Author Report for: Yang DNo contact information in database for Yang D
Li J, Choudhry N, Lv G, Nimishetti N, Reddy MC, Liu H, Allen TD, Zhang J, Yang D Ref: J Pharm Biomed Anal, 232:115415, 2023 : PubMed ESTHER: Li_2023_J.Pharm.Biomed.Anal_232_115415 PubMedSearch: Li 2023 J.Pharm.Biomed.Anal 232 115415 PubMedID: 37120975 Abstract This study investigated the metabolism of LXY18, a quinolone-based compound that suppresses tumorigenesis by blocking AURKB localization. Metabolite profiling of LXY18 in liver microsomes from six species and human S9 fractions revealed that LXY18 undergoes various conserved metabolic reactions, such as N-hydroxylation, N-oxygenation, O-dealkylation, and hydrolysis, resulting in ten metabolites. These metabolites were produced through a combination of CYP450 enzymes, and non-CYP450 enzymes including CES1, and AO. Two metabolites, M1 and M2 were authenticated by chemically synthesized standards. M1 was the hydrolyzed product catalyzed by CES1 whereas M2 was a mono-N-oxidative derivative catalyzed by a CYP450 enzyme. AO was identified as the enzyme responsible for the formation of M3 with the help of AO-specific inhibitors and LXY18 analogs, 5b and 5c. M1 was the intermediate of LXY18 to produce M7, M8, M9, and M10. LXY18 potently inhibited 2C19 with an IC(50) of 290 nM but had a negligible impact on the other CYP450s, indicating a low risk of drug-drug interaction. Altogether, the study provides valuable insights into the metabolic process of LXY18 and its suitability as a drug candidate. The data generated serves as a significant reference point for conducting further safety assessments and optimizing drug development. Title: Engineering a Bacillus subtilis esterase for selective hydrolysis of d, l-menthyl acetate in an organic solvent-free system Qiao J, Yang D, Feng Y, Wei W, Liu X, Zhang Y, Zheng J, Ying X Ref: RSC Adv, 13:10468, 2023 : PubMed ESTHER: Qiao_2023_RSC.Adv_13_10468 PubMedSearch: Qiao 2023 RSC.Adv 13 10468 PubMedID: 37021103 Gene_locus related to this paper: 9baci-a0a2m8sv47 Abstract Esterase/lipase-catalyzed selective hydrolysis of d, l-menthyl esters has become one of the promising approaches for producing l-menthol, one of the most important flavoring chemicals with extensive uses. However, the activity and l-enantioselectivity of the biocatalyst are not sufficient for meeting the industrial requirements. Herein, a highly active para-nitrobenzyl esterase from Bacillus subtilis 168 (pnbA-BS) was cloned and then engineered to enhance its l-enantioselectivity. On the basis of the strategy tailoring the steric exclusion effect and structural flexibility of the region adjacent to the substrate, the substitution of Ala400 to Pro caused a remarkable improvement in the E value from 1.0 to 466.6. The variant A400P was purified and further confirmed with strict l-enantioselectivity in the selective hydrolysis of d, l-menthyl acetate, whereas the improved l-enantioselectivity caused decreased activity. To develop an efficient, easy-to-use, and green methodology, organic solvent was omitted and substrate constant feeding was integrated into the whole-cell catalyzed system. During the catalytic process, the selective hydrolysis of 1.0 M d, l-menthyl acetate in 14 h offered a conversion of 48.9%, e.e.(p) value of >99%, and space-time yield of 160.52 g (l d)(-1). Title: Routine administration of neostigmine after recovery of spontaneous breathing versus neuromuscular monitor-guided administration of neostigmine in pediatric patients: a parallel, randomized, controlled study Yang L, Hu N, Chang H, Yang D, Zuo Y Ref: Trials, 24:19, 2023 : PubMed ESTHER: Yang_2023_Trials_24_19 PubMedSearch: Yang 2023 Trials 24 19 PubMedID: 36611181 Abstract BACKGROUND: Neostigmine used to reverse the muscle relaxants should be guided by neuromuscular monitoring, as the degree of spontaneous pre-reversal recovery is the key to success to reverse the neuromuscular block. But neuromuscular monitoring is not always available for some patients during anesthesia and, in consequence, we need to use other clinical judgment to guide the use of neostigmine to reverse the neuromuscular block. In this trial, we aimed to evaluate the incidence of residual neuromuscular blockade (rNMB) in pediatric patients with routine use of neostigmine after recovery of spontaneous breathing compared with the patients with the use of neostigmine guided by neuromuscular monitoring. METHODS: A parallel, randomized, controlled noninferiority study was conducted. We enrolled aged 3 months to 12 years old patients who underwent inguinal hernia repair under general anesthesia. The enrolled patients were randomly divided into experimental and control groups. After surgery, children in the experimental group were given 0.02 mg/kg neostigmine after recovery of spontaneous breathing. Children in the control group were given 0.02 mg/kg neostigmine when the train-of-four (TOF) ratio was between 0.4 and 0.9. However, no neostigmine was administered if the TOF ratio was higher than 0.9. The primary outcome was the incidence of rNMB after extubation (TOF ratio < 0.9). Secondary outcomes included the incidence of neostigmine-induced muscle paralysis, end of surgery - extubation interval, end of surgery - exit OR interval, the length of stay in the PACU, the incidence of hypoxia in the PACU, the number of children who required assisted ventilation during the PACU stay, and neostigmine-related adverse events. RESULTS: A total of 120 children were included in this study, with 60 in the experimental group and 60 in the control group. There was no significant difference in the incidence of rNMB after extubation between the groups (45/60 vs 44/60, RR 1.02 [95% CI, 0.83 to 1.26], p = 0.84). There was no neostigmine-induced muscle paralysis in either group. Adverse events were similar occurred in both groups. However, time from end of the surgery to leaving the operating room was earlier in the experimental group than in the control group (13.6 +/- 5.2 vs 15.7 +/- 5.6 min, MD -2.10 min [95% CI, -3.70 to -0.50], p = 0.04). The risk ratio of the incidence of TOF ratio < 0.3 for the experimental group was 31.12 (95%CI, 1.89 to 512.61) compared with the control group (12/60 vs 0/60, p = 0.00) in exploratory analysis. CONCLUSIONS: Recovery of spontaneous breathing could be used as a substitute of neuromuscular monitoring to guide neostigmine use in pediatric patients following minor surgeries. However, care should be taken for the residual neuromuscular block. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-IOR-17012890.sRegistered on 5sOctobers2017. Title: Defining the Chemical Additives Driving In Vitro Toxicities of Plastics Chen W, Gong Y, McKie M, Almuhtaram H, Sun J, Barrett H, Yang D, Wu M, Andrews RC, Peng H Ref: Environ Sci Technol, :, 2022 : PubMed ESTHER: Chen_2022_Environ.Sci.Technol__ PubMedSearch: Chen 2022 Environ.Sci.Technol PubMedID: 36173153 Abstract Increases in the global use of plastics have caused concerns regarding potential adverse effects on human health. Plastic products contain hundreds of potentially toxic chemical additives, yet the exact chemicals which drive toxicity currently remain unknown. In this study, we employed nontargeted analysis and in vitro bioassays to identify the toxicity drivers in plastics. A total of 56 chemical additives were tentatively identified in five commonly used plastic polymer pellets (i.e., PP, LDPE, HDPE, PET, and PVC) by employing suspect screening and nontargeted analysis. Phthalates and organophosphates were found to be dominant in PVC pellets. Triphenyl phosphate and 2-ethylhexyl diphenyl phosphate accounted for a high amount (53.6%) of the inhibition effect of PVC pellet extract on human carboxylesterase 1 (hCES1) activity. Inspired by the high abundances of chemical additives in PVC pellets, six different end-user PVC-based products including three widely used PVC water pipes were further examined. Among them, extracts of PVC pipe exerted the strongest PPARgamma activity and cell viability suppression. Organotins were identified as the primary drivers to these in vitro toxicities induced by the PVC pipe extracts. This study clearly delineates specific chemical additives responsible for hCES1 inhibition, PPARgamma activity, and cell viability suppression associated with plastic. Title: Intramolecular C-C Bond Formation Links Anthraquinone and Enediyne Scaffolds in Tiancimycin Biosynthesis Gui C, Kalkreuter E, Liu YC, Adhikari A, Teijaro CN, Yang D, Chang C, Shen B Ref: Journal of the American Chemical Society, :, 2022 : PubMed ESTHER: Gui_2022_J.Am.Chem.Soc__ PubMedSearch: Gui 2022 J.Am.Chem.Soc PubMedID: 36279548 Gene_locus related to this paper: strsp-TnmK1 Abstract First discovered in 1989, the anthraquinone-fused enediynes are a class of DNA-cleaving bacterial natural products composed of a DNA-intercalating anthraquinone moiety and a 10-membered enediyne warhead. However, until recently, there has been a lack of genetically amenable hosts and sequenced biosynthetic gene clusters available for solving the biosynthetic questions surrounding these molecules. Herein, we have identified and biochemically and structurally characterized TnmK1, a member of the alpha/beta-hydrolase fold superfamily responsible for the C-C bond formation linking the anthraquinone moiety and enediyne core together in tiancimycin (TNM) biosynthesis. In doing so, two intermediates, TNM H and TNM I, in anthraquinone-fused enediyne biosynthesis, containing an unprecedented cryptic C16 aldehyde group, were identified. This aldehyde plays a key role in the TnmK1-catalyzed C-C bond formation via a Michael addition, representing the first example of this chemistry for the alpha/beta-hydrolase fold superfamily. Additionally, TNM I shows sub-nanomolar cytotoxicity against selected cancer cell lines, indicating a new mechanism of action compared to previously known anthraquinone-fused enediynes. Together, the findings from this study are expected to impact enzymology, natural product biosynthesis, and future efforts at enediyne discovery and drug development. Title: Negative correlation between early recovery and lipoprotein-associated phospholipase A2 levels after intravenous thrombolysis Li Y, Wang W, Yang H, Guo W, Feng J, Yang D, Guo L, Tan G Ref: J Internal Medicine Res, 50:3000605221093303, 2022 : PubMed ESTHER: Li_2022_J.Int.Med.Res_50_3000605221093303 PubMedSearch: Li 2022 J.Int.Med.Res 50 3000605221093303 PubMedID: 35441552 Abstract OBJECTIVE: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is considered a biomarker for systemic inflammation and the risk of myocardial infarction and stroke. However, little is known about the effect of acute vascular events on marker levels. The purpose of this study was to assess the potential association of early recovery with Lp-PLA2 levels in patients with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT). METHODS: Forty-three consecutive AIS patients who had their first stroke and were hospitalized within 5 hours of the onset of stroke were enrolled. All patients were treated with IVT using alteplase or urokinase. Plasma Lp-PLA2 levels were measured within 24 hours after IVT. Variables that showed a significant association with Lp-PLA2 in univariate analysis were included in the multivariate ordered logistic regression model. RESULTS: Early recovery was associated with Lp-PLA2 levels after IVT, and Lp-PLA2 levels tended to decrease with increased probability of early recovery. This study is the first to report a negative correlation between early recovery and Lp-PLA2 levels after IVT. CONCLUSION: Early recovery after IVT was negatively correlated with Lp-PLA2 A2 levels. Title: Roles of neuroligins in central nervous system development: focus on glial neuroligins and neuron neuroligins Liu X, Hua F, Yang D, Lin Y, Zhang L, Ying J, Sheng H, Wang X Ref: J Transl Med, 20:418, 2022 : PubMed ESTHER: Liu_2022_J.Transl.Med_20_418 PubMedSearch: Liu 2022 J.Transl.Med 20 418 PubMedID: 36088343 Abstract Neuroligins are postsynaptic cell adhesion molecules that are relevant to many neurodevelopmental disorders. They are differentially enriched at the postsynapse and interact with their presynaptic ligands, neurexins, whose differential binding to neuroligins has been shown to regulate synaptogenesis, transmission, and other synaptic properties. The proper functioning of functional networks in the brain depends on the proper connection between neuronal synapses. Impaired synaptogenesis or synaptic transmission results in synaptic dysfunction, and these synaptic pathologies are the basis for many neurodevelopmental disorders. Deletions or mutations in the neuroligins genes have been found in patients with both autism and schizophrenia. It is because of the important role of neuroligins in synaptic connectivity and synaptic dysfunction that studies on neuroligins in the past have mainly focused on their expression in neurons. As studies on the expression of genes specific to various cells of the central nervous system deepened, neuroligins were found to be expressed in non-neuronal cells as well. In the central nervous system, glial cells are the most representative non-neuronal cells, which can also express neuroligins in large amounts, especially astrocytes and oligodendrocytes, and they are involved in the regulation of synaptic function, as are neuronal neuroligins. This review examines the mechanisms of neuron neuroligins and non-neuronal neuroligins in the central nervous system and also discusses the important role of neuroligins in the development of the central nervous system and neurodevelopmental disorders from the perspective of neuronal neuroligins and glial neuroligins. Title: In situ identification of cellular drug targets in mammalian tissue Pang Z, Schafroth MA, Ogasawara D, Wang Y, Nudell V, Lal NK, Yang D, Wang K, Herbst DM and Ye L <4 more author(s)> Pang Z, Schafroth MA, Ogasawara D, Wang Y, Nudell V, Lal NK, Yang D, Wang K, Herbst DM, Ha J, Guijas C, Blankman JL, Cravatt BF, Ye L (- 4) Ref: Cell, 185:1793, 2022 : PubMed ESTHER: Pang_2022_Cell_185_1793 PubMedSearch: Pang 2022 Cell 185 1793 PubMedID: 35483372 Abstract The lack of tools to observe drug-target interactions at cellular resolution in intact tissue has been a major barrier to understanding in vivo drug actions. Here, we develop clearing-assisted tissue click chemistry (CATCH) to optically image covalent drug targets in intact mammalian tissues. CATCH permits specific and robust in situ fluorescence imaging of target-bound drug molecules at subcellular resolution and enables the identification of target cell types. Using well-established inhibitors of endocannabinoid hydrolases and monoamine oxidases, direct or competitive CATCH not only reveals distinct anatomical distributions and predominant cell targets of different drug compounds in the mouse brain but also uncovers unexpected differences in drug engagement across and within brain regions, reflecting rare cell types, as well as dose-dependent target shifts across tissue, cellular, and subcellular compartments that are not accessible by conventional methods. CATCH represents a valuable platform for visualizing in vivo interactions of small molecules in tissue. Title: Analysis of transcript-wide profile regulated by microsatellite instability of colorectal cancer Xu Y, Wang X, Chu Y, Li J, Wang W, Hu X, Zhou F, Zhang H, Zhou L and Peng H <3 more author(s)> Xu Y, Wang X, Chu Y, Li J, Wang W, Hu X, Zhou F, Zhang H, Zhou L, Kuai R, Jin Y, Yang D, Peng H (- 3) Ref: Ann Transl Med, 10:169, 2022 : PubMed ESTHER: Xu_2022_Ann.Transl.Med_10_169 PubMedSearch: Xu 2022 Ann.Transl.Med 10 169 PubMedID: 35280417 Abstract BACKGROUND: Microsatellite instability-high (MSI-H) is a form of genomic instability present in 15% of colorectal cancer (CRC) cases. Several differential gene analyses have been conducted on CRC; however, none have specifically explored the differentially expressed genes in MSI-H CRC. Research on the different gene expressions between MSI-H CRC and microsatellite stable (MSS) CRC, and their different patterns of metastasis will provide invaluable insights for diagnosis, prognosis, and treatment. METHODS: In this study, the differential expression of 46,602 genes were analyzed across 613 different tissue samples from The Cancer Genome Atlas (TCGA)-colon adenocarcinoma (COAD) and TCGA-rectum adenocarcinoma (READ) as part of a gene association analysis. R package TCGAbiolinks (version 2.18.0) was used to download the data set, and DESeq2 (version 1.30.1) was used for the differential gene analysis. The resulting genes were then analyzed for shared pathways with R package clusterProfiler (version 3.0.4). RESULTS: A total of 237 significantly differentially expressed genes (P(adj)<0.05) were found between MSI-H and MSS CRC. Differentially expressed genes include insulin like growth factor 2 (IGF2) and fibroblast growth factor 3 (FGF3), and the enriched pathways mostly involve hearing, digestive regulation, and neurogenesis.463 differentially expressed genes were found between metastatic and non-metastatic CRC. Notably differentially expressed genes in metastatic CRC include DEAD-box helicase 53 (DDX53) and adiponectin, C1Q and collagen domain containing (ADIPOQ), and enriched pathways include the immune system, cell adhesion, and cell signaling. For MSI-H CRC, a total of 34 genes were significantly differently expressed between metastatic and non-metastatic CRC. These include notum, palmitoleoyl-protein carboxylesterase (NOTUM), serpin family B member 2 (SERPINB2), and several keratin (KRT) genes, and the pathway analysis showed the major enrichment of the hormonal and secretion and regulation pathways. Of the differentially expressed genes in metastatic CRC, 25 were immunity related and include fatty acid binding protein 4 (FABP4), and the pathway analysis showed the enrichment of humoral immunity and lymphocyte regulation. CONCLUSIONS: Of the biologically plausible differentially expressed genes, the most notable were NOTUM, KRT6A, KRT14, SERPINB2, and serum amyloid A1 (SAA1). NOTUM, KRT6A, and KRT14 are active in the Wnt pathway. All five are also involved in various inflammation pathways. Title: A Roadmap to the Structure-Related Metabolism Pathways of Per- and Polyfluoroalkyl Substances in the Early Life Stages of Zebrafish (Danio rerio) Han J, Gu W, Barrett H, Yang D, Tang S, Sun J, Liu J, Krause HM, Houck KA, Peng H Ref: Environmental Health Perspectives, 129:77004, 2021 : PubMed ESTHER: Han_2021_Environ.Health.Perspect_129_77004 PubMedSearch: Han 2021 Environ.Health.Perspect 129 77004 PubMedID: 34288731 Abstract BACKGROUND: Thousands of per- and polyfluoroalkyl substances (PFAS) with diverse structures have been detected in the ambient environment. Apart from a few well-studied PFAS, the structure-related toxicokinetics of a broader set of PFAS remain unclear. OBJECTIVES: To understand the toxicokinetics of PFAS, we attempted to characterize the metabolism pathways of 74 structurally diverse PFAS samples from the U.S. Environmental Protection Agency's PFAS screening library. METHODS: Using the early life stages of zebrafish (Danio rerio) as a model, we determined the bioconcentration factors and phenotypic toxicities of 74 PFAS. Then, we applied high-resolution mass spectrometry-based nontargeted analysis to identify metabolites of PFAS in zebrafish larvae after 5 d of exposure by incorporating retention time and mass spectra. In vitro enzymatic activity experiments with human recombinant liver carboxylesterase (hCES1) were employed to validate the structure-related hydrolysis of 11 selected PFAS. RESULTS: Our findings identified five structural categories of PFAS prone to metabolism. The metabolism pathways of PFAS were highly related to their structures as exemplified by fluorotelomer alcohols that the predominance of beta-oxidation or taurine conjugation pathways were primarily determined by the number of hydrocarbons. Hydrolysis was identified as a major metabolism pathway for diverse PFAS, and perfluoroalkyl carboxamides showed the highest in vivo hydrolysis rates, followed by carboxyesters and sulfonamides. The hydrolysis of PFAS was verified with recombinant hCES1, with strong substrate preferences toward perfluoroalkyl carboxamides. CONCLUSIONS: We suggest that the roadmap of the structure-related metabolism pathways of PFAS established in this study would provide a starting point to inform the potential health risks of other PFAS. https://doi.org/10.1289/EHP7169. Title: Functional Characterization and Crystal Structure of the Bifunctional Thioesterase Catalyzing Epimerization and Cyclization in Skyllamycin Biosynthesis Yu J, Juan S, Chi C, Liu T, Geng T, Cai Z, Dong W, Shi C, Ma X and Ma M <6 more author(s)> Yu J, Juan S, Chi C, Liu T, Geng T, Cai Z, Dong W, Shi C, Ma X, Zhang Z, Xing B, Jin H, Zhang L, Dong S, Yang D, Ma M (- 6) Ref: ACS Catal, 11:11733, 2021 : PubMed ESTHER: Yu_2021_ACS.Catalysis_11_11733 PubMedSearch: Yu 2021 ACS.Catalysis 11 11733 Gene_locus related to this paper: strsq-a0a1j0r317 Abstract The d-amino acid residues are hallmark building blocks of nonribosomal peptides. Here, we report the bifunctional thioesterase domain (TE domain) Skyxy-TE that catalyzes both epimerization and cyclization in skyllamycin biosynthesis. Skyxy-TE specifically catalyzes the epimerization of the C-terminal l-amino acid residue of the linear substrate, then catalyzes regioselective intramolecular cyclization. The crystal structure of Skyxy-TE was solved at 2.25 and site-directed mutagenesis was performed, revealing key residues involved in the epimerization and cyclization. This study expands the understanding of the versatile TE domains and facilitates chemoenzymatic synthesis or combinatorial biosynthesis in the future. Title: Patatin primary structural properties and effects on lipid metabolism Wu J, Wu Q, Yang D, Zhou M, Xu J, Wen Q, Cui Y, Bai Y, Xu S and Wang S <1 more author(s)> Wu J, Wu Q, Yang D, Zhou M, Xu J, Wen Q, Cui Y, Bai Y, Xu S, Wang Z, Wang S (- 1) Ref: Food Chem, :128661, 2020 : PubMed ESTHER: Wu_2020_Food.Chem__128661 PubMedSearch: Wu 2020 Food.Chem 128661 PubMedID: 33272761 Abstract Patatin, the major protein found in potatoes, was purified and shows several isoforms. The essential amino acid content of patatin was ashighas 76%, indicating that it is a valuable protein source. Patatin was an O-linked glycoprotein that contained fucose monosaccharides, as well as mannose, rhamnose, glucose, galactose, xylose, and arabinose. Patatin had a fucosylated glycan structural feature, which strongly bound AAL (Aleuria aurantia Leukoagglutinin), a known fucose binding lectin. Moreover, thelipid metabolism regulatory effects of patatin on the fat catabolism, fat absorption, and inhibition of lipase activity were measured after high-fat feeding of zebrafish larvae. Results revealed that 37.0 g/mL patatin promoted 23% lipid decomposition metabolism. Meanwhile patatin could inhibite lipase activity and fat absorption, whose effects accounted for half that of a positive control drug. Our findings suggest that patatin, a fucosylated glycoprotein, could potentially be used as a naturalactiveconstituent with anti-obesity effects. Title: Seawater acidification increases copper toxicity: A multi-biomarker approach with a key marine invertebrate, the Pacific Oyster Crassostrea gigas Cao R, Zhang T, Li X, Zhao Y, Wang Q, Yang D, Qu Y, Liu H, Dong Z, Zhao J Ref: Aquat Toxicol, 210:167, 2019 : PubMed ESTHER: Cao_2019_Aquat.Toxicol_210_167 PubMedSearch: Cao 2019 Aquat.Toxicol 210 167 PubMedID: 30870663 Abstract Ocean acidification (OA) has been found to increase the release of free Cu(2+) in seawater. However, only a handful of studies have investigated the influence of OA on Cu accumulation and cellular toxicity in bivalve species. In this study, Pacific oysters, Crassostrea gigas, were exposed to 25 mug/L Cu(2+) at three pH levels (8.1, 7.8 and 7.6) for 14 and 28 days. Physiological and histopathological parameters [(clearance rate (CR), respiration rate (RR), histopathological damage and condition index (CI)), oxidative stress and neurotoxicity biomarkers [superoxide dismutase (SOD) and glutathione transferase (GST) activities, lipid peroxidation (LPO) and acetylcholinesterase (AChE) activity], combined with glycolytic enzyme activities [pyruvate kinase (PK) and hexokinase (HK)] were investigated in C. gigas. The bioconcentration of Cu was increased in soft tissues of Cu-exposed oysters under OA. Our results suggest that both OA and Cu could lead to physiological disturbance, oxidative stress, cellular damage, disturbance in energy metabolism and neurotoxicity in oysters. The inhibited CR, increased glycolytic enzymes activities and decreased CI suggested that the energy metabolism strategy adopted by oysters was not sustainable in the long term. Furthermore, integrated biomarker response (IBR) results found that OA and Cu exposure lead to severe stress to oysters, and co-exposure was the most stressful condition. Results from this study highlight the need to include OA in future environmental assessments of pollutants and hazardous materials to better elucidate the risks of those environmental perturbations. Title: Structural Insights into the Dual-Substrate Recognition and Catalytic Mechanisms of a Bifunctional Acetyl Ester-Xyloside Hydrolase from Caldicellulosiruptor lactoaceticus Cao H, Sun L, Huang Y, Liu X, Yang D, Liu T, Jia X, Wen B, Gu T and Xin F <1 more author(s)> Cao H, Sun L, Huang Y, Liu X, Yang D, Liu T, Jia X, Wen B, Gu T, Wang F, Xin F (- 1) Ref: ACS Catal, 9:1739, 2019 : PubMed ESTHER: Cao_2019_ACS.Catal_9_1739 PubMedSearch: Cao 2019 ACS.Catal 9 1739 Gene_locus related to this paper: 9firm-g2pvg6 Abstract Enzymes are usually characterized by their evolutionarily conserved catalytic domains; however, this work presents the incidental gain-of-function of an enzyme in a loop region by natural evolution of its amino acids. A bifunctional acetyl ester-xyloside hydrolase (CLH10) was heterologously expressed, purified, and characterized. The primary sequence of CLH10 contains the fragments of the conserved sequence of esterase and glycosidase, which distribute in a mixed type. The crystal structure revealed that the primary sequence folded into two independent structural regions to undertake both acetyl esterase and beta-1,4-xylanase hydrolase functions. CLH10 is capable of cleaving both the beta-1,4-xylosidic bond-linked main chain and the ester bond-linked acetylated side chain of xylan, which renders it valuable because it can degrade acetylated xylan within one enzyme. Significantly, the beta-1,4-xylanase activity of CLH10 appears to have been fortuitously obtained because of the variable Asp10 and Glu139 located in its loop region, which suggested that the exposed loop region might act as a potential hot-spot for the design and generation of promising enzyme function in both directed evolution and rational protein design. Title: The development of 2-acetylphenol-donepezil hybrids as multifunctional agents for the treatment of Alzheimer's disease Zhu G, Wang K, Shi J, Zhang P, Yang D, Fan X, Zhang Z, Liu W, Sang Z Ref: Bioorganic & Medicinal Chemistry Lett, 29:126625, 2019 : PubMed ESTHER: Zhu_2019_Bioorg.Med.Chem.Lett_29_126625 PubMedSearch: Zhu 2019 Bioorg.Med.Chem.Lett 29 126625 PubMedID: 31444085 Abstract A series of 2-acetylphenol-donepezil hybrids was designed and synthesized based on multi-target-directed ligands strategy. The biological activities were evaluated by AChE/BChE inhibition and MAO-A/MAO-B inhibition. The results revealed that the tertiary amines and methylene chain length significantly affected the eeAChE inhibitory potency, in particular, compound TM-14 showed the best eeAChE inhibitory activity with IC(50) value of 2.9 microM, in addition, both kinetic analysis of AChE inhibition and docking study displayed that TM-14 could simultaneously bind to the catalytic active site and peripheral anionic site of AChE. Moreover, compound TM-14 was a selective metal chelator and could form 1:1 TM-14-Cu(2+) complex. The structure-active-relationship also indicated that the O-alkylamine fragment remarkably decreased hMAO-B inhibitory activity, compound TM-2 exhibited potent hMAO-B inhibitory activity (IC(50) = 6.8 microM), which was supported by the molecular docking study. More interestingly, compounds TM-14 and TM-2 could cross the blood-brain barrier in vitro. Therefore, the structure-active-relationship of 2-acetylphenol-donepezil hybrids could encourage the development of multifunction agents with selective AChE inhibition or selective MAO-B inhibition for the treatment of Alzheimer's disease. Title: Polypyridylruthenium(II) complexes exert in vitro and in vivo nematocidal activity and show significant inhibition of parasite acetylcholinesterases Sundaraneedi M, Eichenberger RM, Al-Hallaf R, Yang D, Sotillo J, Rajan S, Wangchuk P, Giacomin PR, Keene FR and Pearson MS <2 more author(s)> Sundaraneedi M, Eichenberger RM, Al-Hallaf R, Yang D, Sotillo J, Rajan S, Wangchuk P, Giacomin PR, Keene FR, Loukas A, Collins JG, Pearson MS (- 2) Ref: International Journal for Parasitology Drugs Drug Resist, 8:1, 2018 : PubMed ESTHER: Sundaraneedi_2018_Int.J.Parasitol.Drugs.Drug.Resist_8_1 PubMedSearch: Sundaraneedi 2018 Int.J.Parasitol.Drugs.Drug.Resist 8 1 PubMedID: 29207309 Abstract Over 4.5 billion people are at risk of infection with soil transmitted helminths and there are concerns about the development of resistance to the handful of frontline nematocides in endemic populations. We investigated the anti-nematode efficacy of a series of polypyridylruthenium(II) complexes and showed they were active against L3 and adult stages of Trichuris muris, the rodent homologue of the causative agent of human trichuriasis, T. trichiura. One of the compounds, Rubb12-mono, which was among the most potent in its ability to kill L3 (IC50 = 3.1 +/- 0.4 muM) and adult (IC50 = 5.2 +/- 0.3 muM) stage worms was assessed for efficacy in a mouse model of trichuriasis by administering 3 consecutive daily oral doses of the drug 3 weeks post infection with the murine whipworm Trichuris muris. Mice treated with Rubb12-mono showed an average 66% reduction (P = 0.015) in faecal egg count over two independent trials. The drugs partially exerted their activity through inhibition of acetylcholinesterases, as worms treated in vitro and in vivo showed significant decreases in the activity of this class of enzymes. Our data show that ruthenium complexes are effective against T. muris, a model gastro-intestinal nematode and soil-transmitted helminth. Further, knowledge of the target of ruthenium drugs can facilitate modification of current compounds to identify analogues which are even more effective and selective against Trichuris and other helminths of human and veterinary importance. Title: Cholinesterase inhibitors for the treatment of delirium in non-ICU settings Yu A, Wu S, Zhang Z, Dening T, Zhao S, Pinner G, Xia J, Yang D Ref: Cochrane Database Syst Rev, 6:CD012494, 2018 : PubMed ESTHER: Yu_2018_Cochrane.Database.Syst.Rev_6_CD012494 PubMedSearch: Yu 2018 Cochrane.Database.Syst.Rev 6 CD012494 PubMedID: 29952000 Abstract BACKGROUND: Delirium is a common clinical syndrome defined as alterations in attention with an additional disturbance in cognition or perception, which develop over a short period of time and tend to fluctuate during the course of the episode. Delirium is commonly treated in hospitals or community settings and is often associated with multiple adverse outcomes such as increased cost, morbidity, and even mortality. The first-line intervention involves a multicomponent non-pharmacological approach that includes ensuring effective communication and reorientation in addition to providing reassurance or a suitable care environment. There are currently no drugs approved specifically for the treatment of delirium. Clinically, however, various medications are employed to provide symptomatic relief, such as antipsychotic medications and cholinesterase inhibitors, among others. OBJECTIVES: To evaluate the effectiveness and safety of cholinesterase inhibitors for treating people with established delirium in a non-intensive care unit (ICU) setting. SEARCH METHODS: We searched ALOIS, which is the Cochrane Dementia and Cognitive Improvement Group's Specialised Register, on 26 October 2017. We also cross-checked the reference lists of included studies to identify any potentially eligible trials. SELECTION CRITERIA: We included randomised controlled trials, published or unpublished, reported in English or Chinese, which compared cholinesterase inhibitors to placebo or other drugs intended to treat people with established delirium in a non-ICU setting. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. The primary outcomes were duration of delirium, severity of delirium, and adverse events. The secondary outcomes were use of rescue medications, persistent cognitive impairment, length of hospitalisation, institutionalisation, mortality, cost of intervention, leaving the study early, and quality of life. For dichotomous outcomes, we calculated the risk ratio (RR) with 95% confidence intervals (CIs); for continuous outcomes we calculated the mean difference (MD) with 95% CIs. We assessed the quality of evidence using GRADE to generate a 'Summary of findings' table. MAIN RESULTS: We included one study involving 15 participants from the UK. The included participants were diagnosed with delirium based on the Confusion Assessment Method (CAM) criteria. Eight males and seven females were included, with a mean age of 82.5 years. Seven of the 15 participants had comorbid dementia at baseline. The risk of bias was low in all domains.The study compared rivastigmine with placebo. We did not find any clear differences between the two groups in terms of duration of delirium (MD -3.6, 95% CI -15.6 to 8.4), adverse events (nausea, RR 0.30, 95% CI 0.01 to 6.29), use of rescue medications (RR 0.13, 95% CI 0.01 to 2.1), mortality (RR 0.10, 95% CI 0.01 to 1.56), and leaving the study early (RR 0.88, 95% CI 0.07 to 11.54). Evidence was not available regarding the severity of delirium, persistent cognitive impairment, length of hospitalisation, cost of intervention, or other predefined secondary outcomes.The quality of evidence is low due to the very small sample size. AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the use of cholinesterase inhibitors for the treatment of delirium in non-ICU settings. No clear benefits or harms associated with cholinesterase inhibitors were observed when compared with placebo due to the lack of data. More trials are required. Title: De novo transcriptome and expression profile analyses of the Asian corn borer (Ostrinia furnacalis) reveals relevant flubendiamide response genes Cui L, Rui C, Yang D, Wang Z, Yuan H Ref: BMC Genomics, 18:20, 2017 : PubMed ESTHER: Cui_2017_BMC.Genomics_18_20 PubMedSearch: Cui 2017 BMC.Genomics 18 20 PubMedID: 28056803 Abstract BACKGROUND: The Asian corn borer (ACB), Ostrinia furnacalis (Guenee), has become the most damaging insect pest of corn in Asia. However, the lack of genome or transcriptome information heavily hinders our further understanding of ACB in every aspect at a molecular level and on a genome-wide scale. Here, we used the Ion Torrent Personal Genome Machine (PGM) Sequencer to explore the ACB transcriptome and to identify relevant genes in response to flubendiamide, showing high selective activity against ACB. Title: Discovery of the leinamycin family of natural products by mining actinobacterial genomes Pan G, Xu Z, Guo Z, Hindra, Ma M, Yang D, Zhou H, Gansemans Y, Zhu X and Shen B <7 more author(s)> Pan G, Xu Z, Guo Z, Hindra, Ma M, Yang D, Zhou H, Gansemans Y, Zhu X, Huang Y, Zhao LX, Jiang Y, Cheng J, Van Nieuwerburgh F, Suh JW, Duan Y, Shen B (- 7) Ref: Proc Natl Acad Sci U S A, 114:E11131, 2017 : PubMed ESTHER: Pan_2017_Proc.Natl.Acad.Sci.U.S.A_114_E11131 PubMedSearch: Pan 2017 Proc.Natl.Acad.Sci.U.S.A 114 E11131 PubMedID: 29229819 Gene_locus related to this paper: 9actn-a0a2m9jcs9, 9actn-a0a2m9ijf7, 9actn-a0a2m9iy91, 9actn-a0a2m9k146, 9actn-a0a2m9m5n6, 9actn-a0a2m9ifq0, 9actn-a0a1c4rpf7 Abstract Nature's ability to generate diverse natural products from simple building blocks has inspired combinatorial biosynthesis. The knowledge-based approach to combinatorial biosynthesis has allowed the production of designer analogs by rational metabolic pathway engineering. While successful, structural alterations are limited, with designer analogs often produced in compromised titers. The discovery-based approach to combinatorial biosynthesis complements the knowledge-based approach by exploring the vast combinatorial biosynthesis repertoire found in Nature. Here we showcase the discovery-based approach to combinatorial biosynthesis by targeting the domain of unknown function and cysteine lyase domain (DUF-SH) didomain, specific for sulfur incorporation from the leinamycin (LNM) biosynthetic machinery, to discover the LNM family of natural products. By mining bacterial genomes from public databases and the actinomycetes strain collection at The Scripps Research Institute, we discovered 49 potential producers that could be grouped into 18 distinct clades based on phylogenetic analysis of the DUF-SH didomains. Further analysis of the representative genomes from each of the clades identified 28 lnm-type gene clusters. Structural diversities encoded by the LNM-type biosynthetic machineries were predicted based on bioinformatics and confirmed by in vitro characterization of selected adenylation proteins and isolation and structural elucidation of the guangnanmycins and weishanmycins. These findings demonstrate the power of the discovery-based approach to combinatorial biosynthesis for natural product discovery and structural diversity and highlight Nature's rich biosynthetic repertoire. Comparative analysis of the LNM-type biosynthetic machineries provides outstanding opportunities to dissect Nature's biosynthetic strategies and apply these findings to combinatorial biosynthesis for natural product discovery and structural diversity. Title: Human intestinal tract serves as an alternative infection route for Middle East respiratory syndrome coronavirus Zhou J, Li C, Zhao G, Chu H, Wang D, Yan HH, Poon VK, Wen L, Wong BH and Yuen KY <15 more author(s)> Zhou J, Li C, Zhao G, Chu H, Wang D, Yan HH, Poon VK, Wen L, Wong BH, Zhao X, Chiu MC, Yang D, Wang Y, Au-Yeung RKH, Chan IH, Sun S, Chan JF, To KK, Memish ZA, Corman VM, Drosten C, Hung IF, Zhou Y, Leung SY, Yuen KY (- 15) Ref: Sci Adv, 3:eaao4966, 2017 : PubMed ESTHER: Zhou_2017_Sci.Adv_3_eaao4966 PubMedSearch: Zhou 2017 Sci.Adv 3 eaao4966 PubMedID: 29152574 Abstract Middle East respiratory syndrome coronavirus (MERS-CoV) has caused human respiratory infections with a high case fatality rate since 2012. However, the mode of virus transmission is not well understood. The findings of epidemiological and virological studies prompted us to hypothesize that the human gastrointestinal tract could serve as an alternative route to acquire MERS-CoV infection. We demonstrated that human primary intestinal epithelial cells, small intestine explants, and intestinal organoids were highly susceptible to MERS-CoV and can sustain robust viral replication. We also identified the evidence of enteric MERS-CoV infection in the stool specimen of a clinical patient. MERS-CoV was considerably resistant to fed-state gastrointestinal fluids but less tolerant to highly acidic fasted-state gastric fluid. In polarized Caco-2 cells cultured in Transwell inserts, apical MERS-CoV inoculation was more effective in establishing infection than basolateral inoculation. Notably, direct intragastric inoculation of MERS-CoV caused a lethal infection in human DPP4 transgenic mice. Histological examination revealed MERS-CoV enteric infection in all inoculated mice, as shown by the presence of virus-positive cells, progressive inflammation, and epithelial degeneration in small intestines, which were exaggerated in the mice pretreated with the proton pump inhibitor pantoprazole. With the progression of the enteric infection, inflammation, virus-positive cells, and live viruses emerged in the lung tissues, indicating the development of sequential respiratory infection. Taken together, these data suggest that the human intestinal tract may serve as an alternative infection route for MERS-CoV. Title: Middle East Respiratory Syndrome Coronavirus Efficiently Infects Human Primary T Lymphocytes and Activates the Extrinsic and Intrinsic Apoptosis Pathways Chu H, Zhou J, Wong BH, Li C, Chan JF, Cheng ZS, Yang D, Wang D, Lee AC and Yuen KY <8 more author(s)> Chu H, Zhou J, Wong BH, Li C, Chan JF, Cheng ZS, Yang D, Wang D, Lee AC, Yeung ML, Cai JP, Chan IH, Ho WK, To KK, Zheng BJ, Yao Y, Qin C, Yuen KY (- 8) Ref: J Infect Dis, 213:904, 2016 : PubMed ESTHER: Chu_2016_J.Infect.Dis_213_904 PubMedSearch: Chu 2016 J.Infect.Dis 213 904 PubMedID: 26203058 Abstract Middle East respiratory syndrome (MERS) is associated with a mortality rate of >35%. We previously showed that MERS coronavirus (MERS-CoV) could infect human macrophages and dendritic cells and induce cytokine dysregulation. Here, we further investigated the interplay between human primary T cells and MERS-CoV in disease pathogenesis. Importantly, our results suggested that MERS-CoV efficiently infected T cells from the peripheral blood and from human lymphoid organs, including the spleen and the tonsil. We further demonstrated that MERS-CoV infection induced apoptosis in T cells, which involved the activation of both the extrinsic and intrinsic apoptosis pathways. Remarkably, immunostaining of spleen sections from MERS-CoV-infected common marmosets demonstrated the presence of viral nucleoprotein in their CD3(+) T cells. Overall, our results suggested that the unusual capacity of MERS-CoV to infect T cells and induce apoptosis might partly contribute to the high pathogenicity of the virus. Title: An in vivo multiplexed small-molecule screening platform Gruner BM, Schulze CJ, Yang D, Ogasawara D, Dix MM, Rogers ZN, Chuang CH, McFarland CD, Chiou SH and Winslow MM <3 more author(s)> Gruner BM, Schulze CJ, Yang D, Ogasawara D, Dix MM, Rogers ZN, Chuang CH, McFarland CD, Chiou SH, Brown JM, Cravatt BF, Bogyo M, Winslow MM (- 3) Ref: Nat Methods, 13:883, 2016 : PubMed ESTHER: Gruner_2016_Nat.Methods_13_883 PubMedSearch: Gruner 2016 Nat.Methods 13 883 PubMedID: 27617390 Inhibitor(s) related to this paper: HT-01, JCP-265, KT203 Abstract Phenotype-based small-molecule screening is a powerful method to identify molecules that regulate cellular functions. However, such screens are generally performed in vitro under conditions that do not necessarily model complex physiological conditions or disease states. Here, we use molecular cell barcoding to enable direct in vivo phenotypic screening of small-molecule libraries. The multiplexed nature of this approach allows rapid in vivo analysis of hundreds to thousands of compounds. Using this platform, we screened >700 covalent inhibitors directed toward hydrolases for their effect on pancreatic cancer metastatic seeding. We identified multiple hits and confirmed the relevant target of one compound as the lipase ABHD6. Pharmacological and genetic studies confirmed the role of this enzyme as a regulator of metastatic fitness. Our results highlight the applicability of this multiplexed screening platform for investigating complex processes in vivo. Title: Calretinin, S100 and protein gene product 9.5 immunostaining of rectal suction biopsies in the diagnosis of Hirschsprung' disease Jiang M, Li K, Li S, Yang L, Yang D, Zhang X, Fang M, Cao G, Wang Y and Tang S <1 more author(s)> Jiang M, Li K, Li S, Yang L, Yang D, Zhang X, Fang M, Cao G, Wang Y, Chen W, Tang S (- 1) Ref: Am J Transl Res, 8:3159, 2016 : PubMed ESTHER: Jiang_2016_Am.J.Transl.Res_8_3159 PubMedSearch: Jiang 2016 Am.J.Transl.Res 8 3159 PubMedID: 27508037 Abstract Evaluation of rectal suction biopsies for the ganglion cells and neural hypertrophy is the basic modality for the diagnosis of Hirschsprung's disease (HD). However, the traditional hematoxylin and eosin staining coupled with acetylcholinesterase histochemistry remain challenging, especially in newborns. Thus we conducted a prospective study to evaluate the usefulness of calretinin combined with S100 and protein gene product 9.5 (PGP9.5) immunostaining of rectal suction biopsies for the diagnosis of HD. A total of 195 patients were enrolled in our study. Of the 195 patients 69% had ganglion cells on the initial diagnostic protocol. Sixty cases were devoid of ganglion cells, and of these, 90% and 91% showed submucosal neural hypertrophy on S-100 staining and PGP9.5 staining, respectively. Eighty-one patients underwent a colonic resection, and of these, 59 had confirmed aganglionic segment, the other 22 patients were diagnosed as intestinal neuronal dysplasia type B (n=13) and isolated hypoganglionosis (n=9). Of the rest 114 patients, 51 cases underwent a full-thickness biopsy, and HD was excluded; sixty-three patients were thoroughly followed-up with no evidence of HD. We encountered two false-negatives and they were proved to be short segment HD after the surgery. The sensitivity and specificity rates of our diagnostic protocol was 96.49% (95% CI, 0.88-0.99) and 100% (95% CI, 0.97-1.00), respectively, excluding 5 patients with inconclusive results. Our findings demonstrated that calretinin coupled with S100 and PGP9.5 immunostaining on suction rectal biopsies is sensitive and specific for diagnosing HD. Title: Strain Prioritization and Genome Mining for Enediyne Natural Products Yan X, Ge H, Huang T, Hindra, Yang D, Teng Q, Crnovcic I, Li X, Rudolf JD and Shen B <9 more author(s)> Yan X, Ge H, Huang T, Hindra, Yang D, Teng Q, Crnovcic I, Li X, Rudolf JD, Lohman JR, Gansemans Y, Zhu X, Huang Y, Zhao LX, Jiang Y, Van Nieuwerburgh F, Rader C, Duan Y, Shen B (- 9) Ref: MBio, 7:, 2016 : PubMed ESTHER: Yan_2016_MBio_7_e02104 PubMedSearch: Yan 2016 MBio 7 e02104 PubMedID: 27999165 Gene_locus related to this paper: 9actn-a0a1q5ckn8, 9actn-a0a1q5j3v0, 9actn-a0a1q5kj90, 9actn-a0a1q5jti2, 9actn-a0a1q5luf4, 9actn-a0a1q4w3c8, 9actn-a0a1q4wvf2, 9actn-a0a1q4yuw0, 9actn-a0a1q5diu2, 9actn-a0a1q5dxi1, 9actn-a0a1q5ftj7, 9actn-a0a1q5h9t1, 9actn-a0a1q5k3r2, 9actn-a0a1q5l4j4, 9actn-a0a1q5l7v2, 9actn-a0a1q5ltu8, 9actn-a0a1q5m0p6, 9actn-a0a1q5mza2, 9pseu-a0a1q4yle9, 9pseu-a0a1q4ylg6, 9actn-a0a1q5hn40, 9actn-a0a1q4zi93, 9actn-a0a1q5d7w2, 9actn-a0a1q5mn15, 9pseu-a0a1q4xtq2, 9actn-a0a1q5le62, 9actn-a0a1q5fgx4, strsp-TnmK1, strsp-TnmK2, strun-UcmK2, 9actn-a0a1q4w6n9, 9actn-a0a1q4yc91, 9actn-a0a1q4yun2, 9actn-a0a1q5g588, 9actn-a0a1q5h571, 9actn-a0a1q5kh06, 9actn-a0a1q5lnf3, 9actn-a0a1q5n7d1 Abstract The enediyne family of natural products has had a profound impact on modern chemistry, biology, and medicine, and yet only 11 enediynes have been structurally characterized to date. Here we report a genome survey of 3,400 actinomycetes, identifying 81 strains that harbor genes encoding the enediyne polyketide synthase cassettes that could be grouped into 28 distinct clades based on phylogenetic analysis. Genome sequencing of 31 representative strains confirmed that each clade harbors a distinct enediyne biosynthetic gene cluster. A genome neighborhood network allows prediction of new structural features and biosynthetic insights that could be exploited for enediyne discovery. We confirmed one clade as new C-1027 producers, with a significantly higher C-1027 titer than the original producer, and discovered a new family of enediyne natural products, the tiancimycins (TNMs), that exhibit potent cytotoxicity against a broad spectrum of cancer cell lines. Our results demonstrate the feasibility of rapid discovery of new enediynes from a large strain collection. IMPORTANCE: Recent advances in microbial genomics clearly revealed that the biosynthetic potential of soil actinomycetes to produce enediynes is underappreciated. A great challenge is to develop innovative methods to discover new enediynes and produce them in sufficient quantities for chemical, biological, and clinical investigations. This work demonstrated the feasibility of rapid discovery of new enediynes from a large strain collection. The new C-1027 producers, with a significantly higher C-1027 titer than the original producer, will impact the practical supply of this important drug lead. The TNMs, with their extremely potent cytotoxicity against various cancer cells and their rapid and complete cancer cell killing characteristics, in comparison with the payloads used in FDA-approved antibody-drug conjugates (ADCs), are poised to be exploited as payload candidates for the next generation of anticancer ADCs. Follow-up studies on the other identified hits promise the discovery of new enediynes, radically expanding the chemical space for the enediyne family. Title: Macrophage CGI-58 Attenuates Inflammatory Responsiveness via Promotion of PPARx03B3; Signaling Yang D, Chen H, Zeng X, Xie P, Wang X, Liu C Ref: Cell Physiol Biochem, 38:696, 2016 : PubMed ESTHER: Yang_2016_Cell.Physiol.Biochem_38_696 PubMedSearch: Yang 2016 Cell.Physiol.Biochem 38 696 PubMedID: 26872126 Abstract BACKGROUND/AIMS: Comparative gene identification-58 (CGI-58), an adipose triglyceride lipase (ATGL) coactivator, strongly promotes ATGL-mediated triglyceride (TG) catabolism. Beyond its function in promoting lipolysis, other features of CGI-58 have been proposed. Here, we investigated the role of CGI-58 in the regulation of inflammatory responsiveness in macrophages. Title: Ontogenic expression of human carboxylesterase-2 and cytochrome P450 3A4 in liver and duodenum: Postnatal surge and organ-dependent regulation Chen YT, Trzoss L, Yang D, Yan B Ref: Toxicology, 330:55, 2015 : PubMed ESTHER: Chen_2015_Toxicology_330_55 PubMedSearch: Chen 2015 Toxicology 330 55 PubMedID: 25724353 Abstract Human carboxylesterase-2 (CES2) and cytochrome P450 3A4 (CYP3A4) are two major drug metabolizing enzymes that play critical roles in hydrolytic and oxidative biotransformation, respectively. They share substrates but may have opposite effect on therapeutic potential such as the metabolism of the anticancer prodrug irinotecan. Both CES2 and CYP3A4 are expressed in the liver and the gastrointestinal tract. This study was conducted to determine whether CES2 and CYP3A4 are expressed under developmental regulation and whether the regulation occurs differentially between the liver and duodenum. A large number of tissues (112) were collected with majority of them from donors at 1-198 days of age. In addition, multi-sampling (liver, duodenum and jejunum) was performed in some donors. The expression was determined at mRNA and protein levels. In the liver, CES2 and CYP3A4 mRNA exhibited a postnatal surge (1 versus 2 months of age) by 2.7 and 29 fold, respectively. CYP3A4 but not CES2 mRNA in certain pediatric groups reached or even exceeded the adult level. The duodenal samples, on the other hand, showed a gene-specific expression pattern at mRNA level. CES2 mRNA increased with age but the opposite was true with CYP3A4 mRNA. The levels of CES2 and CYP3A4 protein, on the other hand, increased with age in both liver and duodenum. The multi-sampling study demonstrated significant correlation of CES2 expression between the duodenum and jejunum. However, neither duodenal nor jejunal expression correlated with hepatic expression of CES2. These findings establish that developmental regulation occurs in a gene and organ-dependent manner. Title: Genome Sequence and Annotation of Trichoderma parareesei, the Ancestor of the Cellulase Producer Trichoderma reesei Yang D, Pomraning K, Kopchinskiy A, Karimi Aghcheh R, Atanasova L, Chenthamara K, Baker SE, Zhang R, Shen Q and Druzhinina IS <2 more author(s)> Yang D, Pomraning K, Kopchinskiy A, Karimi Aghcheh R, Atanasova L, Chenthamara K, Baker SE, Zhang R, Shen Q, Freitag M, Kubicek CP, Druzhinina IS (- 2) Ref: Genome Announc, 3:e00885, 2015 : PubMed ESTHER: Yang_2015_Genome.Announc_3_e00885 PubMedSearch: Yang 2015 Genome.Announc 3 e00885 PubMedID: 26272569 Gene_locus related to this paper: hypjr-a0a024s1s9 Abstract The filamentous fungus Trichoderma parareesei is the asexually reproducing ancestor of Trichoderma reesei, the holomorphic industrial producer of cellulase and hemicellulase. Here, we present the genome sequence of the T. parareesei type strain CBS 125925, which contains genes for 9,318 proteins. Title: Complete Genome Sequence of Paenibacillus polymyxa SQR-21, a Plant Growth-Promoting Rhizobacterium with Antifungal Activity and Rhizosphere Colonization Ability Li S, Yang D, Qiu M, Shao J, Guo R, Shen B, Yin X, Zhang R, Zhang N, Shen Q Ref: Genome Announc, 2:, 2014 : PubMed ESTHER: Li_2014_Genome.Announc_2_e00281 PubMedSearch: Li 2014 Genome.Announc 2 e00281 PubMedID: 24723719 Gene_locus related to this paper: paep6-e0rmc7 Abstract Here we report the complete genome sequence of a plant growth-promoting rhizobacterium (PGPR), Paenibacillus polymyxa SQR-21, which consists of one circular chromosome of 5,828,438 bp with 5,024 coding sequences (CDS). The data presented highlight multiple sets of functional genes associated with its plant-beneficial characteristics. Title: Macrophage CGI-58 deficiency activates ROS-inflammasome pathway to promote insulin resistance in mice Miao H, Ou J, Ma Y, Guo F, Yang Z, Wiggins M, Liu C, Song W, Han X and Yu L <8 more author(s)> Miao H, Ou J, Ma Y, Guo F, Yang Z, Wiggins M, Liu C, Song W, Han X, Wang M, Cao Q, Chung BH, Yang D, Liang H, Xue B, Shi H, Gan L, Yu L (- 8) Ref: Cell Rep, 7:223, 2014 : PubMed ESTHER: Miao_2014_Cell.Rep_7_223 PubMedSearch: Miao 2014 Cell.Rep 7 223 PubMedID: 24703845 Abstract Overnutrition activates a proinflammatory program in macrophages to induce insulin resistance (IR), but its molecular mechanisms remain incompletely understood. Here, we show that saturated fatty acid and lipopolysaccharide, two factors implicated in high-fat diet (HFD)-induced IR, suppress macrophage CGI-58 expression. Macrophage-specific CGI-58 knockout (MaKO) in mice aggravates HFD-induced glucose intolerance and IR, which is associated with augmented systemic/tissue inflammation and proinflammatory activation of adipose tissue macrophages. CGI-58-deficient macrophages exhibit mitochondrial dysfunction due to defective peroxisome proliferator-activated receptor (PPAR)gamma signaling. Consequently, they overproduce reactive oxygen species (ROS) to potentiate secretion of proinflammatory cytokines by activating NLRP3 inflammasome. Anti-ROS treatment or NLRP3 silencing prevents CGI-58-deficient macrophages from oversecreting proinflammatory cytokines and from inducing proinflammatory signaling and IR in the cocultured fat slices. Anti-ROS treatment also prevents exacerbation of inflammation and IR in HFD-fed MaKO mice. Our data thus establish CGI-58 as a suppressor of overnutrition-induced NLRP3 inflammasome activation in macrophages. Title: Transgenic CGI-58 expression in macrophages alleviates the atherosclerotic lesion development in ApoE knockout mice Xie P, Zeng X, Xiao J, Sun B, Yang D Ref: Biochimica & Biophysica Acta, 1841:1683, 2014 : PubMed ESTHER: Xie_2014_Biochim.Biophys.Acta_1841_1683 PubMedSearch: Xie 2014 Biochim.Biophys.Acta 1841 1683 PubMedID: 25178844 Abstract Comparative Gene Identification-58 (CGI-58), as an adipose triglyceride lipase (ATGL) activator, strongly increases ATGL-mediated triglyceride (TG) catabolism. Previous studies have shown that CGI-58 affects intestinal cholesterol homeostasis independently of ATGL activity. Therefore, we hypothesized that CGI-58 was involved in macrophage cholesterol metabolism and consequently atherosclerotic lesion formation. Here, we generated macrophage-specific CGI-58 transgenic mice (Mac-CGI-58 Tg) using an SRA promoter, which was further mated with ApoE-/- mice to create litters of CGI-58 Tg/ApoE-/- mice. These CGI-58 Tg/ApoE-/- mice exhibited an anti-atherosclerosis phenotype compared with wild type (WT) controls (CGI-58 WT/ApoE-/-), illustrated by less plaque area in aortic roots. Moreover, macrophage-specific CGI-58 overexpression in mice resulted in up-regulated levels of plasma total cholesterol and HDL-cholesterol. Consequently, higher expression levels of PPARa, PPARgamma, LXRalpha, ABCA1, and ABCG1 were detected in macrophages from CGI-58 Tg/ApoE-/- mice compared to CGI-58 WT/ApoE-/- counterparts, which were accompanied by elevated macrophage cholesterol efflux toward HDL and Apo A1. Nevertheless, serum levels of TNF-alpha and IL-6 were reduced by macrophage-specific CGI-58 overexpression. Finally, bone marrow (BM) transplantation experiments further revealed that ApoE-/- mice reconstituted with Mac-CGI-58 Tg BM cells (ApoE-/-/Tg-BM chimera) displayed a significant reduction of atherosclerosis lesions compared with control mice reconstituted with Mac-CGI-58 WT BM cells (ApoE-/-/WT-BM chimera). Collectively, these data strongly suggest that CGI-58 overexpression in macrophages may protect against atherosclerosis development in mice. Title: A Novel Risk Haplotype of ALOX5AP Gene is Associated with Ischemic Stroke in Chinese Han Population Yang D, He Y, Li M, Shi C, Song G, Wang Q, Fan Y, Feng Q, Zheng H Ref: Journal of Molecular Neuroscience, 53:493, 2014 : PubMed ESTHER: Yang_2014_J.Mol.Neurosci_53_493 PubMedSearch: Yang 2014 J.Mol.Neurosci 53 493 PubMedID: 24198186 Abstract Previous studies have implicated that two at-risk haplotypes (HapA and HapB) of gene-encoding 5-lipoxygenase-activating protein (ALOX5AP) were significantly associated with stroke. The aim of this study was to explore the association between haplotypes of ALOX5AP gene and risk for ischemic stroke (IS) in Chinese Han population. A total of 492 patients with IS and 490 matched control subjects were recruited. Six ALOX5AP SNPs (SG13S377, SG13S114, SG13S41, SG13S89, SG13S32 and SG13S35) were genotyped by SNaPshot minisequence technique. A common genetic variant SG13S114/AA in the ALOX5AP gene was associated with IS in this Chinese cohort (OR = 2.514, 95 % CI = 1.667 ~ 3.790). HapA (TGA) and HapB (AAAG) had no significant difference in the patients (36.3 and 18.5 %, respectively) and controls (37.6 and 16.3 %, respectively) (P = 0.631 and P = 0.375, respectively). But, the frequency of Hap (GAAG) was significantly higher in the patients than that in the controls after Bonferroni's adjustment (P = 0.006). To conclude, SG13S114/AA of the ALOX5AP gene was associated with an increased risk for IS. A novel risk haplotype, Hap (GAAG) was a genetic risk factor for IS in this Chinese population. Title: Fe(3)O(4) magnetic nanoparticle peroxidase mimetic-based colorimetric assay for the rapid detection of organophosphorus pesticide and nerve agent Liang M, Fan K, Pan Y, Jiang H, Wang F, Yang D, Lu D, Feng J, Zhao J and Yan X <1 more author(s)> Liang M, Fan K, Pan Y, Jiang H, Wang F, Yang D, Lu D, Feng J, Zhao J, Yang L, Yan X (- 1) Ref: Analytical Chemistry, 85:308, 2013 : PubMed ESTHER: Liang_2013_Anal.Chem_85_308 PubMedSearch: Liang 2013 Anal.Chem 85 308 PubMedID: 23153113 Abstract Rapid and sensitive detection methods are in urgent demand for the screening of extensively used organophosphorus pesticides and highly toxic nerve agents for their neurotoxicity. In this study, we developed a novel Fe(3)O(4) magnetic nanoparticle (MNP) peroxidase mimetic-based colorimetric method for the rapid detection of organophosphorus pesticides and nerve agents. The detection assay is composed of MNPs, acetylcholinesterase (AChE), and choline oxidase (CHO). The enzymes AChE and CHO catalyze the formation of H(2)O(2) in the presence of acetylcholine, which then activates MNPs to catalyze the oxidation of colorimetric substrates to produce a color reaction. After incubation with the organophosphorus neurotoxins, the enzymatic activity of AChE was inhibited and produced less H(2)O(2), resulting in a decreased catalytic oxidation of colorimetric substrates over MNP peroxidase mimetics, accompanied by a drop in color intensity. Three organophosphorus compounds were tested on the assay: acephate and methyl-paraoxon as representative organophosphorus pesticides and the nerve agent Sarin. The novel assay displayed substantial color change after incubation in organophosphorus neurotoxins in a concentration-dependent manner. As low as 1 nM Sarin, 10 nM methyl-paraoxon, and 5 muM acephate are easily detected by the novel assay. In conclusion, by employing the peroxidase-mimicking activity of MNPs, the developed colorimetric assay has the potential of becoming a screening tool for the rapid and sensitive assessment of the neurotoxicity of an overwhelming number of organophosphate compounds. Title: Carboxylesterase-2 is a highly sensitive target of the antiobesity agent orlistat with profound implications in the activation of anticancer prodrugs Xiao D, Shi D, Yang D, Barthel B, Koch TH, Yan B Ref: Biochemical Pharmacology, 85:439, 2013 : PubMed ESTHER: Xiao_2013_Biochem.Pharmacol_85_439 PubMedSearch: Xiao 2013 Biochem.Pharmacol 85 439 PubMedID: 23228697 Gene_locus related to this paper: human-CES2 Inhibitor(s) related to this paper: Orlistat Abstract Orlistat has been the most used anti-obesity drug and the mechanism of its action is to reduce lipid absorption by inhibiting gastrointestinal lipases. These enzymes, like carboxylesterases (CESs), structurally belong to the alpha/beta hydrolase fold superfamily. Lipases and CESs are functionally related as well. Some CESs (e.g., human CES1) have been shown to hydrolyze lipids. This study was designed to test the hypothesis that orlistat inhibits CESs with higher potency toward CES1 than CES2, a carboxylesterase with little lipase activity. Liver microsomes and recombinant CESs were tested for the inhibition of the hydrolysis of standard substrates and the anticancer prodrugs pentyl carbamate of p-aminobenzyl carbamate of doxazolidine (PPD) and irinotecan. Contrary to the hypothesis, orlistat at 1nM inhibited CES2 activity by 75% but no inhibition on CES1, placing CES2 one of the most sensitive targets of orlistat. The inhibition varied among some CES2 polymorphic variants. Pretreatment with orlistat reduced the cell killing activity of PPD. Certain mouse but not rat CESs were also highly sensitive. CES2 is responsible for the hydrolysis of many common drugs and abundantly expressed in the gastrointestinal track and liver. Inhibition of this carboxylesterase probably presents a major source for altered therapeutic activity of these medicines if co-administered with orlistat. In addition, orlistat has been linked to various types of organ toxicities, and this study provides an alternative target potentially involved in these toxicological responses. Title: Regulation of carboxylesterase-2 expression by p53 family proteins and enhanced anti-cancer activities among 5-fluorouracil, irinotecan and doxazolidine prodrug Xiao D, Yang D, Guo L, Lu W, Charpentier M, Yan B Ref: British Journal of Pharmacology, 168:1989, 2013 : PubMed ESTHER: Xiao_2013_Br.J.Pharmacol_168_1989 PubMedSearch: Xiao 2013 Br.J.Pharmacol 168 1989 PubMedID: 23373735 Abstract BACKGROUND AND PURPOSE: For four decades, 5-fluorouracil (5-FU) has been a major anti-cancer medicine. This drug is increasingly used with other anti-cancer agents such as irinotecan. Irinotecan and many others such as PPD (pentyl carbamate of p-aminobenzyl carbamate of doxazolidine) require activation by carboxylesterase-2 (CES2). 5-FU, on the other hand, reportedly induces CES2 in colorectal tumour lines. The aims of this study were to determine the molecular basis for the induction and to ascertain interactive cell-killing activity between 5-FU and ester prodrugs. EXPERIMENTAL APPROACH: Colorectal and non-colorectal lines and xenografts were treated with 5-FU and the expression of CES2 was determined. Cell-killing activity of irinotecan and PPD were determined in the presence or absence of CES2 inhibitor. Several molecular experiments were used to determine the molecular basis for the induction. KEY Title: Ethylbenzene-induced hearing loss, neurobehavioral function, and neurotransmitter alterations in petrochemical workers Zhang M, Wang Y, Wang Q, Yang D, Zhang J, Wang F, Gu Q Ref: J Occup Environ Med, 55:1001, 2013 : PubMed ESTHER: Zhang_2013_J.Occup.Environ.Med_55_1001 PubMedSearch: Zhang 2013 J.Occup.Environ.Med 55 1001 PubMedID: 23969497 Abstract OBJECTIVE: To estimate hearing loss, neurobehavioral function, and neurotransmitter alteration induced by ethylbenzene in petrochemical workers. Title: Antioxidant sulforaphane and sensitizer trinitrobenzene sulfonate induce carboxylesterase-1 through a novel element transactivated by nuclear factor-E2 related factor-2 Chen YT, Shi D, Yang D, Yan B Ref: Biochemical Pharmacology, 84:864, 2012 : PubMed ESTHER: Chen_2012_Biochem.Pharmacol_84_864 PubMedSearch: Chen 2012 Biochem.Pharmacol 84 864 PubMedID: 22776248 Abstract Carboxylesterase-1 CES1 the most versatile human carboxylesterase plays critical roles in drug metabolism and lipid mobilization This enzyme is highly induced by antioxidants and sensitizers in various cell lines These compounds are known to activate nuclear factor-E2 related factor-2 Nrf2 by reacting to kelch-like ECH-associated protein-1 Keap1 The aims of this study were to determine whether antioxidant sulforaphane SFN and sensitizer trinitrobenzene sulfonate TNBS target Keap1 similarly and whether they use the same element for CES1 induction Cells over-expressing Keap1 were treated with TNBS or SFN and the formation of disulfide bonds among Keap1 molecules were determined SFN promoted intramolecular disulfide formation whereas TNBS promoted intermolecular disulfide formation of Keap1 Two elements sensitizing/antioxidant response element S/ARE and ARE4 were identified to support Nrf2 in the regulated expression of CES1A1 Both elements were bound by Nrf2 however the S/ARE element supported whereas the ARE4 element repressed Nrf2 transactivation The repression required higher amounts of Nrf2 suggesting that the transactivation through the S/ARE element dominates the trans-repression through the ARE4 element under normal antioxidative condition These findings conclude that compounds although triggering the Keap1-Nrf2 pathway may differ in the mode of reacting with Keap1 These findings also conclude that both positive and negative Nrf2 elements exist even within the same gene and such opposing mechanisms provide fine-tuning in transcriptional regulation by the Keap1-Nrf2 pathway High levels of CES1 are linked to lipid retention Excessive induction of CES1 by antioxidants and sensitizers likely provides a mechanism for potential detrimental effect on human health. Title: Contribution of carboxylesterase in hamster to the intestinal first-pass loss and low bioavailability of ethyl piperate, an effective lipid-lowering drug candidate Lu Y, Bao N, Borjihan G, Ma Y, Hu M, Yu C, Li S, Jia J, Yang D, Wang Y Ref: Drug Metabolism & Disposition: The Biological Fate of Chemicals, 39:796, 2011 : PubMed ESTHER: Lu_2011_Drug.Metab.Dispos_39_796 PubMedSearch: Lu 2011 Drug.Metab.Dispos 39 796 PubMedID: 21346005 Abstract Ethyl piperate is an effective lipid-lowering drug candidate synthesized from piperine. However, its pharmacokinetic characteristics and oral absorption process remain unclear. A liquid chromatography-tandem mass spectrometry method was applied to determine the oral bioavailability of ethyl piperate. Simulated gastrointestinal pH conditions and intestinal washings were prepared to investigate their contributions to the loss of ethyl piperate. Hydrolysis by carboxylesterase (CES) was evaluated in vitro using microsomes and S9 fractions. In situ intestinal single-pass perfusion experiments were performed to estimate the role of CES in ethyl piperate absorption. The bioavailability of ethyl piperate was extremely low (0.47%) in hamster independent of gastrointestinal environmental effects. Ethyl piperate was a typical substrate of CES with kinetic parameters K(m) and V(max) of 7.56 +/- 1.491 muM and 0.16 +/- 0.008 nmol . min(-1) . mg protein(-1), respectively. CES was responsible for 85.8% of the intestinal hydrolysis of ethyl piperate. Specific inhibition of CES with bis-p-nitrophenyl phosphate (BNPP), decreased degradation clearance to 36% of control with no significant change in absorption clearance. This contrasted with the results of Caco-2 monolayer experiments, which showed a dramatic increase in the apparent permeability coefficient after BNPP treatment. mRNA levels for the CES isozyme, CES2A3, were similar among the three regions of hamster intestine and 60% less than those in liver; CES1B1 mRNA levels were even lower in the intestine and showed a proximal-to-distal decrease. In conclusion, CES markedly contributes to intestinal first-pass hydrolysis of ethyl piperate that is sufficient, but not necessary, to cause the observed extremely low bioavailability. Title: Surge in expression of carboxylesterase 1 during the post-neonatal stage enables a rapid gain of the capacity to activate the anti-influenza prodrug oseltamivir Shi D, Yang D, Prinssen EP, Davies BE, Yan B Ref: J Infect Dis, 203:937, 2011 : PubMed ESTHER: Shi_2011_J.Infect.Dis_203_937 PubMedSearch: Shi 2011 J.Infect.Dis 203 937 PubMedID: 21402544 Abstract BACKGROUND: Oseltamivir, a widely used anti-influenza drug, is hydrolytically activated by carboxylesterase 1 (CES1). The expression of this carboxylesterase is developmentally regulated. This study was performed to determine when after birth infants acquire competence of activating this prodrug. METHODS: Liver tissue samples were collected and divided into 5 age groups: group 1 (1-31 d old), group 2 (35-70 d old), group 3 (89-119 d old), group 4 (123-198 d old), and group 5 (>18 years of age). These samples were analyzed for oseltamivir hydrolysis and CES1 expression. RESULTS: Liver samples in group 1 expressed the lowest level of CES1 with the lowest hydrolytic activity toward oseltamivir. A 4-7-fold increase between groups 1 and 2 (1-31 vs 35-70 d of age) was detected in the hydrolysis and expression analyses, respectively. Liver samples in the other 3 pediatric groups (35-198 d of age) exhibited similar expression and hydrolysis levels. Overall, liver samples in group 1 had CES1 expression and hydrolysis levels that were 10% of those of adults, whereas liver samples in the other 3 pediatric groups had levels that were approximately 50% of adult levels. CONCLUSIONS: The post-neonatal surge in CES1 expression ensures the hydrolytic capacity to be gained rapidly after birth in infants, but the larger variability during this period suggests that caution should be exercised on the extrapolated dosing regimens of ester drugs from other age groups. Title: Chlorpyrifos-oxon disrupts zebrafish axonal growth and motor behavior Yang D, Lauridsen H, Buels K, Chi LH, La Du J, Bruun DA, Olson JR, Tanguay RL, Lein PJ Ref: Toxicol Sci, 121:146, 2011 : PubMed ESTHER: Yang_2011_Toxicol.Sci_121_146 PubMedSearch: Yang 2011 Toxicol.Sci 121 146 PubMedID: 21346248 Abstract Axonal morphology is a critical determinant of neuronal connectivity, and perturbation of the rate or extent of axonal growth during development has been linked to neurobehavioral deficits in animal models and humans. We previously demonstrated that the organophosphorus pesticide (OP) chlorpyrifos (CPF) inhibits axonal growth in cultured neurons. In this study, we used a zebrafish model to determine whether CPF, its oxon metabolite (CPFO), or the excreted metabolite trichloro-2-pyridinol (TCPy) alter spatiotemporal patterns of axonal growth in vivo. Static waterborne exposure to CPFO, but not CPF or TCPy, at concentrations >/= 0.03 muM from 24- to 72-h post fertilization significantly inhibited acetylcholinesterase, and high-performance liquid chromatography detected significantly more TCPy in zebrafish exposed to 0.1 muM CPFO versus 1.0 muM CPF. These data suggest that zebrafish lack the metabolic enzymes to activate CPF during these early developmental stages. Consistent with this, CPFO, but not CPF, significantly inhibited axonal growth of sensory neurons, primary motoneurons, and secondary motoneurons at concentrations >/= 0.1 muM. Secondary motoneurons were the most sensitive to axonal growth inhibition by CPFO, which was observed at concentrations that did not cause mortality, gross developmental defects, or aberrant somatic muscle differentiation. CPFO effects on axonal growth correlated with adverse effects on touch-induced swimming behavior, suggesting the functional relevance of these structural changes. These data suggest that altered patterns of neuronal connectivity contribute to the developmental neurotoxicity of CPF and demonstrate the relevance of zebrafish as a model for studying OP developmental neurotoxicity. Title: In vivo MRI identifies cholinergic circuitry deficits in a Down syndrome model Chen Y, Dyakin VV, Branch CA, Ardekani B, Yang D, Guilfoyle DN, Peterson J, Peterhoff C, Ginsberg SD and Nixon RA <1 more author(s)> Chen Y, Dyakin VV, Branch CA, Ardekani B, Yang D, Guilfoyle DN, Peterson J, Peterhoff C, Ginsberg SD, Cataldo AM, Nixon RA (- 1) Ref: Neurobiology of Aging, 30:1453, 2009 : PubMed ESTHER: Chen_2009_Neurobiol.Aging_30_1453 PubMedSearch: Chen 2009 Neurobiol.Aging 30 1453 PubMedID: 18180075 Abstract In vivo quantitative magnetic resonance imaging (MRI) was employed to detect brain pathology and map its distribution within control, disomic mice (2N) and in Ts65Dn and Ts1Cje trisomy mice with features of human Down syndrome (DS). In Ts65Dn, but not Ts1Cje mice, transverse proton spin-spin (T(2)) relaxation time was selectively reduced in the medial septal nucleus (MSN) and in brain regions that receive cholinergic innervation from the MSN, including the hippocampus, cingulate cortex, and retrosplenial cortex. Basal forebrain cholinergic neurons (BFCNs) in the MSN, identified by choline acetyltransferase (ChAT) and nerve growth factor receptors p75(NTR) and TrkA immunolabeling were reduced in Ts65Dn brains and in situ acetylcholinesterase (AChE) activity was depleted distally along projecting cholinergic fibers, and selectively on pre- and postsynaptic profiles in these target areas. T(2) effects were negligible in Ts1Cje mice that are diploid for App and lack BFCN neuropathology, consistent with the suspected relationship of this pathology to increased App dosage. These results establish the utility of quantitative MRI in vivo for identifying Alzheimer's disease-relevant cholinergic changes in animal models of DS and characterizing the selective vulnerability of cholinergic neuron subpopulations. Title: The measurement of serum cholinesterase activities by an integration strategy with expanded linear ranges and negligible substrate-activation Liao F, Yang D, Tang J, Yang X, Liu B, Zhao Y, Zhao L, Liao H, Yu M Ref: Clinical Biochemistry, 42:926, 2009 : PubMed ESTHER: Liao_2009_Clin.Biochem_42_926 PubMedSearch: Liao 2009 Clin.Biochem 42 926 PubMedID: 19101530 Abstract OBJECTIVES: To measure serum cholinesterase (SCHE) with an integration strategy. DESIGN AND METHODS: At 54.0 micromol/L butyrylthiolcholine, SCHE initial rates were calculated with 50.0 micromol/L butyrylthiolcholine and maximal rates via an improved integrated method if substrate consumptions within 5.0 min were over 60%, or were determined by the classical initial rate method. RESULTS: The linear range was from 16 to 1560 nkat/L, and SCHE in clinic sera showed negligible substrate-activation. CONCLUSION: This strategy was effective. Title: Human carboxylesterases HCE1 and HCE2: ontogenic expression, inter-individual variability and differential hydrolysis of oseltamivir, aspirin, deltamethrin and permethrin Yang D, Pearce RE, Wang X, Gaedigk R, Wan YJ, Yan B Ref: Biochemical Pharmacology, 77:238, 2009 : PubMed ESTHER: Yang_2009_Biochem.Pharmacol_77_238 PubMedSearch: Yang 2009 Biochem.Pharmacol 77 238 PubMedID: 18983829 Gene_locus related to this paper: human-CES1, human-CES2 Inhibitor(s) related to this paper: Permethrin Abstract Carboxylesterases hydrolyze chemicals containing such functional groups as a carboxylic acid ester, amide and thioester. The liver contains the highest carboxylesterase activity and expresses two major carboxylesterases: HCE1 and HCE2. In this study, we analyzed 104 individual liver samples for the expression patterns of both carboxylesterases. These samples were divided into three age groups: adults (>or= 18 years of age), children (0 days-10 years) and fetuses (82-224 gestation days). In general, the adult group expressed significantly higher HCE1 and HCE2 than the child group, which expressed significantly higher than the fetal group. The age-related expression was confirmed by RT-qPCR and Western immunoblotting. To determine whether the expression patterns reflected the hydrolytic activity, liver microsomes were pooled from each group and tested for the hydrolysis of drugs such as oseltamivir and insecticides such as deltamethrin. Consistent with the expression patterns, adult microsomes were approximately 4 times as active as child microsomes and 10 times as active as fetal microsomes in hydrolyzing these chemicals. Within the same age group, particularly in the fetal and child groups, a large inter-individual variability was detected in mRNA (430-fold), protein (100-fold) and hydrolytic activity (127-fold). Carboxylesterases are recognized to play critical roles in drug metabolism and insecticide detoxication. The findings on the large variability among different age groups or even within the same age group have important pharmacological and toxicological implications, particularly in relation to pharmacokinetic alterations of ester drugs in children and vulnerability of fetuses and children to pyrethroid insecticides. Title: Pyrethroid insecticides: isoform-dependent hydrolysis, induction of cytochrome P450 3A4 and evidence on the involvement of the pregnane X receptor Yang D, Wang X, Chen YT, Deng R, Yan B Ref: Toxicol Appl Pharmacol, 237:49, 2009 : PubMed ESTHER: Yang_2009_Toxicol.Appl.Pharmacol_237_49 PubMedSearch: Yang 2009 Toxicol.Appl.Pharmacol 237 49 PubMedID: 19249324 Abstract Pyrethroids account for more than one-third of the insecticides currently marketed in the world. In mammals, these insecticides undergo extensive metabolism by carboxylesterases and cytochrome P450s (CYPs). In addition, some pyrethroids are found to induce the expression of CYPs. The aim of this study was to determine whether pyrethroids induce carboxylesterases and CYP3A4, and whether the induction is correlated inversely with their hydrolysis. Human liver microsomes were pooled and tested for the hydrolysis of 11 pyrethroids. All pyrethroids were hydrolyzed by the pooled microsomes, but the hydrolytic rates varied by as many as 14 fold. Some pyrethroids such as bioresmethrin were preferably hydrolyzed by carboxylesterase HCE1, whereas others such as bifenthrin preferably by HCE2. In primary human hepatocytes, all pyrethroids except tetramethrin significantly induced CYP3A4. In contrast, insignificant changes were detected on the expression of carboxylesterases. The induction of CYP3A4 was confirmed in multiple cell lines including HepG2, Hop92 and LS180. Overall, the magnitude of the induction was correlated inversely with the rates of hydrolysis, but positively with the activation of the pregnane X receptor (PXR). Transfection of a carboxylesterase markedly decreased the activation of PXR, and the decrease was in agreement with carboxylesterase-based preference for hydrolysis. In addition, human PXR variants as well as rat PXR differed from human PXR (wild-type) in responding to certain pyrethroids (e.g., lambda-cyhalothrin), suggesting that induction of PXR target genes by these pyrethroids varies depending on polymorphic variants and the PXR species identity. Title: Hepatic lipase gene -514C/T polymorphism in the Guangxi Hei Yi Zhuang and Han populations Wu J, Yin R, Lin W, Pan S, Yang D Ref: Lipids, 43:733, 2008 : PubMed ESTHER: Wu_2008_Lipids_43_733 PubMedSearch: Wu 2008 Lipids 43 733 PubMedID: 18592285 Gene_locus related to this paper: human-LIPC Abstract Hei Yi Zhuang is an isolated subgroup of the Zhuang minority in China. This study was designed to compare the difference in the hepatic lipase gene (LIPC) -514C/T polymorphism and its association with lipid profiles between the Guangxi Hei Yi Zhuang and Han populations. Genotyping of the LIPC -514C/T was performed in 873 subjects of Hei Yi Zhuang and 867 participants of Han Chinese. The frequency of -514T allele was 43.47% in Hei Yi Zhuang, and 36.10% in Han (P < 0.001). The frequencies of CC, CT and TT genotypes were 30.01, 53.04 and 16.95% in Hei Yi Zhuang, and 40.95, 45.91 and 13.14% in Han (P < 0.001); respectively. Serum high-density lipoprotein cholesterol (HDL-C) and apolipoprotein B levels in both ethnic groups were higher in LIPC -514T carriers than in C carriers. In addition, serum triglyceride levels in Han were higher in TT genotype individuals than in CC genotype subjects (P < 0.05). Serum HDL-C levels were positively correlated with age, alcohol consumption and LIPC -514C/T genotypes, and negatively associated with hypertension and cigarette smoking in Hei Yi Zhuang (P < 0.05-0.01), whereas HDL-C levels were positively correlated with age, alcohol consumption and LIPC -514C/T genotypes, and negatively associated with body mass index and cigarette smoking in Han (P < 0.05-0.001). The differences in serum HDL-C levels between the two ethnic groups might partially attribute to the differences in the LIPC -514C/T polymorphism. Title: Chlorpyrifos and chlorpyrifos-oxon inhibit axonal growth by interfering with the morphogenic activity of acetylcholinesterase Yang D, Howard A, Bruun D, Ajua-Alemanj M, Pickart C, Lein PJ Ref: Toxicol Appl Pharmacol, 228:32, 2008 : PubMed ESTHER: Yang_2008_Toxicol.Appl.Pharmacol_228_32 PubMedSearch: Yang 2008 Toxicol.Appl.Pharmacol 228 32 PubMedID: 18076960 Abstract A primary role of acetylcholinesterase (AChE) is regulation of cholinergic neurotransmission by hydrolysis of synaptic acetylcholine. In the developing nervous system, however, AChE also functions as a morphogenic factor to promote axonal growth. This raises the question of whether organophosphorus pesticides (OPs) that are known to selectively bind to and inactivate the enzymatic function of AChE also interfere with its morphogenic function to perturb axonogenesis. To test this hypothesis, we exposed primary cultures of sensory neurons derived from embryonic rat dorsal root ganglia (DRG) to chlorpyrifos (CPF) or its oxon metabolite (CPFO). Both OPs significantly decreased axonal length at concentrations that had no effect on cell viability, protein synthesis or the enzymatic activity of AChE. Comparative analyses of the effects of CPF and CPFO on axonal growth in DRG neurons cultured from AChE nullizygous (AChE -/-) versus wild type (AChE +/+) mice indicated that while these OPs inhibited axonal growth in AChE+/+ DRG neurons, they had no effect on axonal growth in AChE -/- DRG neurons. However, transfection of AChE -/- DRG neurons with cDNA encoding full-length AChE restored the wild type response to the axon inhibitory effects of OPs. These data indicate that inhibition of axonal growth by OPs requires AChE, but the mechanism involves inhibition of the morphogenic rather than enzymatic activity of AChE. These findings suggest a novel mechanism for explaining not only the functional deficits observed in children and animals following developmental exposure to OPs, but also the increased vulnerability of the developing nervous system to OPs. Title: Lipase-catalyzed esterification of conjugated linoleic acid with L-carnitine in solvent-free system and acetonitrile Li Z, Yang D, Jiang L, Ji J, Ji H, Zeng X Ref: Bioprocess Biosyst Eng, 30:331, 2007 : PubMed ESTHER: Li_2007_Bioprocess.Biosyst.Eng_30_331 PubMedSearch: Li 2007 Bioprocess.Biosyst.Eng 30 331 PubMedID: 17503088 Abstract Lipase-catalyzed esterification of conjugated linoleic acid (CLA) with L-carnitine in solvent-free system and acetonitrile was studied. Three lipases (Novzym 435, Amamo AY30 and Amano AYS) have been assayed as suitable biocatalysts in the reaction. It was found that Amano AY30 was the most effective biocatalyst in both solvent-free system and acetonitrile. The conversion rate varied from 8.05 to 60.9% in terms of reaction conditions such as the amount of lipase, the presence of water, the amount of molecular sieves and reaction time. The conversions of substrate in solvent-free system were higher than that in acetonitrile. When the substrates were 1 mmol CLA and 1 mmol L-carnitine, the maximum conversion (60.9%) was obtained in solvent-free system with 150 mg lipase AY30, 50% water content and 150 mg molecular sieves at the reaction time of 24 h. A novel CLA ester product was successfully isolated and characterized by ESI-MS and (1)H NMR. Title: Interleukin-6 alters the cellular responsiveness to clopidogrel, irinotecan, and oseltamivir by suppressing the expression of carboxylesterases HCE1 and HCE2 Yang J, Shi D, Yang D, Song X, Yan B Ref: Molecular Pharmacology, 72:686, 2007 : PubMed ESTHER: Yang_2007_Mol.Pharmacol_72_686 PubMedSearch: Yang 2007 Mol.Pharmacol 72 686 PubMedID: 17537833 Gene_locus related to this paper: human-CES1, human-CES2 Abstract Carboxylesterases constitute a class of enzymes that play important roles in the hydrolytic metabolism of drugs and other xenobiotics. Patients with liver conditions such as cirrhosis show increased secretion of proinflammatory cytokines [e.g., interleukin-6 (IL-6)] and decreased capacity of hydrolysis. In this study, we provide a molecular explanation linking cytokine secretion directly to the decreased capacity of hydrolytic biotransformation. In both primary hepatocytes and HepG2 cells, treatment with IL-6 decreased the expression of human carboxyl-esterases HCE1 and HCE2 by as much as 60%. The decreased expression occurred at both mRNA and protein levels, and it was confirmed by enzymatic assay. In cotransfection experiments, both HCE1 and HCE2 promoters were significantly repressed, and the repression was comparable with the decrease in HCE1 and HCE2 mRNA, suggesting that transrepression is responsible for the suppressed expression. In addition, pretreatment with IL-6 altered the cellular responsiveness in an opposite manner of overexpression of HCE1 and HCE2 toward various ester therapeutic agents (e.g., clopidogrel). Transfection of HCE1, for example, decreased the cytotoxicity induced by antithrombogenic agent clopidogrel, whereas pretreatment with IL-6 increased the cytotoxicity. Such a reversal was observed with other ester drugs, including anticancer agent irinotecan and anti-influenza agent oseltamivir. The altered cellular responsiveness was observed when drugs were assayed at sub- and low-micromolar concentrations, suggesting that suppressed expression of carboxylesterases by IL-6 has profound pharmacological consequences, particularly with those that are hydrolyzed in an isoform-specific manner. Title: Anti-influenza prodrug oseltamivir is activated by carboxylesterase human carboxylesterase 1, and the activation is inhibited by antiplatelet agent clopidogrel Shi D, Yang J, Yang D, LeCluyse EL, Black C, You L, Akhlaghi F, Yan B Ref: Journal of Pharmacology & Experimental Therapeutics, 319:1477, 2006 : PubMed ESTHER: Shi_2006_J.Pharmacol.Exp.Ther_319_1477 PubMedSearch: Shi 2006 J.Pharmacol.Exp.Ther 319 1477 PubMedID: 16966469 Abstract Oseltamivir is the main medicine recommended by the World Health Organization in anticipation of next influenza pandemic. This anti-influenza viral agent is an ester prodrug, and the antiviral activity is achieved by its hydrolytic metabolite: oseltamivir carboxylate. In this study, we report that the hydrolytic activation is catalyzed by carboxylesterase human carboxylesterase (HCE) 1. Liver microsomes rapidly hydrolyzed oseltamivir, but no hydrolysis was detected with intestinal microsomes or plasma. The overall rate of the hydrolysis varied among individual liver samples and was correlated well with the level of HCE1. Recombinant HCE1 but not HCE2 hydrolyzed this prodrug and produced similar kinetic parameters as the liver microsomes. Several HCE1 natural variants differed from the wild-type enzyme on the hydrolysis of oseltamivir. In the presence of antiplatelet agent clopidogrel, the hydrolysis of oseltamivir was inhibited by as much as 90% when the equal concentration was assayed. Given the fact that hydrolysis of oseltamivir is required for its therapeutic activity, concurrent use of both drugs would inhibit the activation of oseltamivir, thus making this antiviral agent therapeutically inactive. This is epidemiologically of significance because people who receive oseltamivir and clopidogrel simultaneously may maintain susceptibility to influenza infection or a source of spreading influenza virus if already infected. Title: Antiplatelet agents aspirin and clopidogrel are hydrolyzed by distinct carboxylesterases, and clopidogrel is transesterificated in the presence of ethyl alcohol Tang M, Mukundan M, Yang J, Charpentier N, LeCluyse EL, Black C, Yang D, Shi D, Yan B Ref: Journal of Pharmacology & Experimental Therapeutics, 319:1467, 2006 : PubMed ESTHER: Tang_2006_J.Pharmacol.Exp.Ther_319_1467 PubMedSearch: Tang 2006 J.Pharmacol.Exp.Ther 319 1467 PubMedID: 16943252 Gene_locus related to this paper: human-CES1 Abstract Aspirin (acetylsalicylic acid) and clopidogrel are two major antithrombogenic agents that are widely used for the treatment and prevention of cerebro- and cardiovascular conditions such as stroke. Combined use produces enhanced therapeutic effect. Aspirin and clopidogrel both are esters, and hydrolysis leads to decreased or inactivated therapeutic activity. The aim of the study was to determine whether aspirin and clopidogrel are hydrolyzed by the same enzyme(s), thus reciprocally prolonging the antithrombogenic activity. To test this possibility, microsomes from the liver and intestine were assayed for the hydrolysis of aspirin and clopidogrel. In contrary to the hypothesis, aspirin and clopidogrel were hydrolyzed in a tissue-differential manner. Liver microsomes hydrolyzed both drugs, whereas intestinal microsomes hydrolyzed aspirin only. Consistent with the tissue distribution of two carboxylesterases human carboxylesterase (HCE) 1 and HCE2, recombinant HCE1 hydrolyzed clopidogrel, whereas recombinant HCE2 hydrolyzed aspirin. In addition, hydrolysis of clopidogrel among liver samples was correlated well with the level of HCE1, and hydrolysis of aspirin with HCE2. Certain natural variants differed from the wild-type enzymes on the hydrolysis of aspirin or clopidogrel. In the presence of ethyl alcohol, clopidogrel is converted to ethyl clopidogrel. Carboxylesterases are important pharmacological determinants for drugs containing ester linkages and exhibit a large interindividual variation. The isoform-specific hydrolysis of aspirin and clopidogrel suggests that these two antithrombogenic agents may have pharmacokinetic interactions with different sets of ester drugs, and the altered hydrolysis by polymorphic mutants provides a molecular explanation to the interindividual variation. Title: Lipoprotein lipase gene polymorphism at the PvuII locus and serum lipid levels in Guangxi Hei Yi Zhuang and Han populations Yin R, Wang Y, Chen G, Lin W, Yang D, Pan S Ref: Clinical Chemistry & Laboratory Medicine, 44:1416, 2006 : PubMed ESTHER: Yin_2006_Clin.Chem.Lab.Med_44_1416 PubMedSearch: Yin 2006 Clin.Chem.Lab.Med 44 1416 PubMedID: 17163816 Abstract BACKGROUND: Hei Yi (which means "black worship" and "black dressing") Zhuang is a specific subgroup of the Zhuang nationality in China. Little is known about the relationship between genetic factors and lipid profiles in this population. Therefore, the present study was undertaken to compare the effects of lipoprotein lipase gene polymorphism at the PvuII locus on lipid levels in the Guangxi Hei Yi Zhuang and Han populations. METHODS: A total of 325 Hei Yi Zhuang subjects aged from 20 to 80 years were surveyed using stratified randomized cluster sampling. Serum levels of lipids and apolipoproteins were measured. Gene polymorphism was determined using polymerase chain reaction and restriction fragment length polymorphism. The results were compared with those for 331 matched Han subjects living in the same district. RESULTS: Serum levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol and apolipoprotein B were significantly lower in Hei Yi Zhuang than in Han subjects (p<0.05-0.01), whereas the levels of high-density lipoprotein cholesterol and the ratio of apolipoprotein A1 to apolipoprotein B were significantly higher in Hei Yi Zhuang than in Han subjects (both p<0.01). The allelic frequencies for P+ and P- were 52.92% and 47.08% in Hei Yi Zhuang, and 58.46% and 41.54% in Han subjects (p<0.05), respectively. The frequencies of P+P+, P+P- and P-P- genotypes were 23.08%, 59.69% and 17.23% in Hei Yi Zhuang, and 29.31%, 58.31% and 12.38% in Han subjects (p>0.05), respectively. There were no significant differences or no significant correlation between serum lipid parameters and genotypes in Hei Yi Zhuang or Han subjects, or for the combined population of Hei Yi Zhuang and Han (all p>0.05). CONCLUSIONS: The allelic frequencies of the lipoprotein lipase gene at the PvuII locus in Hei Yi Zhuang were different from those in Han subjects, but the genotypic frequencies in Hei Yi Zhuang subjects were not different from those in Han subjects. There was no significant correlation between polymorphism of the lipoprotein lipase gene at the PvuII site and serum lipid levels in the two ethnic groups. Title: Chlorpyrifos exerts opposing effects on axonal and dendritic growth in primary neuronal cultures Howard AS, Bucelli R, Jett DA, Bruun D, Yang D, Lein PJ Ref: Toxicol Appl Pharmacol, 207:112, 2005 : PubMed ESTHER: Howard_2005_Toxicol.Appl.Pharmacol_207_112 PubMedSearch: Howard 2005 Toxicol.Appl.Pharmacol 207 112 PubMedID: 16102564 Abstract Evidence that children are widely exposed to organophosphorus pesticides (OPs) and that OPs cause developmental neurotoxicity in animal models raises significant concerns about the risks these compounds pose to the developing human nervous system. Critical to assessing this risk is identifying specific neurodevelopmental events targeted by OPs. Observations that OPs alter brain morphometry in developing rodents and inhibit neurite outgrowth in neural cell lines suggest that OPs perturb neuronal morphogenesis. However, an important question yet to be answered is whether the dysmorphogenic effect of OPs reflects perturbation of axonal or dendritic growth. We addressed this question by quantifying axonal and dendritic growth in primary cultures of embryonic rat sympathetic neurons derived from superior cervical ganglia (SCG) following in vitro exposure to chlorpyrifos (CPF) or its metabolites CPF-oxon (CPFO) and trichloropyridinol (TCP). Axon outgrowth was significantly inhibited by CPF or CPFO, but not TCP, at concentrations > or =0.001 microM or 0.001 nM, respectively. In contrast, all three compounds enhanced BMP-induced dendritic growth. Acetylcholinesterase was inhibited only by the highest concentrations of CPF (> or =1 microM) and CPFO (> or =1 nM); TCP had no effect on this parameter. In summary, these compounds perturb neuronal morphogenesis via opposing effects on axonal and dendritic growth, and both effects are independent of acetylcholinesterase inhibition. These findings have important implications for current risk assessment practices of using acetylcholinesterase inhibition as a biomarker of OP neurotoxicity and suggest that OPs may disrupt normal patterns of neuronal connectivity in the developing nervous system. Title: Functional changes of nicotinic acetylcholine receptor in muscle and lymphocyte of myasthenic rats following acute dimethoate poisoning Yang D, Niu Y, He F Ref: Toxicology, 211:149, 2005 : PubMed ESTHER: Yang_2005_Toxicology_211_149 PubMedSearch: Yang 2005 Toxicology 211 149 PubMedID: 15863258 Abstract The mechanism underlying intermediate myasthenia syndrome (IMS) following acute organophosphate poisoning remains largely unknown. Previous studies indicated that the mechanism of myasthenia in rats and IMS patients is most likely due to a postsynaptic neurotransmission blocking at neuromuscular junctions (NMJ). Nicotinic acetylcholine receptor (nAChR) is a key postsynaptic component at NMJ. Whether functional changes of nAChR are related to the development of myasthenia has not been demonstrated and addressed in vivo so far. In this study, we attempted to investigate temporal and spatial changes of nAChR in the blood lymphocyte, muscle and brain of rats during the course of myasthenia after acute dimethoate poisoning by using radioligand-binding assay. We found that specific nAChR binding activity in the gastrocnemius muscle and blood lymphocytes of myasthenia rats was significantly increased at 48h after dimethoate poisoning. However, no changes of nAChR binding activity were found in the lymphocytes and muscle of non-myasthenia rats which were sacrificed at 1h after intoxication. Interestingly, no changes of nAChR and muscarinic acetylcholine receptor (mAChR) binding activity were found in the cerebrum and cerebellum of all rats after dimethoate intoxication either at 1 or 48h. The change of nAChR specific binding activity in the lymphocytes is parallel with that in the skeletal muscle during the development of myasthenia. This implied that the changes of nAChR receptor binding activity in the skeletal muscle and lymphocytes are highly associated with the development of myasthenia. The functional changes of nAChR at NMJ might play an important role in the paralysis of skeletal muscle following acute organophosphates (OPs) poisoning. Title: Intramolecular disulfide bonds are required for folding hydrolase B into a catalytically active conformation but not for maintaining it during catalysis Song X, Gragen S, Li Y, Ma Y, Liu J, Yang D, Matoney L, Yan B Ref: Biochemical & Biophysical Research Communications, 319:1072, 2004 : PubMed ESTHER: Song_2004_Biochem.Biophys.Res.Commun_319_1072 PubMedSearch: Song 2004 Biochem.Biophys.Res.Commun 319 1072 PubMedID: 15194477 Abstract Carboxylesterases represent a large class of hydrolytic enzymes that are involved in lipid metabolism, pharmacological determination, and detoxication of organophosphorus pesticides. These enzymes have several notable structural features including two intramolecular disulfide bonds. This study was undertaken to test the hypothesis that the disulfide bonds are required during catalysis by stabilizing the catalytically active conformation. Hydrolase B, a rat liver microsomal carboxylesterase, was reduced by dithiothreitol, electrophoretically separated and assayed for hydrolysis. Contrary to the hypothesis, reduced hydrolase B was as active as the native enzyme on the hydrolysis of 1-naphthylacetate, and sulfhydryl alkylation following reduction caused no changes in the hydrolytic activity. Interestingly, substitution of a disulfide bond-forming cysteine with an alanine caused marked reduction or complete loss of the catalytic activity, suggesting that disulfide bond formation plays a role in the biosynthetic process of hydrolase B. In support of this notion, refolding experiments restored a significant amount of hydrolytic activity when hydrolase B was unfolded with urea alone. In contrast, little activity was restored when unfolding was performed in the presence of reducing agent dithiothreitol. These results suggest that formation of the disulfide bonds plays a critical role in folding hydrolase B into the catalytically active conformation, and that the disulfide bonds play little role or function redundantly in maintaining this conformation during catalysis. Title: Human and rodent carboxylesterases: immunorelatedness, overlapping substrate specificity, differential sensitivity to serine enzyme inhibitors, and tumor-related expression Xie M, Yang D, Liu L, Xue B, Yan B Ref: Drug Metabolism & Disposition: The Biological Fate of Chemicals, 30:541, 2002 : PubMed ESTHER: Xie_2002_Drug.Metab.Dispos_30_541 PubMedSearch: Xie 2002 Drug.Metab.Dispos 30 541 PubMedID: 11950785 Abstract Carboxylesterases hydrolyze numerous endogenous and foreign compounds with diverse structures. Humans and rodents express multiple forms of carboxylesterases, which share a high degree of sequence identity (approximately 70%). Alignment analyses locate in carboxylesterases several functional subsites such the catalytic triad as seen in acetylcholinesterase. The aim of this study was to determine among human and rodent carboxylesterases the immunorelatedness, overlapping substrate specificity, differential sensitivity to serine enzyme inhibitors, tissue distribution, and tumor-related expression. Six antibodies against whole carboxylesterases or synthetic peptides were tested for their reactivity toward 11 human or rodent recombinant carboxylesterases. The antibodies against whole proteins generally exhibited a broader cross-reactivity than the anti-peptide antibodies. All carboxylesterases hydrolyzed para-nitrophenylacetate and para-nitrophenylbutyrate. However, the relative activity varied markedly from enzyme to enzyme (>20-fold), and some carboxylesterases showed a clear substrate preference. Carboxylesterases with the same functional subsites had a similar profile on substrate specificity and sensitivity toward phenylmethylsulfonyl fluoride (PMSF) and paraoxon, suggesting that these subsites play determinant roles in the recognition of substrates and inhibitors. Among three human carboxylesterases, HCE-1 hydrolyzed both substrates to a similar extent, whereas HCE-2 and HCE-3 showed an opposite substrate preference. All three enzymes were inhibited by PMSF and paraoxon, but they showed a marked difference in relative sensitivities. Based on immunoblotting analyses, HCE-1 was present in all tissues examined, whereas HCE-2 and HCE-3 were expressed in a tissue-restricted pattern. Colon carcinomas expressed slightly higher levels of HCE-1 and HCE-2 than the adjacent normal tissues, whereas the opposite was true with HCE-3. Title: Repetitive nerve stimulation and stimulation single fiber electromyography studies in rats intoxicated with single or mixed insecticides Yang D, He F, Li T Ref: Toxicology, 161:111, 2001 : PubMed ESTHER: Yang_2001_Toxicology_161_111 PubMedSearch: Yang 2001 Toxicology 161 111 PubMedID: 11295260 Abstract The function of the neuromuscular transmission in rats dosed with phoxim (P), methomyl (M), fenvalerate (F), and mixtures of P+M and P+F was studied by using both the stimulation single fiber electromyography (SSFEMG) and repetitive nerve stimulations (RNS) to determine the single muscle fiber action potential and compound muscle action potential (CMAP) respectively. The results showed that the mean consecutive difference (MCD) in SSFEMG was significantly prolonged in P, P+M and P+F intoxicated rats during the presence of myasthenia, but not in rats dosed with F and M when stimuli were given at 10 Hz or 20 Hz, thus indicating a transmission blocking at the neuromuscular junction (NMJ) induced by P. The frequency of neuromuscular transmission abnormalities detected by SSFEMG was significantly higher than those detected by RNS. This study demonstrated that the neuromuscular junction (NMJ) blocking is more frequently seen in P, P+M and P+F poisoning than in M and F poisoning, and that SSFEMG is a more sensitive electrophysiological method than RNS for detecting neuromuscular transmission blockage in myasthenia rats with acute insecticides poisoning. Title: Human carboxylesterases in term placentae: enzymatic characterization, molecular cloning and evidence for the existence of multiple forms Yan B, Matoney L, Yang D Ref: Placenta, 20:599, 1999 : PubMed ESTHER: Yan_1999_Placenta_20_599 PubMedSearch: Yan 1999 Placenta 20 599 PubMedID: 10452915 Abstract The placenta is a temporary organ that is known to metabolize numerous endogenous and xenobiotic compounds. Carboxylesterases represent a family of enzymes which hydrolyse a variety of esters, amides and thioesters. Many studies have demonstrated that carboxylesterases are widely distributed among mammalian tissues, but little is known about these enzymes in the placenta. The present study was conducted to establish the kinetic parameters of placental carboxylesterases toward several p -nitrophenol and 1-naphthol esters, and to establish the molecular basis for these enzymes in the placenta. The enzymatic rate of the hydrolysis of 1-naphthylacetate and carboxylic esters of p -nitrophenol as a function of substrate concentration (0.01-1.00 m m) was examined with human placental microsomes pooled from six placentae. Data from these studies yielded a linear Lineweaver-Burk plot with each substrate examined. K(m)values for these substrates ranged from 92 to 370 microm, and V(max)values ranged from 85 to 170 nmol/mg/min. These results suggest that each substrate is hydrolysed by a single enzyme, or enzymes that are kinetically indistinguishable, or that one of them is dominant. Microsomes from all individual placentae contained esterase activity toward all four substrates, and exhibited a one- to three-fold variation. The activity toward p -nitrophenylacetate correlated well with the activity toward 1-naphthylacetate (r(2)=0.957). In contrast, the activity toward p -nitrophenylbutyrate correlated poorly with the activity toward 1-naphthylacetate (r(2)=0.121). These results suggest that placental microsomes have more than one carboxylesterase activity. Screening of a placental cDNA library with gene-trapping hybridization resulted in the isolation of three distinct cDNAs, designated PCE-1, PCE-2 and PCE-3. PCE-1 and PCE-2 have a significant sequence identity (approx 99 per cent) with liver carboxylesterases hCE and hCE-2, respectively. PCE-3 has a 96 per cent sequence identity with hCE but only at the first 874 nucleotide of the 5' end. The rest of the 1396 nucleotides of the 3' end exhibit no significant sequence identity with any known mammalian carboxylesterases. A probe derived from the 3' end of PCE-3 detected an approx 2.2 kb messenger transcript, the size of a regular carboxylesterase. However, the entire PCE-3 cDNA has multiple internal stop codons and encodes only 269 amino acids; half the size of a regular carboxylesterase. Northern blotting experiments detected the transcripts coding for PCE-1, PCE-2 or PCE-3 in all placentae, and the levels of these messengers showed an approx six-fold individual variation. Placenta 6 had the highest activity toward all four substrates, and highest levels of the messengers for PCE-1, PCE-2 and PCE-3. In contrast, placenta 1 had relatively high levels of messengers for PCE-1 and PCE-2, but the activity toward these four substrates was only moderate. These results suggest that a discrepancy between the messenger level and the enzyme protein exists or that there are other as yet unidentified carboxylesterase(s) in the placenta which contribute to the hydrolytic activity. Carboxylesterases are known to involve the detoxication and metabolic activation of various drugs, environmental toxicants and carcinogens. Therefore, placental carboxylesterases have both pharmacological and toxicological significance in the development of the fetus. Title: Subdomain chimeras of hepatic lipase and lipoprotein lipase. Localization of heparin and cofactor binding Hill JS, Yang D, Nikazy J, Curtiss LK, Sparrow JT, Wong H Ref: Journal of Biological Chemistry, 273:30979, 1998 : PubMed ESTHER: Hill_1998_J.Biol.Chem_273_30979 PubMedSearch: Hill 1998 J.Biol.Chem 273 30979 PubMedID: 9812994 Abstract To specify and localize carboxyl-terminal domain functions of human hepatic lipase (HL) and human lipoprotein lipase (LPL), two subdomain chimeras were created in which portions of the carboxyl-terminal domain were exchanged between the two lipases. The first chimera (HL-LPLC1) was composed of residues 1-344 of human HL, residues 331-388 of human LPL, and residues 415-476 of human HL. The second chimera (HL-LPLC2) consisted of just two segments, residues 1-414 of human HL and residues 389-448 of human LPL. These chimeric constructs effectively divided the HL C-terminal domain into halves, with corresponding LPL sequences either in the first or second portion of that domain. Both chimeras were lipolytically active and hydrolyzed triolein emulsions to a similar extent compared with native HL and LPL. Heparin-Sepharose chromatography demonstrated that HL-LPLC1 and HL-LPLC2 eluted at 0.80 and 1.3 M NaCl, respectively, elution positions that corresponded to native HL and LPL. Hence, substitution of LPL sequences into the HL carboxyl-terminal domain resulted in the production of functional lipases, but with distinct heparin binding properties. In addition, HL-LPLC2 trioleinase activity was responsive to apoC-II activation, although the -fold stimulation was less than that observed with native LPL. Moreover, an apoC-II fragment (residues 44-79) was specifically cross-linked to LPL and HL-LPLC2, but not to HL or HL-LPLC1. Finally, both chimeras hydrolyzed phospholipid with a specific activity similar to that of HL, which was unaffected by the presence of apoC-II. These findings indicated that in addition to a region found within the amino-terminal domain of LPL, apoC-II also interacted with the last half of the carboxyl-terminal domain (residues 389-448) to achieve maximal lipolytic activation. In addition, the relative heparin affinity of HL and LPL was determined by the final 60 carboxyl-terminal residues of each enzyme. Title: Hepatic lipase: high-level expression and subunit structure determination Hill JS, Davis RC, Yang D, Schotz MC, Wong H Ref: Methods Enzymol, 284:232, 1997 : PubMed ESTHER: Hill_1997_Methods.Enzymol_284_232 PubMedSearch: Hill 1997 Methods.Enzymol 284 232 PubMedID: 9379936 Title: Lipase engineering: a window into structure-function relationships Wong H, Davis RC, Hill JS, Yang D, Schotz MC Ref: Methods Enzymol, 284:171, 1997 : PubMed ESTHER: Wong_1997_Methods.Enzymol_284_171 PubMedSearch: Wong 1997 Methods.Enzymol 284 171 PubMedID: 9379933 Abstract Utilization of genetic engineering techniques to create novel functional lipases has increased knowledge of structure-function relationships in this important class of enzymes. The examples of engineered lipases presented in this chapter addressed the investigation of domain-specific properties, heparin binding, and subunit orientation. Conclusions reached are credible because the designed lipases retained catalytic activity, implying native, or near-native, conformation. This approach has demonstrated vigor by determining the domain location of several important enzyme functions and by providing the first evidence that LPL subunits are arranged in a head-to-tail orientation. In conjunction with physical techniques, such as crystallography and nuclear magnetic resonance spectroscopy, the engineered lipase approach could reveal new insights into the mechanism by which lipolysis is accomplished. The studies described here represent only the first attempts to explore that subject; more sophisticated lipase engineering will be used in future as a window into structure-function relationships. Title: Cloning and expression of hydrolase C, a member of the rat carboxylesterase family Yan B, Yang D, Parkinson A Ref: Archives of Biochemistry & Biophysics, 317:222, 1995 : PubMed ESTHER: Yan_1995_Arch.Biochem.Biophys_317_222 PubMedSearch: Yan 1995 Arch.Biochem.Biophys 317 222 PubMedID: 7872788 Gene_locus related to this paper: ratno-lmcxe Abstract Using polymerase chain reaction (PCR), we have isolated a cDNA that encodes a rat liver carboxylesterase. This novel enzyme, designated hydrolase C, is structurally very similar to hydrolase B, a microsomal carboxylesterase expressed in rat liver and kidney. Hydrolase B and C are 96% identical in nucleotide sequence and 93% identical in deduced amino acid sequence. Both enzymes have an 18-amino-acid signal peptide at the N-terminus. The C-terminus of hydrolase B and C contains an HXEL consensus sequence for retaining proteins in the endoplasmic reticulum. As expected, when the cDNA encoding hydrolase C was expressed in a baculovirus/Sf21 cell system, the recombinant enzyme was localized in the endoplasmic reticulum. Hydrolase B and C both have putative N-linked glycosylation sites at Asn1 and Asn61. The active site of hydrolase B and C appears to be composed of a nucleophile, Ser203, a basic residue, His448, and an acidic residue, either Asp97 or Glu228. Based on cloning experiments, restriction endonuclease mapping and Northern blotting, hydrolase B is expressed in both rat liver and kidney, whereas hydrolase C is expressed predominantly, perhaps exclusively, in liver. When expressed in Escherichia coli, hydrolase C was catalytically inactive and unstable, but when expressed in the baculovirus/Sf21 cell system hydrolase C it was stable and catalytically active toward 1-naphthylacetate and esters of para-nitrophenol. Hydrolase C is the fourth member of the rat carboxylesterase family to be cloned and sequenced. In terms of nucleotide and deduced amino acid sequence, hydrolase C is highly similar to hydrolase B, but differs from hydrolase B in terms of its catalytic activity and tissue distribution. Recombinant hydrolase C has properties similar to those described for esterase RL2, which was purified from rat liver microsomes by Hosokawa et al. (Arch. Biochem. Biophys. 277, 219-227, 1990), although additional studies will be required to establish conclusively the identity of this enzyme. The high degree of sequence identity (96%) between hydrolase B and C, particularly in the 3' untranslated region, suggests that the genes encoding these two carboxylesterases evolved by duplication and divergence of a common ancestral gene. Title: Rat serum carboxylesterase. Cloning, expression, regulation, and evidence of secretion from liver Yan B, Yang D, Bullock P, Parkinson A Ref: Journal of Biological Chemistry, 270:19128, 1995 : PubMed ESTHER: Yan_1995_J.Biol.Chem_270_19128 PubMedSearch: Yan 1995 J.Biol.Chem 270 19128 PubMedID: 7642579 Gene_locus related to this paper: human-CES1 Abstract Multiple forms of carboxylesterase have been identified in rat liver, and five carboxylesterases (designated hydrolases A, B, C, S, and egasyn) have been cloned. Hydrolases A, B, C, and egasyn all have a C-terminal consensus sequence (HXEL) for retaining proteins in the endoplasmic reticulum, and these carboxylesterases are found in rat liver microsomes. In contrast, hydrolase S lacks this C-terminal consensus sequence and is presumed to be secreted. In order to test this hypothesis, a polyclonal antibody was raised against recombinant hydrolase S from cDNA-directed expression in Escherichia coli. In addition to hydrolases A, B, and C (57-59 kDa), this antibody recognized a 67-kDa protein in rat liver microsomes and a 71-kDa protein in rat serum. The 71-kDa protein detected in rat serum was also detected in the extracellular medium from primary cultures of rat hepatocytes. Non-denaturing gel electrophoresis with staining for esterase activity showed that a serum carboxylesterase comigrated with the 71-kDa protein. Immunoprecipitation of the 71-kDa enzyme from rat serum decreased esterase activity toward 1-naphthylacetate and para-nitrophenylacetate. The 71-kDa protein immunoprecipitated from rat serum had an N-terminal amino acid sequence identical to that predicted from the cDNA encoding hydrolase S, providing further evidence that hydrolase S is synthesized in and secreted by the liver. The levels of the 67-kDa protein in rat liver microsomes and the levels of the 71-kDa protein in rat serum were co-regulated. Deglycosylation of microsomes and serum converted the 67- and 71-kDa proteins to a 58-kDa peptide, which matches the molecular mass calculated from the cDNA for hydrolase S. These results suggest that the 67-kDa protein in liver microsomes is a precursor form of hydrolase S that undergoes further glycosylation before being secreted into serum. In rats, liver appears to be the only source of hydrolase S because no mRNA encoding hydrolase S could be detected in several extrahepatic tissues. Serum carboxylesterases have been found to play an important role in lipid metabolism and detoxication of organophosphates, therefore, the secretion of hydrolase S and the modulation of its expression by xenobiotics may have physiological as well as toxicological significance. Title: Rat kidney carboxylesterase. Cloning, sequencing, cellular localization, and relationship to rat liver hydrolase Yan B, Yang D, Brady M, Parkinson A Ref: Journal of Biological Chemistry, 269:29688, 1994 : PubMed ESTHER: Yan_1994_J.Biol.Chem_269_29688 PubMedSearch: Yan 1994 J.Biol.Chem 269 29688 PubMedID: 7961958 Gene_locus related to this paper: ratno-kmcxe, ratno-lmcxe Abstract We recently purified from rat liver microsomes a carboxylesterase, designated hydrolase B, that catalyzes the hydrolysis of para-nitrophenylacetate with low affinity (Km approximately 400 microM) and is relatively insensitive to the inhibitory effects of phenylmethylsulfonyl fluoride. A carboxylesterase with identical properties is also present in rat kidney microsomes, at levels comparable to those in liver microsomes. The kidney enzyme is immunochemically indistinguishable from hydrolase B by Western immunoblotting and Ouchterlony double diffusion analysis. This study describes the cloning and sequencing of hydrolase B. A 1809-base pair (bp) cDNA was isolated from a rat kidney cDNA library screened with antibody against hydrolase B. Screening the same cDNA library by two-step polymerase chain reaction with external and internal primers based on the sequence of the 1809-bp cDNA and a primer based on the sequence of the adjoining lambda gt11 arm yielded a 279-bp cDNA that overlapped by 179 bp with the 1809-bp-sequence. Together these two cDNAs spanned a 1909-bp sequence with an opening reading frame encoding 561 amino acids, which includes all 543 amino acid residues in the mature protein plus an 18-amino acid signal peptide at the N terminus. The mature protein encoded by this kidney cDNA matches perfectly the N-terminal amino acid sequence of purified hydrolase B for 30 amino acid residues, as determined by automated Edman degradation. The mature protein contains 5 cysteine residues, two potential N-linked glycosylation sites, and a C-terminal tetrapeptide (His-Asn-Glu-Leu) that matches the HXEL consensus sequence for retaining proteins in the lumen of the endoplasmic reticulum. Based on alignment of conserved amino acid sequences in several mammalian carboxylesterases, and based on the mechanism of catalysis of serine proteases, the catalytic triad in hydrolase B is apparently composed of the nucleophile Ser203, the basic amino acid His448, and the acidic amino acid Asp97 or Glu228. Northern blots probed with the 1809-bp cDNA identified high levels of a approximately 2-kilobase mRNA for hydrolase B in liver and kidney. Little or no mRNA for hydrolase B was detected in testis, lung, prostate, brain, and heart, which confirms the tissue distribution of hydrolase B based on catalytic activity and Western immunoblotting. Immunocytochemical studies established that hydrolase B is localized in the centrilobular region of the liver and in the proximal tubules of the kidney, where it presumably plays a role in the metabolism of xenobiotics and possibly endogenous lipids, although a precise physiological role for hydrolase B remains to be determined. | |||||||
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