Pang Y

References (18)

Title : Sensitive detection of butyrylcholinesterase activity based on a stimuli-responsive fluorescence reaction - Pang_2023_Spectrochim.Acta.A.Mol.Biomol.Spectrosc_299_122886
Author(s) : Pang Y , Ma Z , Song Q , Wang Z , Shi YE
Ref : Spectrochim Acta A Mol Biomol Spectrosc , 299 :122886 , 2023
Abstract : A fluorogenic reaction between the chelate of Mn(II)-citric acid and terephthalic acid (PTA) was discovered, which was carried out through heating the aqueous mixture of Mn(2+), citric acid and PTA. Detailed investigations indicated the reaction products were 2-hydroxyterephthalic acid (PTA-OH), which was attributed to the reaction between PTA and OH, formed by the triggering of Mn(II)-citric acid in the presence of dissolved O(2). PTA-OH showed a strong blue fluorescence, peaked at 420 nm, and the fluorescence intensity presented a sensitive response to pH of the reaction system. Based on these mechanisms, the fluorogenic reaction was used for the detection of butyrylcholinesterase activity, achieving a detection limit of 0.15 U/L. The detection strategy was successfully applied in human serum samples, and it was also extended for the detection of organophosphorus pesticides and radical scavengers. Such a facile fluorogenic reaction and its stimuli-responsive properties offered an effective tool for designing detection pathways in the fields of clinical diagnosis, environmental monitoring and bioimaging.
ESTHER : Pang_2023_Spectrochim.Acta.A.Mol.Biomol.Spectrosc_299_122886
PubMedSearch : Pang_2023_Spectrochim.Acta.A.Mol.Biomol.Spectrosc_299_122886
PubMedID: 37210854

Title : Microbial-host-isozyme analyses reveal microbial DPP4 as a potential antidiabetic target - Wang_2023_Science_381_eadd5787
Author(s) : Wang K , Zhang Z , Hang J , Liu J , Guo F , Ding Y , Li M , Nie Q , Lin J , Zhuo Y , Sun L , Luo X , Zhong Q , Ye C , Yun C , Zhang Y , Wang J , Bao R , Pang Y , Wang G , Gonzalez FJ , Lei X , Qiao J , Jiang C
Ref : Science , 381 :eadd5787 , 2023
Abstract : A mechanistic understanding of how microbial proteins affect the host could yield deeper insights into gut microbiota-host cross-talk. We developed an enzyme activity-screening platform to investigate how gut microbiota-derived enzymes might influence host physiology. We discovered that dipeptidyl peptidase 4 (DPP4) is expressed by specific bacterial taxa of the microbiota. Microbial DPP4 was able to decrease the active glucagon like peptide-1 (GLP-1) and disrupt glucose metabolism in mice with a leaky gut. Furthermore, the current drugs targeting human DPP4, including sitagliptin, had little effect on microbial DPP4. Using high-throughput screening, we identified daurisoline-d4 (Dau-d4) as a selective microbial DPP4 inhibitor that improves glucose tolerance in diabetic mice.
ESTHER : Wang_2023_Science_381_eadd5787
PubMedSearch : Wang_2023_Science_381_eadd5787
PubMedID: 37535747
Gene_locus related to this paper: bactn-BT4193

Title : Bladder epithelial cell phosphate transporter inhibition protects mice against uropathogenic Escherichia coli infection - Pang_2022_Cell.Rep_39_110698
Author(s) : Pang Y , Cheng Z , Zhang S , Li S , Li X , Zhang X , Feng Y , Cui H , Chen Z , Liu L , Li Q , Huang J , Zhang M , Zhu S , Wang L , Feng L
Ref : Cell Rep , 39 :110698 , 2022
Abstract : Urinary tract infections are predominantly caused by uropathogenic Escherichia coli (UPEC). UPEC infects bladder epithelial cells (BECs) via fusiform vesicles, escapes into the cytosol to evade exocytosis, and establishes intracellular bacterial communities (IBCs) for the next round of infection. The UPEC vesicle escape mechanism remains unclear. Here we show that UPEC senses host immune responses and initiates escape by upregulating a key phospholipase. The UPEC phospholipase PldA disrupts the vesicle membrane, and pldA expression is activated by phosphate reduction in vesicles. The host phosphate transporter PIT1 is located on the fusiform vesicle membrane, transporting phosphate into the cytosol. UPEC infection upregulates PIT1 via nuclear factor kappaB (NF-kappaB), resulting in phosphate reduction. Silencing PIT1 blocks UPEC vesicle escape in BECs, inhibits IBC formation in mouse bladders, and protects mice from UPEC infection. Our results shed light on pathogenic bacteria responding to intracellular phosphate shortage and tackling host defense and provide insights for development of new therapeutic agents to treat UPEC infection.
ESTHER : Pang_2022_Cell.Rep_39_110698
PubMedSearch : Pang_2022_Cell.Rep_39_110698
PubMedID: 35443182

Title : Genome-wide analysis of the strigolactone biosynthetic and signaling genes in grapevine and their response to salt and drought stresses - Yu_2022_PeerJ_10_e13551
Author(s) : Yu Y , Xu J , Wang C , Pang Y , Li L , Tang X , Li B , Sun Q
Ref : PeerJ , 10 :e13551 , 2022
Abstract : Strigolactones (SLs) are a novel class of plant hormones that play critical roles in regulating various developmental processes and stress tolerance. Although the SL biosynthetic and signaling genes were already determined in some plants such as Arabidopsis and rice, the information of SL-related genes in grapevine (Vitis vinifera L.) remains largely unknown. In this study, the SL-related genes were identified from the whole grapevine genome, and their expression patterns under salt and drought stresses were determined. The results indicated that the five genes that involved in the SL biosynthesis included one each of the D27, CCD7, CCD8, MAX1 and LBO genes, as well as the three genes that involved in the SL signaling included one each of the D14, MAX2, D53 genes. Phylogenetic analysis suggested that these SL-related proteins are highly conserved among different plant species. Promoter analysis showed that the prevalence of a variety of cis-acting elements associated with hormones and abiotic stress existed in the promoter regions of these SL-related genes. Furthermore, the transcription expression analysis demonstrated that most SL-related genes are involved in the salt and drought stresses response in grapevine. These findings provided valuable information for further investigation and functional analysis of SL biosynthetic and signaling genes in response to salt and drought stresses in grapevine.
ESTHER : Yu_2022_PeerJ_10_e13551
PubMedSearch : Yu_2022_PeerJ_10_e13551
PubMedID: 35712547

Title : Promising tacrine\/huperzine A-based dimeric acetylcholinesterase inhibitors for neurodegenerative disorders: From relieving symptoms to modifying diseases through multitarget - Mak_2021_J.Neurochem__
Author(s) : Mak S , Li W , Fu H , Luo J , Cui W , Hu S , Pang Y , Carlier PR , Tsim KWK , Pi R , Han Y
Ref : Journal of Neurochemistry , : , 2021
Abstract : Neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, are devastating diseases in the elderly world, which are closely associated with progressive neuronal loss induced by a variety of genetic and/or environmental factors. Unfortunately, currently available treatments for neurodegenerative disorders can only relieve the symptoms but not modify the pathological processes. Over the past decades, our group by collaborating with Profs. Yuan-Ping Pang and Paul R. Carlier has developed three series of homo/hetero dimeric acetylcholinesterase inhibitors derived from tacrine and/or huperzine A. The representative dimers bis(3)-Cognitin (B3C), bis(12)-hupyridone, and tacrine(10)-hupyridone might possess disease-modifying effects through the modulation of N-methyl-d-aspartic acid receptors, the activation of myocyte enhancer factor 2D gene transcription, and the promotion of neurotrophic factor secretion. In this review, we summarize that the representative dimers, such as B3C, provide neuroprotection against a variety of neurotoxins via multiple targets, including the inhibitions of N-methyl-d-aspartic acid receptor with pathological-activated potential, neuronal nitric oxide synthase, and beta-amyloid cascades synergistically. More importantly, B3C might offer disease-modifying potentials by activating myocyte enhancer factor 2D transcription, inducing neuritogenesis, and promoting the expressions of neurotrophic factors in vitro and in vivo. Taken together, the novel dimers might offer synergistic disease-modifying effects, proving that dimerization might serve as one of the strategies to develop new generation of therapeutics for neurodegenerative disorders.
ESTHER : Mak_2021_J.Neurochem__
PubMedSearch : Mak_2021_J.Neurochem__
PubMedID: 33930191

Title : Characterization and genomic analysis of an efficient dibutyl phthalate degrading bacterium Microbacterium sp. USTB-Y - Zhao_2021_World.J.Microbiol.Biotechnol_37_212
Author(s) : Zhao Z , Liu C , Xu Q , Ahmad S , Zhang H , Pang Y , Aikemu A , Liu Y , Yan H
Ref : World J Microbiol Biotechnol , 37 :212 , 2021
Abstract : A promising bacterial strain for biodegrading dibutyl phthalate (DBP) was successfully isolated from activated sludge and characterized as a potential novel Microbacterium sp. USTB-Y based on 16S rRNA sequence analysis and whole genome average nucleotide identity (ANI). Initial DBP of 50 mg/L could be completely biodegraded by USTB-Y both in mineral salt medium and in DBP artificially contaminated soil within 12 h at the optimal culture conditions of pH 7.5 and 30 degC, which indicates that USTB-Y has a strong ability in DBP biodegradation. Phthalic acid (PA) was identified as the end-product of DBP biodegraded by USTB-Y using GC/MS. The draft genome of USTB-Y was sequenced by Illumina NovaSeq and 29 and 188 genes encoding for putative esterase/carboxylesterase and hydrolase/alpha/beta hydrolase were annotated based on NR (non redundant protein sequence database) analysis, respectively. Gene3781 and gene3780 from strain USTB-Y showed 100% identity with dpeH and mpeH from Microbacterium sp. PAE-1. But no phthalate catabolic gene (pht) cluster was found in the genome of strain USTB-Y. The results in the present study are valuable for obtaining a more holistic understanding on diverse genetic mechanisms of PAEs biodegrading Microbacterium sp. strains.
ESTHER : Zhao_2021_World.J.Microbiol.Biotechnol_37_212
PubMedSearch : Zhao_2021_World.J.Microbiol.Biotechnol_37_212
PubMedID: 34738191
Gene_locus related to this paper: 9mico-DpeH , 9mico-MpeH

Title : Selenepezil, a Selenium-Containing Compound, Exerts Neuroprotective Effect via Modulation of the Keap1-Nrf2-ARE Pathway and Attenuates Abeta-Induced Cognitive Impairment in Vivo - Yan_2019_ACS.Chem.Neurosci_10_2903
Author(s) : Yan J , Pang Y , Zhuang J , Lin H , Zhang Q , Han L , Ke P , Huang X
Ref : ACS Chem Neurosci , 10 :2903 , 2019
Abstract : Oxidative stress is a major risk factor for neurodegenerative disease. The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2 related factor 2 (Nrf2)-antioxidant response element (ARE) pathway is one of the most potent defensive systems against oxidative stress. Selenepezil, a selenium-based compound, was previously found to exhibit excellent acetylcholinesterase (AChE) inhibition, to mimic endogenous glutathione peroxidase (GPx) activity, and to exhibit scavenging activity for hydrogen peroxide in vitro. However, none of these activities have been evaluated in a cellular model, and detailed molecular mechanisms are not elucidated. Moreover, whether selenepezil ameliorates memory deficits in vivo remains unknown. This study validated the cytoprotective effect of selenepezil against 6-hydroxydopamine (6-OHDA)- or H2O2-induced SH-SY5Y cell damage via alleviation or neutralization of intracellular microtubule disorder, reactive oxygen species (ROS) accumulation, mitochondrial dysfunction, and cell apoptosis. Our study clearly demonstrated that selenepezil pretreatment exhibited remarkable cytoprotective effect in a Nrf2-dependent manner via activating the Keap1-Nrf2-ARE pathway and stimulating the transcription of Nrf2-ARE-regulated cytoprotective genes. Moreover, selenepezil.HCl exerts neuroprotective effect via attenuating Abeta-induced cognitive impairment in Alzheimer's disease (AD) rat and was more active than the reference drug donepezil. In summary, selenepezil deserves further consideration for AD therapy.
ESTHER : Yan_2019_ACS.Chem.Neurosci_10_2903
PubMedSearch : Yan_2019_ACS.Chem.Neurosci_10_2903
PubMedID: 31035749

Title : Synthesis and biological evaluation of a new series of ebselen derivatives as glutathione peroxidase (GPx) mimics and cholinesterase inhibitors against Alzheimer's disease - Luo_2014_Bioorg.Med.Chem_22_1355
Author(s) : Luo Z , Liang L , Sheng J , Pang Y , Li J , Huang L , Li X
Ref : Bioorganic & Medicinal Chemistry , 22 :1355 , 2014
Abstract : A series of ebselen derivatives were designed, synthesised and evaluated as inhibitors of cholinesterases (ChEs) and glutathione peroxidase (GPx) mimics. Most of the compounds were found to be potent against AChEs and BCHE, compounds 5e and 5i, proved to be the most potent against AChE with IC(5)(0) values of 0.76 and 0.46 muM, respectively. Among these hybrids, most of the compounds were found to be good GPx mimics compare with ebselen. The selected compounds 5e and 5i were also used to determine the catalytic parameters and in vitro hydrogen peroxide scavenging activity. The results indicate that compounds 5e and 5i may be excellent multifunctional agents for the treatment of AD.
ESTHER : Luo_2014_Bioorg.Med.Chem_22_1355
PubMedSearch : Luo_2014_Bioorg.Med.Chem_22_1355
PubMedID: 24461494

Title : Activation of transcription factor MEF2D by bis(3)-cognitin protects dopaminergic neurons and ameliorates Parkinsonian motor defects - Yao_2012_J.Biol.Chem_287_34246
Author(s) : Yao L , Li W , She H , Dou J , Jia L , He Y , Yang Q , Zhu J , Capiro NL , Walker DI , Pennell KD , Pang Y , Liu Y , Han Y , Mao Z
Ref : Journal of Biological Chemistry , 287 :34246 , 2012
Abstract : Parkinson disease (PD) is characterized by the selective demise of dopaminergic (DA) neurons in the substantial nigra pars compacta. Dysregulation of transcriptional factor myocyte enhancer factor 2D (MEF2D) has been implicated in the pathogenic process in in vivo and in vitro models of PD. Here, we identified a small molecule bis(3)-cognitin (B3C) as a potent activator of MEF2D. We showed that B3C attenuated the toxic effects of neurotoxin 1-methyl-4-phenylpyridinium (MPP(+)) by activating MEF2D via multiple mechanisms. B3C significantly reduced MPP(+)-induced oxidative stress and potentiated Akt to down-regulate the activity of MEF2 inhibitor glycogen synthase kinase 3beta (GSK3beta) in a DA neuronal cell line SN4741. Furthermore, B3C effectively rescued MEF2D from MPP(+)-induced decline in both nucleic and mitochondrial compartments. B3C offered SN4741 cells potent protection against MPP(+)-induced apoptosis via MEF2D. Interestingly, B3C also protected SN4741 cells from wild type or mutant A53T alpha-synuclein-induced cytotoxicity. Using the in vivo PD model of C57BL/6 mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP), we showed that B3C maintained redox homeostasis, promoted Akt function activity, and restored MEF2D level in midbrain neurons. Moreover, B3C greatly prevented the loss of tyrosine hydroxylase signal in substantial nigra pars compacta DA neurons and ameliorated behavioral impairments in mice treated with MPTP. Collectedly, our studies identified B3C as a potent neuroprotective agent whose effectiveness relies on its ability to effectively up-regulate MEF2D in DA neurons against toxic stress in models of PD in vitro and in vivo.
ESTHER : Yao_2012_J.Biol.Chem_287_34246
PubMedSearch : Yao_2012_J.Biol.Chem_287_34246
PubMedID: 22891246

Title : Pathologically activated neuroprotection via uncompetitive blockade of N-methyl-D-aspartate receptors with fast off-rate by novel multifunctional dimer bis(propyl)-cognitin - Luo_2010_J.Biol.Chem_285_19947
Author(s) : Luo J , Li W , Zhao Y , Fu H , Ma DL , Tang J , Li C , Peoples RW , Li F , Wang Q , Huang P , Xia J , Pang Y , Han Y
Ref : Journal of Biological Chemistry , 285 :19947 , 2010
Abstract : Uncompetitive N-methyl-d-aspartate (NMDA) receptor antagonists with fast off-rate (UFO) may represent promising drug candidates for various neurodegenerative disorders. In this study, we report that bis(propyl)-cognitin, a novel dimeric acetylcholinesterase inhibitor and gamma-aminobutyric acid subtype A receptor antagonist, is such an antagonist of NMDA receptors. In cultured rat hippocampal neurons, we demonstrated that bis(propyl)-cognitin voltage-dependently, selectively, and moderately inhibited NMDA-activated currents. The inhibitory effects of bis(propyl)-cognitin increased with the rise in NMDA and glycine concentrations. Kinetics analysis showed that the inhibition was of fast onset and offset with an off-rate time constant of 1.9 s. Molecular docking simulations showed moderate hydrophobic interaction between bis(propyl)-cognitin and the MK-801 binding region in the ion channel pore of the NMDA receptor. Bis(propyl)-cognitin was further found to compete with [(3)H]MK-801 with a K(i) value of 0.27 mum, and the mutation of NR1(N616R) significantly reduced its inhibitory potency. Under glutamate-mediated pathological conditions, bis(propyl)-cognitin, in contrast to bis(heptyl)-cognitin, prevented excitotoxicity with increasing effectiveness against escalating levels of glutamate and much more effectively protected against middle cerebral artery occlusion-induced brain damage than did memantine. More interestingly, under NMDA receptor-mediated physiological conditions, bis(propyl)-cognitin enhanced long-term potentiation in hippocampal slices, whereas MK-801 reduced and memantine did not alter this process. These results suggest that bis(propyl)-cognitin is a UFO antagonist of NMDA receptors with moderate affinity, which may provide a pathologically activated therapy for various neurodegenerative disorders associated with NMDA receptor dysregulation.
ESTHER : Luo_2010_J.Biol.Chem_285_19947
PubMedSearch : Luo_2010_J.Biol.Chem_285_19947
PubMedID: 20404346

Title : Novel anti-Alzheimer's dimer Bis(7)-cognitin: cellular and molecular mechanisms of neuroprotection through multiple targets - Li_2009_Neurotherapeutics_6_187
Author(s) : Li W , Mak M , Jiang H , Wang Q , Pang Y , Chen K , Han Y
Ref : Neurotherapeutics , 6 :187 , 2009
Abstract : Alzheimer's disease (AD) is a progressive and degenerative brain disorder that has emerged as one of the major public health problems in adults. Unfortunately, its molecular pathology and therapeutic strategies remain elusive. Because there are multiple factors closely indicated in the pathogenesis of AD, multiple drug therapy will be required to address the varied pathological aspects of this disease. Existing pharmacological approaches with one-molecule-one-target are limited in their ability to modify the pathology of AD. Novel therapeutics strategies comprise multifunctional compounds specifically designed to target concurrently on different sites at multifactorial etiopathogenesis of AD, thereby providing greater therapeutic efficacy. Over the past decade, our group has developed several series of dimeric acetylcholinesterase (AChE) inhibitors derived from tacrine and huperzine A, a unique anti-Alzheimer's drug originally discovered from a traditional Chinese medicinal plant. Bis(7)-Cognitin, one of our novel dimers, through inhibition of AChE, N-methyl-D-aspartate receptor, nitric oxide synthase, and amyloid precursor protein/beta-amyloid cascade concurrently, possesses remarkable neuroprotective activities. More importantly, the synergism between these targets might serve as one of the most effective therapeutic strategies to arrest/modify pathological process of AD in addition to improving the cognitive functions for AD.
ESTHER : Li_2009_Neurotherapeutics_6_187
PubMedSearch : Li_2009_Neurotherapeutics_6_187
PubMedID: 19110209

Title : Mitochondrial proteomic analysis and characterization of the intracellular mechanisms of bis(7)-tacrine in protecting against glutamate-induced excitotoxicity in primary cultured neurons - Fu_2007_J.Proteome.Res_6_2435
Author(s) : Fu H , Li W , Liu Y , Lao Y , Liu W , Chen C , Yu H , Lee NT , Chang DC , Li P , Pang Y , Tsim KWK , Li M , Han Y
Ref : J Proteome Res , 6 :2435 , 2007
Abstract : Increasing evidence supports that the mitochondrial dysfunction, mainly caused by abnormal changes in mitochondrial proteins, plays a pivotal role in glutamate-induced excitotoxicity, which is closely associated with the pathogenesis of acute and chronic neurodegenerative disorders, such as stroke and Alzheimer's disease. In this study, post-treatment of cerebellar granule neurons with bis(7)-tacrine significantly reversed declines in mitochondrial membrane potential, ATP production, and neuronal cell death induced by glutamate. Moreover, this reversal was independent of NMDA antagonism, acetylcholinesterase inhibition, and cholinergic pathways. Using two-dimensional differential in-gel electrophoresis, we conducted a comparative analysis of mitochondrial protein patterns. In all, 29 proteins exhibiting significant differences in their abundances were identified in the glutamate-treated group when compared with the control. The expression patterns in 22 out of these proteins could be reversed by post-treatment with bis(7)-tacrine. Most of the differentially expressed proteins are involved in energy metabolism, oxidative stress, and apoptosis. In particular, the altered patterns of four of these proteins were further validated by Western blot analysis. Our findings suggest that multiple signaling pathways initiated by the altered mitochondrial proteins may mediate glutamate-induced excitotoxicity and also offer potentially useful intracellular targets for the neuroprotection provided by bis(7)-tacrine.
ESTHER : Fu_2007_J.Proteome.Res_6_2435
PubMedSearch : Fu_2007_J.Proteome.Res_6_2435
PubMedID: 17530875

Title : Bis(7)-tacrine attenuates beta amyloid-induced neuronal apoptosis by regulating L-type calcium channels - Fu_2006_J.Neurochem_98_1400
Author(s) : Fu H , Li W , Lao Y , Luo J , Lee NT , Kan KK , Tsang HW , Tsim KWK , Pang Y , Li Z , Chang DC , Li M , Han Y
Ref : Journal of Neurochemistry , 98 :1400 , 2006
Abstract : Beta amyloid protein (Abeta) and acetylcholinesterase (AChE) have been shown to be closely implicated in the pathogenesis of Alzheimer's disease. In the current study, we investigated the effects of bis(7)-tacrine, a novel dimeric AChE inhibitor, on Abeta-induced neurotoxicity in primary cortical neurons. Bis(7)-tacrine, but not other AChE inhibitors, elicited a marked reduction of both fibrillar and soluble oligomeric forms of Abeta-induced apoptosis as evidenced by chromatin condensation and DNA specific fragmentation. Both nicotinic and muscarinic receptor antagonists failed to block the effects of bis(7)-tacrine. Instead, nimodipine, a blocker of L-type voltage-dependent Ca2+ channels (VDCCs), attenuated Abeta neurotoxicity, whereas N-, P/Q- or R-type VDCCs blockers and ionotropic glutamate receptor antagonists did not. Fluorescence Ca2+ imaging assay revealed that, similar to nimodipine, bis(7)-tacrine reversed Abeta-triggered intracellular Ca2+ increase, which was mainly contributed by the extracellular Ca2+ instead of endoplasmic reticulum and mitochondria Ca2+. Concurrently, using whole cell patch-clamping technique, it was found that bis(7)-tacrine significantly reduced the augmentation of high voltage-activated inward calcium currents induced by Abeta. These results suggest that bis(7)-tacrine attenuates Abeta-induced neuronal apoptosis by regulating L-type VDCCs, offers a novel modality as to how the agent exerts neuroprotective effects.
ESTHER : Fu_2006_J.Neurochem_98_1400
PubMedSearch : Fu_2006_J.Neurochem_98_1400
PubMedID: 16771827

Title : Neuroprotection via inhibition of nitric oxide synthase by bis(7)-tacrine - Li_2006_Neuroreport_17_471
Author(s) : Li W , Lee NT , Fu H , Kan KK , Pang Y , Li M , Tsim KWK , Li X , Han Y
Ref : Neuroreport , 17 :471 , 2006
Abstract : Here we report that bis(7)-tacrine, a novel acetylcholinesterase inhibitor, exerts neuroprotective effects by inhibition of nitric oxide synthase. In cortical neurons at 12 days in vitro, bis(7)-tacrine concentration-dependently reduced cell death induced by glutamate, beta-amyloid and L-arginine, but not by nitric sodium nitroprusside. N-monomethyl-L-arginine, a nitric oxide synthase inhibitor, also prevented the former three types but not the last type of the cytotoxicity; however, nitric oxide scavengers blocked all of these insults, indicating that nitric oxide mediated these neuronal injuries. Furthermore, with nitric oxide synthase activity assays, it was found that bis(7)-tacrine not only suppressed the activation of nitric oxide synthase caused by glutamate in cortical neurons, but also directly inhibited the activity of nitric oxide synthase in vitro.
ESTHER : Li_2006_Neuroreport_17_471
PubMedSearch : Li_2006_Neuroreport_17_471
PubMedID: 16543809

Title : Novel dimeric acetylcholinesterase inhibitor bis7-tacrine, but not donepezil, prevents glutamate-induced neuronal apoptosis by blocking N-methyl-D-aspartate receptors - Li_2005_J.Biol.Chem_280_18179
Author(s) : Li W , Pi R , Chan HH , Fu H , Lee NT , Tsang HW , Pu Y , Chang DC , Li C , Luo J , Xiong K , Li Z , Xue H , Carlier PR , Pang Y , Tsim KWK , Li M , Han Y
Ref : Journal of Biological Chemistry , 280 :18179 , 2005
Abstract : The neuroprotective properties of bis(7)-tacrine, a novel dimeric acetylcholinesterase (AChE) inhibitor, on glutamate-induced excitotoxicity were investigated in primary cultured cerebellar granule neurons (CGNs). Exposure of CGNs to 75 mum glutamate resulted in neuronal apoptosis as demonstrated by Hoechst staining, TUNEL, and DNA fragmentation assays. The bis(7)-tacrine treatment (0.01-1 mum) on CGNs markedly reduced glutamate-induced apoptosis in dose- and time-dependent manners. However, donepezil and other AChE inhibitors, even at concentrations of inhibiting AChE to the similar extents as 1 mum bis(7)-tacrine, failed to prevent glutamate-induced excitotoxicity in CGNs; moreover, both atropine and dihydro-beta-erythroidine, the cholinoreceptor antagonists, did not affect the anti-apoptotic properties of bis(7)-tacrine, suggesting that the neuroprotection of bis(7)-tacrine appears to be independent of inhibiting AChE and cholinergic transmission. In addition, ERK1/2 and p38 pathways, downstream signals of N-methyl-d-aspartate (NMDA) receptors, were rapidly activated after the exposure of glutamate to CGNs. Bis(7)-tacrine inhibited the apoptosis and the activation of these two signals with the same efficacy as the coapplication of PD98059 and SB203580. Furthermore, using fluorescence Ca(2+) imaging, patch clamp, and receptor-ligand binding techniques, bis(7)-tacrine was found effectively to buffer the intracellular Ca(2+) increase triggered by glutamate, to reduce NMDA-activated currents and to compete with [(3)H]MK-801 with an IC(50) value of 0.763 mum in rat cerebellar cortex membranes. These findings strongly suggest that bis(7)-tacrine prevents glutamate-induced neuronal apoptosis through directly blocking NMDA receptors at the MK-801-binding site, which offers a new and clinically significant modality as to how the agent exerts neuroprotective effects.
ESTHER : Li_2005_J.Biol.Chem_280_18179
PubMedSearch : Li_2005_J.Biol.Chem_280_18179
PubMedID: 15710623

Title : Bis(7)-tacrine, a novel acetylcholinesterase inhibitor, reverses AF64A-induced deficits in navigational memory in rats - Liu_2000_Neurosci.Lett_282_165
Author(s) : Liu J , Ho W , Lee NT , Carlier PR , Pang Y , Han Y
Ref : Neuroscience Letters , 282 :165 , 2000
Abstract : The novel dimer bis(7)-tacrine (1,7-N-Heptylene-bis-9,9'-amino-1,2,3, 4-tetrahydroacridine), which exhibits higher potency, selectivity and oral activity on acetylcholinesterase inhibition in vivo than tacrine, was evaluated for its ability to reverse AF64A-induced spatial memory impairment in rats using the Morris water maze. The intracerebroventricular injection of AF64A (3 nmol/side) resulted in a substantial increase in the escape latency to find the platform (F(1,7)=30.2, P<0.01). The observed impairment of spatial memory was paralleled by a 47% decrease in choline acetyltransferase activity in the hippocampus. Oral administration of bis(7)-tacrine (0.22-0.89 micromol/kg) dose-dependently reversed the AF64A-induced latency delay to the level of the saline control group (F(4,28)=7.45, P<0. 05). The present study provides additional evidence of bis(7)-tacrine as an ideal candidate for the palliative treatment of Alzheimer's disease.
ESTHER : Liu_2000_Neurosci.Lett_282_165
PubMedSearch : Liu_2000_Neurosci.Lett_282_165
PubMedID: 10717417

Title : Corrigendum to 'Protection against ischemic injury in primary cultured mouse astrocytes by bis(7)-tacrine, a novel acetylcholinesterase inhibitor' -
Author(s) : Wu D , Xiao X , Ng AK , Chen PM , Chung W , Lee NT , Carlier PR , Pang Y , Yu AC , Han Y
Ref : Neuroscience Letters , 290 :84 , 2000
PubMedID: 10925180

Title : Bis(7)-tacrine, a promising anti-Alzheimer's agent, reduces hydrogen peroxide-induced injury in rat pheochromocytoma cells: comparison with tacrine - Xiao_2000_Neurosci.Lett_290_197
Author(s) : Xiao XQ , Lee NT , Carlier PR , Pang Y , Han YF
Ref : Neuroscience Letters , 290 :197 , 2000
Abstract : The present study investigates the effects of bis(7)-tacrine, a novel dimeric acetylcholinesterase inhibitor, on hydrogen peroxide(H(2)O(2))-induced cell injury with comparison to the corresponding monomer, tacrine. Exposure of rat pheochromocytoma line PC12 cells to H(2)O(2) induced significant cell damage. This reagent also caused redox desequilibrium as indicated by a decrease in activities of intracellular antioxidant enzymes such as glutathione peroxidase as well as catalase and an accumulation of malondialdehyde, a product of lipid peroxidation. Pretreatment of cells with bis(7)-tacrine or tacrine attenuated H(2)O(2)-induced cell toxicity, and bis(7)-tacrine demonstrated higher potency than tacrine in improving redox desequilibrium. These results suggest that bis(7)-tacrine and tacrine significantly protect against H(2)O(2) insult, which might be beneficial for their potential usage in the prevention and treatment of Alzheimer's disease.
ESTHER : Xiao_2000_Neurosci.Lett_290_197
PubMedSearch : Xiao_2000_Neurosci.Lett_290_197
PubMedID: 10963897