
Abstract : Acetylcholinesterase (AChE) produced by spinal cord motoneurons accumulates within axo-dendritic spinal cord synapses. It is also secreted from motoneuron cell bodies, through their axons, into the region of neuromuscular junctions, where it terminates cholinergic neurotransmission. Here we show that transgenic mice expressing human AChE in their spinal cord motoneurons display primarily normal axo-dendritic spinal cord cholinergic synapses in spite of the clear excess of transgenic over host AChE within these synapses. This is in contrast to our recent observation that a modest excess of AChE drastically affects the structure and long-term functioning of neuromuscular junctions in these mice although they express human AChE in their spinal cord, but not muscle. Enlarged muscle endplates with either exaggerated or drastically shortened post-synaptic folds then lead to a progressive neuromotor decline and massive amyotrophy (Andres et al., 1997). These findings demonstrate that excess neuronal AChE may cause distinct effects on spinal cord and neuromuscular synapses and attribute the late-onset neuromotor deterioration observed in AChE transgenic mice to neuromuscular junction abnormalities.
ESTHER : Andres_1998_Neurochem.Int_32_449
PubMedSearch : Andres_1998_Neurochem.Int_32_449
PubMedID: 9676744

Title : Genetic Manipulations of Catalytic and Non-Catalytic Functions of Human Cholinesterases -
Author(s) : Soreq H
Ref : In: Structure and Function of Cholinesterases and Related Proteins - Proceedings of Sixth International Meeting on Cholinesterases , (Doctor, B.P., Taylor, P., Quinn, D.M., Rotundo, R.L., Gentry, M.K. Eds) Plenum Publishing Corp. :35 , 1998

Title : Acetylcholinesterase enhances neurite growth and synapse development through alternative contributions of its hydrolytic capacity, core protein, and variable C termini - Sternfeld_1998_J.Neurosci_18_1240
Author(s) : Sternfeld M , Ming G , Song H , Sela K , Timberg R , Poo MM , Soreq H
Ref : Journal of Neuroscience , 18 :1240 , 1998
Abstract : Accumulated indirect evidence suggests nerve growth-promoting activities for acetylcholinesterase (AChE). To determine unequivocally whether such activities exist, whether they are related to the capacities of this enzyme to hydrolyze acetylcholine and enhance synapse development, and whether they are associated with alternative splicing variants of AChEmRNA, we used four recombinant human AChEDNA vectors. When Xenopus laevis embryos were injected with a vector expressing the synapse-characteristic human AChE-E6, which contains the exon 6-encoded C terminus, cultured spinal neurons expressing this enzyme grew threefold faster than co-cultured control neurons. Similar enhancement occurred in neurons expressing an insertion-inactivated human AChE-E6-IN protein, containing the same C terminus, and displaying indistinguishable immunochemical and electrophoretic migration properties from AChE-E6, but incapable of hydrolyzing acetylcholine. In contrast, the nonsynaptic secretory human AChE-I4, which contains the pseudointron 4-derived C terminus, did not affect neurite growth. Moreover, no growth promotion occurred in neurons expressing the catalytically active C-terminally truncated human AChE-E4, demonstrating a dominant role for the E6-derived C terminus in neurite extension. Also, AChE-E6 was the only active enzyme variant to be associated with Xenopus membranes. However, postsynaptic length measurements demonstrated that both AChE-E6 and AChE-E4 enhanced the development of neuromuscular junctions in vivo, unlike the catalytically inert AChE-E6-IN and the nonsynaptic AChE-I4. These findings demonstrate an evolutionarily conserved synaptogenic activity for AChE that depends on its hydrolytic capacity but not on its membrane association. Moreover, this synaptogenic effect differs from the growth-promoting activity of AChE, which is unrelated to its hydrolytic capacity yet depends on its exon 6-mediated membrane association.
ESTHER : Sternfeld_1998_J.Neurosci_18_1240
PubMedSearch : Sternfeld_1998_J.Neurosci_18_1240
PubMedID: 9454834

Title : The Human Ache Locus Includes a Polymorphic Enhancer Domain 17KB Upstream from the Transcription Start Site -
Author(s) : Shapira M , Korner M , Bosgraaf L , Tur-Kaspa I , Soreq H
Ref : In: Structure and Function of Cholinesterases and Related Proteins - Proceedings of Sixth International Meeting on Cholinesterases , (Doctor, B.P., Taylor, P., Quinn, D.M., Rotundo, R.L., Gentry, M.K. Eds) Plenum Publishing Corp. :111 , 1998

Title : Transgenic mammary gland expression of readthrough human AChE: A model system for cholinesterase regulation in mammalian body fluids -
Author(s) : Salmon AY , Sternfeld M , Ginzberg D , Patrick J , Soreq H
Ref : Journal de Physiologie (Paris) , 92 :489 , 1998

Title : Position effect variegations and brain-specific silencing in transgenic mice overexpressing human acetylcholinesterase variants - Sternfeld_1998_J.Physiol.Paris_92_249
Author(s) : Sternfeld M , Patrick JD , Soreq H
Ref : Journal de Physiologie (Paris) , 92 :249 , 1998
Abstract : Position effect variegations as well as brain-specific silencing were observed in novel transgenic mouse pedigrees expressing human acetylcholinesterase (AChE) variants. Muscle AChE activities varied between 1.6- and 350-fold of control in these lines, one carrying insertion-inactivated InE6-AChE and two with 'readthrough' I4/E5 AChE, all under control of the ubiquitous CMV promoter. In contrast, brain AChE levels remained within a range of 1.5-fold over control, suggesting an upper limit of brain AChE which is compatible with life.
ESTHER : Sternfeld_1998_J.Physiol.Paris_92_249
PubMedSearch : Sternfeld_1998_J.Physiol.Paris_92_249
PubMedID: 9789818

Title : Human acetylcholinesterase transgenic mice show elevated muscle expression and brain specific silencing -
Author(s) : Sternfeld M , Patrick JD , Soreq H
Ref : Journal de Physiologie (Paris) , 92 :499 , 1998

Title : Cholinergic mechanisms - tenth international symposium - Soreq_1998_IDrugs_1_787
Author(s) : Soreq H
Ref : IDrugs , 1 :787 , 1998
Abstract : This meeting, the tenth in a series of conferences that was established in Stockholm in 1970, focused on fundamental and applied aspects of processes involving acetylcholine (ACh) as a neurotransmitter. The role of cholinergic mechanisms in central and peripheral nervous systems, sensory organs and muscles was addressed. Several deficiencies in neuromuscular cholinergic neurotransmission were discussed, including myasthenia gravis and the genetic basis of inherited myasthenic syndromes. In the brain, cholinergic communication is central to basic processes, such as sleep, arousal and memory, addiction to nicotine and various neurological and psychiatric disorders, including dementia and certain epilepsies. Cholinergic drugs are currently in use, or in advanced stages of development, for the chronic treatment of Alzheimer's disease (AD) and myasthenia gravis, as well as for the treatment of acute intoxication with organophosphate or carbamate inhibitors of the ACh hydrolyzing enzyme acetyl-cholinesterase (AChE). AChE inhibitors include commonly used insecticides, but also the infamous nerve agents; therefore, the ill-defined Gulf War Syndrome was also discussed. The meeting became the venue where basic mechanisms and the structure-function properties of key molecules involved in cholinergic neurotransmission were discussed in view of their implications for toxicology, pharmacology, medicine and the environment. The presentations in this meeting were all collected, edited by Dr Jean Massouli (Ecole Normale Superieure, Paris, France) and published by Elsevier (ISBN:2-84299-065-X) in September, 1998. In the following report, the aspects of this meeting that are closely related to drug development and use are covered.
ESTHER : Soreq_1998_IDrugs_1_787
PubMedSearch : Soreq_1998_IDrugs_1_787
PubMedID: 18465647

Title : Elevated acetylcholine release in the hippocampus of transgenic mice expressing the human acetylcholinesterase -
Author(s) : Erb C , Klein J , Salmon A , Soreq H , Loffelholz K
Ref : Journal de Physiologie (Paris) , 92 :428 , 1998

Title : Multilevel Approaches to AChE-Induced Impairments in Learning and Memory -
Author(s) : Seidman S , Cohen O , Ginzberg D , Eichengreen E , Pollak Y , Yirmiya R , Soreq H
Ref : In: Structure and Function of Cholinesterases and Related Proteins - Proceedings of Sixth International Meeting on Cholinesterases , (Doctor, B.P., Taylor, P., Quinn, D.M., Rotundo, R.L., Gentry, M.K. Eds) Plenum Publishing Corp. :183 , 1998

Title : Acute stress facilitates long-lasting changes in cholinergic gene expression - Kaufer_1998_Nature_393_373
Author(s) : Kaufer D , Friedman A , Seidman S , Soreq H
Ref : Nature , 393 :373 , 1998
Abstract : Acute traumatic stress may lead to post-traumatic stress disorder (PTSD), which is characterized by delayed neuropsychiatric symptoms including depression, irritability, and impaired cognitive performance. Curiously, inhibitors of the acetylcholine-hydrolysing enzyme acetylcholinesterase may induce psychopathologies that are reminiscent of PTSD. It is unknown how a single stressful event mediates long-term neuronal plasticity. Moreover, no mechanism has been proposed to explain the convergent neuropsychological outcomes of stress and of acetylcholinesterase inhibition. However, acute stress elicits a transient increase in the amounts released of the neurotransmitter acetylcholine and a phase of enhanced neuronal excitability. Inhibitors of acetylcholinesterase also promote enhanced electrical brain activity, presumably by increasing the survival of acetylcholine at the synapse. Here we report that there is similar bidirectional modulation of genes that regulate acetylcholine availability after stress and blockade of acetylcholinesterase. These calcium-dependent changes in gene expression coincide with phases of rapid enhancement and delayed depression of neuronal excitability. Both of these phases are mediated by muscarinic acetylcholine receptors. Our results suggest a model in which robust cholinergic stimulation triggers rapid induction of the gene encoding the transcription factor c-Fos. This protein then mediates selective regulatory effects on the long-lasting activities of genes involved in acetylcholine metabolism.
ESTHER : Kaufer_1998_Nature_393_373
PubMedSearch : Kaufer_1998_Nature_393_373
PubMedID: 9620801

Title : Long-term modulations of cholinergic neurotransmission following chronic stress -
Author(s) : Kaufer D , Friedman A , Pavlovsky L , Soreq H
Ref : Journal de Physiologie (Paris) , 92 :446 , 1998

Title : Functional redundancy of acetylcholinesterase and neuroligin in mammalian neuritogenesis - Grifman_1998_Proc.Natl.Acad.Sci.U.S.A_95_13935
Author(s) : Grifman M , Galyam N , Seidman S , Soreq H
Ref : Proc Natl Acad Sci U S A , 95 :13935 , 1998
Abstract : Accumulated evidence attributes noncatalytic morphogenic activitie(s) to acetylcholinesterase (AChE). Despite sequence homologies, functional overlaps between AChE and catalytically inactive AChE-like cell surface adhesion proteins have been demonstrated only for the Drosophila protein neurotactin. Furthermore, no mechanism had been proposed to enable signal transduction by AChE, an extracellular enzyme. Here, we report impaired neurite outgrowth and loss of neurexin Ialpha mRNA under antisense suppression of AChE in PC12 cells (AS-ACHE cells). Neurite growth was partially rescued by addition of recombinant AChE to the solid substrate or by transfection with various catalytically active and inactive AChE variants. Moreover, overexpression of the homologous neurexin I ligand, neuroligin-1, restored both neurite extension and expression of neurexin Ialpha. Differential PCR display revealed expression of a novel gene, nitzin, in AS-ACHE cells. Nitzin displays 42% homology to the band 4.1 protein superfamily capable of linking integral membrane proteins to the cytoskeleton. Nitzin mRNA is high throughout the developing nervous system, is partially colocalized with AChE, and increases in rescued AS-ACHE cells. Our findings demonstrate redundant neurite growth-promoting activities for AChE and neuroligin and implicate interactions of AChE-like proteins and neurexins as potential mediators of cytoarchitectural changes supporting neuritogenesis.
ESTHER : Grifman_1998_Proc.Natl.Acad.Sci.U.S.A_95_13935
PubMedSearch : Grifman_1998_Proc.Natl.Acad.Sci.U.S.A_95_13935
PubMedID: 9811904

Title : Probing accessible sites for ribozymes on human acetylcholinesterase RNA - Birikh_1997_Rna_3_429
Author(s) : Birikh KR , Berlin YA , Soreq H , Eckstein F
Ref : Rna , 3 :429 , 1997
Abstract : In order to design ribozymes for the efficient cleavage of a human acetylcholinesterase (AChE) in vitro transcript, a completely randomized decadeoxyribonucleotide (dN10) was used in conjunction with RNase H to identify suitable sites for annealing. Based on the observed cleavage pattern, ribozymes were designed to cleave the transcript at these positions. Five ribozymes so designed proved to be efficient in the transcript cleavage (k(react)/Km ranged from 0.9 x 10(4) to 68.2 x 10(4) M(-1) min(-10)). The best was 150-fold more active than the best designed on the basis of the MFold program. Thus, the RNase H mapping demonstrated a high predictive power for favorable ribozyme cleavage sites. The digestion pattern with RNase H differed dramatically from that observed with the single-strand-specific mung bean nuclease.
ESTHER : Birikh_1997_Rna_3_429
PubMedSearch : Birikh_1997_Rna_3_429
PubMedID: 9085849

Title : Acetylcholinesterase-transgenic mice display embryonic modulations in spinal cord choline acetyltransferase and neurexin Ibeta gene expression followed by late-onset neuromotor deterioration - Andres_1997_Proc.Natl.Acad.Sci.U.S.A_94_8173
Author(s) : Andres C , Beeri R , Friedman A , Lev-Lehman E , Henis S , Timberg R , Shani M , Soreq H
Ref : Proc Natl Acad Sci U S A , 94 :8173 , 1997
Abstract : To explore the possibility that overproduction of neuronal acetylcholinesterase (AChE) confers changes in both cholinergic and morphogenic intercellular interactions, we studied developmental responses to neuronal AChE overexpression in motoneurons and neuromuscular junctions of AChE-transgenic mice. Perikarya of spinal cord motoneurons were consistently enlarged from embryonic through adult stages in AChE-transgenic mice. Atypical motoneuron development was accompanied by premature enhancement in the embryonic spinal cord expression of choline acetyltransferase mRNA, encoding the acetylcholine-synthesizing enzyme choline acetyltransferase. In contrast, the mRNA encoding for neurexin-Ibeta, the heterophilic ligand of the AChE-homologous neuronal cell surface protein neuroligin, was drastically lower in embryonic transgenic spinal cord than in controls. Postnatal cessation of these dual transcriptional responses was followed by late-onset deterioration in neuromotor performance that was associated with gross aberrations in neuromuscular ultrastructure and with pronounced amyotrophy. These findings demonstrate embryonic feedback mechanisms to neuronal AChE overexpression that are attributable to both cholinergic and cell-cell interaction pathways, suggesting that embryonic neurexin Ibeta expression is concerted in vivo with AChE levels and indicating that postnatal changes in neuronal AChE-associated proteins may be involved in late-onset neuromotor pathologies.
ESTHER : Andres_1997_Proc.Natl.Acad.Sci.U.S.A_94_8173
PubMedSearch : Andres_1997_Proc.Natl.Acad.Sci.U.S.A_94_8173
PubMedID: 9223334

Title : Normal and atypical butyrylcholinesterases in placental development, function, and malfunction - Sternfeld_1997_Cell.Mol.Neurobiol_17_315
Author(s) : Sternfeld M , Rachmilewitz J , Loewenstein-Lichtenstein Y , Andres C , Timberg R , Ben-Ari S , Glick C , Soreq H , Zakut H
Ref : Cellular Molecular Neurobiology , 17 :315 , 1997
Abstract : 1. In utero exposure to poisons and drugs (e.g., anticholinesterases, cocaine) is frequently associated with spontaneous absorption and placental malfunction. The major protein interacting with these compounds is butyrylcholinesterase (BuChE), which attenuates the effects of such xenobiotics by their hydrolysis or sequestration. Therefore, we studied BuChE expression during placental development. 2. RT-PCR revealed both BuChEmRNA and acetylcholinesterase (AChE) mRNA throughout gestation. However, cytochemical staining detected primarily BuChE activity in first-trimester placenta but AChE activity in term placenta. 3. As the atypical variant of BuChE has a narrower specificity for substrates and inhibitors than the normal enzyme, we investigated its interactions with alpha-solanine and cocaine, and sought a correlation between the occurrence of this variant and placental malfunction. 4. Atypical BuChE of serum or recombinant origin presented > 10-fold weaker affinities than normal BuChE for cocaine and alpha-solanine. However, BuChE in the serum of the heterozygote and a homozygous normal were similar in their drug affinities. Therefore, heterozygous serum or placenta can protect the fetus from drug or poison exposure, unlike homozygous atypical serum or placenta. 5. Genotype analyses revealed that heterozygous carriers of atypical BuChE were threefold less frequent among 49 patients with placental malfunction than among 76 controls of the entire Israeli population. These observations exclude heterozygote carriers of atypical BuChE from being at high risk for placental malfunction under exposure to anticholinesterases.
ESTHER : Sternfeld_1997_Cell.Mol.Neurobiol_17_315
PubMedSearch : Sternfeld_1997_Cell.Mol.Neurobiol_17_315
PubMedID: 9187488

Title : In vitro phosphorylation of acetylcholinesterase at non-consensus protein kinase A sites enhances the rate of acetylcholine hydrolysis - Grifman_1997_Brain.Res.Mol.Brain.Res_51_179
Author(s) : Grifman M , Arbel A , Ginzberg D , Glick D , Elgavish S , Shaanan B , Soreq H
Ref : Brain Research Mol Brain Res , 51 :179 , 1997
Abstract : Here, we report that the catalytic subunit of cAMP-dependent protein kinase (PKA) but not casein kinase II or protein kinase C phosphorylates recombinant human acetylcholinesterase (AChE) in vitro. This enhances acetylthiocholine hydrolysis up to 10-fold as compared to untreated AChE, while leaving unaffected the enzyme's affinity for this substrate and for various active and peripheral site inhibitors. Alkaline phosphatase treatment enhanced the electrophoretic migration, under denaturing conditions, of part of the AChE proteins isolated from various mammalian sources and raised the isoelectric point of some of the treated AChE molecules, indicating that part of the AChE molecules are also phosphorylated in vivo. Enhancement of acetylthiocholine hydrolysis also occurred with Torpedo AChE, which has no consensus motif for PKA phosphorylation. Further, mutating the single PKA site in human AChE (threonine-249) did not prevent this enhancement, suggesting that in both cases it was due to phosphorylation at non-consensus sites. In vivo suppression of the acetylcholine hydrolyzing activity of AChE and consequent impairment in cholinergic neurotransmission occur under exposure to both natural and pharmacological compounds, including organophosphate and carbamate insecticides and chemical warfare agents. Phosphorylation of AChE may possibly offer a rapid feedback mechanism that can compensate for impairments in cholinergic neurotransmission, modulating the hydrolytic activity of this enzyme and enabling acetylcholine hydrolysis to proceed under such challenges.
ESTHER : Grifman_1997_Brain.Res.Mol.Brain.Res_51_179
PubMedSearch : Grifman_1997_Brain.Res.Mol.Brain.Res_51_179
PubMedID: 9427520

Title : Enhanced hemicholinium binding and attenuated dendrite branching in cognitively impaired acetylcholinesterase-transgenic mice - Beeri_1997_J.Neurochem_69_2441
Author(s) : Beeri R , Le Novere N , Mervis R , Huberman T , Grauer E , Changeux JP , Soreq H
Ref : Journal of Neurochemistry , 69 :2441 , 1997
Abstract : In a search for behavioral, neuroanatomical, and metabolic characteristics of Alzheimer's disease that may result from cholinergic malfunction, we used transgenic mice overexpressing acetylcholinesterase (AChE) mRNA and active enzyme in brain neurons. Mapping by in situ hybridization revealed that transgenic and host AChE mRNAs were distributed similarly. In a Morris water maze working memory paradigm, adult transgenic mice did not display the characteristic improvement found in control mice either between or within test days and spent less time than control mice in the platform zone. In 5-week-old transgenic mice, the basilar dendritic trees of layer 5 pyramidal neurons from the frontoparietal cortex were essentially as developed as in age-matched controls. However, branching totally ceased after this age, whereas in control adults it continued up to at least 7 months. Therefore, dendritic arbors became smaller in adult transgenic mice than those of controls. Furthermore, the average number of spines was significantly lower on dendritic branches of 7-month-old but not 5-week-old transgenics as compared with controls. Binding of tritiated hemicholinium-3, a blocker of the high-affinity choline uptake characteristic of active cholinergic terminals, was over twofold enhanced in the brain of transgenic mice. In contrast, no differences were observed in the mRNA and ligand binding levels of several different subtypes of nicotinic and muscarinic acetylcholine receptors. These findings suggest that three different hallmarks associated with Alzheimer's disease--namely, progressive cognitive failure, cessation of dendrite branching and spine formation, and enhanced high-affinity choline uptake--are outcomes of cholinergic malfunction.
ESTHER : Beeri_1997_J.Neurochem_69_2441
PubMedSearch : Beeri_1997_J.Neurochem_69_2441
PubMedID: 9375677

Title : Immature human megakaryocytes produce nuclear-associated acetylcholinesterase - Lev-Lehman_1997_Blood_89_3644
Author(s) : Lev-Lehman E , Deutsch V , Eldor A , Soreq H
Ref : Blood , 89 :3644 , 1997
Abstract : Acetylcholinesterase (AChE) is expressed in murine megakaryocytes (MK), where its antisense inhibition suppresses differentiation, yet was never detected in human MK. Here, we report that AChE is produced in normal human bone marrow MK and in cell lines derived thereof. Reverse transcriptase-polymerase chain reaction (RT-PCR) amplification showed two ACHEmRNA forms in human megakaryoblastic DAMI cells. In situ hybridization demonstrated ACHEmRNA surrounding the nucleus of small DAMI cells and the nuclear lobes of large, polyploid cells. Differentiation induction with phorbol ester and exposure to recombinant human thrombopoietin suppressed both ACHEmRNA and AChE activity. The residual AChE in mature differentiated cells acquired higher stability and detergent-sensitivity as compared with AChE in small proliferating cells. AChE activity was primarily associated with nuclei of both DAMI cells and small (10 microm) primary proliferating human bone marrow MK identified with GPIIb/IIIa antibodies. This activity was significantly reduced in medium size MK (10 to 25 microm) and was almost undetectable in large MK (>25 microm), yet was twofold more abundant in some large MK from idiopathic thrombocytopenia purpura (ITP) patients with accelerated MK maturation. The loss of AChE activity at the transition from proliferating to differentiating MK highlights species-specific differences in its expression, suggesting a distinct role for AChE in human MK development.
ESTHER : Lev-Lehman_1997_Blood_89_3644
PubMedSearch : Lev-Lehman_1997_Blood_89_3644
PubMedID: 9160669

Title : Genetic manipulations of cholinergic communication reveal trans-acting control mechanisms over acetylcholine receptors. - Broide_1997_J.Recept.Signal.Transduct.Res_17_279
Author(s) : Broide RS , Grifman M , Shapira M , Ginzberg D , Soreq H
Ref : Journal of Receptor & Signal Transduction Research , 17 :279 , 1997
Abstract : Several approaches have been developed for genetic modulations of receptor expression. These initiated with gene cloning and heterologous expression in microinjected Xenopus oocytes, and proceeded through transgenic expression and genomic disruption of receptor genes in mice. In addition, antisense treatments have reduced receptor levels in a transient, reversible manner. Integration of foreign DNA with host genomic sequences yields both cis- and trans-acting responses. These may depend on the DNA integration site, host cells condition and most importantly, the affected signal transduction circuit. For example, acetylcholinesterase (AChE) overexpression in microinjected Xenopus tadpoles has been shown to upregulate alpha-bungarotoxin binding levels, indicating trans-acting control conferring overproduction of muscle nicotinic acetylcholine receptors. In transgenic mice expressing human AChE, the hypothermic response to oxotremorine was suppressed, reflecting modified levels of brain muscarinic receptors. To dissociate the feedback processes occurring in transfected cells from responses related to DNA integration, we examined the endogenous expression of the alpha 7 neuronal nicotinic acetylcholine receptor in PC12 cells transfected with DNA vectors carrying alternative splicing variants of human AChE mRNA. Our findings demonstrate suppression of alpha 7 receptor levels associated with the accumulation of foreign DNA in the transfected cells. Acetylcholine receptor levels thus depend on multiple elements, each of which should be considered when genetic interventions are employed.
ESTHER : Broide_1997_J.Recept.Signal.Transduct.Res_17_279
PubMedSearch : Broide_1997_J.Recept.Signal.Transduct.Res_17_279
PubMedID: 9029496

Title : Overexpression of alternative human acetylcholinesterase forms modulates process extensions in cultured glioma cells - Karpel_1996_J.Neurochem_66_114
Author(s) : Karpel R , Sternfeld M , Ginzberg D , Guhl E , Graessmann A , Soreq H
Ref : Journal of Neurochemistry , 66 :114 , 1996
Abstract : In addition to its well-known synaptic function, acetylcholinesterase was recently shown to stimulate neurite outgrowth from cultured chick neurons in a manner unrelated to its catalytic activity. It remained unclear, however, whether each of the variant acetylcholinesterase enzyme forms can promote such process extension and whether this effect of acetylcholinesterase was limited to neurite outgrowth. Using DNA microinjections and stable transfections of cultured glioma cells, we explored the possibility that specific acetylcholinesterase isoforms affect cellular development and morphology of CNS astrocytes. Cells microinjected with human ACHEDNA constructs that differ in their exon-intron composition displayed rapid yet stable induction of cell body enlargement and process extensions. Cells transfected with ACHEDNA carrying the neuronal-characteristic 3'-E6 domain also displayed stable process extensions. However, stable transfections with ACHEDNAs including the 3'-alternative 14/E5 region induced the appearance of small, round cells in a dominant manner. This was associated with expression of 14/E5-ACHEmRNA transcripts and the production of soluble acetylcholinesterase monomers that were catalytically indistinguishable from the 3'-E6 enzyme but displayed higher electrophoretic mobility than that of the 3'-E6 form. Thus, variable expression levels and alternative splicing modes of the ACHE gene correlated in these experiments with glial development in a manner that was apparently unrelated to catalysis.
ESTHER : Karpel_1996_J.Neurochem_66_114
PubMedSearch : Karpel_1996_J.Neurochem_66_114
PubMedID: 8522942

Title : Overlapping drug interaction sites of human butyrylcholinesterase dissected by site-directed mutagenesis - Loewenstein-Lichtenstein_1996_Mol.Pharmacol_50_1423
Author(s) : Loewenstein-Lichtenstein Y , Glick D , Gluzman N , Sternfeld M , Zakut H , Soreq H
Ref : Molecular Pharmacology , 50 :1423 , 1996
Abstract : Butyrylcholinesterase [BCHE (acylcholine acyl hydrolase); EC] limits the access of drugs, including tacrine, to other proteins. The "atypical" BCHE variant, in which Asp70 at the rim of the active site gorge is substituted by glycine, displayed a more drastically weakened interaction with tacrine than with cocaine, dibucaine, succinylcholine, BW284c51 [1,5-bis(4-allyldimethylammoniumphenyl)pentan-3-one dibromide], or alpha-solanine. To delineate the protein domains that are responsible for this phenomenon, we mutated residues within the rim of the active site gorge, the region parallel to the peripheral site in the homologous enzyme acetylcholinesterase [AChE (acetylcholine acetyl hydrolase); EC], the oxyanion hole, and the choline-binding site. When expressed in microinjected Xenopus laevis oocytes, all mutant DNAs yielded comparable amounts of immunoreactive protein products. Most mutants retained catalytic activity close to that of wild-type BCHE and were capable of binding ligands. However, certain modifications in and around the oxyanion hole caused a dramatic loss in activity. The affinities for tacrine were reduced more dramatically than for all other ligands, including cocaine, in both oxyanion hole and choline-binding site mutants. Modified ligand affinities further demonstrated a peripheral site in residues homologous with those of AChE. BCHE mutations that prevented tacrine interactions also hampered its ability to bind other drugs and inhibitors, which suggests a partial overlap of the binding sites. This predicts that in addition to their genetic predisposition to adverse responses to tacrine, homozygous carriers of "atypical" BCHE will be overly sensitive to additional anticholinesterases and especially so when exposed to several anticholinesterases in combination.
ESTHER : Loewenstein-Lichtenstein_1996_Mol.Pharmacol_50_1423
PubMedSearch : Loewenstein-Lichtenstein_1996_Mol.Pharmacol_50_1423
PubMedID: 8967962
Gene_locus related to this paper: human-BCHE

Title : Murine and human mast cell express acetylcholinesterase - Nechushtan_1996_FEBS.Lett_379_1
Author(s) : Nechushtan H , Soreq H , Kuperstein V , Tshori S , Razin E
Ref : FEBS Letters , 379 :1 , 1996
Abstract : Expression of catalytically active protein was detected in a murine mast cell line. The primary type of AChE mRNA produced by these cells was found to be the brain and muscle type by PCR amplification of alternative exons from the 3' of mast cells AChE cDNA. AChE was further found to be expressed in the HMC-1 the human mast cell precursor line. Furthermore, utilizing the single cell RT-PCR method we detected AChE mRNA expression in Fc epsilon RI-positive single cells derived from human colonic mucosal biopsies. Our findings predict the involvement of mast cell AChE in neuronal-mast cell interactions.
ESTHER : Nechushtan_1996_FEBS.Lett_379_1
PubMedSearch : Nechushtan_1996_FEBS.Lett_379_1
PubMedID: 8566217

Title : Cholinergic drug resistance and impaired spatial learning in transgenic mice overexpressing human brain acetylcholinesterase -
Author(s) : Andres C , Beeri R , Huberman T , Shani M , Soreq H
Ref : Prog Brain Res , 109 :265 , 1996
PubMedID: 9009715

Title : Pyridostigmine brain penetration under stress enhances neuronal excitability and induces early immediate transcriptional response [see comments] - Friedman_1996_Nature.Med_2_1382
Author(s) : Friedman A , Kaufer D , Shemer J , Hendler I , Soreq H , Tur-Kaspa I
Ref : Nature Medicine , 2 :1382 , 1996
Abstract : Pyridostigmine, a carbamate acetylcholinesterase (AChE) inhibitor, is routinely employed in the treatment of the autoimmune disease myasthenia gravis. Pyridostigmine is also recommended by most Western armies for use as pretreatment under threat of chemical warfare, because of its protective effect against organophosphate poisoning. Because of this drug's quaternary ammonium group, which prevents its penetration through the blood-brain barrier, the symptoms associated with its routine use primarily reflect perturbations in peripheral nervous system functions. Unexpectedly, under a similar regimen, pyridostigmine administration during the Persian Gulf War resulted in a greater than threefold increase in the frequency of reported central nervous system symptoms. This increase was not due to enhanced absorption (or decreased elimination) of the drug, because the inhibition efficacy of serum butyryl-cholinesterase was not modified. Because previous animal studies have shown stress-induced disruption of the blood-brain barrier, an alternative possibility was that the stress situation associated with war allowed pyridostigmine penetration into the brain. Here we report that after mice were subjected to a forced swim protocol (shown previously to simulate stress), an increase in blood-brain barrier permeability reduced the pyridostigmine dose required to inhibit mouse brain AChE activity by 50% to less than 1/100th of the usual dose. Under these conditions, peripherally administered pyridostigmine increased the brain levels of c-fos oncogene and AChE mRNAs. Moreover, in vitro exposure to pyridostigmine increased both electrical excitability and c-fos mRNA levels in brain slices, demonstrating that the observed changes could be directly induced by pyridostigmine. These findings suggest that peripherally acting drugs administered under stress may reach the brain and affect centrally controlled functions.
ESTHER : Friedman_1996_Nature.Med_2_1382
PubMedSearch : Friedman_1996_Nature.Med_2_1382
PubMedID: 8946841

Title : Genetic Predisposition for Variable Response to Anticholinesterase Therapy Anticipated in Carriers of the Butyrylcholinesterase Atypical Mutation -
Author(s) : Loewenstein Y , Schwarz M , Glick D , Norgaard-Pedersen B , Zakut H , Soreq H
Ref : In Enzyme of the Cholinesterase Family - Proceedings of Fifth International Meeting on Cholinesterases , (Quinn, D.M., Balasubramanian, A.S., Doctor, B.P., Taylor, P., Eds) Plenum Publishing Corp. :471 , 1995

Title : Antisense Oligonucleotides Suppressing Expression of Cholinesterase Genes Modulate Hematopoiesis in Vivo and ex Vivo -
Author(s) : Soreq H , Lev-Lehman E , Patinkin D , Grifman M , Ehrlich G , Ginzberg D , Eckstein F , Zakut H
Ref : In Enzyme of the Cholinesterase Family - Proceedings of Fifth International Meeting on Cholinesterases , (Quinn, D.M., Balasubramanian, A.S., Doctor, B.P., Taylor, P., Eds) Plenum Publishing Corp. :1 , 1995

Title : Alternative Exon 6 Directs Synaptic Localization of Recombinant Human Acetylcholinesterase in Neuromuscular Junctions of Xenopus laevis Embryos -
Author(s) : Sternfeld M , Seidman S , Ben Aziz-Aloya R , Shapira M , Timberg R , Kaufer D , Soreq H
Ref : In Enzyme of the Cholinesterase Family - Proceedings of Fifth International Meeting on Cholinesterases , (Quinn, D.M., Balasubramanian, A.S., Doctor, B.P., Taylor, P., Eds) Plenum Publishing Corp. :45 , 1995

Title : Engineering of human cholinesterases explains and predicts diverse consequences of administration of various drugs and poisons. - Schwarz_1995_Pharmacol.Ther_67_283
Author(s) : Schwarz M , Glick D , Loewenstein Y , Soreq H
Ref : Pharmacol Ther , 67 :283 , 1995
Abstract :
ESTHER : Schwarz_1995_Pharmacol.Ther_67_283
PubMedSearch : Schwarz_1995_Pharmacol.Ther_67_283
PubMedID: 7494866

Title : Successive organophosphate inhibition and oxime reactivation reveals distinct responses of recombinant human cholinesterase variants - Schwarz_1995_Mol.Brain.Res_31_101
Author(s) : Schwarz M , Loewenstein-Lichtenstein Y , Glick D , Liao J , Norgaard-Pedersen B , Soreq H
Ref : Brain Research Mol Brain Res , 31 :101 , 1995
Abstract : To explore the molecular basis of the biochemical differences among acetylcholinesterase (AChE), butyrylcholinesterase (BCHE) and their alternative splicing and allelic variants, we investigated the acylation phase of cholinesterase catalysis, using phosphorylation as an analogous reaction. Rate constants for organophosphate (DFP) inactivation, as well as for oxime (PAM)-promoted reactivation, were calculated for antibody-immobilized human cholinesterases produced in Xenopus oocytes from natural and site-directed variants of the corresponding DNA constructs. BCHE displayed inactivation and reactivation rates 200- and 25-fold higher than either product of 3'-variable AChE DNAs, consistent with a putative in vivo function for BCHE as a detoxifier that protects AChE from inactivation. Chimeric substitution of active site gorge-lining residues in BCHE with the more anionic and aromatic residues of AChE, reduced inactivation 60-fold but reactivation only 4-fold, and the rate-limiting step of its catalysis appeared to be deacylation. In contrast, a positive charge at the acyl-binding site of BCHE decreased inactivation 8-fold and reactivation 30-fold. Finally, substitution of Asp70 by glycine, as in the natural 'atypical' BCHE variant, did not change the inactivation rate yet reduced reactivation 4-fold. Thus, a combination of electrostatic active site charges with aromatic residue differences at the gorge lining can explain the biochemical distinction between AChE and BCHE. Also, gorge-lining residues, including Asp70, appear to affect the deacylation step of catalysis by BCHE. Individuals carrying the 'atypical' BCHE allele may hence be unresponsive to oxime reactivation therapy following organophosphate poisoning.
ESTHER : Schwarz_1995_Mol.Brain.Res_31_101
PubMedSearch : Schwarz_1995_Mol.Brain.Res_31_101
PubMedID: 7476018

Title : Genetic predisposition to adverse consequences of anti-cholinesterases in 'atypical' BCHE carriers - Loewenstein-Lichtenstein_1995_Nat.Med_1_1082
Author(s) : Loewenstein-Lichtenstein Y , Schwarz M , Glick D , Norgaard-Pedersen B , Zakut H , Soreq H
Ref : Nat Med , 1 :1082 , 1995
Abstract : Normal butyrylcholinesterase (BuChE), but not several of its common genetic variants, serves as a scavenger for certain anti-cholinesterases (anti-ChEs). Consideration of this phenomenon becomes urgent in view of the large-scale prophylactic use of the anti-ChE, pyridostigmine, during the 1991 Persian Gulf War, in anticipation of nerve gas attack and of the anti-ChE, tacrine, for improving residual cholinergic neurotransmission in Alzheimer's disease patients. Adverse symptoms were reported for subjects in both groups, but have not been attributed to specific causes. Here, we report on an Israeli soldier, homozygous for 'atypical' BuChE, who suffered severe symptoms following pyridostigmine prophylaxis during the Persian Gulf War. His serum BuChE and recombinant 'atypical' BuChE were far less sensitive than normal BuChE to inhibition by pyridostigmine and several other carbamate anti-ChEs. Moreover, atypical BuChE demonstrated 1/200th the affinity for tacrine of normal BuChE or the related enzyme acetylcholinesterase (AChE). Genetic differences among BuChE variants may thus explain at least some of the adverse responses to anti-ChE therapies.
ESTHER : Loewenstein-Lichtenstein_1995_Nat.Med_1_1082
PubMedSearch : Loewenstein-Lichtenstein_1995_Nat.Med_1_1082
PubMedID: 7489367

Title : Synaptic and epidermal accumulations of human acetylcholinesterase are encoded by alternative 3'-terminal exons - Seidman_1995_Mol.Cell.Biol_15_2993
Author(s) : Seidman S , Sternfeld M , Ben-Aziz-Aloya R , Timberg R , Kaufer-Nachum D , Soreq H
Ref : Molecular & Cellular Biology , 15 :2993 , 1995
Abstract : Tissue-specific heterogeneity among mammalian acetylcholinesterases (AChE) has been associated with 3' alternative splicing of the primary AChE gene transcript. We have previously demonstrated that human AChE DNA encoding the brain and muscle AChE form and bearing the 3' exon E6 (ACHE-E6) induces accumulation of catalytically active AChE in myotomes and neuromuscular junctions (NMJs) of 2- and 3-day-old Xenopus embryos. Here, we explore the possibility that the 3'-terminal exons of two alternative human AChE cDNA constructs include evolutionarily conserved tissue-recognizable elements. To this end, DNAs encoding alternative human AChE mRNAs were microinjected into cleaving embryos of Xenopus laevis. In contrast to the myotomal expression demonstrated by ACHE-E6, DNA carrying intron 14 and alternative exon E5 (ACHE-I4/E5) promoted punctuated staining of epidermal cells and secretion of AChE into the external medium. Moreover, ACHE-E6-injected embryos displayed enhanced NMJ development, whereas ACHE-I4/E5-derived enzyme was conspicuously absent from muscles and NMJs and its expression in embryos had no apparent effect on NMJ development. In addition, cell-associated AChE from embryos injected with ACHE-I4/E5 DNA was biochemically distinct from that encoded by the muscle-expressible ACHE-E6, displaying higher electrophoretic mobility and greater solubility in low-salt buffer. These findings suggest that alternative 3'-terminal exons dictate tissue-specific accumulation and a particular biological role(s) of AChE, associate the 3' exon E6 with NMJ development, and indicate the existence of a putative secretory AChE form derived from the alternative I4/E5 AChE mRNA.
ESTHER : Seidman_1995_Mol.Cell.Biol_15_2993
PubMedSearch : Seidman_1995_Mol.Cell.Biol_15_2993
PubMedID: 7760797

Title : HER-2 amplification but not butyrylcholinesterase multability reflects aggressiveness of European-originated ovarian tumors - Dobianer_1995_Gynecol.Oncol_56_200
Author(s) : Dobianer K , Hruza C , Ehrlich G , Sevelda P , Czerwenka K , Soreq H , Spona J , Zakut H
Ref : Gynecologic Oncology , 56 :200 , 1995
Abstract : Tumorigenic roles were variably suggested for HER-2 and INT-2 oncogene amplifications and the "atypical" aspartate to glycine mutability in the butyrylcholinesterase (BCHE) gene in ovarian adenocarcinomas. To examine this notion we searched for correlations between these three phenomena and ovarian tumor classification and aggressiveness, using quantitative polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP), and direct PCR sequencing. Our findings revealed no alleles carrying the atypical BCHE mutability in 30 European-originated patients with ovarian tumors compared with 11% (2/18) such alleles in Israeli patients with malignant ovarian tumors. This apparently reflected population diversity rather than disease relationship. INT-2 amplification was observed in 14/94 (15%) of the European patients; however, there was no correlation between this phenomenon and clinicopathological indices in the corresponding patients. In contrast, in 94 tumor samples we found that 40% (38/94) of the cases had HER-2 amplification. Moreover, there was a highly significant correlation (P < 0.008) between the over fivefold HER-2 amplification and ovarian tumor severity. These findings demonstrate an informative value for HER-2 amplification tests in tumor DNA, but not for INT-2 amplification or BCHE mutability, for the assessment of treatment.
ESTHER : Dobianer_1995_Gynecol.Oncol_56_200
PubMedSearch : Dobianer_1995_Gynecol.Oncol_56_200
PubMedID: 7896186

Title : Transgenic expression of human acetylcholinesterase induces progressive cognitive deterioration in mice - Beeri_1995_Curr.Biol_5_1063
Author(s) : Beeri R , Andres C , Lev-Lehman E , Timberg R , Huberman T , Shani M , Soreq H
Ref : Current Biology , 5 :1063 , 1995
Abstract : BACKGROUND Cognitive deterioration is a characteristic symptom of Alzheimer's disease. This deterioration is notably associated with structural changes and subsequent cell death which occur, primarily, in acetylcholine-producing neurons, progressively damaging cholinergic neurotransmission. We have reported previously that excess acetylcholinesterase (AChE) alters structural features of neuromuscular junctions in transgenic Xenopus tadpoles. However, the potential of cholinergic imbalance to induce progressive decline of memory and learning in mammals has not been explored. RESULTS: To approach the molecular mechanisms underlying the progressive memory deficiencies associated with impaired cholinergic neurotransmission, we created transgenic mice that express human AChE in brain neurons. With enzyme levels up to two-fold higher than in control mice, transgenic mice displayed an age-independent resistance to the hypothermic effects of the AChE inhibitor, paraoxon. In addition to this improved scavenging capacity for anti-AChEs, however, these transgenic mice also resisted muscarinic, nicotinic and serotonergic agonists, indicating that secondary pharmacological changes had occurred. The transgenic mice also developed progressive learning and memory impairments, although their locomotor activities and open-field behaviour remained similar to those of matched control mice. By six months of age, transgenic mice lost their ability to respond to training in a spatial learning water maze test, whereas they performed normally in this test at the age of four weeks. This animal model is therefore suitable for investigating the transcriptional changes associated with cognitive deterioration and for testing drugs that may attenuate progressive damage. CONCLUSION: We conclude that upsetting cholinergic balance may by itself cause progressive memory decline in mammals, suggesting that congenital and/or acquired changes in this vulnerable balance may contribute to the physiopathology of Alzheimer's disease.
ESTHER : Beeri_1995_Curr.Biol_5_1063
PubMedSearch : Beeri_1995_Curr.Biol_5_1063
PubMedID: 8542283

Title : Site-directed mutagenesis of active site residues reveals plasticity of human butyrylcholinesterase in substrate and inhibitor interactions - Gnatt_1994_J.Neurochem_62_749
Author(s) : Gnatt A , Loewenstein Y , Yaron A , Schwarz M , Soreq H
Ref : Journal of Neurochemistry , 62 :749 , 1994
Abstract : In search of the molecular mechanisms underlying the broad substrate and inhibitor specificities of butyrylcholinesterase (BCHE), we employed site-directed mutagenesis to modify the catalytic triad residue Ser198, the acyl pocket Leu286 and adjacent Phe329 residues, and Met437 and Tyr440 located near the choline binding site. Mutant proteins were produced in microinjected Xenopus oocytes, and Km values towards butyrylthiocholine and IC50 values for the organophosphates diisopropylfluorophosphonate (DFP), diethoxyphosphinylthiocholine iodide (echothiophate), and tetraisopropylpyrophosphoramide (iso-OMPA) were determined. Substitution of Ser198 by cysteine and Met437 by aspartate nearly abolished activity, and other mutations of Ser198 completely abolished it. Tyr440 and Leu286 mutants remained active, but with higher Km and IC50 values. Rates of inhibition by DFP were roughly parallel to IC50 values for several Leu286 mutants. Both Km and IC50 values increased for Leu286 mutants in the order Asp < Gln < Lys. In contrast, cysteine, leucine, and glutamine mutants of Phe329 displayed unmodified Km values toward butyrylthiocholine, but up to 10-fold decreased IC50 values for DFP, iso-OMPA, and echothiophate. These findings add Tyr440 and Phe329 to the list of residues interacting with substrate and ligands, demonstrate plasticity in the active site region of BCHE, and foreshadow the design of recombinant BCHEs with tailored scavenging properties.
ESTHER : Gnatt_1994_J.Neurochem_62_749
PubMedSearch : Gnatt_1994_J.Neurochem_62_749
PubMedID: 8294937

Title : Antisense inhibition of acetylcholinesterase gene expression causes transient hematopoietic alterations in vivo - Lev-Lehman_1994_Gene.Ther_1_127
Author(s) : Lev-Lehman E , Ginzberg D , Hornreich G , Ehrlich G , Meshorer A , Eckstein F , Soreq H , Zakut H
Ref : Gene Therapy , 1 :127 , 1994
Abstract : Hematopoietic acetylcholinesterase (ACHE) gene expression and its implication for development were studied by in vivo administration to mice of an antisense phosphorothioate oligonucleotide targetted toward ACHE (AS-ACHE). Hematopoietic alterations were observed by differential cell counts and ACHE mRNA levels determined by quantified RNA polymerase chain reaction (RNA-PCR) and in situ hybridization analyses. In control mice, injected with phosphate-buffered saline and untreated, ACHE mRNA labeling with ACHE [35S]cRNA was about 10-fold higher on megakaryocytes (MK) compared with all other bone marrow cells and increased by 20-fold during MK development, similar to reports for MK actin mRNA. Drastic reductions occurred in the bone marrow lymphocyte and erythroid fractions 12 days following intraperitoneal injection of AS-ACHE (5 micrograms/g weight) into groups of four mice. RNA-PCR revealed over 1000-fold decreases in ACHE mRNA levels in lymph nodes and bone marrow at this time, while actin mRNA levels dropped by 10 and 100-fold in lymph nodes and bone marrow of AS-ACHE treated mice compared with controls. In view of the developmental increase in MK actin, this suggested arrest in MK development as well. By 20 days postinjection, bone marrow actin mRNA was fully restored and the sensitive in situ hybridization technique revealed that ACHE mRNA levels were also restored and reached levels only 2-3-fold lower than in controls in all bone marrow cells of AS-ACHE treated mice. Moreover, lymphocytes and erythroid cells repopulated to levels 25% above normal, and promegakaryocyte and mature MK fractions of the total MK were 3 and 2-fold higher, respectively, than in controls.
ESTHER : Lev-Lehman_1994_Gene.Ther_1_127
PubMedSearch : Lev-Lehman_1994_Gene.Ther_1_127
PubMedID: 7584068

Title : Antisense oligonucleotide inhibition of acetylcholinesterase gene expression induces progenitor cell expansion and suppresses hematopoietic apoptosis ex vivo - Soreq_1994_Proc.Natl.Acad.Sci.U.S.A_91_7907
Author(s) : Soreq H , Patinkin D , Lev-Lehman E , Grifman M , Ginzberg D , Eckstein F , Zakut H
Ref : Proc Natl Acad Sci U S A , 91 :7907 , 1994
Abstract : To examine the role of acetylcholinesterase (EC in hematopoietic cell proliferation and differentiation, we administered a 15-mer phosphorothioate oligonucleotide, antisense to the corresponding ACHE gene (AS-ACHE), to primary mouse bone marrow cultures. Within 2 hr of AS-ACHE addition to the culture, ACHE mRNA levels dropped by approximately 90%, as compared with those in cells treated with the "sense" oligomer, S-ACHE. Four days after AS-ACHE treatment, ACHE mRNA increased to levels 10-fold higher than in S-ACHE cultures or in fresh bone marrow. At this later time point, differential PCR display revealed significant differences between cellular mRNA transcripts in bone marrow and those in AS-ACHE- or S-ACHE-treated cultures. These oligonucleotide-triggered effects underlay considerable alterations at the cellular level: AS-ACHE but not S-ACHE increased cell counts, reflecting enhanced proliferation. In the presence of erythropoietin it also enhanced colony counts, reflecting expansion of progenitors. AS-ACHE further suppressed apoptosis-related fragmentation of cellular DNA in the progeny cells, and it diverted hematopoiesis toward production of primitive blasts and macrophages in a dose-dependent manner promoted by erythropoietin. These findings suggest that the hematopoietic role of acetylcholinesterase, anticipated to be inverse to the observed antisense effects, is to reduce proliferation of the multipotent stem cells committed to erythropoiesis and megakaryocytopoiesis and macrophage production and to promote apoptosis in their progeny. Moreover, these findings may explain the tumorigenic association of perturbations in ACHE gene expression with leukemia.
ESTHER : Soreq_1994_Proc.Natl.Acad.Sci.U.S.A_91_7907
PubMedSearch : Soreq_1994_Proc.Natl.Acad.Sci.U.S.A_91_7907
PubMedID: 8058733

Title : Cholinotoxic effects on acetylcholinesterase gene expression are associated with brain-region specific alterations in G,C-rich transcripts - Lev-Lehman_1994_Brain.Res_661_75
Author(s) : Lev-Lehman E , el-Tamer A , Yaron A , Grifman M , Ginzberg D , Hanin I , Soreq H
Ref : Brain Research , 661 :75 , 1994
Abstract : To study the mechanisms underlying cholinotoxic brain damage, we examined ethylcholine aziridinium (AF64A) effects on cholinesterase genes. In vitro, AF64A hardly affected cholinesterase activities yet inhibited transcription of the G,C-rich AChE DNA encoding acetylcholinesterase (AChE) more than the A,T-rich butyrylcholinesterase (BChE) DNA. In vivo, intracerebroventricular injection of 2 nmol of AF64A decreased AChE mRNA in striatum and septum by 3- and 25-fold by day 7, with no change in BChE mRNA or AChE activity. In contrast, hippocampal AChE mRNA increased 10-fold by day 7 and BChE mRNA and AChE activity decreased 2-fold. By day 60 post-treatment, both AChE mRNA and AChE levels returned to normal in all regions except hippocampus, where AChE activity and BChE mRNA were decreased by 2-fold. Moreover, differential PCR displays revealed persistent induction, specific to the hippocampus of treated rats, of several unidentified G,C-rich transcripts, suggesting particular responsiveness of hippocampal G,C-rich genes to cholinotoxicity.
ESTHER : Lev-Lehman_1994_Brain.Res_661_75
PubMedSearch : Lev-Lehman_1994_Brain.Res_661_75
PubMedID: 7834388

Title : Antisense inhibition of butyrylcholinesterase gene expression predicts adverse hematopoietic consequences to cholinesterase inhibitors - Patinkin_1994_Cell.Mol.Neurobiol_14_459
Author(s) : Patinkin D , Lev-Lehman E , Zakut H , Eckstein F , Soreq H
Ref : Cellular Molecular Neurobiology , 14 :459 , 1994
Abstract : 1. To investigate the possibility that cholinesterase inhibitors may cause adverse hematopoietic effects, we employed antisense oligodeoxynucleotides selectively inhibiting butyrylcholinesterase gene expression (AS-BCHE). Complementary sense (S) oligonucleotides served as controls. 2. In primary bone marrow cell cultures grown with interleukin 3 (IL-3), AS-BCHE but not S-BCHE reduced growth of megakaryocyte colony-forming units (CFU-MK) in a dose-dependent manner at the micromolar range. 3. In cultures grown with IL-3, transferrin, and erythropoietin (Epo), cell counts increased up to twofold, yet colony counts (CFU-GEMM) remained unchanged under AS-BCHE treatment. 4. Electrophoretic measurements of DNA ladder as an apoptotic index revealed that the above oligonucleotide effects were not due to nonspecific induction of programmed cell death. 5. Differential cell counts demonstrated increased myeloidogenesis and reduced levels of early megakaryocytes in CFU-GEMM under AS-BCHE, suggesting requirement of the BCHE protein for megakaryopoiesis. 6. In vivo injection of AS-BCHE reduced BCHE mRNA levels in both young and mature megakaryocytes for as long as 20 days, as shown by in situ hybridization. 7. Ex vivo growth of primary bone marrow cells revealed a twofold reduction in CFU-MK colonies grown from the AS-BCHE- but not the S-BCHE-injected mice, 15 days posttreatment. 8. These findings demonstrate that deficient butyrylcholinesterase expression, and hence interference with this enzyme's activity through treatment with or exposure to cholinesterase inhibitors, may cause hematopoietic differences in treated patients.
ESTHER : Patinkin_1994_Cell.Mol.Neurobiol_14_459
PubMedSearch : Patinkin_1994_Cell.Mol.Neurobiol_14_459
PubMedID: 7621507

Title : Transgenic engineering of neuromuscular junctions in Xenopus laevis embryos transiently overexpressing key cholinergic proteins - Shapira_1994_Proc.Natl.Acad.Sci.U.S.A_91_9072
Author(s) : Shapira M , Seidman S , Sternfeld M , Timberg R , Kaufer D , Patrick J , Soreq H
Ref : Proceedings of the National Academy of Sciences of the United States of America , 91 :9072 , 1994
Abstract : To examine the role of key cholinergic proteins in the formation of neuromuscular junctions (NMJs), we expressed DNAs encoding the mouse muscle nicotinic acetylcholine receptor (nAChR) or human brain and muscle acetylcholinesterase (hAChE) in developing Xenopus laevis embryos. Acetylthiocholine hydrolysis and alpha-bungarotoxin binding in homogenates of transgenic embryos revealed transient overexpression of the respective proteins for at least 4 days postfertilization. Moreover, hAChE injection induced an approximately 2-fold increase in endogenous Xenopus nAChR. Electron microscopy coupled with cytochemical staining for AChE activity revealed that AChE-stained areas, which reached 0.17 microns2 in NMJs of control embryos raised at 21 degrees C, increased up to 0.53 and 0.60 microns2 in nAChR and hAChE transgenics, respectively. These increases coincided with the appearance of a class of large NMJs with average postsynaptic lengths up to 1.8-fold greater than controls. As much as 57% and 34% of the NMJs in animals transgenic for nAChR and hAChE, respectively, displayed AChE activity in nerve terminals in addition to muscle labeling, as compared with 10% nerve-labeled NMJs in control animals. Moreover, area, but not length values, were > 2-fold larger in hAChE-expressing NMJs labeled in their nerve terminals than in those labeled in muscle alone, reflecting a hAChE-induced increase in synaptic cleft width. These findings indicate that modulation of cholinergic neurotransmission in NMJs modifies the features of nerve-muscle connections.
ESTHER : Shapira_1994_Proc.Natl.Acad.Sci.U.S.A_91_9072
PubMedSearch : Shapira_1994_Proc.Natl.Acad.Sci.U.S.A_91_9072
PubMedID: 8090771

Title : Overexpressed monomeric human acetylcholinesterase induces subtle ultrastructural modifications in developing neuromuscular junctions of Xenopus laevis embryos - Seidman_1994_J.Neurochem_62_1670
Author(s) : Seidman S , Aziz-Aloya RB , Timberg R , Loewenstein Y , Velan B , Shafferman A , Liao J , Norgaard-Pedersen B , Brodbeck U , Soreq H
Ref : Journal of Neurochemistry , 62 :1670 , 1994
Abstract : Formation of a functional neuromuscular junction (NMJ) involves the biosynthesis and transport of numerous muscle-specific proteins, among them the acetylcholine-hydrolyzing enzyme acetylcholinesterase (AChE). To study the mechanisms underlying this process, we have expressed DNA encoding human AChE downstream of the cytomegalovirus promoter in oocytes and developing embryos of Xenopus laevis. Recombinant human AChE (rHAChE) produced in Xenopus was biochemically and immunochemically indistinguishable from native human AChE but clearly distinguished from the endogenous frog enzyme. In microinjected embryos, high levels of catalytically active rHAChE induced a transient state of over-expression that persisted for at least 4 days postfertilization. rHAChE appeared exclusively as nonassembled monomers in embryos at times when endogenous Xenopus AChE displayed complex oligomeric assembly. Nonetheless, cell-associated rHAChE accumulated in myotomes of 2- and 3-day-old embryos within the same subcellular compartments as native Xenopus AChE. NMJs from 3-day-old DNA-injected embryos displayed fourfold or greater overexpression of AChE, a 30% increase in postsynaptic membrane length, and increased folding of the postsynaptic membrane. These findings indicate that an evolutionarily conserved property directs the intracellular trafficking and synaptic targeting of AChE in muscle and support a role for AChE in vertebrate synaptogenesis.
ESTHER : Seidman_1994_J.Neurochem_62_1670
PubMedSearch : Seidman_1994_J.Neurochem_62_1670
PubMedID: 8158119

Title : Testicular amplification and impaired transmission of human butyrylcholinesterase cDNA in transgenic mice - Beeri_1994_Hum.Reprod_9_284
Author(s) : Beeri R , Gnatt A , Lapidot-Lifson Y , Ginzberg D , Shani M , Soreq H , Zakut H
Ref : Hum Reprod , 9 :284 , 1994
Abstract : Gene amplification occurs frequently in tumour tissues yet is, in general, non-inheritable. To study the molecular mechanisms conferring this restraint, we created transgenic mice carrying a human butyrylcholinesterase (BCHE) coding sequence, previously found to be amplified in a father and son. Blot hybridization of tail DNA samples revealed somatic transgene amplifications with variable restriction patterns and intensities, suggesting the occurrence of independent amplification events, in 31% (11/35) of mice from the FII generation but in only 3.5% (2/58) of the FIII and FIV generations. In contrast, > 10-fold amplifications of the BCHE transgene and the endogenous acetylcholinesterase and c-raf genes appeared in both testis and epididymis DNA from > 80% of FIII mice. Drastic, selective reductions in testis BCHEmRNA but not in actin mRNA were detected by the PCR amplification of testis cDNA from the transgenic mice, and apparently resulted in the limited transmission of amplified genes. The testicular amplification of the BCHE transgene may potentially represent a general phenomenon with clinical implications in human infertility.
ESTHER : Beeri_1994_Hum.Reprod_9_284
PubMedSearch : Beeri_1994_Hum.Reprod_9_284
PubMedID: 8027285

Title : Expression of three alternative acetylcholinesterase messenger RNAs in human tumor cell lines of different tissue origins - Karpel_1994_Exp.Cell.Res_210_268
Author(s) : Karpel R , Ben-Aziz-Aloya R , Sternfeld M , Ehrlich G , Ginzberg D , Tarroni P , Clementi F , Zakut H , Soreq H
Ref : Experimental Cell Research , 210 :268 , 1994
Abstract : To study the molecular mechanisms underlying the intensive expression of acetylcholinesterase (AChE) in different tumor types, we characterized levels and composition of its messenger RNA (mRNA) sequences in heterologous tumor cell lines, primary tumor biopsies, and normal fetal and adult tissues and determined their exon-intron origin within the corresponding ACHE gene. Reverse transcription followed by polymerase chain reaction (RT-PCR) revealed three alternatively spliced ACHE mRNAs in NT2/D1 teratocarcinoma, NCI-N-592 small cell lung carcinoma, TE671 medulloblastoma, K-562 erythroleukemia, and 293 transformed embryonal kidney cells. The three ACHE mRNAs include the principal species expressed in brain and muscle and two additional transcripts containing insertions of 751 or 829 residues downstream from the exon 4 domain. The inserted region, which represents an intron in brain and muscle, is expressed in the tumor cell lines either as a "readthrough" form or with 78 residues deleted from its 5' end. A major band of 2.5 kb was labeled with ACHE cDNA in poly(A)+ RNA blots from medulloblastoma cells or brain tissue, whereas a PCR-amplified probe from the inserted domain labeled a 3.4-kb band but not the 2.5-kb band in poly(A)+ RNA from small cell lung carcinoma. The ACHE mRNAs including the alternative insertions were found only in cell lines with levels of the principal ACHE mRNA species equal to or higher than those in brain (1-10 molecules/cell), determined by following the kinetics of mRNA PCR amplification. Genomic DNA sequencing revealed that the inserted domains in the ACHE mRNAs expressed in the tumor cell lines encode C-terminal peptides of 40 and 14 residues. These include a free cysteine, terminate with the consensus HG element, and continue by a 29-residue-long C-terminal hydrophobic cleavable peptide, properties characteristic of precursors to phosphoinositide (PI)-linked proteins. In extension of the reported expression of PI-linked AChE in hemopoietic cells including K-562, our findings demonstrate the existence of ACHE mRNAs with the potential to encode one hydrophilic and two PI-linked forms of AChE in tumor cells from both hemopoietic and nonhemopoietic origins.
ESTHER : Karpel_1994_Exp.Cell.Res_210_268
PubMedSearch : Karpel_1994_Exp.Cell.Res_210_268
PubMedID: 8299725

Title : Population diversity and distinct haplotype frequencies associated with ACHE and BCHE genes of Israeli Jews from trans-Caucasian Georgia and from Europe - Ehrlich_1994_Genomics_22_288
Author(s) : Ehrlich G , Ginzberg D , Loewenstein Y , Glick D , Kerem B , Ben-Ari S , Zakut H , Soreq H
Ref : Genomics , 22 :288 , 1994
Abstract : Variant alleles of the butyrylcholinesterase gene, BCHE, have often been used to trace the genetic histories of populations. The D70G substitution in BCHE causes prolonged postanesthesia apnea ("atypical" phenotype); H322N substitution in the closely related acetylcholinesterase gene, ACHE, is the basis of the mutually incompatible Yt blood groups. In both genes, additional point mutations were reported to be linked to these phenotypically evident ones. To examine whether the intragenic linkage reported for the ACHE and BCHE mutations in Americans is universal, we studied frequencies of these mutations in trans-Caucasian Georgian Jews, a population that has remained relatively isolated for 1500 years. To this end we employed PCR amplification followed by DNA sequencing and enzymatic restriction and compared the frequencies we found to corresponding reported phenotype data. Georgian Jews' N322 ACHE was a rather low 7.0% and was totally linked to a P446 mutation, in agreement with a recent report. In BCHE, however, G70 was a relatively high 5.8%, and the V497 and T539 mutations were not found, either in Georgian or in Ashkenazi Jews, in contrast to reported findings in Americans. Our findings reveal distinct displays of ACHE and BCHE haplotypes in Georgian Jews and suggest different founder effects, genetic drifts, and/or selection pressures in the evolution of each of these genes.
ESTHER : Ehrlich_1994_Genomics_22_288
PubMedSearch : Ehrlich_1994_Genomics_22_288
PubMedID: 7806214

Title : Mutations and impaired expression in the ACHE and BCHE genes: neurological implications - Soreq_1994_Biomed.Pharmacother_48_253
Author(s) : Soreq H , Ehrlich G , Schwarz M , Loewenstein Y , Glick D , Zakut H
Ref : Biomed Pharmacother , 48 :253 , 1994
Abstract : The acetylcholine hydrolysing cholinesterases control the termination of cholinergic signalling in multiple tissues and are targets for a variety of drugs, natural and man-made poisons and common insecticides. Molecular cloning and gene mapping studies revealed the primary structure of human acetyl- and butyrylcholinesterase and localized the corresponding ACHE and BCHE genes to the chromosomal positions 3q26-ter and 7q22, respectively. Several different point mutations in the coding region of BCHE were found to be particularly abundant in the Israeli population. Analytical expression studies in microinjected Xenopus oocytes have demonstrated that the biochemical properties of cholinesterases may be modified by rationalized site-directed mutagenesis and in chimeric ACHE/BCHE constructs. These properties are differently altered in the various allelic BCHE variants, conferring resistance to several anti-cholinesterases, which may explain the evolutionary emergence of these multiple alleles. At the clinical level, abnormal expression of both ACHE and BCHE and the in vivo amplification of the ACHE and BCHE genes has been variously associated with abnormal megakaryocytopoiesis, leukemias and brain and ovarian tumors. Moreover, antisense oligonucleotides blocking the expression of these genes were shown to interfere with hemocytopoiesis in culture, implicating these genes in cholinergic influence on cell growth and proliferation.
ESTHER : Soreq_1994_Biomed.Pharmacother_48_253
PubMedSearch : Soreq_1994_Biomed.Pharmacother_48_253
PubMedID: 7999987

Title : Use of partially phosphorothioated antisense oligodeoxynucleotides for sequence-dependent modulation of hematopoiesis in culture - Ehrlich_1994_Antisense.Res.Dev_4_173
Author(s) : Ehrlich G , Patinkin D , Ginzberg D , Zakut H , Eckstein F , Soreq H
Ref : Antisense Research Development , 4 :173 , 1994
Abstract : To distinguish between sequence-dependent effects and non-specific cytotoxicity of phosphorothioate antisense oligonucleotides (AS-oligos), we introduced AS-oligos blocking expression of 2Hs, the Homo sapiens cell division controller cdc2 kinase, its hematopoietically expressed homolog CHED, and the acetylcholine-hydrolyzing enzyme butyrylcholinesterase (BCHE) into primary murine bone marrow (BM) culture. Antisense oligonucleotides were fully phosphorothioated (Ts) or prepared with three phosphorothioate groups at their 3' termini (S3). Each of these oligos could cause reductions in colony counts either as a result of its sequence-dependent biological capacity or due to sequence-independent cytotoxicity. The Ts and S3 forms of the matching sense oligo, S-BCHE, served for comparison. The S3 forms of AS-2Hs, AS-BCHE, and S-BCHE caused more limited drops in colony counts than their Ts counterparts, reflecting lower cytotoxicity. When incubated with electroblotted BM proteins, Ts but not S3 oligos intensively labeled two protein bands. Moreover, 5'-end 32P-labeled (Ts) S-BCHE labeled nuclear proteins in situ in small, mitotic cells, suggesting correlation between oligo-protein interactions and the sequence-independent cytotoxicity of Ts AS-oligos. Extension of the apparently nontoxic AS-CHED by two adenosine residues at the 3' end, creating a potential for intramolecular hydrogen bond formation, resulted in increased toxicity. These findings recommend the use of nonlooped, partially phosphorothioated oligos for the modulation of hematopoiesis.
ESTHER : Ehrlich_1994_Antisense.Res.Dev_4_173
PubMedSearch : Ehrlich_1994_Antisense.Res.Dev_4_173
PubMedID: 7849488

Title : Promoter elements and alternative splicing in the human ACHE gene -
Author(s) : Ben-Aziz-Aloya R , Sternfeld M , Soreq H
Ref : Progress in Brain Research , 98 :147 , 1993
PubMedID: 8248502

Title : Chimeric human cholinesterase. Identification of interaction sites responsible for recognition of acetyl- or butyrylcholinesterase-specific ligands - Loewenstein_1993_J.Mol.Biol_234_289
Author(s) : Loewenstein Y , Gnatt A , Neville LF , Soreq H
Ref : Journal of Molecular Biology , 234 :289 , 1993
Abstract : Acetyl- and butyrylcholinesterases (AChE, BCHE) from various species differ in their substrate specificities and sensitivities to a wide range of inhibitors, yet display conserved sequence, structure and catalytic properties. To determine features that confer these selective properties, residues 58 through 133 of recombinant human BCHE were replaced with the corresponding sequence from human AChE. The replaced region (> 60% identity) spans the Asp70 residue, important for ligand interactions, and the choline binding site, and introduces differences of charge and hydrophobicity in the outer rim and on the surface of the active site gorge. Expressed in microinjected Xenopus laevis oocytes, the resultant chimera retained the catalytic activity, substrate specificity and the Km value toward butyrylthiocholine characteristic of BCHE. Further, it did not acquire substrate inhibition, which is unique to AChE, although it lost the property of substrate activation, characteristic of BCHE. Moreover, the chimera resembled BCHE in its sensitivity to succinylcholine and physostigmine, but acquired the AChE-like sensitivity to echothiophate and iso-OMPA, and displayed an intermediate pattern of inhibition, more similar to that of AChE than of BCHE, toward bambuterol, dibucaine and BW284C51. These findings demonstrate that the exchanged residues are involved in inhibitor recognition, but not in substrate distinction and in direct catalysis. Furthermore, substrate interaction with the exchanged domain may mediate structural changes leading to substrate activation in BCHE and inhibition in AChE. The two AChE-specific aromatic tyrosine residues positioned near Asp70 within this region are hence implicated in the peripheral anionic site of cholinesterases, which is involved in the recognition of various ligands.
ESTHER : Loewenstein_1993_J.Mol.Biol_234_289
PubMedSearch : Loewenstein_1993_J.Mol.Biol_234_289
PubMedID: 8230213

Title : Structure-function relationship studies in human cholinesterases reveal genomic origins for individual variations in cholinergic drug responses. - Loewenstein_1993_Prog.Neuropsychopharmacol.Biol.Psychiatry_17_905
Author(s) : Loewenstein Y , Gnatt A , Neville LF , Zakut H , Soreq H
Ref : Prog Neuropsychopharmacol Biological Psychiatry , 17 :905 , 1993
Abstract : 1. Due to their involvement in the termination of neurotransmission at cholinergic synapses and neuromuscular junctions, cholinesterases are the target proteins for numerous drugs of neuro-psychopharmacology importance. 2. In order to perform structure-function relationship studies on human cholinesterases with respect to such drugs, a set of expression vectors was engineered, all of which include cloned cDNA inserts encoding various forms of human acetyl- and butyrylcholinesterase. These vectors were designed to be transcribed in vitro into their corresponding mRNA products which, when microinjected into Xenopus oocytes, are efficiently translated to yield their catalytically active enzymes, each with its distinct substrate specificity and sensitivity to selective inhibitors. 3. A fully automated microtiter plate assay for evaluating the inhibition of said enzymes by tested cholinergic drugs and/or poisons has been developed, in conjunction with computerized data analysis, which offers prediction of such inhibition data on the authentic human enzymes and their natural or mutagenized variants. 4. Thus, it was found that asp70-->gly substitution renders butyrylcholinesterase succinylcholine insensitive and resistant to oxime reactivation while ser 425-->Pro with gly70 gives rise to the "atypical" butyrylcholinesterase phenotype, abolishing dibucaine binding. 5. Furthermore, differences in cholinesterase affinities to physostigmine, ecothiophate and bambuterol were shown in these natural variants. 6. Definition of key residues important for drug interactions may initiate rational design of more specific cholinesterase inhibitors, with fewer side effects. This, in turn, offers therapeutic potential in the treatment of clinical syndromes such as Alzheimer's and Parkinson's disease, glaucoma and myasthenia gravis.
ESTHER : Loewenstein_1993_Prog.Neuropsychopharmacol.Biol.Psychiatry_17_905
PubMedSearch : Loewenstein_1993_Prog.Neuropsychopharmacol.Biol.Psychiatry_17_905
PubMedID: 8278601

Title : Expression of a human acetylcholinesterase promoter-reporter construct in developing neuromuscular junctions of Xenopus embryos - Ben-Aziz-Aloya_1993_Proc.Natl.Acad.Sci.U.S.A_90_2471
Author(s) : Ben-Aziz-Aloya R , Seidman S , Timberg R , Sternfeld M , Zakut H , Soreq H
Ref : Proceedings of the National Academy of Sciences of the United States of America , 90 :2471 , 1993
Abstract : We have employed Xenopus embryos to express human acetylcholinesterase (AcChoEase; EC in developing synapses. Transcription of AcChoEase mRNA was driven by a 2.2-kb sequence upstream from the initiator AUG in the ACHE gene encoding AcChoEase, with multiple potential sites for binding universal and tissue-specific transcription factors. These included clustered MyoD elements, E-box, SP1, EGR1, AP-2, and the development-related GAGA motif. A DNA construct composed of this sequence linked to a 2.1-kb sequence encoding human AcChoEase was designated human AcChoEase promoter-reporter (HpACHE). HpACHE but none of its several 5'-truncated derivatives was transcriptionally active in developing Xenopus embryos. Furthermore, PCR analysis using chimeric PCR primers revealed usage of the same 1.5-kb intron and 74-bp exon within the HpACHE sequence in microinjected embryos and various human tissues. Cytochemical staining revealed conspicuous accumulation of overexpressed AcChoEase in neuromuscular junctions and within muscle fibers of apparently normal 2-day Xenopus embryos injected with HpACHE. The same reporter driven by the cytomegalovirus promoter was similarly efficient in directing the heterologous human enzyme toward neuromuscular junctions, attributing the evolutionary conservation of AcChoEase targeting to the coding sequence. Our findings demonstrate that a short DNA sequence is sufficient to promote the exogenous transcription and faithful splicing of human AcChoEase mRNA in developing Xenopus embryos and foreshadow their use for integrative studies of cholinergic signaling and synapse formation.
ESTHER : Ben-Aziz-Aloya_1993_Proc.Natl.Acad.Sci.U.S.A_90_2471
PubMedSearch : Ben-Aziz-Aloya_1993_Proc.Natl.Acad.Sci.U.S.A_90_2471
PubMedID: 8460160

Title : Molecular dissection of cholinesterase domains responsible for carbamate toxicity - Loewenstein_1993_Chem.Biol.Interact_87_209
Author(s) : Loewenstein Y , Denarie M , Zakut H , Soreq H
Ref : Chemico-Biological Interactions , 87 :209 , 1993
Abstract : Carbamate compounds marked for their cholinesterase (ChE) inhibition are widely used as therapeutics and as insecticides. Groups of closely related carbamate molecules provide an important tool in the understanding of the domains responsible for binding these ligands to ChEs. Comparative inhibition profiles were derived for five N-methyl carbamates, mostly carbofuran derivatives, differing in length and branching of their hydrocarbonic chain towards human erythrocyte acetylcholinesterase (H.AChE), human serum butyrylcholinesterase (H.BChE) in its normal form or in a mutant form containing the point mutation Asp70-->Gly, and Drosophila nervous system ChE. Carbofuran was more toxic to all three ChEs than any of the other derivatives, with IC50 values which differed by more than 1000-fold. Drosophila ChE appeared to be most sensitive to all of the examined carbamates, and H.AChE was consistently more sensitive than H.BChE. Moreover, inhibition efficiency for H.BChE decreased more effectively than it did for H.AChE with increased length and complexity of the side chain, indicating less flexible carbamate binding site in BChE as compared with AChE. The Asp70-->Gly mutation had no apparent effect on H.BChE inhibition by N-methyl carbamates, suggesting that the Asp70 domain localized near the rim of the active site groove is not important in carbamate binding. Comparison of the carbamate IC50 values with published LD50 values demonstrated correlation between the in vivo toxicity and inhibition of BChE by carbamates, suggesting a biological in addition to scavenging importance for BChE in mammals. Pinpointing different domains characteristic of carbamate binding in each member of the ChE family can thus shed light on the variable toxicity of these inhibitors to insects and mammals, predict the toxicity of yet untested inhibitor molecules and help in designing novel and improved ChE inhibitors.
ESTHER : Loewenstein_1993_Chem.Biol.Interact_87_209
PubMedSearch : Loewenstein_1993_Chem.Biol.Interact_87_209
PubMedID: 8343977

Title : [Medical aspects and structural implications of cholinesterase inhibitors] -
Author(s) : Soreq H , Meir R , Zakut H
Ref : Harefuah , 123 :100 , 1992
PubMedID: 1516859

Title : Excavations into the active-site gorge of cholinesterases. - Soreq_1992_Trends.Biochem.Sci_17_353
Author(s) : Soreq H , Gnatt A , Loewenstein Y , Neville LF
Ref : Trends in Biochemical Sciences , 17 :353 , 1992
Abstract : Acetyl- and butyrylcholinesterase (ACHE, BCHE) from evolutionarily distant species display a high degree of primary sequence homology and have biochemically similar catalytic properties, yet they differ in substrate specificity and affinity for various inhibitors. The biochemical information derived from analyses of ACHE and BCHE from human, Torpedo, mouse, and Drosophila, as well as that from the recombinant forms of their natural variants and site-directed mutants, can currently be re-examined in view of the recent X-ray crystallography data revealing the three-dimensional structure of Torpedo ACHE. The picture that emerges deepens the insight into the biochemical basis for choline ester catalysis and the complex mechanism of interaction between cholinesterases and their numerous ligands.
ESTHER : Soreq_1992_Trends.Biochem.Sci_17_353
PubMedSearch : Soreq_1992_Trends.Biochem.Sci_17_353
PubMedID: 1412713

Title : Cloning and antisense oligodeoxynucleotide inhibition of a human homolog of cdc2 required in hematopoiesis - Lapidot-Lifson_1992_Proc.Natl.Acad.Sci.U.S.A_89_579
Author(s) : Lapidot-Lifson Y , Patinkin D , Prody CA , Ehrlich G , Seidman S , Ben-Aziz R , Benseler F , Eckstein F , Zakut H , Soreq H
Ref : Proc Natl Acad Sci U S A , 89 :579 , 1992
Abstract : Mechanisms triggering the commitment of pluripotent bone marrow stem cells to differentiated lineages such as mononuclear macrophages or multinucleated megakaryocytes are still unknown, although several lines of evidence suggested correlation between cholinergic signaling and hematopoietic differentiation. We now present cloning of a cDNA coding for CHED (cholinesterase-related cell division controller), a human homolog of the Schizosaccharomyces pombe cell division cycle 2 (cdc2)-like kinases, universal controllers of the mitotic cell cycle. Library screening, RNA blot hybridization, and direct PCR amplification of cDNA reverse-transcribed from cellular mRNA revealed that CHED mRNA is expressed in multiple tissues, including bone marrow. The CHED protein includes the consensus ATP binding and phosphorylation domains characteristic of kinases, displays 34-42% identically aligned amino acid residues with other cdc2-related kinases, and is considerably longer at its amino and carboxyl termini. An antisense oligodeoxynucleotide designed to interrupt CHED's expression (AS-CHED) significantly reduced the ratio between CHED mRNA and actin mRNA within 1 hr of its addition to cultures, a reduction that persisted for 4 days. AS-CHED treatment selectively inhibited megakaryocyte development in murine bone marrow cultures but did not prevent other hematopoietic pathways, as evidenced by increasing numbers of mononuclear cells. An oligodeoxynucleotide blocking production of the acetylcholine-hydrolyzing enzyme, butyrylcholinesterase, displayed a similar inhibition of megakaryocytopoiesis. In contrast, an oligodeoxynucleotide blocking production of the human 2Hs cdc2 homolog interfered with production of the human 2Hs cdc2 homolog interfered with cellular proliferation without altering the cell-type composition of these cultures. Therefore, these findings strengthen the link between cholinergic signaling and cell division control in hematopoiesis and implicate both CHED and cholinesterases in this differentiation process.
ESTHER : Lapidot-Lifson_1992_Proc.Natl.Acad.Sci.U.S.A_89_579
PubMedSearch : Lapidot-Lifson_1992_Proc.Natl.Acad.Sci.U.S.A_89_579
PubMedID: 1731328

Title : In vivo gene amplification in non-cancerous cells: cholinesterase genes and oncogenes amplify in thrombocytopenia associated with lupus erythematosus - Zakut_1992_Mut.Res_276_275
Author(s) : Zakut H , Lapidot-Lifson Y , Beeri R , Ballin A , Soreq H
Ref : Mutation Research , 276 :275 , 1992
Abstract : The ACHE and BCHE genes, encoding the acetylcholine hydrolysing enzymes acetylcholinesterase (ACHE) and butyrylcholinesterase (BCHE), co-amplify with several oncogenes in leukemic patients with platelet deficiency (thrombocytopenia). This and other experiments implicated ACHE and BCHE in the development of bone marrow megakaryocytes, the progenitors of platelets. Therefore, we wished to find out whether cholinesterase gene amplification would also occur in non-cancerous platelet disorders and, if so, whether oncogenes would amplify in such cases as well. The autoimmune disease systemic lupus erythematosus (SLE) presents an appropriate model system for this issue, since patients with SLE may suffer from thrombocytopenia resistant to most treatment modalities. Here, we report a 40-80-fold amplification of genomic sequences from the ACHE and BCHE genes as well as the C-raf, V-sis and C-fes/fps oncogenes in peripheral blood cells from an SLE patient with severe thrombocytopenia. PvuII restriction analysis and DNA blot hybridization of the amplified ACHE and BCHE sequences demonstrated apparent aberrations in both genes, suggesting that malfunctioning of modified, partially amplified cholinesterase genes may be involved in the etiology of thrombocytopenia associated with SLE. These observations imply that cholinergic mechanisms regulate megakaryocytopoiesis, shed new light on the diverse hematologic findings characteristic of SLE, and may become valuable as diagnostic, treatment and prognostic tools in the follow-up of patients suffering from thrombocytopenia associated with SLE. Furthermore, these findings reinforce the notion that cholinesterase gene amplifications are causally related with platelet abnormalities in multiple hemopoietic disorders.
ESTHER : Zakut_1992_Mut.Res_276_275
PubMedSearch : Zakut_1992_Mut.Res_276_275
PubMedID: 1374519

Title : Mapping the human acetylcholinesterase gene to chromosome 7q22 by fluorescent in situ hybridization coupled with selective PCR amplification from a somatic hybrid cell panel and chromosome-sorted DNA libraries - Ehrlich_1992_Genomics_13_1192
Author(s) : Ehrlich G , Viegas-Pequignot E , Ginzberg D , Sindel L , Soreq H , Zakut H
Ref : Genomics , 13 :1192 , 1992
Abstract : To establish the chromosomal location of the human ACHE gene encoding the acetylcholine hydrolyzing enzyme acetylcholinesterase (ACHE, acetylcholine acetylhydrolase, E.C., a human-specific polymerase chain reaction (PCR) procedure that supports the selective amplification of ACHE DNA fragments from human genomic DNA was employed with 19 human-hamster somatic cell hybrids carrying one or more human chromosomes. Informative ACHE-specific PCR fragments were produced from two cell lines, both of which include human chromosome 7, but not with DNA from 17 cell hybrids carrying various combinations of all human chromosomes other than 7. Fluorescent in situ hybridization of biotinylated ACHE DNA with metaphase chromosomes from human peripheral blood lymphocytes revealed prominent labeling on the 7q22 position. Therefore, further tests were performed to confirm the chromosome 7 location. DNA samples from the two cell lines including chromosome 7 and the ACHE gene were positive with PCR primers informative for the human cystic fibrosis CFTR gene, known to reside at the 7q31.1 position, but negative for the ACHE-related butyrylcholinesterase (BCHE, acylcholine acylhydrolase, E.C. gene, mapped at the 3q26-ter position, confirming that these lines contain chromosome 7 but not chromosome 3. In contrast, three other cell lines including chromosome 3, but not 7, were BCHE-positive and ACHE-negative. In addition, genomic DNA from a sorted chromosome 7 library supported the production of ACHE- but not BCHE-specific PCR products, whereas with DNA from a sorted chromosome 3 library, the BCHE but not the ACHE fragment was amplified.
ESTHER : Ehrlich_1992_Genomics_13_1192
PubMedSearch : Ehrlich_1992_Genomics_13_1192
PubMedID: 1380483

Title : Xenopus oocyte microinjection: from gene to protein. -
Author(s) : Soreq H , Seidman S
Ref : Methods Enzymol , 207 :225 , 1992
PubMedID: 1528119

Title : Intramolecular relationships in cholinesterases revealed by oocyte expression of site-directed and natural variants of human BCHE - Neville_1992_EMBO.J_11_1641
Author(s) : Neville LF , Gnatt A , Loewenstein Y , Seidman S , Ehrlich G , Soreq H
Ref : EMBO Journal , 11 :1641 , 1992
Abstract : Structure-function relationships of cholinesterases (CHEs) were studied by expressing site-directed and naturally occurring mutants of human butyrylcholinesterase (BCHE) in microinjected Xenopus oocytes. Site-directed mutagenesis of the conserved electronegative Glu441,Ile442,Glu443 domain to Gly441,Ile442,Gln443 drastically reduced the rate of butyrylthiocholine (BTCh) hydrolysis and caused pronounced resistance to dibucaine binding. These findings implicate the charged Glu441,Ile442,Glu443 domain as necessary for a functional CHE catalytic triad as well as for binding quinoline derivatives. Asp70 to Gly substitution characteristic of 'atypical' BCHE, failed to alter its Km towards BTCh or dibucaine binding but reduced hydrolytic activity to 25% of control. Normal hydrolytic activity was restored to Gly70 BCHE by additional His114 or Tyr561 mutations, both of which co-appear with Gly70 in natural BCHE variants, which implies a likely selection advantage for these double BCHE mutants over the single Gly70 BCHE variant. Gly70 BCHE variants also displayed lower binding as compared with Asp70 BCHE to cholinergic drugs, certain choline esters and solanidine. These effects were ameliorated in part by additional mutations or in binding solanidine complexed with sugar residues. These observations indicate that structural interactions exist between N' and C' terminal domains in CHEs which contribute to substrate and inhibitor binding and suggest a crucial involvement of both electrostatic and hydrophobic domains in the build-up of the CHE active center.
ESTHER : Neville_1992_EMBO.J_11_1641
PubMedSearch : Neville_1992_EMBO.J_11_1641
PubMedID: 1373381

Title : Chorionic villus cDNA library displays expression of butyrylcholinesterase: putative genetic disposition for ecological danger - Zakut_1991_Prenat.Diagnos_11_597
Author(s) : Zakut H , Lieman-Hurwitz J , Zamir R , Sindell L , Ginzberg D , Soreq H
Ref : Prenat Diagnos , 11 :597 , 1991
Abstract : Gene expression in chorionic villi may be particularly vulnerable to environmental exposure to poisonous substances. To reveal villus gene products which are thus subject to poisoning, molecular cloning was employed. A single sample of apparently normal chorionic villi (approximately 40 mg, from 9 weeks' gestation) was microscopically dissected to ensure purity of fetal tissue. Total RNA was extracted by isothiocyanate and directly employed for reverse transcription. A chorionic villus cDNA library was constructed from this preparation in the phage vector lambda gt10 and contained 60,000 independent recombinants. In the present study, this cDNA library was screened with labelled cDNA probes encoding human butyrylcholinesterase (BCHE) and acetylcholinesterase (ACHE). Nine BCHEcDNA clones were isolated out of 1.6 x 10(6) phages (5.7 x 10(-6) of screened recombinants) and exhibited similar restriction patterns to those observed for BCHEcDNA from other human tissues. In contrast, no ACHEcDNA clones could be found in 4.0 x 10(6) screened phages (less than 2.5 x 10(-6) of recombinants). These findings demonstrate efficient transcription (similar to fetal brain levels) from the BCHE gene but not from the ACHE gene in chorionic villi, and support the notion that BCHE is involved in chorionic villus growth and development.
ESTHER : Zakut_1991_Prenat.Diagnos_11_597
PubMedSearch : Zakut_1991_Prenat.Diagnos_11_597
PubMedID: 1722578

Title : Search for the Molecular Origins of Butyrylcholinesterase Polymorphism by cDNA Screening, Deletion Mutagenesis, and Xenopus Oocyte Co-Injections -
Author(s) : Dreyfus PA , Pincon-Raymond M , Zakut H , Seidman S , Soreq H
Ref : In: Cholinesterases: Structure, Function, Mechanism, Genetics, and Cell Biology , (Massoulie J, Barnard EA, Chatonnet A, Bacou F, Doctor BP, Quinn DM) American Chemical Society, Washington, DC :162 , 1991

Title : Differential Codon Usage and Distinct Surface Probabilities in Human Acetylcholinesterase and Butyrylcholinesterase -
Author(s) : Ben-Aziz R , Gnatt A , Prody C , Lev-Lehman E , Neville LF , Seidman S , Ginzberg D , Soreq H , Lapidot-Lifson Y , Zakut H
Ref : In: Cholinesterases: Structure, Function, Mechanism, Genetics, and Cell Biology , (Massoulie J, Barnard EA, Chatonnet A, Bacou F, Doctor BP, Quinn DM) American Chemical Society, Washington, DC :172 , 1991

Title : Poster: Modified ligand-binding properties of butyrylcholinesterase-muteins produced in microinjected Xenopus oocytes -
Author(s) : Neville LF , Gnatt A , Seidman S , Loewenstein Y , Padan R , Soreq H
Ref : In: Cholinesterases: Structure, Function, Mechanism, Genetics, and Cell Biology , (Massoulie J, Barnard EA, Chatonnet A, Bacou F, Doctor BP, Quinn DM) American Chemical Society, Washington, DC :197 198 , 1991

Title : Recombinant human acetylcholinesterase is secreted from transiently transfected 293 cells as a soluble globular enzyme - Velan_1991_Cell.Mol.Neurobiol_11_143
Author(s) : Velan B , Kronman C , Grosfeld H , Leitner M , Gozes Y , Flashner Y , Sery T , Cohen S , Ben-Aziz R , Seidman S , Shafferman A , Soreq H
Ref : Cellular Molecular Neurobiology , 11 :143 , 1991
Abstract : 1. Coding sequences for the human acetylcholinesterase (HuAChE; EC hydrophilic subunit were subcloned in an expression plasmid vector under the control of cytomegalovirus IE gene enhancer-promoter. The human embryonic kidney cell line 293, transiently transfected with this vector, expressed catalytically active acetylcholinesterase. 2. The recombinant gene product exhibits biochemical traits similar to native "true" acetylcholinesterase as manifested by characteristic substrate inhibition, a Km of 117 microM toward acetylthiocholine, and a high sensitivity to the specific acetylcholinesterase inhibitor BW284C51. 3. The transiently transfected 293 cells (100 mm dish) produce in 24 hr active enzyme capable of hydrolyzing 1500 nmol acetylthiocholine per min. Eighty percent of the enzymatic activity appears in the cell growth medium as soluble acetylcholinesterase; most of the cell associated activity is confined to the cytosolic fraction requiring neither detergent nor high salt for its solubilization. 4. The active secreted recombinant enzyme appears in the monomeric, dimeric, and tetrameric globular hydrophilic molecular forms. 5. In conclusion, the catalytic subunit expressed from the hydrophilic AChE cDNA species has the inherent potential to be secreted in the soluble globular form and to generate polymorphism through self-association.
ESTHER : Velan_1991_Cell.Mol.Neurobiol_11_143
PubMedSearch : Velan_1991_Cell.Mol.Neurobiol_11_143
PubMedID: 1849451

Title : A role for cholinesterases in tumorigenesis?. [Review] [48 refs] - Soreq_1991_Cancer.Cells_3_511
Author(s) : Soreq H , Lapidot-Lifson Y , Zakut H
Ref : Cancer Cells , 3 :511 , 1991
Abstract : Hydrolysis of the neurotransmitter acetylcholine by acetylcholinesterase (ACHE) and butyrylcholinesterase (BCHE) is the rate-limiting step in the termination of cholinergic signaling at neuromuscular junctions. A growing body of evidence suggests that these enzymes also play a role in tumorigenesis. The ACHE and BCHE genes are amplified, mutated, and/or aberrantly expressed in a variety of human tumor types. These changes could be the result of chromosome breakage, since there is an unusually high frequency of chromosomal abnormalities near the map positions of these genes (3q26-ter and 11p-ter, respectively) in such tumors, particularly hemopoietic malignancies. Both ACHE and BCHE contain the consensus peptide motif S/T-P-X-Z, which is found in many substrates of cdc2-related protein kinases. Here we consider the intriguing possibility that phosphorylation by cdc2-related kinases may be the molecular mechanism linking cholinesterases with tumor cell proliferation. We also discuss the notion that inhibition of these enzymes by commonly used organophosphorous poisons may be tumorigenic in humans.
ESTHER : Soreq_1991_Cancer.Cells_3_511
PubMedSearch : Soreq_1991_Cancer.Cells_3_511
PubMedID: 1820094

Title : Human acetylcholinesterase and butyrylcholinesterase are encoded by two distinct genes - Gnatt_1991_Cell.Mol.Neurobiol_11_91
Author(s) : Gnatt A , Ginzberg D , Lieman-Hurwitz J , Zamir R , Zakut H , Soreq H
Ref : Cellular Molecular Neurobiology , 11 :91 , 1991
Abstract : 1. Various hybridization approaches were employed to investigate structural and chromosomal interrelationships between the human cholinesterase genes CHE and ACHE encoding the polymorphic, closely related, and coordinately regulated enzymes having butyrylcholinesterase (BCHE) and acetylcholinesterase (AChE) activities. 2. Homologous cosmid recombination with a 190-base pair 5' fragment from BCHEcDNA resulted in the isolation of four overlapping cosmid clones, apparently derived from a single gene with several introns. The Cosmid CHEDNA included a 700-base pair fragment known to be expressed at the 3' end of BCHEcDNA from nervous system tumors and which has been mapped by in situ hybridization to the unique 3q26-ter position. In contrast, cosmid CHEDNA did not hybridize with full-length AChEcDNA, proving that the complete CHE gene does not include AChE-encoding sequences either in exons or in its introns. 3. The chromosomal origin of BCHE-encoding sequences was further examined by two unrelated gene mapping approaches. Filter hybridization with DNA from human/hamster hybrid cell lines revealed BCHEcDNA-hybridizing sequences only in cell lines including human chromosome 3. However, three BCHEcDNA-homologous sequences were observed at chromosomal positions 3q21, 3q26-ter, and 16q21 by a highly stringent in situ hybridization protocol, including washes at high temperature and low salt. 4. These findings stress the selectivity of cosmid recombination and chromosome blots, raise the possibility of individual differences in BCHEcDNA-hybridizing sequences, and present an example for a family highly similar proteins encoded by distinct, nonhomologous genes.
ESTHER : Gnatt_1991_Cell.Mol.Neurobiol_11_91
PubMedSearch : Gnatt_1991_Cell.Mol.Neurobiol_11_91
PubMedID: 2013062

Title : Acetylcholinesterase and butyrylcholinesterase genes coamplify in primary ovarian carcinomas - Zakut_1990_J.Clin.Invest_86_900
Author(s) : Zakut H , Ehrlich G , Ayalon A , Prody CA , Malinger G , Seidman S , Ginzberg D , Kehlenbach R , Soreq H
Ref : Journal of Clinical Investigation , 86 :900 , 1990
Abstract : The genes for acetylcholinesterase (ACHE) and butyrylcholinesterase (CHE) are expressed in multiple tumor tissues, including ovarian carcinomas. Both CHE and ACHE genes coamplify in leukemias. To examine the relationship of gene amplification to the expression of these genes in tumors, ACHE and CHE genes and their expression were studied in primary ovarian carcinomas. DNA blot hybridization demonstrated a significant amplification and mutagenesis of both genes in 6 of 11 malignant tumors studied. This was greater or of the same order of magnitude as the amplification of the oncogenes c-rafi, v-sis, and c-fes in these tumors. No amplification was found in normal ovarian tissues or benign ovarian cysts. Xenopus oocyte microinjections, blot and in situ hybridizations, and immuno- and cytochemical staining revealed translatable CHEmRNA and its active protein product in discrete tumor foci. The frequent coamplification in ovarian carcinomas of ACHE and CHE genes implicates cholinesterases in neoplastic growth and/or proliferation.
ESTHER : Zakut_1990_J.Clin.Invest_86_900
PubMedSearch : Zakut_1990_J.Clin.Invest_86_900
PubMedID: 2394839

Title : Expression and in vivo amplification of the human acetylcholinesterase and butyrylcholinesterase genes -
Author(s) : Soreq H , Zakut H
Ref : Prog Brain Res , 84 :51 , 1990
PubMedID: 2267318

Title : Expression of alternatively terminated unusual human butyrylcholinesterase messenger RNA transcripts, mapping to chromosome 3q26-ter, in nervous system tumors - Gnatt_1990_Cancer.Res_50_1983
Author(s) : Gnatt A , Prody CA , Zamir R , Lieman-Hurwitz J , Zakut H , Soreq H
Ref : Cancer Research , 50 :1983 , 1990
Abstract : To study the molecular origin of the altered regulation of butyrylcholinesterase (BCHE) in nervous system tumors, BCHE complementary DNA (cDNA) sequences from human glioblastoma and neuroblastoma cDNA libraries were compared with BCHE cDNAs from normal fetal and adult tissues. A single 2.6-kilobase BCHE cDNA sequence was found in all normal tissues, whereas an additional alternatively terminated BCHE cDNA clone was found in both tumor libraries. The tumor-specific cDNA contained a 3',0.7-kilobase nontranslatable extension, as well as several nucleotide alterations in the normal polyadenylation site. Single-base mutations in the coding region of this unusual BCHE cDNA infer two amino acid substitutions: Asp70----Gly and Ser425----Pro. The Asp70----Gly change has recently been implicated with "atypical" BCHE, which is deficient in its capacity to hydrolyze succinylcholine. The 3.6-kilobase mRNA was less abundant in RNA blot hybridization than the 2.6-kilobase mRNA, which is in agreement with the low ratios between the 3.6- and 2.6-kilobase BCHE cDNA clones in glioblastoma and neuroblastoma libraries. Furthermore, size fractionation and microinjection of glioblastoma polyadenylated RNA, followed by enzyme activity and selective inhibition measurements, demonstrated two peaks of functional BCHE mRNA, the heavier one probably reflecting the longer transcripts. Chromosomal mapping of the 0.7-kilobase 3' fragment by in situ hybridization localized it to a unique 3q26-ter position, where we recently found an inheritably amplified "silent" defective CHE gene in a family exposed to the cholinesterase inhibitor methyl parathion. Our findings confirm previous genetic linkage mapping of the functional CHE gene to the 3q26-ter position and demonstrate that extended functional mRNA transcripts encoding a BCHE form with two modified amino acids are produced from this gene in glioblastoma and neuroblastoma cells.
ESTHER : Gnatt_1990_Cancer.Res_50_1983
PubMedSearch : Gnatt_1990_Cancer.Res_50_1983
PubMedID: 2317787

Title : Manipulations of cholinesterase gene expression modulate murine megakaryocytopoiesis in vitro - Patinkin_1990_Mol.Cell.Biol_10_6046
Author(s) : Patinkin D , Seidman S , Eckstein F , Benseler F , Zakut H , Soreq H
Ref : Molecular & Cellular Biology , 10 :6046 , 1990
Abstract : Megakaryocytopoiesis was selectively inhibited in cultured murine bone marrow cells by a 15-mer oligodeoxynucleotide complementary to the initiator AUG region in butyrylcholinesterase mRNA. Furthermore, conditioned medium from Xenopus oocytes producing recombinant butyrylcholinesterase stimulated megakaryocytopoiesis. These observations implicate butyrylcholinesterase in megakaryocytopoiesis and suggest application of oligodeoxynucleotides for modulating bone marrow development.
ESTHER : Patinkin_1990_Mol.Cell.Biol_10_6046
PubMedSearch : Patinkin_1990_Mol.Cell.Biol_10_6046
PubMedID: 2233731

Title : Improving poor in vitro transcription from G,C-rich genes -
Author(s) : Ben-Aziz R , Soreq H
Ref : Nucleic Acids Research , 18 :3418 , 1990
PubMedID: 2356139

Title : Anionic site interactions in human butyrylcholinesterase disrupted by two single point mutations - Neville_1990_J.Biol.Chem_265_20735
Author(s) : Neville LF , Gnatt A , Padan R , Seidman S , Soreq H
Ref : Journal of Biological Chemistry , 265 :20735 , 1990
Abstract : Structure-function relationships of recombinant human butyrylcholinesterase (CHE) variants were investigated by Xenopus oocyte microinjection. A Ser-425 to Pro-425 mutation failed to modify ligand binding properties. In contrast, Asp-70 to Gly-70 substitution significantly reduced CHE binding capacity for succinylcholine and specific inhibitors, demonstrating Asp-70 as a key anionic site component for certain ligands. Furthermore, the presence of both mutations rendered CHE totally resistant to succinylcholine and dibucaine inhibition, while all mutant proteins bound butyrylthiocholine, benzoylcholine, and propionylcholine normally. These findings imply structural interactions between the conserved Asp-70 and Ser-425 regions in cholinesterases and suggest the contribution of additional electronegative amino acids to anionic site binding.
ESTHER : Neville_1990_J.Biol.Chem_265_20735
PubMedSearch : Neville_1990_J.Biol.Chem_265_20735
PubMedID: 2249982

Title : Coinjection of Xenopus oocytes with cDNA-produced and native mRNAs: a mo