Author Report for: Patel SNo contact information in database for Patel S
Kondev V, Bluett R, Najeed M, Rosas-Vidal LE, Grueter BA, Patel S Ref: Neurobiol Stress, 22:100510, 2023 : PubMed ESTHER: Kondev_2023_Neurobiol.Stress_22_100510 PubMedSearch: Kondev 2023 Neurobiol.Stress 22 100510 PubMedID: 36594052 Gene_locus related to this paper: human-DAGLA, mouse-q6wqj1 Abstract The endogenous cannabinoid, 2-arachidonoylglycerol (2-AG), plays a key role in the regulation of anxiety- and stress-related behavioral phenotypes and may represent a novel target for the treatment of anxiety disorders. However, recent studies have suggested a more complex role for 2-AG signaling in the regulation of stress responsivity, including increases in acute fear responses after 2-AG augmentation under some conditions. Thus, 2-AG signaling within distinct brain regions and circuits could regulate anxiety-like behavior and stress responsivity in opposing manners. The ventral hippocampus (vHPC) is a critical region for emotional processing, anxiety-like behaviors, and stress responding. Here, we use a conditional knock-out of the 2-AG synthesis enzyme, diacylglycerol lipase alpha (DAGLalpha), to study the role of vHPC 2-AG signaling in the regulation of affective behavior. We show that vHPC DAGLalpha deletion decreases avoidance behaviors both basally and following an acute stress exposure. Genetic deletion of vHPC DAGLalpha also promotes stress resiliency, with no effect on fear acquisition, expression, or contextual fear generalization. Using slice electrophysiology, we demonstrate that vHPC DAGLalpha deletion shifts vHPC activity towards enhanced inhibition. Together, these data indicate endogenous 2-AG signaling in the vHPC promotes avoidance and increases stress reactivity, confirming the notion that 2-AG signaling within distinct brain regions may exert divergent effects on anxiety states and stress adaptability. Title: Repurposing of digoxin in pain and inflammation: An evidence-based study Patel S, Gururani R, Jain S, Tripathi N, Paliwal S, Sharma S Ref: Drug Dev Res, :, 2022 : PubMed ESTHER: Patel_2022_Drug.Dev.Res__ PubMedSearch: Patel 2022 Drug.Dev.Res PubMedID: 35315525 Abstract In recent years, the drug repositioning strategy has gained considerable attention in the drug discovery process that involves establishing new therapeutic uses of already known drugs. In line with this, we have identified digoxin a cardiac glycoside, as a potent inhibitor of soluble epoxide hydrolase (sEH) enzyme employing in silico high throughput screening protocols and further confirmed using in vitro cell-free sEH inhibitory assay and in vivo preclinical studies in rodents for its repurposing in hyperalgesia, inflammation, and related disorders. Oral administration of digoxin at dose 0.2 mg/kg significantly reduced (p < .0001) the allodynia in mice induced by using hot plate (3.6 +/- 1.9) and tail-flick test (7.58 +/- 0.9). In addition, digoxin at a dose of 0.2 mg/kg showed marked reduction (94%, p < .0001) in acetic acid-induced abdominal contraction in rats. Further, digoxin also demonstrated antipyretic activity (37.04 +/- 0.2, p < .0001) and showed notable reduction (0.60 +/- 0.06) in carrageenan-induced paw edema in rats. Also, the histopathological evaluation revealed that digoxin treatment attenuated the edema, neutrophil infiltration, and alveolar septal thickening in lung tissue. These findings are novel and highlight the newer insights towards repurposing digoxin as a new lead in the treatment of hyperalgesia, inflammation, and related disorders. Title: Repositioning of tubocurarine as analgesic and anti-inflammatory agent: Exploring beyond myorelaxant activity Patel S, Shukla J, Jain S, Paliwal V, Tripathi N, Paliwal S, Sharma S Ref: Biochemical Pharmacology, 205:115248, 2022 : PubMed ESTHER: Patel_2022_Biochem.Pharmacol_205_115248 PubMedSearch: Patel 2022 Biochem.Pharmacol 205 115248 PubMedID: 36113566 Abstract BACKGROUND AND PURPOSE: Tubocurarine (d-TC), a non-depolarizing competitive blocker of nicotinic acetylcholine receptors is extensively utilized for the relaxation of skeletal muscles. Drug repositioning is a forthright approach to reduce the cost and speed up drug development process. Herein, we have attempted to evaluate the analgesic and anti-inflammatory activity of d-TC for its possible repurposing in pain and inflammation-related issues. EXPERIMENTAL APPROACH: We examined the soluble epoxide hydrolase inhibitory (sEHI) activity of d-TC employing in silico high throughput screening protocols, in vitro cell-free sEH inhibitory assay, and in in vivo rodent models for its repositioning in pain and inflammation-related disorders. KEY RESULTS: In molecular docking study, d-TC displayed impressive hydrogen bonding interactions within the cavity of sEH enzyme with good docking score. d-TC also exhibited notable sEH inhibitory activity (IC(50) 3.72 nm) at the in vitro assay. Oral absorption capability of d-TC (0.1 and 0.2 mg/mL) was determined using an in vitro everted intestinal sac model employing rat ileum tissue that revealed significant oral absorption of d-TC. Besides, in vivo studies revealed that oral administration of d-TC (0.1 and 0.2 mg/kg) in rodents significantly attenuated hyperalgesia (cold plate test, tail immersion test and formalin test) and inflammation (estimation of rectal temperature, acetic acid induced pleurisy test and cotton pellet-induced granuloma test) induced in robust preclinical models. Conclusion and implications These findings are novel and warrant immediate efforts to reposition d-TC as a new therapeutic candidate in the management of hyperalgesia, inflammation, and associated conditions. Title: A Review on Recent Development of Novel Heterocycles as Acetylcholinesterase inhibitor for the treatment of Alzheimer's disease Patel A, Shah D, Patel Y, Patel S, Mehta M, Bambharoliya T Ref: Curr Drug Targets, :, 2022 : PubMed ESTHER: Patel_2022_Curr.Drug.Targets__ PubMedSearch: Patel 2022 Curr.Drug.Targets PubMedID: 36515018 Abstract Alzheimer's Disease (AD), affecting a large population worldwide, is characterized by the old population's loss of memory and learning ability. Cholinergic deficiency is associated with AD, and various cholinesterase inhibitors have been developed to treat AD, including naturally-derived inhibitors, synthetic analogs, and hybrids. Acetylcholinesterase (AChE) has obtained a renewed interest as a therapeutic target in Alzheimer's disease (AD) due to increased neural cells' function by increasing the concentration of acetylcholine. In this review, we reported the recent development of novel heterocyclic compounds such as coumarin-benzotriazole hybrids, carbazole derivatives, tacrine conjugates, N-benzyl-piperidine-aryl-acyl hydrazones hybrid, spiropyrazoline derivatives, coumarin-dithiocarbamate hybrids, etc. as AChE inhibitors for the treatment of Alzheimer disease. All the bioactive compounds show an effect on different cells and interact simultaneously with the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE with a narrow range of IC50 values from 0.4 nm to 88.21 microm using Ellman's in vitro AChE assay method and show high BBB permeability in-vitro. In addition, the in-vitro fluorescence assay study using Amplex Red assay kits revealed that all the compounds could inhibit self-induced beta-amyloid (Abeta) aggregation with the highest inhibition range from 31.4 to 82%. Furthermore, most of the compounds show a low toxicity profile during in vivo studies. The results suggest that all the compounds constitute promising leads for the AChE targeted approach for Alzheimer's disease. Title: Rare Presentation of Subcutaneous Fat Necrosis at Multiple Sites with Unclear Etiology: A Case Report Patel S, Shah S, Patel V Ref: J Orthop Case Rep, 12:78, 2022 : PubMed ESTHER: Patel_2022_J.Orthop.Case.Rep_12_78 PubMedSearch: Patel 2022 J.Orthop.Case.Rep 12 78 PubMedID: 37065530 Abstract INTRODUCTION: Fat necrosis can occur in any area rich in fatty tissue. It occurs due to aseptic saponification of the fat by lipases. The most common site of it is the breast. CASE PRESENTATION: This article reports the case of a 43-year-old woman that came into the orthopedic outpatient department with a history of two masses, one on each buttock. The patient had a history of surgical excision of adiponecrotic mass from the right knee a year back. All the three masses appeared around the same time. Ultrasonography was done to surgically excise the left gluteal mass. The histopathology of the excised mass then confirmed subcutaneous fat necrosis. CONCLUSION: Fat necrosis can also be found in the knee and buttocks, and that too without any definite etiology. Imaging and biopsy can help with the diagnosis. It is necessary to familiarize oneself with adiponecrosis so as to differentiate it from other grave conditions that it mimics, such as cancer. Title: Pesticides as the drivers of neuropsychotic diseases, cancers, and teratogenicity among agro-workers as well as general public Patel S, Sangeeta S Ref: Environ Sci Pollut Res Int, 26:91, 2019 : PubMed ESTHER: Patel_2019_Environ.Sci.Pollut.Res.Int_26_91 PubMedSearch: Patel 2019 Environ.Sci.Pollut.Res.Int 26 91 PubMedID: 30411285 Abstract The need to maximize agricultural productivity has made pesticides an indispensable part of current times. Farmers are unaware of the lurking consequences of the pesticide exposure, which endanger their health. It also puts the unsuspecting consumers in peril. The pesticides (from organophosphates, organochlorine, and carbamate class) disrupt the immune and hormonal signaling, causing recurrent inflammation, which leads to a wide array pathologies, including teratogenicity. Numerous farmers have fallen victim to neural disorders-driven suicides and lungs, prostate/breast cancer-caused untimely deaths. Green revolution which significantly escalated agricultural productivity is backfiring now. It is high time that environmental and agricultural authorities act to restrain the excessive usage of the detrimental chemicals and educate farmers regarding the crisis. This review discusses the biological mechanisms of pesticide-driven pathogenesis (such as the activation or inhibition of caspase, serine protease, acetylcholinesterase) and presents the pesticide-exposure-caused health deterioration in USA, India, and Africa. This holistic and critical review should be an eye-opener for general public, and a guide for researchers. Title: Therapeutic endocannabinoid augmentation for mood and anxiety disorders: comparative profiling of FAAH, MAGL and dual inhibitors Bedse G, Bluett RJ, Patrick TA, Romness NK, Gaulden AD, Kingsley PJ, Plath N, Marnett LJ, Patel S Ref: Transl Psychiatry, 8:92, 2018 : PubMed ESTHER: Bedse_2018_Transl.Psychiatry_8_92 PubMedSearch: Bedse 2018 Transl.Psychiatry 8 92 PubMedID: 29695817 Abstract Recent studies have demonstrated anxiolytic potential of pharmacological endocannabinoid (eCB) augmentation approaches in a variety of preclinical models. Pharmacological inhibition of endocannabinoid-degrading enzymes, such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), elicit promising anxiolytic effects in rodent models with limited adverse behavioral effects, however, the efficacy of dual FAAH/MAGL inhibition has not been investigated. In the present study, we compared the effects of FAAH (PF-3845), MAGL (JZL184) and dual FAAH/MAGL (JZL195) inhibitors on (1) anxiety-like behaviors under non-stressed and stressed conditions, (2) locomotor activity and body temperature, (3) lipid levels in the brain and (4) cognitive functions. Behavioral analysis showed that PF-3845 or JZL184, but not JZL195, was able to prevent restraint stress-induced anxiety in the light-dark box assay when administered before stress exposure. Moreover, JZL195 treatment was not able to reverse foot shock-induced anxiety-like behavior in the elevated zero maze or light-dark box. JZL195, but not PF-3845 or JZL184, decreased body temperature and increased anxiety-like behavior in the open-field test. Overall, JZL195 did not show anxiolytic efficacy and the effects of JZL184 were more robust than that of PF-3845 in the models examined. These results showed that increasing either endogenous AEA or 2-AG separately produces anti-anxiety effects under stressful conditions but the same effects are not obtained from simultaneously increasing both AEA and 2-AG. Title: Inhibition of Diacylglycerol Lipase Impairs Fear Extinction in Mice Cavener VS, Gaulden A, Pennipede D, Jagasia P, Uddin J, Marnett LJ, Patel S Ref: Front Neurosci, 12:479, 2018 : PubMed ESTHER: Cavener_2018_Front.Neurosci_12_479 PubMedSearch: Cavener 2018 Front.Neurosci 12 479 PubMedID: 30108473 Abstract Elucidating the underlying molecular mechanisms regulating fear and extinction learning may offer insights that can lead to novel treatments for debilitating anxiety and trauma-related disorders including posttraumatic stress disorder. The endocannabinoid (eCB) system is a retrograde inhibitory signaling pathway involved in regulating central responses to stress. The eCB 2-arachidonoylglycerol (2-AG) has recently been proposed to serve as a homeostatic signal mitigating adverse effects of stress exposure, however, less well understood is 2-AG's role in fear learning and fear extinction. In this study, we have sought to explore 2-AG's role in fear conditioning and fear extinction by disrupting 2-AG synthesis utilizing the DAGL inhibitor (DO34) and DAGLalpha knock-out mice (DAGLalpha(-/-)). We found that DAGLalpha(-/-) mice, and male and female C57B6/J mice treated with DO34, exhibited impairment in extinction learning in an auditory cue fear-conditioning paradigm. DO34 did not increase unconditioned freezing. Interestingly, inhibition of fatty-acid amide hydrolase was not able to restore normal fear extinction in DO34-treated mice suggesting increased Anandamide cannot compensate for deficient 2-AG signaling in the regulation of fear extinction. Moreover, augmentation of CB1R signaling with tetrahydrocannabinol also failed to restore normal fear extinction in DO34-treated mice. Overall, these data support the hypothesis that DAGLalpha plays an important role in fear extinction learning. Although genetic and pharmacological disruption of DAGL activity causes widespread lipidomic remodeling, these data combined with previous studies putatively suggest that deficient 2-AG signaling could be a susceptibility endophenotype for the development of trauma-related psychiatric disorders. Title: Flavonoids as acetylcholinesterase inhibitors: Current therapeutic standing and future prospects Khan H, Marya, Amin S, Kamal MA, Patel S Ref: Biomed Pharmacother, 101:860, 2018 : PubMed ESTHER: Khan_2018_Biomed.Pharmacother_101_860 PubMedSearch: Khan 2018 Biomed.Pharmacother 101 860 PubMedID: 29635895 Abstract BACKGROUND: Acetylcholinesterase (AChE), a serine hydrolase, is primarily responsible for the termination of signal transmission in the cholinergic system, owing to its outstanding hydrolyzing potential. Its substrate acetylcholine (ACh), is a neurotransmitter of the cholinergic system, with a predominant effect on motor neurons involved in memory formation. So, by decreasing the activity of this enzyme by employment of specific inhibitors, a number of motor neuron disorders such as myasthenia gravis, glaucoma, Lewy body dementia, and Alzheimer's disease, among others, can be treated. However, the current-available AChE inhibitors have several limitations in terms of efficacy, therapeutic range, and safety. SCOPE AND APPROACH: Primarily due to the non-compliance of current therapies, new, effective and safe inhibitors are being searched for, especially those which act through multiple receptor sites, but do not elicit undesirable effects. In this regard, the evaluation of phytochemicals such as flavonoids, can be a rational approach. The therapeutic potential of flavonoids has already been recognized agaisnt several ailments. This review deals with various plant-derived flavonoids, their preclinical potential as AChE inhibitors, in established assays, possible mechanisms of action, and structural activity relationship (SAR). RESULTS AND CONCLUSIONS: Subsequently, a number of plant-derived flavonoids with outstanding efficacy and potency as AChE inhibitors, the mechanistic, their safety profiles, and pharmacokinetic attributes have been discussed. Through derivatization of these reported flavonoids, some limitation in efficacy or pharmacokinetic parameters can be addressed. The selected flavonoids ought to be tested in clinical studies to discover new neuro-therapeutic candidates. Title: Detection of Cyclooxygenase-2-Derived Oxygenation Products of the Endogenous Cannabinoid 2-Arachidonoylglycerol in Mouse Brain Morgan AJ, Kingsley PJ, Mitchener MM, Altemus M, Patrick TA, Gaulden AD, Marnett LJ, Patel S Ref: ACS Chem Neurosci, 9:1552, 2018 : PubMed ESTHER: Morgan_2018_ACS.Chem.Neurosci_9_1552 PubMedSearch: Morgan 2018 ACS.Chem.Neurosci 9 1552 PubMedID: 29722963 Abstract Cyclooxygenase-2 (COX-2) catalyzes the formation of prostaglandins, which are involved in immune regulation, vascular function, and synaptic signaling. COX-2 also inactivates the endogenous cannabinoid (eCB) 2-arachidonoylglycerol (2-AG) via oxygenation of its arachidonic acid backbone to form a variety of prostaglandin glyceryl esters (PG-Gs). Although this oxygenation reaction is readily observed in vitro and in intact cells, detection of COX-2-derived 2-AG oxygenation products has not been previously reported in neuronal tissue. Here we show that 2-AG is metabolized in the brain of transgenic COX-2-overexpressing mice and mice treated with lipopolysaccharide to form multiple species of PG-Gs that are detectable only when monoacylglycerol lipase is concomitantly blocked. Formation of these PG-Gs is prevented by acute pharmacological inhibition of COX-2. These data provide evidence that neuronal COX-2 is capable of oxygenating 2-AG to form a variety PG-Gs in vivo and support further investigation of the physiological functions of PG-Gs. Title: Pharmacological and Toxicological Profile of Harmane-beta-Carboline Alkaloid: Friend or Foe Khan H, Patel S, Kamal MA Ref: Curr Drug Metab, 18:853, 2017 : PubMed ESTHER: Khan_2017_Curr.Drug.Metab_18_853 PubMedSearch: Khan 2017 Curr.Drug.Metab 18 853 PubMedID: 28595532 Abstract BACKGROUND: The plant secondary metabolites have an outstanding therapeutic potential and success over the years. In fact, it is the foundation of numerous clinically used drugs. Similarly, these is a general perception that these products are inherent safety. However, such products might have toxic/unwanted lethal effects therefore, along with biological relevance, toxicological evaluation is equally important for clinical applications. Therefore, harmane- beta-carboline alkaloid was investigated for both therapeutic and toxicological potential. METHODS: The literature related to the therapeutic/toxicological effects of the alkaloid was searched using various scientific data bases including Google, ScienceDirect, PubMed, SpringerLink, ASC. The peer reviewed articles were only selected. RESULTS: The harmane-beta-carboline alkaloid has shown several pharmacological activities such as antianxiety, antidepressant, antiplatelet, antidiabetic, acetylcholinesterase and myeloperoxidase inhibition, antioxidant, antiparasitic, hypotensive, morphine withdrawal syndrome alleviation, and antinociceptive effects. On the other hand, it exhibited tremorogenic effect, for a symptom of Parkinson's disease. Adverse effect of the alkaloid on learning and memory have also been observed. CONCLUSIONS: All together, it is, concluded in this review that harmane elicited marked pharmacological effects but simultaneously, it possessed some serious side effects that could be the primary hurdle in the way of its clinical testing. Title: The endocannabinoid system as a target for novel anxiolytic drugs Patel S, Hill MN, Cheer JF, Wotjak CT, Holmes A Ref: Neurosci Biobehav Rev, 76:56, 2017 : PubMed ESTHER: Patel_2017_Neurosci.Biobehav.Rev_76_56 PubMedSearch: Patel 2017 Neurosci.Biobehav.Rev 76 56 PubMedID: 28434588 Abstract The endocannabinoid (eCB) system has attracted attention for its role in various behavioral and brain functions, and as a therapeutic target in neuropsychiatric disease states, including anxiety disorders and other conditions resulting from dysfunctional responses to stress. In this mini-review, we highlight components of the eCB system that offer potential 'druggable' targets for new anxiolytic medications, emphasizing some of the less well-discussed options. We discuss how selectively amplifying eCBs recruitment by interfering with eCB-degradation, via fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), has been linked to reductions in anxiety-like behaviors in rodents and variation in human anxiety symptoms. We also discuss a non-canonical route to regulate eCB degradation that involves interfering with cyclooxygenase-2 (COX-2). Next, we discuss approaches to targeting eCB receptor-signaling in ways that do not involve the cannabinoid receptor subtype 1 (CB1R); by targeting the CB2R subtype and the transient receptor potential vanilloid type 1 (TRPV1). Finally, we review evidence that cannabidiol (CBD), while representing a less specific pharmacological approach, may be another way to modulate eCBs and interacting neurotransmitter systems to alleviate anxiety. Taken together, these various approaches provide a range of plausible paths to developing novel compounds that could prove useful for treating trauma-related and anxiety disorders. Title: Ketamine and MAG Lipase Inhibitor-Dependent Reversal of Evolving Depressive-Like Behavior During Forced Abstinence From Alcohol Drinking Holleran KM, Wilson HH, Fetterly TL, Bluett RJ, Centanni SW, Gilfarb RA, Rocco LE, Patel S, Winder DG Ref: Neuropsychopharmacology, 41:2062, 2016 : PubMed ESTHER: Holleran_2016_Neuropsychopharmacology_41_2062 PubMedSearch: Holleran 2016 Neuropsychopharmacology 41 2062 PubMedID: 26751284 Abstract Although alcoholism and depression are highly comorbid, treatment options that take this into account are lacking, and mouse models of alcohol (ethanol (EtOH)) intake-induced depressive-like behavior have not been well established. Recent studies utilizing contingent EtOH administration through prolonged two-bottle choice access have demonstrated depression-like behavior following EtOH abstinence in singly housed female C57BL/6J mice. In the present study, we found that depression-like behavior in the forced swim test (FST) is revealed only after a protracted (2 weeks), but not acute (24 h), abstinence period. No effect on anxiety-like behavior in the EPM was observed. Further, we found that, once established, the affective disturbance is long-lasting, as we observed significantly enhanced latencies to approach food even 35 days after ethanol withdrawal in the novelty-suppressed feeding test (NSFT). We were able to reverse affective disturbances measured in the NSFT following EtOH abstinence utilizing the N-methyl D-aspartate receptor (NMDAR) antagonist and antidepressant ketamine but not memantine, another NMDAR antagonist. Pretreatment with the monoacylglycerol (MAG) lipase inhibitor JZL-184 also reduced affective disturbances in the NSFT in ethanol withdrawn mice, and this effect was prevented by co-administration of the CB1 inverse agonist rimonabant. Endocannabinoid levels were decreased within the BLA during abstinence compared with during drinking. Finally, we demonstrate that the depressive behaviors observed do not require a sucrose fade and that this drinking paradigm may favor the development of habit-like EtOH consumption. These data could set the stage for developing novel treatment approaches for alcohol-withdrawal-induced mood and anxiety disorders. Title: Interconnected microbiomes and resistomes in low-income human habitats Pehrsson EC, Tsukayama P, Patel S, Mejia-Bautista M, Sosa-Soto G, Navarrete KM, Calderon M, Cabrera L, Hoyos-Arango W and Dantas G <3 more author(s)> Pehrsson EC, Tsukayama P, Patel S, Mejia-Bautista M, Sosa-Soto G, Navarrete KM, Calderon M, Cabrera L, Hoyos-Arango W, Bertoli MT, Berg DE, Gilman RH, Dantas G (- 3) Ref: Nature, 533:212, 2016 : PubMed ESTHER: Pehrsson_2016_Nature_533_212 PubMedSearch: Pehrsson 2016 Nature 533 212 PubMedID: 27172044 Abstract Antibiotic-resistant infections annually claim hundreds of thousands of lives worldwide. This problem is exacerbated by exchange of resistance genes between pathogens and benign microbes from diverse habitats. Mapping resistance gene dissemination between humans and their environment is a public health priority. Here we characterized the bacterial community structure and resistance exchange networks of hundreds of interconnected human faecal and environmental samples from two low-income Latin American communities. We found that resistomes across habitats are generally structured by bacterial phylogeny along ecological gradients, but identified key resistance genes that cross habitat boundaries and determined their association with mobile genetic elements. We also assessed the effectiveness of widely used excreta management strategies in reducing faecal bacteria and resistance genes in these settings representative of low- and middle-income countries. Our results lay the foundation for quantitative risk assessment and surveillance of resistance gene dissemination across interconnected habitats in settings representing over two-thirds of the world's population. Title: Identification of Genes Conferring Tolerance to Lignocellulose-Derived Inhibitors by Functional Selections in Soil Metagenomes Forsberg KJ, Patel S, Witt E, Wang B, Ellison TD, Dantas G Ref: Applied Environmental Microbiology, 82:528, 2015 : PubMed ESTHER: Forsberg_2015_Appl.Environ.Microbiol_82_528 PubMedSearch: Forsberg 2015 Appl.Environ.Microbiol 82 528 PubMedID: 26546427 Gene_locus related to this paper: 9bact-a0a0u2zp04 Abstract The production of fuels or chemicals from lignocellulose currently requires thermochemical pretreatment to release fermentable sugars. These harsh conditions also generate numerous small-molecule inhibitors of microbial growth and fermentation, limiting production. We applied small-insert functional metagenomic selections to discover genes that confer microbial tolerance to these inhibitors, identifying both individual genes and general biological processes associated with tolerance to multiple inhibitory compounds. Having screened over 248 Gb of DNA cloned from 16 diverse soil metagenomes, we describe gain-of-function tolerance against acid, alcohol, and aldehyde inhibitors derived from hemicellulose and lignin, demonstrating that uncultured soil microbial communities hold tremendous genetic potential to address the toxicity of pretreated lignocellulose. We recovered genes previously known to confer tolerance to lignocellulosic inhibitors as well as novel genes that confer tolerance via unknown functions. For instance, we implicated galactose metabolism in overcoming the toxicity of lignin monomers and identified a decarboxylase that confers tolerance to ferulic acid; this enzyme has been shown to catalyze the production of 4-vinyl guaiacol, a valuable precursor to vanillin production. These metagenomic tolerance genes can enable the flexible design of hardy microbial catalysts, customized to withstand inhibitors abundant in specific bioprocessing applications. Title: Using Gene Ontology to describe the role of the neurexin-neuroligin-SHANK complex in human, mouse and rat and its relevance to autism Patel S, Roncaglia P, Lovering RC Ref: BMC Bioinformatics, 16:186, 2015 : PubMed ESTHER: Patel_2015_BMC.Bioinformatics_16_186 PubMedSearch: Patel 2015 BMC.Bioinformatics 16 186 PubMedID: 26047810 Abstract BACKGROUND: People with an autistic spectrum disorder (ASD) display a variety of characteristic behavioral traits, including impaired social interaction, communication difficulties and repetitive behavior. This complex neurodevelopment disorder is known to be associated with a combination of genetic and environmental factors. Neurexins and neuroligins play a key role in synaptogenesis and neurexin-neuroligin adhesion is one of several processes that have been implicated in autism spectrum disorders. Title: Omarigliptin (MK-3102): a novel long-acting DPP-4 inhibitor for once-weekly treatment of type 2 diabetes Biftu T, Sinha-Roy R, Chen P, Qian X, Feng D, Kuethe JT, Scapin G, Gao YD, Yan Y and Weber AE <19 more author(s)> Biftu T, Sinha-Roy R, Chen P, Qian X, Feng D, Kuethe JT, Scapin G, Gao YD, Yan Y, Krueger D, Bak A, Eiermann G, He J, Cox J, Hicks J, Lyons K, He H, Salituro G, Tong S, Patel S, Doss G, Petrov A, Wu J, Xu SS, Sewall C, Zhang X, Zhang B, Thornberry NA, Weber AE (- 19) Ref: Journal of Medicinal Chemistry, 57:3205, 2014 : PubMed ESTHER: Biftu_2014_J.Med.Chem_57_3205 PubMedSearch: Biftu 2014 J.Med.Chem 57 3205 PubMedID: 24660890 Gene_locus related to this paper: human-DPP4 Inhibitor(s) related to this paper: Omarigliptin Abstract In our effort to discover DPP-4 inhibitors with added benefits over currently commercially available DPP-4 inhibitors, MK-3102 (omarigliptin), was identified as a potent and selective dipeptidyl peptidase 4 (DPP-4) inhibitor with an excellent pharmacokinetic profile amenable for once-weekly human dosing and selected as a clinical development candidate. This manuscript summarizes the mechanism of action, scientific rationale, medicinal chemistry, pharmacokinetic properties, and human efficacy data for omarigliptin, which is currently in phase 3 clinical development. Title: Bacterial phylogeny structures soil resistomes across habitats Forsberg KJ, Patel S, Gibson MK, Lauber CL, Knight R, Fierer N, Dantas G Ref: Nature, 509:612, 2014 : PubMed ESTHER: Forsberg_2014_Nature_509_612 PubMedSearch: Forsberg 2014 Nature 509 612 PubMedID: 24847883 Abstract Ancient and diverse antibiotic resistance genes (ARGs) have previously been identified from soil, including genes identical to those in human pathogens. Despite the apparent overlap between soil and clinical resistomes, factors influencing ARG composition in soil and their movement between genomes and habitats remain largely unknown. General metagenome functions often correlate with the underlying structure of bacterial communities. However, ARGs are proposed to be highly mobile, prompting speculation that resistomes may not correlate with phylogenetic signatures or ecological divisions. To investigate these relationships, we performed functional metagenomic selections for resistance to 18 antibiotics from 18 agricultural and grassland soils. The 2,895 ARGs we discovered were mostly new, and represent all major resistance mechanisms. We demonstrate that distinct soil types harbour distinct resistomes, and that the addition of nitrogen fertilizer strongly influenced soil ARG content. Resistome composition also correlated with microbial phylogenetic and taxonomic structure, both across and within soil types. Consistent with this strong correlation, mobility elements (genes responsible for horizontal gene transfer between bacteria such as transposases and integrases) syntenic with ARGs were rare in soil by comparison with sequenced pathogens, suggesting that ARGs may not transfer between soil bacteria as readily as is observed between human pathogens. Together, our results indicate that bacterial community composition is the primary determinant of soil ARG content, challenging previous hypotheses that horizontal gene transfer effectively decouples resistomes from phylogeny. Title: Long-Term Efficacy and Safety of Linagliptin in Patients With Type 2 Diabetes and Severe Renal Impairment: A 1-year, randomized, double-blind, placebo-controlled study McGill JB, Sloan L, Newman J, Patel S, Sauce C, von Eynatten M, Woerle HJ Ref: Diabetes Care, 36:237, 2013 : PubMed ESTHER: McGill_2013_Diabetes.Care_36_237 PubMedSearch: McGill 2013 Diabetes.Care 36 237 PubMedID: 23033241 Abstract OBJECTIVE This placebo-controlled study assessed long-term efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in patients with type 2 diabetes and severe renal impairment (RI). RESEARCH DESIGN AND METHODS In this 1-year, double-blind study, 133 patients with type 2 diabetes (HbA(1c) 7.0-10.0%) and severe RI (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m(2)) at screening were randomized to linagliptin 5 mg (n = 68) or placebo (n = 65) once daily, added to existing background therapy. The primary efficacy end point was HbA(1c) change from baseline to week 12. Efficacy and safety end points were assessed after 1 year. RESULTS At week 12, adjusted mean HbA(1c) decreased by -0.76% with linagliptin and -0.15% with placebo (treatment difference, -0.60%; 95% CI -0.89 to -0.31; P < 0.0001). HbA(1c) improvements were sustained with linagliptin (-0.71%) over placebo (0.01%) at 1 year (treatment difference -0.72%, -1.03 to -0.41; P < 0.0001). Mean insulin doses decreased by -6.2 units with linagliptin and -0.3 units with placebo. Overall adverse event incidence was similar over 1 year (94.1 vs. 92.3%). Incidence of severe hypoglycemia with linagliptin and placebo was comparably low (three patients per group). Linagliptin and placebo had little effect on renal function (median change in eGFR, -0.8 vs. -2.2 mL/min/1.73 m(2)), and no drug-related renal failure occurred. CONCLUSIONS In patients with type 2 diabetes and severe RI, linagliptin provided clinically meaningful improvements in glycemic control with very low risk of severe hypoglycemia, stable body weight, and no cases of drug-related renal failure. The potential for linagliptin to spare insulin and provide long-term renal safety warrants further investigations. Title: CaMKII regulates diacylglycerol lipase-alpha and striatal endocannabinoid signaling Shonesy BC, Wang X, Rose KL, Ramikie TS, Cavener VS, Rentz T, Baucum AJ, 2nd, Jalan-Sakrikar N, Mackie K and Colbran RJ <2 more author(s)> Shonesy BC, Wang X, Rose KL, Ramikie TS, Cavener VS, Rentz T, Baucum AJ, 2nd, Jalan-Sakrikar N, Mackie K, Winder DG, Patel S, Colbran RJ (- 2) Ref: Nat Neurosci, 16:456, 2013 : PubMed ESTHER: Shonesy_2013_Nat.Neurosci_16_456 PubMedSearch: Shonesy 2013 Nat.Neurosci 16 456 PubMedID: 23502535 Abstract The endocannabinoid 2-arachidonoylglycerol (2-AG) mediates activity-dependent depression of excitatory neurotransmission at central synapses, but the molecular regulation of 2-AG synthesis is not well understood. Here we identify a functional interaction between the 2-AG synthetic enzyme diacylglycerol lipase-alpha (DGLalpha) and calcium/calmodulin dependent protein kinase II (CaMKII). Activated CaMKII interacted with the C-terminal domain of DGLalpha, phosphorylated two serine residues and inhibited DGLalpha activity. Consistent with an inhibitory role for CaMKII in 2-AG synthesis, in vivo genetic inhibition of CaMKII increased striatal DGL activity and basal levels of 2-AG, and CaMKII inhibition augmented short-term retrograde endocannabinoid signaling at striatal glutamatergic synapses. Lastly, blockade of 2-AG breakdown using concentrations of JZL-184 that have no effect in wild-type mice produced a hypolocomotor response in mice with reduced CaMKII activity. These findings provide mechanistic insights into the molecular regulation of striatal endocannabinoid signaling with implications for physiological control of motor function. Title: Cotinine reduces amyloid-beta aggregation and improves memory in Alzheimer's disease mice Echeverria V, Zeitlin R, Burgess S, Patel S, Barman A, Thakur G, Mamcarz M, Wang L, Sattelle DB and Arendash GW <4 more author(s)> Echeverria V, Zeitlin R, Burgess S, Patel S, Barman A, Thakur G, Mamcarz M, Wang L, Sattelle DB, Kirschner DA, Mori T, Leblanc RM, Prabhakar R, Arendash GW (- 4) Ref: J Alzheimers Dis, 24:817, 2011 : PubMed ESTHER: Echeverria_2011_J.Alzheimers.Dis_24_817 PubMedSearch: Echeverria 2011 J.Alzheimers.Dis 24 817 PubMedID: 21321389 Inhibitor(s) related to this paper: Cotinine Abstract Alzheimer's disease (AD) affects millions of people world-wide and new effective and safe therapies are needed. Cotinine, the main metabolite of nicotine, has a long half-life and does not have cardiovascular or addictive side effects in humans. We studied the effect of cotinine on amyloid-beta (Abeta) aggregation as well as addressed its impact on working and reference memories. Cotinine reduced Abeta deposition, improved working and reference memories, and inhibited Abeta oligomerization in the brains of transgenic (Tg) 6799 AD mice. In vitro studies confirmed the inhibitory effect of cotinine on Abeta1-42 aggregation. Cotinine stimulated Akt signaling, including the inhibition of glycogen synthase kinase 3beta (GSK3beta), which promotes neuronal survival and the synaptic plasticity processes underlying learning and memory in the hippocampus and cortex of wild type and Tg6799 AD mice. Simulation of the cotinine-Abeta1-42 complex using molecular dynamics showed that cotinine may interact with key histidine residues of Abeta1-42, altering its structure and inhibiting its aggregation. The good safety profile in humans and its beneficial effects suggest that cotinine may be an excellent therapeutic candidate for the treatment of AD. Title: Hormone-sensitive lipase modulates adipose metabolism through PPARgamma Shen WJ, Yu Z, Patel S, Jue D, Liu LF, Kraemer FB Ref: Biochimica & Biophysica Acta, 1811:9, 2011 : PubMed ESTHER: Shen_2011_Biochim.Biophys.Acta_1811_9 PubMedSearch: Shen 2011 Biochim.Biophys.Acta 1811 9 PubMedID: 20950707 Abstract Hormone-sensitive lipase (HSL) is rate limiting for diacylglycerol and cholesteryl ester hydrolysis in adipose tissue and essential for complete hormone-stimulated lipolysis. Gene expression profiling in HSL-/- mice suggests that HSL is important for modulating adipogenesis and adipose metabolism. To test whether HSL is required for the supply of intrinsic ligands for PPARgamma for normal adipose differentiation, HSL-/- and wild-type (WT) littermates were fed normal chow (NC) and high-fat (HF) diets supplemented with or without rosiglitazone (200 mg/kg) for 16 weeks. Results show that supplementing rosiglitazone to an NC diet completely normalized the decreased body weight and adipose depots in HSL-/- mice. Additionally, rosiglitazone resulted in similar serum glucose, total cholesterol, FFA, and adiponectin values in WT and HSL-/- mice. Furthermore, rosiglitazone normalized the expression of genes involved in adipocyte differentiation, markers of adipocyte differentiation, and enzymes involved in triacylglycerol synthesis and metabolism, and cholesteryl ester homeostasis, in HSL-/- mice. Supplementing rosiglitazone to an HF diet resulted in improved glucose tolerance in both WT and HSL-/- animals and also partial normalization in HSL-/- mice of abnormal WAT gene expression, serum chemistries, organ and body weight changes. In vitro studies showed that adipocytes from WT animals can provide ligands for activation of PPARgamma and that activation is further boosted following lipolytic stimulation, whereas adipocytes from HSL-/- mice displayed attenuated activation of PPARgamma, with no change following lipolytic stimulation. These results suggest that one of the mechanisms by which HSL modulates adipose metabolism is by providing intrinsic ligands or pro-ligands for PPARgamma. Title: Hormone-sensitive lipase-knockout mice maintain high bone density during aging Shen WJ, Liu LF, Patel S, Kraemer FB Ref: FASEB Journal, 25:2722, 2011 : PubMed ESTHER: Shen_2011_FASEB.J_25_2722 PubMedSearch: Shen 2011 FASEB.J 25 2722 PubMedID: 21566206 Abstract We tested the hypothesis that the actions of hormone-sensitive lipase (HSL) affect the microenvironment of the bone marrow and that removal of HSL function by gene deletion maintains high bone mass in aging mice. We compared littermate control wild-type (WT) and HSL(-/-) mice during aging for changes in serum biochemical values, trabecular bone density using micro-computed tomography, bone histomorphometry, and characteristics of primary bone marrow cells and preosteoblasts. There is a regulated expression of HSL and genes involved in lipid metabolism in the bone marrow during aging. HSL(-/-) mice have increased serum levels of insulin and osteocalcin with decreased leptin levels. Compared with the marked adipocyte infiltration in WT bone marrow (65% by area) at 14 mo, HSL(-/-) mice have fewer (16%, P<0.05) and smaller adipocytes in bone marrow. While peak bone density is similar, HSL(-/-) mice maintain a higher bone density (bone volume/total volume 6.1%) with age than WT mice (2.6%, P<0.05). Primary osteoblasts from HSL(-/-) mice show increased growth rates and higher osteogenic potential, manifested by increased expression of Runx2 (3.5-fold, P<0.05) and osteocalcin (4-fold, P<0.05). The absence of HSL directs cells within the bone marrow toward osteoblast differentiation and favors the maintenance of bone density with aging. Title: Reversible gating of endocannabinoid plasticity in the amygdala by chronic stress: a potential role for monoacylglycerol lipase inhibition in the prevention of stress-induced behavioral adaptation Sumislawski JJ, Ramikie TS, Patel S Ref: Neuropsychopharmacology, 36:2750, 2011 : PubMed ESTHER: Sumislawski_2011_Neuropsychopharmacology_36_2750 PubMedSearch: Sumislawski 2011 Neuropsychopharmacology 36 2750 PubMedID: 21849983 Abstract Chronic stress is the primary environmental risk factor for the development and exacerbation of affective disorders, thus understanding the neuroadaptations that occur in response to stress is a critical step in the development of novel therapeutics for depressive and anxiety disorders. Brain endocannabinoid (eCB) signaling is known to modulate emotional behavior and stress responses, and levels of the eCB 2-arachidonoylglycerol (2-AG) are elevated in response to chronic homotypic stress exposure. However, the role of 2-AG in the synaptic and behavioral adaptations to chronic stress is poorly understood. Here, we show that stress-induced development of anxiety-like behavior is paralleled by a transient appearance of low-frequency stimulation-induced, 2-AG-mediated long-term depression at GABAergic synapses in the basolateral amygdala, a key region involved in motivation, affective regulation, and emotional learning. This enhancement of 2-AG signaling is mediated, in part, via downregulation of the primary 2-AG-degrading enzyme monoacylglycerol lipase (MAGL). Acute in vivo inhibition of MAGL had little effect on anxiety-related behaviors. However, chronic stress-induced anxiety-like behavior and emergence of long-term depression of GABAergic transmission was prevented by chronic MAGL inhibition, likely via an occlusive mechanism. These data indicate that chronic stress reversibly gates eCB synaptic plasticity at inhibitory synapses in the amygdala, and in vivo augmentation of 2-AG levels prevents both behavioral and synaptic adaptations to chronic stress. Title: Vimentin is a functional partner of hormone sensitive lipase and facilitates lipolysis Shen WJ, Patel S, Eriksson JE, Kraemer FB Ref: J Proteome Res, 9:1786, 2010 : PubMed ESTHER: Shen_2010_J.Proteome.Res_9_1786 PubMedSearch: Shen 2010 J.Proteome.Res 9 1786 PubMedID: 20143880 Abstract Lipolysis involves a number of components including signaling pathways, droplet-associated proteins, and lipases such as hormone-sensitive lipase (HSL). We used surface enhanced laser desorption/ionization time-of-flight mass spectroscopy to identify cellular proteins that might interact with HSL and potentially influence lipolysis. Using recombinant HSL as bait on protein chips, clusters of proteins of 14.7-18.9, 25.8-26.8, 36.1, 44.3-49.1, and 53.7 kDa were identified that interact with HSL, particularly when lysates were examined from beta-agonist treated mouse adipocytes. The ability to detect these interacting proteins was markedly diminished when the adipocytes were treated with insulin. A very similar pattern of proteins was identified when anti-HSL IgG was used as the bait. Following immunocapture, the identification of the prominent 53.7 kDa protein was carried out by tryptic digestion and MS analysis and determined to be vimentin. The interaction of HSL with vimentin, and its hormonal dependence, was confirmed by coimmunoprecipitation. beta-Agonist stimulated lipolysis and the rate of HSL translocation were impaired in vimentin null adipocytes, even though normal amounts of lipases and droplet-associated proteins are expressed. The current studies provide evidence that vimentin participates in lipolysis through direct, hormonally regulated interactions with HSL. Title: Functional interaction of hormone-sensitive lipase and perilipin in lipolysis Shen WJ, Patel S, Miyoshi H, Greenberg AS, Kraemer FB Ref: J Lipid Res, 50:2306, 2009 : PubMed ESTHER: Shen_2009_J.Lipid.Res_50_2306 PubMedSearch: Shen 2009 J.Lipid.Res 50 2306 PubMedID: 19515989 Abstract Adipocyte lipolysis is controlled by complex interactions of lipases, cofactors, and structural proteins associated with lipid droplets. Perilipin (Plin) A is a major droplet-associated protein that functions as a scaffold, both suppressing basal and facilitating cAMP-dependent protein kinase (PKA)-stimulated lipolysis. Plin is required for the translocation of hormone-sensitive lipase (HSL) from the cytosol to lipid droplets upon stimulation. In these studies, we provide direct evidence for a physical interaction of HSL with Plin. By coexpressing HSL with truncation mutations of Plin, we demonstrate using coimmunoprecipitation that HSL can interact with an N-terminal region located between amino acids 141 and 200 of Plin A as well as with a C-terminal region located between amino acids 406 and 480. The N-terminal construct, Plin 1-200, which does not associate with lipid droplets but interacts with HSL, can function as a dominant negative for PKA-stimulated lipolysis. Using confocal microscopy of Plin truncations, we demonstrate that sequences between amino acids 463 and 517 may be important for or participate in lipid targeting. The results suggest the translocation of HSL to the lipid droplet occurs by virtue of Plin localization to the surface of lipid droplets and a physical interaction of HSL occurring with sequences within the N-terminal region of Plin. Title: Discovery of new binding elements in DPP-4 inhibition and their applications in novel DPP-4 inhibitor design Liang GB, Qian X, Biftu T, Singh S, Gao YD, Scapin G, Patel S, Leiting B, Patel R and Weber AE <3 more author(s)> Liang GB, Qian X, Biftu T, Singh S, Gao YD, Scapin G, Patel S, Leiting B, Patel R, Wu J, Zhang X, Thornberry NA, Weber AE (- 3) Ref: Bioorganic & Medicinal Chemistry Lett, 18:3706, 2008 : PubMed ESTHER: Liang_2008_Bioorg.Med.Chem.Lett_18_3706 PubMedSearch: Liang 2008 Bioorg.Med.Chem.Lett 18 3706 PubMedID: 18524582 Gene_locus related to this paper: human-DPP4 Inhibitor(s) related to this paper: DB07181 Abstract Probing with tool molecules, and by modeling and X-ray crystallography the binding modes of two structurally distinct series of DPP-4 inhibitors led to the discovery of a rare aromatic fluorine H-bond and the spatial requirement for better biaryl binding in the DPP-4 enzyme active site. These newly found binding elements were successfully incorporated into novel DPP-4 inhibitors. Title: (3R)-4-[(3R)-3-Amino-4-(2,4,5-trifluorophenyl)butanoyl]-3-(2,2,2-trifluoroethyl)- 1,4-diazepan-2-one, a selective dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes Biftu T, Feng D, Qian X, Liang GB, Kieczykowski G, Eiermann G, He H, Leiting B, Lyons K and Weber AE <10 more author(s)> Biftu T, Feng D, Qian X, Liang GB, Kieczykowski G, Eiermann G, He H, Leiting B, Lyons K, Petrov A, Sinha-Roy R, Zhang B, Scapin G, Patel S, Gao YD, Singh S, Wu J, Zhang X, Thornberry NA, Weber AE (- 10) Ref: Bioorganic & Medicinal Chemistry Lett, 17:49, 2007 : PubMed ESTHER: Biftu_2007_Bioorg.Med.Chem.Lett_17_49 PubMedSearch: Biftu 2007 Bioorg.Med.Chem.Lett 17 49 PubMedID: 17055272 Gene_locus related to this paper: human-DPP4 Inhibitor(s) related to this paper: Diazepanone-Analog-18, Diazepanone-Analog-1 Abstract Replacement of the triazolopiperazine ring of sitagliptin (DPP-4 IC(50)=18nM) with 3-(2,2,2-trifluoroethyl)-1,4-diazepan-2-one gave dipeptidyl peptidase IV (DPP-4) inhibitor 1 which is potent (DPP-4 IC(50)=2.6nM), selective, and efficacious in an oral glucose tolerance test in mice. It was selected for extensive preclinical development as a potential back-up candidate to sitagliptin. Title: Rational design of a novel, potent, and orally bioavailable cyclohexylamine DPP-4 inhibitor by application of molecular modeling and X-ray crystallography of sitagliptin Biftu T, Scapin G, Singh S, Feng D, Becker JW, Eiermann G, He H, Lyons K, Patel S and Weber AE <7 more author(s)> Biftu T, Scapin G, Singh S, Feng D, Becker JW, Eiermann G, He H, Lyons K, Patel S, Petrov A, Sinha-Roy R, Zhang B, Wu J, Zhang X, Doss GA, Thornberry NA, Weber AE (- 7) Ref: Bioorganic & Medicinal Chemistry Lett, 17:3384, 2007 : PubMed ESTHER: Biftu_2007_Bioorg.Med.Chem.Lett_17_3384 PubMedSearch: Biftu 2007 Bioorg.Med.Chem.Lett 17 3384 PubMedID: 17433672 Gene_locus related to this paper: human-DPP4 Inhibitor(s) related to this paper: CHEMBL233360 Abstract Molecular modeling was used to design a rigid analog of sitagliptin 1. The X-ray crystal structure of sitagliptin bound to DPP-4 suggested that the central beta-amino butyl amide moiety could be replaced with a cyclohexylamine group. This was confirmed by structural analysis and the resulting analog 2a was synthesized and found to be a potent DPP-4 inhibitor (IC(50)=21 nM) with excellent in vivo activity and pharmacokinetic profile. Title: Regulation of hormone-sensitive lipase in islets Shen WJ, Liang Y, Wang J, Harada K, Patel S, Michie SA, Osuga J, Ishibashi S, Kraemer FB Ref: Diabetes Res Clin Pract, 75:14, 2007 : PubMed ESTHER: Shen_2007_Diabetes.Res.Clin.Pract_75_14 PubMedSearch: Shen 2007 Diabetes.Res.Clin.Pract 75 14 PubMedID: 16765472 Abstract An unique isoform of hormone-sensitive lipase (HSL) is expressed in beta-cells. Recent findings suggest that HSL could be involved in the regulation of glucose stimulated insulin secretion (GSIS), however, these findings are controversial. To test the hypothesis that HSL is involved in control of normal GSIS via changes in its expression and/or activity in response to stimuli, we examined the effects of free fatty acid (FFA) loading and glucagon like peptide-1 (GLP-1) stimulation on the regulation of HSL expression and activity. With prolonged FFA loading, there was increased expression of beta-cell HSL and increased HSL hydrolytic activity in clonal beta-cells. Short-term treatment with GLP-1 increased HSL activity without changing the expression of the beta-cell isoform of HSL. Basal insulin secretion was increased, whereas GLP-1 potentiation of GSIS was decreased in islets isolated from HSL-/- mice, as compared to islets from wild type mice. Furthermore, using PancChip 2.2 cDNA microarrays (NIDDK consortium), the gene expression profile in the islets of HSL-/- mice was compared with wild type mice. Results showed changes in several metabolic pathways due to changes in lipid homeostasis caused by inactivation of HSL. Quantitative PCR for selected genes also revealed changes in genes that are related to insulin secretion, such as UCP-2. Therefore, these results suggest that the beta-cell isoform of HSL is involved in maintaining lipid homeostasis in islets and contributes to the proper control of GSIS. Title: Effects of rosiglitazone and high fat diet on lipase/esterase expression in adipose tissue Shen WJ, Patel S, Yu Z, Jue D, Kraemer FB Ref: Biochimica & Biophysica Acta, 1771:177, 2007 : PubMed ESTHER: Shen_2007_Biochim.Biophys.Acta_1771_177 PubMedSearch: Shen 2007 Biochim.Biophys.Acta 1771 177 PubMedID: 17215164 Gene_locus related to this paper: human-ABHD11 Abstract A number of intracellular lipase/esterase have been reported in adipose tissue either by functional assays of activity or through proteomic analysis. In the current work, we have studied the relative expression level of 12 members of the lipase/esterase family that are found in white adipose tissue. We found that the relative mRNA levels of ATGL and HSL are the most abundant, being 2-3 fold greater than TGH or ADPN; whereas other intracellular neutral lipase/esterases were expressed at substantially lower levels. High fat feeding did not alter the mRNA expression levels of most lipase/esterases, but did reduce CGI-58 and WBSCR21. Likewise, rosiglitazone treatment did not alter the mRNA expression levels of most lipase/esterases, but did increase ATGL, TGH, CGI-58 and WBSCR21, while reducing ADPN. WAT from HSL-/- mice showed no compensatory increase in any lipase/esterases, rather mRNA levels of most lipase/esterases were reduced. In contrast, BAT from HSL-/- mice showed an increase in ATGL expression, as well as a decrease in ES-1, APEH and WBSCR21. Analysis of the immunoreactive protein levels of some of the lipases confirmed the results seen with mRNA. In conclusion, these data highlight the complexity of the regulation of the expression of intracellular neutral lipase/esterases involved in lipolysis. Title: Mutational analysis of the regulatory module of hormone-sensitive lipase Wang J, Shen WJ, Patel S, Harada K, Kraemer FB Ref: Biochemistry, 44:1953, 2005 : PubMed ESTHER: Wang_2005_Biochemistry_44_1953 PubMedSearch: Wang 2005 Biochemistry 44 1953 PubMedID: 15697220 Abstract Hormone-sensitive lipase (HSL) is a rate-limiting enzyme in lipolysis that displays broad substrate specificity. HSL function is regulated by reversible phosphorylation that occurs within a 150 aa "regulatory module" of the protein. The current studies used mutational analysis to dissect the contribution of the "regulatory module" in HSL activity and substrate specificity. Deletion of the entire "regulatory module" or replacement of the "regulatory module" with the "lid" of lipoprotein lipase resulted in enzymatically inactive proteins. Deletion of sequentially longer stretches of the "regulatory module" resulted in a stepwise reduction in hydrolytic activity. Analysis of 7-19 amino acid deletional mutants that spanned the "regulatory module" showed that the N-terminal partial deletion mutants retained normal hydrolytic activity and activation by PKA. In contrast, the C-terminal partial deletion mutants displayed reduced hydrolytic activities, with preferential loss of activity against lipid-, as opposed to water-soluble, substrates. Single amino acid mutations of F650C, P651A, and F654D reduced activity against lipid-, but not water-soluble, substrates. The current results suggest that the length of the "regulatory module" and specific sequences within the C-terminal portion of the "regulatory module" of HSL (amino acids 644-683) are crucial for activity and appear to be responsible for determining lipase activity. Title: Enzymes of drug metabolism during delirium White S, Calver BL, Newsway V, Wade R, Patel S, Bayer A, O'Mahony MS Ref: Age Ageing, 34:603, 2005 : PubMed ESTHER: White_2005_Age.Ageing_34_603 PubMedSearch: White 2005 Age.Ageing 34 603 PubMedID: 16267186 Abstract BACKGROUND: Delirium is common in ill medical patients. Several drugs and polypharmacy are recognised risk factors, yet little is known about drug metabolism in people with delirium. OBJECTIVE: The aim of this study was to investigate the activities of plasma esterases (drug metabolising enzymes) in delirium. DESIGN: This was a prospective study of delirium present at time of hospital admission (community acquired) or developing later (hospital acquired) in patients admitted as a medical emergency and aged 75 years or over. Title: Hormone-sensitive lipase is required for high-density lipoprotein cholesteryl ester-supported adrenal steroidogenesis Kraemer FB, Shen WJ, Harada K, Patel S, Osuga J, Ishibashi S, Azhar S Ref: Mol Endocrinol, 18:549, 2004 : PubMed ESTHER: Kraemer_2004_Mol.Endocrinol_18_549 PubMedSearch: Kraemer 2004 Mol.Endocrinol 18 549 PubMedID: 14657254 Gene_locus related to this paper: human-LIPE Abstract Steroid hormones are synthesized using cholesterol as precursor, with a substantial portion supplied by the selective uptake of lipoprotein-derived cholesteryl esters. Adrenals express a high level of neutral cholesteryl ester hydrolase activity, and recently hormone-sensitive lipase (HSL) was shown to be responsible for most adrenal neutral cholesteryl ester hydrolase activity. To determine the functional importance of HSL in adrenal steroidogenesis, adrenal cells were isolated from control and HSL-/- mice, and the in vitro production of corticosterone was quantified. Results show that, even though adrenal cholesteryl ester content was substantially elevated in both male and female HSL-/- mice, basal corticosterone production was reduced approximately 50%. The maximum corticosterone production induced by dibutyryl cAMP, and lipoproteins was approximately 75-85% lower in adrenal cells from HSL-/- mice compared with control. There is no intrinsic defect in the conversion of cholesterol into steroids in HSL-/- mice. Dibutyryl cAMP-stimulated conversion of high-density lipoprotein cholesteryl esters into corticosterone was reduced 97% in HSL-/- mice. An increase in low-density lipoprotein receptor expression appears to be one of the compensatory mechanisms for cholesterol delivery in HSL-/- mice. These findings suggest that HSL is functionally linked to the selective pathway and is critically involved in the intracellular processing and availability of cholesterol for adrenal steroidogenesis. Title: Resistance to high-fat diet-induced obesity and altered expression of adipose-specific genes in HSL-deficient mice Harada K, Shen WJ, Patel S, Natu V, Wang J, Osuga J, Ishibashi S, Kraemer FB Ref: American Journal of Physiology Endocrinol Metab, 285:E1182, 2003 : PubMed ESTHER: Harada_2003_Am.J.Physiol.Endocrinol.Metab_285_E1182 PubMedSearch: Harada 2003 Am.J.Physiol.Endocrinol.Metab 285 E1182 PubMedID: 12954598 Abstract To elucidate the role of hormone-sensitive lipase (HSL) in diet-induced obesity, HSL-deficient (HSL-/-) and wild-type mice were fed normal chow or high-fat diets. HSL-/- mice were resistant to diet-induced obesity showing higher core body temperatures. Weight and triacylglycerol contents were decreased in white adipose tissue (WAT) but increased in both brown adipose tissue (BAT) and liver of HSL-/- mice. Serum insulin levels in the fed state and tumor necrosis factor-alpha mRNA levels in adipose tissues were higher, whereas serum levels of adipocyte complement-related protein of 30 kDa (ACRP30)/adiponectin and leptin, as well as mRNA levels of ACRP30/adiponectin, leptin, resistin, and adipsin in WAT, were lower in HSL-/- mice than in controls. Expression of transcription factors associated with adipogenesis (peroxisome proliferator-activated receptor-gamma, CAAT/enhancer-binding protein-alpha) and lipogenesis (carbohydrate response element-binding protein, adipocyte determination- and differentiation-dependent factor-1/sterol regulatory element-binding protein-1c), as well as of adipose differentiation markers (adipocyte lipid-binding protein, perilipin, lipoprotein lipase), lipogenic enzymes (glycerol-3-phosphate acyltransferase, acyl-CoA:diacylglycerol acyltransferase-1 and -2, fatty acid synthase, ATP citrate lyase) and insulin signaling proteins (insulin receptor, insulin receptor substrate-1, GLUT4), was suppressed in WAT but not in BAT of HSL-/- mice. In contrast, expression of genes associated with cholesterol metabolism (sterol-regulatory element-binding protein-2, 3-hydroxy-3-methylglutaryl-CoA reductase, acyl-CoA:cholesterol acyltransferase-1) and thermogenesis (uncoupling protein-2) was upregulated in both WAT and BAT of HSL-/- mice. Our results suggest that impaired lipolysis in HSL deficiency affects lipid metabolism through alterations of adipose differentiation and adipose-derived hormone levels. Title: Interaction of hormone-sensitive lipase with steroidogenic acute regulatory protein: facilitation of cholesterol transfer in adrenal Shen WJ, Patel S, Natu V, Hong R, Wang J, Azhar S, Kraemer FB Ref: Journal of Biological Chemistry, 278:43870, 2003 : PubMed ESTHER: Shen_2003_J.Biol.Chem_278_43870 PubMedSearch: Shen 2003 J.Biol.Chem 278 43870 PubMedID: 12925534 Abstract Hormone-sensitive lipase (HSL) is responsible for the neutral cholesteryl ester hydrolase activity in steroidogenic tissues. Through its action, HSL is involved in regulating intracellular cholesterol metabolism and making unesterified cholesterol available for steroid hormone production. Steroidogenic acute regulatory protein (StAR) facilitates the movement of cholesterol from the outer mitochondrial membrane to the inner mitochondrial membrane and is a critical regulatory step in steroidogenesis. In the current studies we demonstrate a direct interaction of HSL with StAR using in vitro glutathione S-transferase pull-down experiments. The 37-kDa StAR is coimmunoprecipitated with HSL from adrenals of animals treated with ACTH. Deletional mutations show that HSL interacts with the N-terminal as well as a central region of StAR. Coexpression of HSL and StAR in Chinese hamster ovary cells results in higher cholesteryl ester hydrolytic activity of HSL. Transient overexpression of HSL in Y1 adrenocortical cells increases mitochondrial cholesterol content under conditions in which StAR is induced. It is proposed that the interaction of HSL with StAR in cytosol increases the hydrolytic activity of HSL and that together HSL and StAR facilitate cholesterol movement from lipid droplets to mitochondria for steroidogenesis. Title: Finishing a whole-genome shotgun: release 3 of the Drosophila melanogaster euchromatic genome sequence Celniker SE, Wheeler DA, Kronmiller B, Carlson JW, Halpern A, Patel S, Adams M, Champe M, Dugan SP and Rubin GM <22 more author(s)> Celniker SE, Wheeler DA, Kronmiller B, Carlson JW, Halpern A, Patel S, Adams M, Champe M, Dugan SP, Frise E, Hodgson A, George RA, Hoskins RA, Laverty T, Muzny DM, Nelson CR, Pacleb JM, Park S, Pfeiffer BD, Richards S, Sodergren EJ, Svirskas R, Tabor PE, Wan K, Stapleton M, Sutton GG, Venter C, Weinstock G, Scherer SE, Myers EW, Gibbs RA, Rubin GM (- 22) Ref: Genome Biol, 3:RESEARCH0079, 2002 : PubMed ESTHER: Celniker_2002_Genome.Biol_3_RESEARCH0079 PubMedSearch: Celniker 2002 Genome.Biol 3 RESEARCH0079 PubMedID: 12537568 Gene_locus related to this paper: drome-CG8058, drome-CG9542, drome-CG11309, drome-CG11406, drome-CG17097, drome-CG17374, drome-glita, drome-KRAKEN Abstract BACKGROUND: The Drosophila melanogaster genome was the first metazoan genome to have been sequenced by the whole-genome shotgun (WGS) method. Two issues relating to this achievement were widely debated in the genomics community: how correct is the sequence with respect to base-pair (bp) accuracy and frequency of assembly errors? And, how difficult is it to bring a WGS sequence to the accepted standard for finished sequence? We are now in a position to answer these questions. Title: The transposable elements of the Drosophila melanogaster euchromatin: a genomics perspective Kaminker JS, Bergman CM, Kronmiller B, Carlson J, Svirskas R, Patel S, Frise E, Wheeler DA, Lewis SE and Celniker SE <2 more author(s)> Kaminker JS, Bergman CM, Kronmiller B, Carlson J, Svirskas R, Patel S, Frise E, Wheeler DA, Lewis SE, Rubin GM, Ashburner M, Celniker SE (- 2) Ref: Genome Biol, 3:RESEARCH0084, 2002 : PubMed ESTHER: Kaminker_2002_Genome.Biol_3_RESEARCH0084 PubMedSearch: Kaminker 2002 Genome.Biol 3 RESEARCH0084 PubMedID: 12537573 Gene_locus related to this paper: drome-CG8058, drome-CG9542, drome-CG11309, drome-CG11406, drome-CG17097, drome-glita, drome-KRAKEN Abstract BACKGROUND: Transposable elements are found in the genomes of nearly all eukaryotes. The recent completion of the Release 3 euchromatic genomic sequence of Drosophila melanogaster by the Berkeley Drosophila Genome Project has provided precise sequence for the repetitive elements in the Drosophila euchromatin. We have used this genomic sequence to describe the euchromatic transposable elements in the sequenced strain of this species. Title: Adrenal neutral cholesteryl ester hydrolase: identification, subcellular distribution, and sex differences Kraemer FB, Shen WJ, Natu V, Patel S, Osuga J, Ishibashi S, Azhar S Ref: Endocrinology, 143:801, 2002 : PubMed ESTHER: Kraemer_2002_Endocrinology_143_801 PubMedSearch: Kraemer 2002 Endocrinology 143 801 PubMedID: 11861500 Abstract Adrenals express a high level of neutral cholesteryl ester hydrolase (CEH) activity, and male rats have greater activity than females; however, the identity of the enzyme(s) responsible for this activity and the basis for the sex differences are unknown. Using mice in which hormone-sensitive lipase (HSL) was inactivated by homologous recombination (HSL -/-), neutral CEH activity was reduced more than 98% compared with controls. Female HSL -/- mice showed a reduction in stimulated corticosterone values. Mechanical separation of rat adrenals revealed less HSL in the outer than the inner cortex. Examination of subfractions of rat adrenals showed that immunoreactive HSL was prominently expressed in microsomes, with lesser amounts in the cytosol and little to no HSL in mitochondrial and nuclear fractions or the lipid droplet. Four- to 10-fold more neutral CEH activity was in the microsomal fraction than any other fraction. No sex differences in the expression or subcellular distribution of HSL protein were found; however, neutral CEH activity was lower in the microsomal fraction of females, and female adrenals contained more cholesteryl esters. Thus, HSL appears to be responsible for most, if not all, of adrenal neutral CEH activity, is prominently expressed in microsomes, and its activity is influenced by sex. Title: The effect of community-acquired pneumonia on plasma esterases in older people Abou-Hatab K, Ganeshalingam K, O'Mahony MS, Giurani F, Patel S, Woodhouse K Ref: European Journal of Clinical Pharmacology, 57:55, 2001 : PubMed ESTHER: Abou-Hatab_2001_Eur.J.Clin.Pharmacol_57_55 PubMedSearch: Abou-Hatab 2001 Eur.J.Clin.Pharmacol 57 55 PubMedID: 11372593 Abstract INTRODUCTION: Pneumonia is a major cause of morbidity and mortality in older people. The poor outcome of older pneumonia patients despite treatment is still not understood. OBJECTIVE: The aim of this study was to examine the effect of community-acquired pneumonia on enzymes of drug metabolism in older people. Title: Relationship between age and plasma esterases Abou-Hatab K, O'Mahony MS, Patel S, Woodhouse K Ref: Age Ageing, 30:41, 2001 : PubMed ESTHER: Abou-Hatab_2001_Age.Ageing_30_41 PubMedSearch: Abou-Hatab 2001 Age.Ageing 30 41 PubMedID: 11322671 Abstract INTRODUCTION: the older population is the most medicated. Despite high drug usage, older people are generally excluded from the research underpinning new drug development. This means that drugs are prescribed to older people with very little understanding of how they are likely to metabolize them. More research is needed to investigate the possible effects of ageing on the biotransformation of drugs. We therefore undertook a cross-sectional study examining the effect of age on the activities of benzoylcholinesterase, butyrylcholinesterase, acetylcholinesterase and aspirin esterase. Title: Stimulation of lipolysis and hormone-sensitive lipase via the extracellular signal-regulated kinase pathway Greenberg AS, Shen WJ, Muliro K, Patel S, Souza SC, Roth RA, Kraemer FB Ref: Journal of Biological Chemistry, 276:45456, 2001 : PubMed ESTHER: Greenberg_2001_J.Biol.Chem_276_45456 PubMedSearch: Greenberg 2001 J.Biol.Chem 276 45456 PubMedID: 11581251 Abstract Hormonally stimulated lipolysis occurs by activation of cyclic AMP-dependent protein kinase (PKA) which phosphorylates hormone-sensitive lipase (HSL) and increases adipocyte lipolysis. Evidence suggests that catecholamines not only can activate PKA, but also the mitogen-activated protein kinase pathway and extracellular signal-regulated kinase (ERK). We now demonstrate that two different inhibitors of MEK, the upstream activator of ERK, block catecholamine- and beta(3)-stimulated lipolysis by approximately 30%. Furthermore, treatment of adipocytes with dioctanoylglycerol, which activates ERK, increases lipolysis, although MEK inhibitors decrease dioctanoylglycerol-stimulated activation of lipolysis. Using a tamoxifen regulatable Raf system expressed in 3T3-L1 preadipocytes, exposure to tamoxifen causes a 14-fold activation of ERK within 15-30 min and results in approximately 2-fold increase in HSL activity. In addition, when differentiated 3T3-L1 cells expressing the regulatable Raf were exposed to tamoxifen, a 2-fold increase in lipolysis is observed. HSL is a substrate of activated ERK and site-directed mutagenesis of putative ERK consensus phosphorylation sites in HSL identified Ser(600) as the site phosphorylated by active ERK. When S600A HSL was expressed in 3T3-L1 cells expressing the regulatable Raf, tamoxifen treatment fails to increase its activity. Thus, activation of the ERK pathway appears to be able to regulate adipocyte lipolysis by phosphorylating HSL on Ser(600) and increasing the activity of HSL. Title: Palmitoylation of the vasopressin V1a receptor reveals different conformational requirements for signaling, agonist-induced receptor phosphorylation, and sequestration Hawtin SR, Tobin AB, Patel S, Wheatley M Ref: Journal of Biological Chemistry, 276:38139, 2001 : PubMed ESTHER: Hawtin_2001_J.Biol.Chem_276_38139 PubMedSearch: Hawtin 2001 J.Biol.Chem 276 38139 PubMedID: 11466323 Abstract In this study, we establish that the V1a vasopressin receptor (V1aR) is palmitoylated, and we show that this modification has an important functional role. Palmitoylation of the V1aR occurs within the Cys371/Cys372 couplet located in the proximal C-terminal tail domain. Substitution of these residues in a [C371G/C372G]V1aR construct effectively disrupted receptor palmitoylation. Our data also indicate an additional palmitoylation site at another locus in the receptor, as yet undefined. [3H]Palmitate incorporation was agonist-sensitive and increased following exposure to [Arg8]vasopressin (AVP). Given the hydrophobic nature of the acyl chain, palmitoylation of the C terminus of G-protein-coupled receptors has been proposed to form an additional intracellular loop. Consequently, palmitoylation/depalmitoylation will have a profound effect on the local conformation of this domain. The V1aR palmitoylation status regulated both phosphorylation and sequestration of the receptor, and furthermore, palmitoylation, phosphorylation, and sequestration were all regulated by AVP. The palmitoylation-defective construct [C371G/C372G]V1aR exhibited decreased phosphorylation compared to wild-type V1aR, under both basal and AVP-stimulated conditions, and was sequestered at a faster rate. In contrast, the binding of four different classes of ligand and intracellular signaling were not affected by palmitoylation. This study therefore establishes that there are different conformational requirements for signaling, agonist-induced phosphorylation, and sequestration of the V1aR. Title: Characterization of the functional interaction of adipocyte lipid-binding protein with hormone-sensitive lipase Shen WJ, Liang Y, Hong R, Patel S, Natu V, Sridhar K, Jenkins A, Bernlohr DA, Kraemer FB Ref: Journal of Biological Chemistry, 276:49443, 2001 : PubMed ESTHER: Shen_2001_J.Biol.Chem_276_49443 PubMedSearch: Shen 2001 J.Biol.Chem 276 49443 PubMedID: 11682468 Abstract Hormone-sensitive lipase (HSL) is an intracellular lipase that plays an important role in the hydrolysis of triacylglycerol in adipose tissue. HSL has been shown to interact with adipocyte lipid-binding protein (ALBP), a member of the family of intracellular lipid-binding proteins that bind fatty acids and other hydrophobic ligands. The current studies have addressed the functional significance of the association and mapped the site of interaction between HSL and ALBP. Incubation of homogeneous ALBP with purified, recombinant HSL in vitro resulted in a 2-fold increase in substrate hydrolysis. Moreover, the ability of oleate to inhibit HSL hydrolytic activity was attenuated by co-incubation with ALBP. Co-transfection of Chinese hamster ovary cells with HSL and ALBP resulted in greater hydrolytic activity than transfection of cells with HSL and vector alone. Deletional mutations of HSL localized the region of HSL that interacts with ALBP to amino acids 192-200, and site-directed mutagenesis of individual amino acids in this region identified His-194 and Glu-199 as critical for mediating the interaction of HSL with ALBP. Interestingly, HSL mutants H194L and E199A, each of which retained normal basal hydrolytic activity, failed to display an increase in hydrolytic activity when co-transfected with wild type ALBP. Therefore, ALBP increases the hydrolytic activity of HSL through its ability to bind and sequester fatty acids and via specific protein-protein interaction. Thus, HSL and ALBP constitute a functionally important lipolytic complex. Title: Absence of cardiac lipid accumulation in transgenic mice with heart-specific HSL overexpression Suzuki J, Shen WJ, Nelson BD, Patel S, Veerkamp JH, Selwood SP, Murphy GM, Jr., Reaven E, Kraemer FB Ref: American Journal of Physiology Endocrinol Metab, 281:E857, 2001 : PubMed ESTHER: Suzuki_2001_Am.J.Physiol.Endocrinol.Metab_281_E857 PubMedSearch: Suzuki 2001 Am.J.Physiol.Endocrinol.Metab 281 E857 PubMedID: 11551864 Abstract Hormone-sensitive lipase (HSL) hydrolyzes triglyceride (TG) in adipose tissue. HSL is also expressed in heart. To explore the actions of cardiac HSL, heart-specific, tetracycline (Tc)-controlled HSL-overexpressing mice were generated. Tc-responsive element-HSL transgenic (Tg) mice were generated and crossed with myosin heavy chain (MHC)alpha-tTA Tg mice, which express the Tc-responsive transactivator (tTA) in the heart. The double-Tg mice (MHC-HSL) were maintained with doxycycline (Dox) to suppress Tg HSL. Upon removal of Dox, cardiac HSL activity and protein increased 12- and 8-fold, respectively, and the expression was heart specific. Although cardiac TG content increased twofold in control mice after an overnight fast, it did not increase in HSL-induced mice. Electron microscopy showed numerous lipid droplets in the myocardium of fasted control mice, whereas fasted HSL-induced mice showed virtually no droplets. Microarray analysis showed altered expression of cardiac genes for fatty acid oxidation, transcription factors, signaling molecules, cytoskeletal proteins, and histocompatibility antigens in HSL-induced mice. Thus cardiac HSL plays a role in controlling accumulation of triglyceride droplets and can affect the expression of a number of cardiac genes. Title: Plasma esterase activities in young and old patients undergoing open inguinal hernia repair Abou-Hatab K, O'Mahony MS, Patel S, Carey D, Woodhouse K Ref: Arch Gerontol Geriatr, 31:193, 2000 : PubMed ESTHER: Abou-Hatab_2000_Arch.Gerontol.Geriatr_31_193 PubMedSearch: Abou-Hatab 2000 Arch.Gerontol.Geriatr 31 193 PubMedID: 11154773 Abstract Previous research has shown substantial decrements in enzymes of drug metabolism (esterases) in older patients following fracture neck of femur and hip replacement surgery. The main aim of this study was to examine the effect of open inguinal hernia repair on the activities of four plasma esterases in old and young patients. Seventeen older patients (mean age+/-S.E.M. was 67.6+/-1.8) and 12 young patients (mean age+/-S.E.M. was 38+/-3.3) undergoing open hernia repair for clinical reasons were recruited. The activities of plasma benzoylcholinesterase, butyrylcholinesterase, acetylcholinesterase, and aspirin esterase were determined spectrophotometrically, before the operation, 1 day post operatively and 1 week later. There was no significant effect of hernia repair surgery on any of the four enzymes measured in young or old patients. Neither was there any significant difference in enzyme activity between young and old at any of the three time points. Hernia repair surgery is not associated with decrements in enzymes of drug metabolism in man. This contrasts with the previous findings in hip replacement surgery. Title: Conditionally immortalized, multipotential and multifunctional neural stem cell lines as an approach to clinical transplantation Gray JA, Grigoryan G, Virley D, Patel S, Sinden JD, Hodges H Ref: Cell Transplantation, 9:153, 2000 : PubMed ESTHER: Gray_2000_Cell.Transplant_9_153 PubMedSearch: Gray 2000 Cell.Transplant 9 153 PubMedID: 10811390 Abstract Experiments are described using rats with two kinds of brain damage and consequent cognitive deficit (in the Morris water maze, three-door runway, and radial maze): 1) ischemic damage to the CA1 hippocampal cell field after four-vessel occlusion (4VO), and 2) damage to the forebrain cholinergic projection system by local injection of excitotoxins to the nuclei of origin or prolonged ethanol administration. Cell suspension grafts derived from primary fetal brain tissue display a stringent requirement for homotypical cell replacement in the 4VO model: cells from the embryonic day (E)18-19 CA1 hippocampal subfield, but not from CA3 or dentate gyrus or from E16 basal forebrain (cholinergic rich) led to recovery of cognitive function. After damage to the cholinergic system, conversely, recovery of function was seen with cell suspension grafts from E16 basal forebrain or cholinergic-rich E14 ventral mesencephalon, but not with implants of hippocampal tissue. These two models therefore provided a test of multifunctionality for a clonal line of conditionally immortalized neural stem cells, MHP36, derived from the E14 "immortomouse" hippocampal anlage. Implanted above the damaged CA1 cell field in 4VO-treated adult rats, these cells (multipotential in vitro) migrated to the damaged area, reconstituted the gross morphology of the CA1 pyramidal layer, took up both neuronal and glial phenotypes, and gave rise to cognitive recovery. Similar recovery of function and restoration of species-typical morphology was observed when MHP36 cells were implanted into marmosets with excitotoxic CAI damage. MHP36 implants led to recovery of cognitive function also in two experiments with rats with excitotoxic damage to the cholinergic system damage, either unilaterally in the nucleus basalis or bilaterally in both the nucleus basalis and the medial septal area. Thus, MHP36 cells are both multipotent (able to take up multiple cellular phenotypes) and multifunctional (able to repair diverse types of brain damage). Title: Hormone-sensitive lipase functions as an oligomer Shen WJ, Patel S, Hong R, Kraemer FB Ref: Biochemistry, 39:2392, 2000 : PubMed ESTHER: Shen_2000_Biochemistry_39_2392 PubMedSearch: Shen 2000 Biochemistry 39 2392 PubMedID: 10694408 Abstract Hormone-sensitive lipase (HSL) is a cytosolic neutral lipase whose activity is regulated by reversible phosphorylation and which is thought to be the rate-limiting enzyme for the mobilization of FFA from adipose tissue. In the current studies the subunit structure of HSL has been explored using sucrose gradient centrifugation and in vivo and in vitro protein-protein interactions. Evidence is provided to demonstrate that HSL exists as a functional dimer composed of homologous subunits. Dimeric HSL displayed approximately 40-fold greater activity against cholesteryl ester substrate when compared with monomeric HSL without any differences in affinity for the substrate. Truncations of HSL identified the importance of the N-terminal 300 amino acids, as well as other regions, in participating in the oligomerization of HSL. These studies support the notion that the N-terminal region of HSL represents a docking domain for protein-protein interactions and provide an additional mechanism for the posttranslational control of HSL activity in the cell via oligomerization. Title: Mutational analysis of structural features of rat hormone-sensitive lipase Shen WJ, Patel S, Natu V, Kraemer FB Ref: Biochemistry, 37:8973, 1998 : PubMed ESTHER: Shen_1998_Biochemistry_37_8973 PubMedSearch: Shen 1998 Biochemistry 37 8973 PubMedID: 9636039 Abstract Hormone-sensitive lipase (HSL) is a cytosolic neutral lipase that hydrolyzes intracellular stores of triacylglycerols and cholesteryl esters. HSL activity is regulated via phosphorylation-dephosphorylation, with cyclic AMP-dependent protein kinase increasing activity following phosphorylation of a single serine and Ca2+/calmodulin-dependent protein kinase II phosphorylating another serine at a basal site. The current studies used site-directed mutagenesis to show that Ser-563 of rat HSL is phosphorylated by cyclic AMP-dependent protein kinase and that Ser-565 is phosphorylated by Ca2+/calmodulin-dependent protein kinase II. Mutation of Ser-563-->Ala eliminated HSL hydrolytic activity against cholesteryl ester, triacylglycerol, and diacylglycerol substrates to the same extent as mutation of Ser-423-->Ala, the presumed catalytic site. Mutation of Ser-565-->Ala modestly decreased HSL activity. In contrast, mutation of Ser-563-->Asp preserved HSL hydrolytic activity and even increased activity 20% above the control wild-type enzyme. Molecular modeling of the catalytic pocket of HSL suggested the involvement of Val-710. Mutation of Val-710-->Ala resulted in an 85% loss of HSL hydrolytic activity. The results of these studies illustrate the importance of the presence of a hydroxyl group or negative charge at residue 563, either for proper conformation of rat HSL or for proper stabilization of substrate to allow maintenance of hydrolytic activity, as well as the importance of the involvement of additional amino acids in the catalytic pocket of the enzyme. Title: Hypothermia induced by cholinomimetic drugs is blocked by galanin: possible involvement of ATP-sensitive K+ channels Patel S, Hutson PH Ref: European Journal of Pharmacology, 255:25, 1994 : PubMed ESTHER: Patel_1994_Eur.J.Pharmacol_255_25 PubMedSearch: Patel 1994 Eur.J.Pharmacol 255 25 PubMedID: 7517882 Abstract Central administration of galanin in the mouse dose-dependently blocked the hypothermia induced by the muscarinic receptor agonist, 2-ethyl 8-methyl-2,8-diazospiro[4,5]decan-1,3-dion hydrobromide, RS86 (minimum effective dose, MED = 3 nmol) and the acetylcholinesterase inhibitor tetrahydroaminoacridine, (MED = 3 nmol). This inhibitory effect was reversed over the dose range (0.1, 0.3, 1, 3 nmol) by the galanin receptor antagonist galantide (MED = 0.3 nmol). Furthermore, the ATP-sensitive K+ channel blockers glibenclamide (MED = 1 nmol) and gliquidone (10 nmol) both prevented the inhibitory effects of galanin on RS86 induced hypothermia. Glibenclamide (10 nmol) also reversed the inhibitory effects of galanin on tetrahydroaminoacridine induced hypothermia. Preincubation of rat cortical membranes with galanin (10 nM, 1000 nM) in vitro had no effect on binding affinity, receptor number or pharmacology of the rat cortical muscarinic receptor. In contrast to the high affinity of glibenclamide, galanin only weakly displaced [3H]glibenclamide binding in mouse whole brain homogenates (36% at 10 microM). These studies suggest that the inhibitory effect of galanin on cholinergically mediated hypothermia induced by RS86 and tetrahydroaminoacridine may be exerted via an action at ATP-sensitive K+ channels but is unlikely to be acting directly at the site labelled by [3H]glibenclamide. Title: L-687,306: a functionally selective and potent muscarinic M1 receptor agonist Freedman SB, Patel S, Harley EA, Iversen LL, Baker R, Showell GA, Saunders J, McKnight A, Newberry N and Hargreaves R <1 more author(s)> Freedman SB, Patel S, Harley EA, Iversen LL, Baker R, Showell GA, Saunders J, McKnight A, Newberry N, Scholey K, Hargreaves R (- 1) Ref: European Journal of Pharmacology, 215:135, 1992 : PubMed ESTHER: Freedman_1992_Eur.J.Pharmacol_215_135 PubMedSearch: Freedman 1992 Eur.J.Pharmacol 215 135 PubMedID: 1516645 Abstract The oxadiazole L-687,306 is a high affinity muscarinic agonist with a N-methylscopolamine/oxotremorine-M binding profile predictive of a partial agonist. L-687,306 showed marked selectivity in functional pharmacological assays. L-687,306 was a partial agonist at muscarinic M1 receptors in the rat ganglion but a high affinity competitive antagonist at guinea-pig cardiac M2 and ileal M3 muscarinic receptors. This compound gives an opportunity to study receptor reserve involved in muscarinic receptors in vitro and in vivo. Title: Synthesis and muscarinic activity of quinuclidinyl- and (1-azanorbornyl)pyrazine derivatives Street LJ, Baker R, Book T, Reeve AJ, Saunders J, Willson T, Marwood RS, Patel S, Freedman SB Ref: Journal of Medicinal Chemistry, 35:295, 1992 : PubMed ESTHER: Street_1992_J.Med.Chem_35_295 PubMedSearch: Street 1992 J.Med.Chem 35 295 PubMedID: 1732546 Abstract The synthesis and cortical muscarinic activity of a novel series of pyrazine-based agonists is described. Quinuclidine and azanorbornane derivatives were prepared either by reaction of lithiated pyrazines with azabicyclic ketones, followed by chlorination and reduction, or by reaction of the lithium enolate of the azabicyclic ester with 2-chloropyrazines followed by ester hydrolysis and decarboxylation. Substitution at all three positions of the heteroaromatic ring has been explored. Optimal muscarinic agonist activity was observed for unsubstituted pyrazines in the azanorbornane series. The exo-1-azanorbornane 18a is one of the most efficacious and potent centrally active muscarinic agonists known. Studies on the 3-substituted derivatives have provided evidence of the preferred conformation of these ligands for optimal muscarinic activity. Substitution at C6 gave ligands with increased affinity and reduced efficacy. Moving the position of the diazine ring nitrogens to give pyrimidine and pyridazine derivatives resulted in a significant loss of muscarinic activity. Title: Tetrahydropyridyloxadiazoles: semirigid muscarinic ligands Showell GA, Gibbons TL, Kneen CO, MacLeod AM, Merchant K, Saunders J, Freedman SB, Patel S, Baker R Ref: Journal of Medicinal Chemistry, 34:1086, 1991 : PubMed ESTHER: Showell_1991_J.Med.Chem_34_1086 PubMedSearch: Showell 1991 J.Med.Chem 34 1086 PubMedID: 2002451 Abstract Recent studies have described novel azabicycle-based muscarinic agonists which readily penetrate into the central nervous system and are capable of displaying high efficacy at cortical sites. The current paper describes the synthesis and biochemical assessment of semirigid muscarinic ligands which were used to map the requirements of the cortical muscarinic receptor and to study the degree of conformational flexibility required to cause receptor activation. Analogues 6 and 9 provide high-efficacy muscarinic agonists at cortical sites; however, C-alkylation on the tetrahydropyridine ring resulted in more rigid analogues and showed lower predicted efficacy. Molecular mechanics calculations indicated a preference for the E rotameric form. This conformation was also observed in the X-ray crystal structure of ethenyloxadiazole 12. The new compounds were tested in a biochemical assay designed to measure receptor affinity and to predict cortical efficacy. Title: Synthesis and muscarinic activities of 1,2,4-thiadiazoles MacLeod AM, Baker R, Freedman SB, Patel S, Merchant KJ, Roe M, Saunders J Ref: Journal of Medicinal Chemistry, 33:2052, 1990 : PubMed ESTHER: MacLeod_1990_J.Med.Chem_33_2052 PubMedSearch: MacLeod 1990 J.Med.Chem 33 2052 PubMedID: 2362286 Abstract A series of novel 1,2,4-thiadiazoles bearing a mono- or bicyclic amine at C5 were prepared. Quinuclidine and 1-azabicyclo[2.2.1]heptane derivatives were synthesized by reaction of the lithium enolate of the 3-methoxycarbonyl compounds followed by ester hydrolysis and decarboxylation. The receptor-binding affinity and efficacy of these compounds as muscarinic ligands was assessed by radioligand binding assays using [3H]-N-methylscopolamine and [3H]oxotremorine-M. Optimal agonist affinity was observed for 3'-methyl compounds. Smaller substituents (H) retained efficacy with reduced affinity while larger groups led to substantially lower efficacy. The observed binding affinity was influenced both by the conformational energy of rotation around the C3-C5' bond and the steric requirement of the mono- or bicyclic amine. Title: Poster: Direct measurement of muscannic agonists and antagonists in the mouse central nervous system ratio Freedman SB, Harley EA, Patel S Ref: Trends in Pharmacological Sciences, Suppl:114, 1989 : PubMed ESTHER: Freedman_1989_Trends.Pharmacol.Sci_Suppl_114 PubMedSearch: Freedman 1989 Trends.Pharmacol.Sci Suppl 114 Title: The biochemical and immunocytochemical characterisation of an antigen on the membrane of basal cells of the epidermis Gusterson BA, McIlhinney RA, Patel S, Knight J, Monaghan P, Ormerod MG Ref: Differentiation, 30:102, 1985 : PubMed ESTHER: Gusterson_1985_Differentiation_30_102 PubMedSearch: Gusterson 1985 Differentiation 30 102 PubMedID: 3830750 Abstract A murine monoclonal antibody, LICR-LON-23.10, which had been raised against a well-differentiated squamous cell carcinoma cell line (LICR-LON-HN5), recognises an antigen which is present on the membrane of basal cells of the epidermis. The tissue distribution of the antigen, as defined using immunohistochemical techniques, suggests that it is expressed preferentially on cells which are adjacent to a basement membrane. In squamous cell carcinomas, the antigen is expressed uniformly on undifferentiated cells, but in areas of keratinisation, the antigen is absent. The antigen recognised by the antibody was characterised as being a pair of glycoproteins with molecular masses of 120 and 135 daltons. The antibody was used for flow-cytometric analyses of epidermal keratinocyte preparations. Together with other basal cell markers, this antibody may be useful in the characterisation of the epidermal basal cell population as well as in broadening our understanding of the interaction between epithelial cell populations and their relationship with basement-membrane components. Title: Purification of a human plasma membrane glycoprotein from human red blood cells by affinity chromatography using a monoclonal antibody McIlhinney RA, Patel S Ref: Journal of Biological Chemistry, 260:489, 1985 : PubMed ESTHER: McIlhinney_1985_J.Biol.Chem_260_489 PubMedSearch: McIlhinney 1985 J.Biol.Chem 260 489 PubMedID: 3965459 Abstract Using the monoclonal antibody LICR-LON-Fib75.1 coupled to Sepharose as an affinity chromatography column, a membrane glycoprotein with an apparent molecular weight of 18,000 on sodium dodecyl sulfate-polyacrylamide gels has been purified from human red blood cells. The purified protein contained 25% carbohydrate by weight, the predominant sugars being galactose, mannose, and glucosamine. Amino acid analysis indicated that the protein was relatively rich in aspartate, glutamate, valine, and leucine and had a low proline and methionine content. The molecule could be removed from intact red blood cells by trypsin and could be labeled with iodine by lactoperoxidase-catalyzed cell surface iodination of red blood cells. The protein could also be labeled using the lipidsoluble photoactivatable reagent 3-(trifluoromethyl)-3-(m-[125I]iodophenyl) diazirine) and partitioned into the lower phase of the phase-separable detergent Triton X-114. During size-exclusion chromatography in different detergents alterations were observed in the apparent molecular weight of the protein. These results suggest that this Fib75.1-binding protein is an external red blood cell membrane glycoprotein which is capable of binding detergent. Proteins with a similar molecular weight have also been isolated from two human tumor cell lines by immunoprecipitation with this monoclonal antibody. Title: Monoclonal antibodies recognizing epitopes carried on both glycolipids and glycoproteins of the human milk fat globule membrane McIlhinney RA, Patel S, Gore ME Ref: Biochemical Journal, 227:155, 1985 : PubMed ESTHER: McIlhinney_1985_Biochem.J_227_155 PubMedSearch: McIlhinney 1985 Biochem.J 227 155 PubMedID: 2581559 Abstract The molecules of the human milk fat globule membrane (MFGM) which bind four murine monoclonal antibodies (LICR LON M3, M8, M18 and M24) raised against the human MFGM have been identified. By using 'Western' blotting [Burnette (1981) Anal. Biochem. 112, 195-203] it was shown that each antibody reacted with a different set of proteins. M3 and M24 were similar in their pattern of reaction with the membrane proteins, but were quite distinct from M8 and M18, which also differed from each other. Glycopeptides prepared from the MFGM by exhaustive Pronase digestion were able to inhibit partially the binding of M3 and M24, and prevent totally the binding of M8 and M18, to the MFGM in an enzyme-linked immunoabsorbent assay. Oligosaccharides obtained by the deproteination of human milk also completely inhibited the binding of M3, M18 and M24 to the MFGM. However, the binding of M8 was not inhibited by these saccharides, and therefore M8 may not be recognizing a simple carbohydrate determinant. By using an enzyme-linked assay, M8 and M18 were shown not to bind to MFGM glycolipid, whereas M3 and M24 did, and this was confirmed by overlaying thin layer chromatograms of MFGM lipids with these antibodies. Both M3 and M24 showed a similar complex pattern of reaction, binding to more than one glycolipid moiety. By these means all four antibodies have been shown to react with antigens which involve carbohydrate side chains carried on different proteins, and two were also shown to react with such determinants on glycolipids. Title: Characterization of the fibronectin synthesized by human germ cell tumors McIlhinney RA, Patel S Ref: Cancer Research, 43:1282, 1983 : PubMed ESTHER: McIlhinney_1983_Cancer.Res_43_1282 PubMedSearch: McIlhinney 1983 Cancer.Res 43 1282 PubMedID: 6825099 Abstract The ability of the human germ cell tumor cell lines Tera 1, Tera 2, PA-1, LICR LON HT 39/7, LICR LON HT3B1, and LICR LON HT 53 to synthesize and secrete fibronectin has been studied. The presence of cellular fibronectin was examined using indirect immunofluorescence, whereas the synthesis and secretion of the protein were studied using specific immunoprecipitation from cultures radioactively labeled with [35S]methionine. Two of the cell lines, LICR LON HT 39/7 and Tera 1, did not synthesize fibronectin, whereas all the other cell lines did. Plasma membrane fibronectin could not be demonstrated on any of the cell lines, although cytoplasmic fibronectin was easily demonstrable. The cells appear therefore to synthesize fibronectin but not retain it. Sodium dodecyl sulfate:polyacrylamide gel electrophoresis of the secreted fibronectin produced by the human teratoma cell lines showed that it had an apparent molecular weight greater than that produced by adult human breast fibroblasts or human plasma fibronectin. Peptide mapping of this secreted germ cell tumor fibronectin, by partial proteolytic cleavage, yielded peptide patterns similar to those obtained from either human plasma fibronectin or adult human breast fibroblast fibronectin. The difference in molecular weight between the fibronectins may therefore be due to changes in their patterns of glycosylation. Title: Effects of 12-O-tetradecanylphorbol 13-acetate (TPA) on a clonal human teratoma-derived embryonal carcinoma cell line McIlhinney RA, Patel S, Monaghan P Ref: Experimental Cell Research, 144:297, 1983 : PubMed ESTHER: McIlhinney_1983_Exp.Cell.Res_144_297 PubMedSearch: McIlhinney 1983 Exp.Cell.Res 144 297 PubMedID: 6188625 Abstract The response of a human embryonal carcinoma cell line LICR LON HT39/7 to 12-O-tetradecanylphorbol 13-acetate (TPA) has been studied. Cells treated with 5 ng/ml of TPA undergo marked morphological changes, becoming flattened with nuclear enlargement and developing a grainy and often vacuolated cytoplasm. Parallel changes in the cell surface phenotype of the treated cells also occur. These include the appearance of membrane fibronectin, the embryonic antigen SSEA-1, and a glycoprotein antigen recognised by a monoclonal antibody. There is also increased expression of histocompatibility antigens. Other membrane molecules, such as peanut agglutinin receptor(s) and a 200 000 membrane glycoprotein appear to be removed from the membrane following TPA treatment. The high levels of alkaline phosphatase normally present in LICR LON HT39/7 are also reduced by TPA. Changes in the ultrastructure of the cells have also been observed, such as increases in nuclear complexity and in the number of intermediate filaments in the treated cells. This latter observation has been confirmed by immunofluorescent staining of the cells for prekeratins, which show an extensive network following the addition of TPA, but not before. 2-Dimensional gel electrophoresis of the proteins synthesized by LICR LON HT39/7 before and after addition of TPA has shown that there are a number of alterations in the proteins synthesised by the treated cells. Furthermore, immunoprecipitation of the culture supernatants from these cells has shown that TPA induces the synthesis and secretion of fibronectin. The alterations in the phenotype of LICR LON HT39/7 induced by TPA are irreversible and the altered cells, whilst they stop dividing, can be maintained for at least three weeks in culture. The analogue of TPA 12-O-tetradecanylphorbol 13-myristate does not produce the effects described above. Title: Elimination of carcinoma cells from human bone marrow Buckman R, McIlhinney RA, Shepherd V, Patel S, Coombes RC, Neville AM Ref: Lancet, 2:1428, 1982 : PubMed ESTHER: Buckman_1982_Lancet_2_1428 PubMedSearch: Buckman 1982 Lancet 2 1428 PubMedID: 6129508 Abstract The value of a monoclonal antibody, LICR-LON-Fib-75 (Fib-75), which mediates complement lysis and recognises an antigen present on all epithelial-tumour cells so far studied but not on lymphoid cells or bone-marrow stem cells, in clearing infiltrated bone marrow was assessed. Chromium-51-release and trypan-blue-exclusion assays showed that no tumour cells were viable after exposure to Fib-75 and complement except when large clumps (greater than 500 cells) were present, whereas Fib-75 had no significant effect on bone-marrow cells, as judged by colony-forming-unit and pluripotential-stem-cell assays. | |||||||
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