Title: Construction of Fusion Protein with Carbohydrate-Binding Module and Leaf-Branch Compost Cutinase to Enhance the Degradation Efficiency of Polyethylene Terephthalate Chen Y, Zhang S, Zhai Z, Ma J, Liang X, Li Q Ref: Int J Mol Sci, 24:2780, 2023 : PubMed
Poly(ethylene terephthalate) (PET) is a manufactured plastic broadly available, whereas improper disposal of PET waste has become a serious burden on the environment. Leaf-branch compost cutinase (LCC) is one of the most powerful and promising PET hydrolases, and its mutant LCC(ICCG) shows high catalytic activity and excellent thermal stability. However, low binding affinity with PET has been found to dramatically limit its further industrial application. Herein, TrCBM and CfCBM were rationally selected from the CAZy database to construct fusion proteins with LCC(ICCG), and mechanistic studies revealed that these two domains could bind with PET favorably via polar amino acids. The optimal temperatures of LCC(ICCG)-TrCBM and CfCBM-LCC(ICCG) were measured to be 70 and 80 degreesC, respectively. Moreover, these two fusion proteins exhibited favorable thermal stability, maintaining 53.1% and 48.8% of initial activity after the incubation at 90 degreesC for 300 min. Compared with LCC(ICCG), the binding affinity of LCC(ICCG)-TrCBM and CfCBM-LCC(ICCG) for PET has been improved by 1.4- and 1.3-fold, respectively, and meanwhile their degradation efficiency on PET films was enhanced by 3.7% and 24.2%. Overall, this study demonstrated that the strategy of constructing fusion proteins is practical and prospective to facilitate the enzymatic PET degradation ability.
Title: Lactobacillus plantarum HF02 alleviates lipid accumulation and intestinal microbiota dysbiosis in high-fat diet-induced obese mice Chen H, Zhao H, Qi X, Sun Y, Li Q, Ma Y Ref: J Sci Food Agric, :, 2023 : PubMed
BACKGROUND: Obesity is closely associated with lipid accumulation and intestinal microbiota dysbiosis. It has been proved that probiotics supplement contributes to alleviate obesity. The objective of this study was to investigate the mechanism by which Lactobacillus plantarum HF02 (LP-HF02) alleviated lipid accumulation and intestinal microbiota dysbiosis in high-fat diet (HFD)-induced obese mice. RESULTS: Our results showed that LP-HF02 ameliorated body weight, dyslipidemia, liver lipid accumulation, and liver injury in obese mice. As expected, LP-HF02 inhibited pancreatic lipase activity in small intestinal contents and increased fecal triglyceride levels, thereby reducing dietary fat hydrolysis and absorption. Moreover, LP-HF02 ameliorated the intestinal microbiota composition, as evidenced by enhanced the ratio of Bacteroides to Firmicutes, decreased the abundance of pathogenic bacteria (including Bacteroides, Alistipes, Blautia, and Colidextribacter) and increased the abundance of beneficial bacteria (including Muribaculaceae, Akkermansia, Faecalibaculum, and Rikenellaceae_RC9_gut_group). LP-HF02 also increased fecal short-chain fatty acids (SCFAs) levels and colonic mucosal thickness, and subsequently decreased serum lipopolysaccharide (LPS), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha) levels in obese mice. Additionally, RT-qPCR and western blot results demonstrated that LP-HF02 ameliorated hepatic lipid accumulation via activating the AMP-activated protein kinase (AMPK) pathway. CONCLUSION: Therefore, our results indicated that LP-HF02 could be considered as a probiotic preparation for preventing obesity. This article is protected by copyright. All rights reserved.
Title: Preparation of an HI-6-loaded brain-targeted liposomes based on the nasal delivery route and the evaluation of its reactivation of central toxic acetylcholinesterase Fan N, Li Q, Liu Y, Ma B, Li M, Yin D Ref: Eur J Pharm Sci, :106406, 2023 : PubMed
PURPOSE: Organophosphorus compounds (OPs) is a serious threat to human health and life safety, but because of the existence of blood-brain barrier, most of the therapeutic drugs can not enter the center, reactivate centrally located toxic acetylcholinesterase (AChE), it is urgent to find an efficient treatment method. METHODS: The c(RGDyK) cyclic peptide modified HI-6-loaded brain targeting liposomes [c(RGDyK)-PEG(2000)-HI-6-lipo] were prepared by ammonium sulfate gradient method. The in vitro blood-brain barrier (BBB) model was established, and the function of the liposomes was evaluated. The animal model of DDVP poisoning was established, and the central toxic enzyme reactivation ability of c(RGDyK)-PEG(2000)-HI-6-lipo by both the intravenous and nasal administration route was verified. RESULTS: The HI-6-loaded liposomes with brain targeting function were successfully synthesized and prepared with high encapsulation efficiency (70.23 +/- 2.18%), drug loading (2.86 +/- 0.07)%, average particle size 242.9 nm (polydispersion index 0.149), and potential -16.2 mV. Combined with the in vitro and in vivo studies, the c(RGDyK)-PEG(2000)-HI-6-lipo has better ability to cross the BBB. In addition, compared with intravenous injection, nasal administration was proved to be more effective against organophosphorus poisoning, and the reactivation rate of brain acetylcholinesterase reached (26.19 +/- 7.70)%. CONCLUSION: The prepared c(RGDyK)-PEG(2000)-HI-6-lipo has a better ability to cross BBB. Nasal administration, as a way to bypass the BBB and directly deliver drugs into the brain, effectively improves the bioavailability of HI-6 in the brain. This study holds promise by providing a non-invasive approach to deliver water-soluble oxime antidote into the brain and reactivate central acetylcholinesterase via the naso-brain route.
Title: The kinetic and molecular docking analysis of interactions between three V-type nerve agents and four human cholinesterases Li K, Liu Y, Li Q, Guo L, Xie J Ref: Chemico-Biological Interactions, 372:110369, 2023 : PubMed
G and V-type nerve agents represent the most toxic chemical warfare agents. Their primary toxicity was the consequence of the covalent inhibition of the pivotal acetylcholinesterase (AChE), which induces overstimulation of cholinergic receptors and overaccumulation of cholines, eventually leading to death by respiratory arrest. The inhibitory and reactivation kinetics of cholinesterase (ChE) are essential for the toxicology and countermeasures of nerve agents. Medical defensive research on V-type nerve agents (V agents) has been mainly reported on VX and VR. Here we demonstrated the first systematical kinetic analysis between the type of ChE [native or recombinant human AChE and butyrylcholinesterase (BChE)] and three V agents, including VX, VR, and Vs, another isomer of VX, and highlighted the effects of native and recombinant ChE differences. The spontaneous reactivation and aging kinetics data of Vs-inhibited BChEs were firstly reported here. The results showed that AChE was more easily inhibited by three V agent compared to BChE, regardless of whether it is native or recombinant. The increased inhibitory potency order on AChE was VX, Vs, then VR, and on BChE was VX, then Vs and VR. The difference between native and recombinant ChE could influence the inhibition, aging, and spontaneous reactivation kinetics of three V agents, whether AChE or BChE, which was systematically revealed for the first time. For inhibition kinetics, the k(i) of three V agents for recombinant AChE was significantly higher than native AChE, and the stronger the inhibitory potency of V agents, the more pronounced difference in k(i). In terms of aging and spontaneous reactivation kinetics, recombinant ChE was found to be more prone to spontaneous reactivation, but more resistant to aging compared to native ChE, particularly for AChE. The performed covalent molecular docking results partially explained the effects of differences between native and recombinant ChE on enzyme kinetics from the perspective of binding energy and conformation.
INTRODUCTION: Poly (ethylene terephthalate) (PET) is one of the most abundant polyester materials used in daily life and it is also one of the main culprits of environmental pollution. ICCG (F243I/D238C/S283C/Y127G) is enzyme with four modifications of leaf-branch compost cutinase (LCC) that display outstanding performance in hydrolyzing PET and hold a great potential in further applications. METHOD: Here, we used ICCG to degrade PET particles of various sizes and use the density of attack sites (attack) and kinetic parameters to evaluate the effect of particle size on enzyme degradation efficiency. We are surprised to observe that there is a certain relationship between Km and attack. In order to further confirm the relationship, we obtained three different enzymes (Y95K, M166S and H218S) by site-directed mutagenesis on the basis of ICCG. RESULT: The results confirmed that there was a negative correlation between Km and attack. In addition, we also found that increasing the affinity between the enzyme and the substrate does not necessarily lead to the increase of degradation rate. CONCLUSION: These findings show that the granulation of PET and the selection of appropriate particle size are helpful to improve its industrial application value. At the same time, additional protein engineering to increase ICCG performance is realistic, but it can't be limited to enhance the affinity between enzyme and substrate.
Title: Development of Long-Acting Dipeptidyl Peptidase-4 Inhibitors: Structural Evolution and Long-Acting Determinants Li Q, Deng X, Xu YJ, Dong L Ref: Journal of Medicinal Chemistry, :, 2023 : PubMed
Considerable effort has been made to achieve less frequent dosing in the development of DPP-4 inhibitors. Enthusiasm for long-acting DPP-4 inhibitors is based on the promise that such agents with less frequent dosing regimens are associated with improved patient adherence, but the rational design of long-acting DPP-4 inhibitors remains a major challenge. In this Perspective, the development of long-acting DPP-4 inhibitors is comprehensively summarized to highlight the evolution of initial lead compounds on the path toward developing long-acting DPP-4 inhibitors over nearly three decades. The determinants for long duration of action are then examined, including the nature of the target, potency, binding kinetics, crystal structures, selectivity, and preclinical and clinical pharmacokinetic and pharmacodynamic profiles. More importantly, several possible approaches for the rational design of long-acting drugs are discussed. We hope that this information will facilitate the design and development of safer and more effective long-acting DPP-4 inhibitors and other oral drugs.
Title: Insecticidal potential of a Consolida ajacis extract and its major compound (ethyl linoleate) against the diamondback moth, Plutella xylostella Peng J, Chen Z, Chen X, Zheng R, Lu S, Seyab M, Yang F, Li Q, Tang Q Ref: Pestic Biochem Physiol, 195:105557, 2023 : PubMed
The diamondback moth (Plutella xylostella) is one of the most destructive lepidopteran pests of cruciferous vegetables. However, DBM has developed resistance to current chemical and biological insecticides used for its control, indicating the necessity for finding new insecticides against it. Bio-insecticides derived from plant extracts are eco-friendly alternatives to synthetic pesticides. The aims of this study were to evaluate the insecticidal activity of Consolida ajacis seed extracts against DBM, the underlying mechanism of the control effect of promising extracts, and the identification of the main insecticidal compounds of these extracts. The results showed that ethyl acetate extract of C. ajacis seed exhibited strong contact toxicity (LC(50): 5.05 mg/mL), ingestion toxicity, antifeedant, and oviposition deterrent activities against DBM, among the extracts evaluated. At 72 h, glutathiase, acetylcholinesterase, carboxylesterase, peroxidase, and superoxide dismutase activities were inhibited, but catalase activity was activated. The main compound identified from the extract was ethyl linoleate, which had the most significant insecticidal activity on the diamondback moths. This study's findings provide a better understanding of the insecticidal activity of ethyl acetate extract obtained from C. ajacis and its main component (ethyl linoleate). This will help in the development of new insecticides to control DBM.
Title: Reusable carboxylesterase immobilized in ZIF for efficient degradation of chlorpyrifos in enviromental water Wang B, Chen J, Wu S, Fang J, Li Q, Wang G Ref: Pestic Biochem Physiol, 194:105519, 2023 : PubMed
The past few decades have witnessed biodegradation of pesticides as a significant method in remediation of the environment for its specificity, efficiency and biocompatibility. However, the tolerability and recyclability of the enzymes in pesticide degradation and the development of enzymes that biodegrad pesticides are still urgent problems to be solved so far. Herein, a novel hyper-thermostable and chlorpyrifos-hydrolyzing carboxylesterase EstC was immobilized by biomineralization using zeolitic imidazolate framework (ZIF), one of the metal-organic frameworks (MOFs) with highly diverse structure and porosity. Compared with free enzyme, EstC@ZIF with a cruciate flower-like morphology presented scarcely variation in catalytic efficiency and generally improved the tolerance to organic solvents or detergents. Furthermore, there was scarcely decrease in the catalytic efficiency of EstC@ZIF and it also showed good reusability with about 50% residual activity after 12 continuous uses. Notably, EstC@ZIF could be used in actual water environment with an excellent value of degradation rate of 90.27% in 120 min, and the degradation efficiency remained about 50% after 9 repetitions. The present strategy of immobilizing carboxylesterase to treat pesticide-contaminated water broadens the method of immobilized enzymes on MOFs, and envisions its recyclable applicability in globe environmental remediation.
A novel dual-signal fluorescent sensor was developed for detecting organophosphorus pesticides (OPs). It relies on the catalytic activities of acetylcholinesterase (AChE) and choline oxidase (ChOx) to generate hydrogen peroxide (H(2)O(2)) through the conversion of acetylcholine (ACh) to choline.H(2)O(2) then oxidizes ferrocene-modified tetraphenylethylene (TPE-Fc) to its oxidized state (TPE-Fc(+)), resulting in enhanced cyan fluorescence due to aggregation. Simultaneously, ferrocene oxidation generates hydroxyl radicals (OH), causing a decrease in orange fluorescence of glutathione-synthesized gold nanoclusters (GSH-AuNCs). The presence of OPs restricts AChE activity, reducing H(2)O(2) production. Increasing OPs concentration leads to decreased cyan fluorescence and increased orange fluorescence, enabling visual OPs detection. The sensor has a linear dynamic range of 10-2000 ng/mL with a detection limit of 2.05 ng/mL. Smartphone-based color identification and a WeChat mini program were utilized for rapid OPs analysis with successful outcomes.
INTRODUCTION: Mutations of CEL gene were first reported to cause a new type of maturity-onset diabetes of the young (MODY) denoted as MODY8 and then were also found in patients with type 1 (T1D) and type 2 diabetes (T2D). However, its genotype-phenotype relationship has not been fully determined and how carboxyl ester lipase (CEL) variants result in diabetes remains unclear. The aim of our study was to identify pathogenic variants of CEL in patients with diabetes and confirm their pathogenicity. RESEARCH DESIGN AND METHODS: All five patients enrolled in our study were admitted to Shandong Provincial Hospital and diagnosed with diabetes in the past year. Whole-exome sequencing was performed to identify pathogenic variants in three patients with MODY-like diabetes, one newborn baby with T1D and one patient with atypical T2D, as well as their immediate family members. Then the consequences of the identified variants were predicted by bioinformatic analysis. Furthermore, pathogenic effects of two novel CEL variants were evaluated in HEK293 cells transfected with wild-type and mutant plasmids. Finally, we summarized all CEL gene variants recorded in Human Gene Mutation Database and analyzed the mutation distribution of CEL. RESULTS: Five novel heterozygous variants were identified in CEL gene and they were predicted to be pathogenic by bioinformatic analysis. Moreover, in vitro studies indicated that the expression of CEL(R540C) was remarkably increased, while p.G729_T739del variant did not significantly affect the expression of CEL. Both novel variants obviously abrogated the secretion of CEL. Furthermore, we summarized all reported CEL variants and found that 74.3% of missense mutations were located in exons 1, 3, 4, 10 and 11 and most missense variants clustered near catalytic triad, Arg-83 and Arg-443. CONCLUSION: Our study identified five novel CEL variants in patients with different subtypes of diabetes, expanding the gene mutation spectrum of CEL and confirmed the pathogenicity of several novel variants.
Two parallel pathways compartmentalized in the chloroplast and the endoplasmic reticulum (ER) contribute to thylakoid lipid synthesis in plants, but how these two pathways are coordinated during thylakoid biogenesis and remodeling remain unknown. We report here the molecular characterization of a homologous ADIPOSE TRIGLYCERIDE LIPASE-LIKE gene, previously referred to as ATGLL. The ATGLL gene is ubiquitously expressed throughout development and rapidly upregulated in response to a wide range of environmental cues. We show that ATGLL is a chloroplast non-regioselective lipase with a hydrolytic activity preferentially towards 16:0 of diacylglycerol (DAG). Comprehensive lipid profiling and radiotracer labeling studies revealed negative correlation of ATGLL expression and the relative contribution of the chloroplast lipid pathway to thylakoid lipid biosynthesis. Additionally, we show that genetic manipulation of ATGLL expression resulted in changes in triacylglycerol levels in leaves. We propose that ATGLL, through affecting the level of prokaryotic DAG in the chloroplast, plays important roles in balancing the two glycerolipid pathways and in maintaining lipid homeostasis in plants.
Title: Improving efficiency and reducing enzyme inactivation during lipase-mediated epoxidation of alpha-pinene in a double-phase reaction system Yu L, Zou C, Li Q, Liu Z, Liu Y, Tang A Ref: Bioprocess Biosyst Eng, :, 2023 : PubMed
Chemoenzymatic epoxidation of olefin mediated by lipase is a green and environmentally friendly alternative process. However, the mass transfer barrier and lipase deactivation caused by the traditional organic-water biphasic reaction system have always been the focus of researchers' attention. To overcome these issues, we investigated the effects of reaction temperature and two important substrates (H(2)O(2) and acyl donor) on the epoxidation reaction and interfacial mass transfer. As a result, we determined the optimal reaction conditions: a temperature of 30 degreesC, 30 wt-% H(2)O(2) as the oxygen source, and 1 M lauric acid as the oxygen carrier. Additionally, by simulating the conditions of shaking flask reactions, we designed a batch reactor and added a metal mesh to effectively block the direct contact between high-concentration hydrogen peroxide and the enzyme. Under these optimal conditions, the epoxidation reaction was carried out for 5 h, and the product yield reached a maximum of 93.2%. Furthermore, after seven repetitive experiments, the lipase still maintained a relative activity of 51.2%.
Title: Near-infrared ratiometric fluorescent strategy for butyrylcholinesterase activity and its application in the detection of pesticide residue in food samples and biological imaging Yuan W, Wan C, Zhang J, Li Q, Zhang P, Zheng K, Zhang Q, Ding C Ref: Spectrochim Acta A Mol Biomol Spectrosc, 297:122719, 2023 : PubMed
Butyrylcholinesterase (BChE) is an essential esterase synthesized by the liver, and its level is considered as a vital index for health evaluation. Therefore, it is of great need to develop a highly sensitive and selective tool to monitor BChE activity, which remains a considerable challenge on account of its usage in complex biological systems. A near-infrared (NIR) fluorescent probe was elaborated in this work, employing cyanine backbone to provide the intrinsic NIR fluorescence and avoid interference from bioluminescence. There presented an intriguing structural transformation upon the sensing event to shrink the conjugation in this protocol, leading to an eye-catching fluorescence change from NIR (816 nm) to red (637 nm) region, which gave rise to the proposed ratiometric assay. After an overall investigation, this receptor was verified to be applicable in a wide bio-area with ratiometric pattern, including the cellular level and slice platform. It was worth mentioning that this receptor was also discovered to be capable of monitoring pesticide dichlorvos (DDVP) residue in food samples with high sensitivity and accuracy, with significant potential to be developed as an alternative candidate for monitoring environmental pollution.
Title: Construction of a QSAR Model Based on Flavonoids and Screening of Natural Pancreatic Lipase Inhibitors Yuan Y, Pan F, Zhu Z, Yang Z, Wang O, Li Q, Zhao L Ref: Nutrients, 15:, 2023 : PubMed
Pancreatic lipase (PL) is a key hydrolase in lipid metabolism. Inhibition of PL activity can intervene in obesity, a global sub-health disease. The natural product is considered a good alternative to chemically synthesized drugs due to its advantages, such as low side effects. However, traditional experimental screening methods are labor-intensive and cost-consuming, and there is an urgent need to develop high-throughput screening methods for the discovery of anti-PL natural products. In this study, a high-throughput virtual screening process for anti-PL natural products is provided. Firstly, a predictable anti-PL natural product QSAR model (R(2)(train) = 0.9444, R(2)(test) = 0.8962) were developed using the artificial intelligence drug design software MolAIcal based on genetic algorithms and their conformational relationships. 1068 highly similar (FS > 0.8) natural products were rapidly enriched based on the structure-activity similarity principle, combined with the QSAR model and the ADMET model, for rapid prediction of a total of five potentially efficient anti-PL natural products (IC(50pre) < 2 microM). Subsequently, molecular docking, molecular dynamics simulation, and MMGBSA free energy calculation were performed to not only reveal the interaction of candidate novel natural products with the amino acid residues of PL but also to validate the stability of these novel natural compounds bound to PL. In conclusion, this study greatly simplifies the screening and discovery of anti-PL natural products and accelerates the development of novel anti-obesity functional foods.
Title: Utilization of the By-Product of Corn: Guided Identification of Bioactive Terpenoids from Stigma Maydis (Corn Silk) Zhou WY, Niu JQ, Li Q, Du NN, Li JY, Lin B, Yao GD, Huang XX, Song SJ Ref: Journal of Agricultural and Food Chemistry, :, 2023 : PubMed
Stigma maydis (corn silk) (S. maydis) is a food-based by-product of maize and possesses great nutritional and pharmaceutical value. This study aimed to explore bioactive components from S. maydis. By the guidance of bioactivity-guided approach and Global Natural Products Social (GNPS) molecular networking, 12 terpenoids were discovered from S. maydis. The structures of 11 undescribed compounds (1-11) were determined by detailed spectroscopic analyses, single-crystal X-ray diffraction analysis, specific rotation calculations, electronic circular dichroism (ECD) calculations, and NMR calculations. The neuroprotective and acetylcholinesterase (AChE) inhibitory effects of 1-12 were examined, and most of them showed significant or moderate activities. The underlying neuroprotective mechanism of 4 and 5 was revealed by Hoechst 33258, AO-EB, and JC-1 staining assays. This work illustrated the potential of S. maydis as a prospective natural source of bioactive compounds in food and pharmaceutical industries.
Title: Preparation and characterization of immobilized 5-HT(1A) receptor stationary phase for high throughput screening of the receptor-binding ligands from complex systems like Curcuma wenyujin Y. H. Chen et C. Ling extract Chen YY, Jin YH, Shayiranbieke A, Zhao X, Fan HS, Li Q, Zhao XF Ref: J Pharm Biomed Anal, 211:114632, 2022 : PubMed
The incidence of depression has increased significantly during the COVID-19 pandemic. This disease is closely associated with serotonin (1A) (5-HT(1A)) receptor and often treated by complex prescription containing Curcuma wenyujin Y. H. Chen et C. Ling. Therefore, we hypothesized that this herb contains bioactive compounds specially binding to the receptor. However, the rapid discovery of new ligands of 5-HT(1A) receptor is still challenging due to the lack of efficient screening methods. To address this problem, we developed and characterized a novel approach for the rapid screening of ligands by using immobilized 5-HT(1A) receptor as the chromatographic stationary phase. Briefly, haloalkane dehalogenase was fused at the C-terminal of 5-HT(1A) receptor, and the modified 5-HT(1A) receptor was immobilized on amino-microspheres by the reaction between haloalkane dehalogenase and 6-chlorohexanoic acid linker. Scanning electron microscope and X-ray photo-electron were used to characterize the morphology and element of the immobilized receptor. The binding of three specific ligands to 5-HT(1A) receptor was investigated by two different methods. Moreover, we examined the feasibility of 5-HT(1A) receptor colume in high throughput screening of new ligands from complex systems as exemplified by Curcuma wenyujin Y. H. Chen et C. Ling. Gweicurculactone, 2-hydroxy-1-(3,4-dihydroxybenzene)-7-(4'-hydroxybezene)-heptane and curcuminol F were identified as the ligands of 5-HT(1A) receptor with the binding energies of -7.06 kcal/mol, -7.77 kcal/mol and -5.26 kcal/mol, respectively. Collectively, these results indicated that the immobilized 5-HT(1A) receptor was capable of screening bioactive compound from complex system, providing an effective methodology for high throughput screening.
Herein, we report a series of selective sub-nanomolar inhibitors against butyrylcholinesterase (BChE). These compounds, bearing a novel N-benzyl benzamide scaffold, inhibited BChE with IC(50) from picomolar to nanomolar. The inhibitory activity was confirmed by the surface plasmon resonance assay, showing a sub-nanomolar K(D) value, which revealed that the compounds exert the inhibitory effect through directly binding to BChE. Several compounds showed neuroprotective effects verified by the oxidative damage model. Furthermore, the safety of S11-1014 and S11-1033 was demonstrated by the in vivo acute toxicity test. In the behavior study, 0.5 mg/kg S11-1014 or S11-1033 exhibited a marked therapeutic effect, which was almost equal to the treatment with 1 mg/kg rivastigmine, against the cognitive impairment induced by Abeta(1-42). The pharmacokinetics studies characterized the metabolic stability of S11-1014. Thus, N-benzyl benzamide inhibitors are promising compounds with drug-like properties for improving cognitive dysfunction, providing a potential strategy for the treatment of Alzheimer's disease.
Title: Plasma exchange therapy for familial chylomicronemia syndrome in infant: A case report Han L, Qiang G, Yang L, Kou R, Li Q, Xin M, Liu R, Zhang Z Ref: Medicine (Baltimore), 101:e29689, 2022 : PubMed
INTRODUCTION: Familial chylomicronemia syndrome (FCS) is a rare genetic disease. FCS usually manifests by the age of 10 years, and 25% of cases of FCS occur during infancy. Here we present a case of FCS in a male infant and summarize our experiences on the diagnosis and therapy of this case. PATIENT CONCERNS: A male infant aged 1 month and 8 days had recurrent hematochezia and hyperchylomicronemia. DIAGNOSIS: FCS based on symptoms and genetic test. INTERVENTIONS: Plasma exchange therapy. OUTCOMES: His development was normal with a good spirit and satisfactory weight gain, and no hematochezia occurred again. CONCLUSION: Genetic test is important for accurate diagnosis of FCS, and we identified a new mutation of lipoprotein lipase gene c.88C>A which conformed to autosomal recessive inheritance. Plasma exchange therapy can be applied to infants with FCS with low risk and good outcomes.
BACKGROUND: A critical and controversial issue is whether antiviral therapy should be recommended in chronic hepatitis B virus (HBV) infection patients with persistently normal alanine aminotransferase (PNALT) and detectable HBV DNA. The study aimed to develop a non-invasive model for predicting significant liver histological changes (SLHC), which is the histological indication for antiviral therapy in chronic hepatitis B (CHB) patients with PNALT and detectable HBV DNA. METHODS: 398 chronic HBV infection patients with PNALT and detectable HBV DNA who underwent liver biopsy were divided into the estimation set (n = 256) and validation set (n = 142). A multivariate logistic regression model was developed to predict SLHC in the estimation set, and the diagnostic performance was further validated in the validation set. RESULTS: 132 patients (33.2%) with PNALT and detectable HBV DNA had SLHC. Aspartate aminotransferase (AST), cholinesterase (ChE), and liver stiffness measurement (LSM) were identified as the independent predictors of SLHC. The AUROC of the SLHC index, which combined AST, ChE, and LSM, was 0.824 and 0.816 in the estimation and validation set, respectively, for the prediction of SLHC. Applying the SLHC index >= 0.15, the presence of SLHC could be excluded with high negative predictive value in the estimation set (93.2%) and in the validation set (90.2%). Applying the SLHC index <= 0.55, the presence of SLHC could be considered with high positive predictive value in the estimation set (79.2%) and in the validation set (76.5%). CONCLUSION: The SLHC index provides a high accuracy in predicting liver histological indication for antiviral therapy in CHB patients with PNALT and detectable HBV DNA.
Title: Computational design of a cutinase for plastic biodegradation by mining molecular dynamics simulations trajectories Li Q, Zheng Y, Su T, Wang Q, Liang Q, Zhang Z, Qi Q, Tian J Ref: Comput Struct Biotechnol J, 20:459, 2022 : PubMed
Polyethylene terephthalate (PET) has caused serious environmental concerns but could be degraded at high temperature. Previous studies show that cutinase from Thermobifida fusca KW3 (TfCut2) is capable of degrading and upcycling PET but is limited by its thermal stability. Nowadays, Popular protein stability modification methods rely mostly on the crystal structures, but ignore the fact that the actual conformation of protein is complex and constantly changing. To solve these problems, we developed a computational approach to design variants with enhanced protein thermal stability by mining Molecular Dynamics simulation trajectories using Machine Learning methods (MDL). The optimal classification accuracy and the optimal Pearson correlation coefficient of MDL model were 0.780 and 0.716, respectively. And we successfully designed variants with high deltaT (m) values using MDL method. The optimal variant S121P/D174S/D204P had the highest deltaT (m) value of 9.3 degreesC, and the PET degradation ratio increased by 46.42-fold at 70 degC, compared with that of wild type TfCut2. These results deepen our understanding on the complex conformations of proteins and may enhance the plastic recycling and sustainability at glass transition temperature.
Title: Redox-regulated synthesis of fluorescent polydopamine nanoparticles for detection of butyrylcholinesterase activity Li Q, Guo YM, Li GL Ref: Spectrochim Acta A Mol Biomol Spectrosc, 274:121097, 2022 : PubMed
Butyrylcholinesterase (BChE) is an enzyme which is relevant to a variety of diseases, and often serve as a common biomarker of health. In this work, a novel fluorescence sensor based on redox-regulated synthesis of polydopamine nanoparticles (PDANPs) has been developed for simple and sensitive sensing BChE activity. A facile and rapid one-step approach for the preparation of fluorescent PDANPs uses potassium permanganate to oxidize dopamine. We demonstrated that the fluorescence intensity of PDANPs is dependent on the dose of potassium permanganate. Butyrylcholinesterase catalyzes the hydrolysis of butyrylthiocholine iodide (BTCh) to produce thiolcholine (TCh) which in a redox reaction with potassium permanganate prevents the formation of fluorescent PDANP. As a result, the activity of BChE can be determined in line with changes in the fluorescence of PDANPs. Based on this finding, a convenient and label-free fluorescence sensor for BChE activity was established via redox-control of the fluorescence intensity of PDANPs. A dynamic response range for BChE is acquired within 0.5 - 200 U/L along with a detection limit of 0.047 U/L. Importantly, the proposed method achieves practical application toward BChE in human sera. Moreover, its satisfying performance for screening of inhibitors was also proved. Hence, the proposed sensor holds great potential for cholinesterase-related biomedical investigation.
Butyrylcholinesterase (BChE) has been more and more attractive for treating neurodegenerative diseases, especially Alzheimer's disease (AD). In this study, we conducted activity and druggability optimization based on the structures that were previously reported. Most compounds exhibited pronounced BChE inhibitory capacity with nanomolar IC(50) values. Based on the results of inhibiting activity and cyto-safety evaluations, two compounds (7, eqBChE IC(50) = 2.94 nM, hBChE IC(50) = 34.6 nM, and 20, eqBChE IC(50) = 0.15 nM, hBChE IC(50) = 45.2 nM) have been selected as candidates. High stability of compound 20 contributed to significantly improved blood concentration and tissue exposure, resulting in a reduced administration and effective dose in pharmacodynamic experiments. Two candidates exhibited remarkable neuroprotective properties and cognition improving activity, by benefiting cholinergic system, reducing the total Abeta amount and increasing the ghrelin content. Simultaneous modulation in the center and periphery greatly improves the efficiency of BChE inhibitors. Considering the regulation on ghrelin level, BChE inhibition could improve not only symptoms but also nutritional status of AD patients.
Polyethylene terephthalate (PET) is one of the most abundantly produced synthetic polyesters. The vast number of waste plastics including PET has challenged the waste management sector while also posing a serious threat to the environment due to improper littering. Recently, enzymatic PET degradation has been shown to be a viable option for a circular plastic economy, which can mitigate the plastic pollution. While protein engineering studies on specific PET degradation enzymes such as leaf-branch compost cutinase (LCC), Thermobifida sp. cutinases and Ideonella sakaiensis PETase (IsPETase) have been extensively published, other homologous PET degrading enzymes have received less attention. Ple629 is a polyester hydrolase identified from marine microbial consortium having activity on PET and the bioplastic polybutylene adipate terephthalate (PBAT). In order to explore its catalytic mechanism and improve its potential for PET hydrolysis, we solved its crystal structure in complex with a PET monomer analogue, and validated its structural and mechanistic similarity to known PET hydrolases. By structural comparisons, we identified some hot spot positions described in previous research on protein engineering of PET hydrolases. We substitute these amino acid residues in Ple629, and obtained variants with improved activity and thermo-stability. The most promising variant D226A/S279A exhibited a more than 5.5-fold improved activity on PET nanoparticles than the wild-type enzyme, suggesting its potential applicability in the biotechnological plastic recycling.
The effects of the phytohormone strigolactone (SL) and smoke-derived karrikins (KARs) on plants are generally distinct, despite the fact that they are perceived through very similar mechanisms. The homologous receptors DWARF14 (D14) and KARRIKIN-INSENSITIVE2 (KAI2), together with the F-box protein MORE AXILLARY GROWTH2 (MAX2), mediate SL and KAR responses, respectively, by targeting different SMAX1-LIKE (SMXL) family proteins for degradation. These mechanisms are putatively well-insulated, with D14-MAX2 targeting SMXL6, SMXL7, and SMXL8sand KAI2-MAX2 targeting SMAX1 and SMXL2 in Arabidopsis thaliana. Recent evidence challenges this model. We investigated whether D14 can target SMAX1 and whether this occurs naturally. Genetic analysis indicates that the SL analog GR24 promotes D14-SMAX1 crosstalk. Although D14 shows weaker interactions with SMAX1 than with SMXL2 or SMXL7, D14 mediates GR24-induced degradation of SMAX1 in plants. Osmotic stress triggers SMAX1 degradation, which is protective, through SL biosynthesis and signaling genes. Thus, D14-SMAX1 crosstalk may be beneficial and not simply a vestige of the evolution of the SL pathway.
Plastic waste is rapidly accumulating in the environment and becoming a huge global challenge. Many studies have highlighted the role of microbial metabolic engineering for the valorization of polyethylene terephthalate (PET) waste. In this study, we proposed a new conceptual scheme for upcycling of PET. We constructed a multifunctional Pseudomonas putida KT2440 to simultaneously secrete PET hydrolase LCC, a leaf-branch compost cutinase, and synthesize muconic acid (MA) using the PET hydrolysate. The final product MA and extracellular LCC can be separated from the supernatant of the culture by ultrafiltration, and the latter was used for the next round of PET hydrolysis. A total of 0.50 g MA was produced from 1 g PET in each cycle of the whole biological processes, reaching 68% of the theoretical conversion. This new conceptual scheme for the valorization of PET waste should have advantages over existing PET upcycling schemes and provides new ideas for the utilization of other macromolecular resources that are difficult to decompose, such as lignin.
Title: Characterization of a new chlorimuron-ethyl-degrading strain Cedecea sp. LAM2020 and biodegradation pathway revealed by multiomics analysis Ma Q, Han X, Song J, Wang J, Li Q, Parales RE, Li L, Ruan Z Ref: J Hazard Mater, 443:130197, 2022 : PubMed
The widespread use of the herbicide chlorimuron-methyl is hazard to rotational crops and causes soil degradation problems. Biodegradation is considered a promising way for removing herbicide residues from the environment. Here, a new isolated strain, Cedecea sp. LAM2020, enabled complete degradation of 100 mg/L chlorimuron-methyl within five days. Transcriptome analysis revealed that ABC transporters, atrazine degradation and purine metabolism were enriched in the KEGG pathway. Integrating GO and KEGG classification with related reports, we predict that carboxylesterases are involved in the biodegradation of chlorimuron-methyl by LAM2020. Heterologous expression of the carboxylesterase gene carH showed 26.67% degradation of 50 mg/L chlorimuron-methyl within 6 h. The intracellular potential biological response and extracellular degradation process of chlorimuron-ethyl were analyzed by the nontarget metabolomic and mass spectrometry respectively, and the biodegradation characteristics and complete mineralization pathway was revealed. The cleavage of the sulfonylurea bridge and the ester bond achieved the first step in the degradation of chlorimuron-methyl. Together, these results reveal the presence of acidolysis and enzymatic degradation of chlorimuron-methyl by strain LAM2020. Hydroponic corn experiment showed that the addition of strain LAM2020 alleviated the toxic effects of chlorimuron-ethyl on the plants. Collectively, strain LAM2020 may be a promising microbial agent for plants chlorimuron-ethyl detoxification and soil biofertilizer.
Urinary tract infections are predominantly caused by uropathogenic Escherichia coli (UPEC). UPEC infects bladder epithelial cells (BECs) via fusiform vesicles, escapes into the cytosol to evade exocytosis, and establishes intracellular bacterial communities (IBCs) for the next round of infection. The UPEC vesicle escape mechanism remains unclear. Here we show that UPEC senses host immune responses and initiates escape by upregulating a key phospholipase. The UPEC phospholipase PldA disrupts the vesicle membrane, and pldA expression is activated by phosphate reduction in vesicles. The host phosphate transporter PIT1 is located on the fusiform vesicle membrane, transporting phosphate into the cytosol. UPEC infection upregulates PIT1 via nuclear factor kappaB (NF-kappaB), resulting in phosphate reduction. Silencing PIT1 blocks UPEC vesicle escape in BECs, inhibits IBC formation in mouse bladders, and protects mice from UPEC infection. Our results shed light on pathogenic bacteria responding to intracellular phosphate shortage and tackling host defense and provide insights for development of new therapeutic agents to treat UPEC infection.
Significance: Karrikins are chemicals in smoke that stimulate regrowth of many plants after fire. However, karrikin responses are not limited to species from fire-prone environments and can affect growth after germination. Putatively, this is because karrikins mimic an unknown signal in plants, KAI2 ligand (KL). Karrikins likely require modification in plants to become bioactive. We identify a gene, KUF1, that appears to negatively regulate biosynthesis of KL and metabolism of a specific karrikin. KUF1 expression increases in response to karrikin or KL signaling, thus forming a negative feedback loop that limits further activation of the signaling pathway. This discovery will advance understanding of how karrikins are perceived and how smoke-activated germination evolved. It will also aid identification of the elusive KL.
Inspired by the crucial roles of (hetero)aryl rings in cholinesterase inhibitors and the pyrrole ring in new drug discovery, we synthesized 19 pyrrole derivatives and investigated their cholinesterase inhibitory activity. As a result, compounds 3o, 3p, and 3s with a 1,3-diaryl-pyrrole skeleton showed high selectivity toward BChE over AChE with a best IC(50) value of 1.71 +/- 0.087smicroM, which were comparable to donepezil. The pharmaceutical potential of these structures was further predicted and compounds 3o and 3p were proved to meet well with the Lipinsky's five rules. In combination of the inhibition kinetic studies with the results of molecular docking, we concluded that compound 3p inhibited BChE in a mixed competitive mode. This research has proved the potential of the 1,3-diaryl-pyrrole skeleton as a kind of selective BChE inhibitor.
Title: Substrate-free fluorescence ratiometric detection of serum acetylcholinesterase activity with a self-assembled CsPbBr(3) perovskite nanocrystals/tetraphenylporphyrin tetrasulfonic acid nanocomposite Wang H, Wang J, Li Q, Du J Ref: Talanta, 250:123746, 2022 : PubMed
A dual-emission fluorescent nanoprobe was successfully constructed through self-assembling CsPbBr(3) perovskite nanocrystals (CsPbBr(3) PNCs) and tetraphenylporphyrin tetrasulfonic acid (TPPS). Acetylcholinesterase (AChE) is observed to directly quench the green fluorescence of CsPbBr(3) PNCs at 520 nm in the absence of an enzyme substrate, but has no significant influence on the red emission of TPPS at 650 nm. The decreased value of the fluorescence intensities ratio at 520 to 650 nm (deltaF(520)/F(650)) is proportional to the logarithmic value of AChE activity ranging from 0.05 to 1.0 U/L. The limit of detection is as low as 0.0042 U/L. The relative standard deviation is 3.6% in eleven consecutive measurements of 0.2 U/L AChE. The method exhibits a good anti-interference capacity since it does not respond to most concomitant species. Satisfactory results are acquired for the determination of AChE activity in human serum samples.
Designing of multiple-target directed ligands (MTDLs) has emerged as an attractive strategy for Alzheimer's disease (AD). Fusing the benzylpiperidine motif from AChE inhibitor donepezil and the 1,2,4-oxadiazole core from the Nrf2 activator 25 that was previously reported, we designed and synthesized a series of multifunctional anti-AD hybrids. The optimal hybrid 15a exhibited excellent AChE inhibitory (eeAChE IC(50) = 0.07 +/- 0.01 microM; hAChE IC(50) = 0.38 +/- 0.04 microM) and significant Nrf2 inductivity. It upregulated the protein and transcription level of Nrf2 and its downstream proteins HO-1, NQO1, and GCLM and promoted Nrf2 translocation from cytoplasm into nuclei. Additionally, 15a exhibited important neuroprotective function in protecting the cells from being damaged by H(2)O(2) and Abeta(1-42) aggregation and exerted antioxidant stress and anti-inflammatory activities in reducing the production of ROS and pro-inflammatory cytokines. Moreover, 15a effectively shortened the latency time and escape distance to the target, increased the arrival times, and simplified the tracks in Morris water maze test induced by scopolamine and Abeta(1-42). At the same time, it significantly reduced the levels of proinflammatory factors in the mice model brains. These effects of 15a in improving cognition and alleviating inflammation were even better than the combination of AChE inhibitor and Nrf2 activator, suggesting a remarkable benefit for AD treatment. 15a could serve as a novel hit compound with Nrf2 inductive activity and AChE inhibitory activity for further research.
Title: Sensitive detection of organophosphorus pesticides based on the localized surface plasmon resonance and fluorescence dual-signal readout Wang K, Li Q, Wang Y, Wu Y, Liu Z, Liu S Ref: Anal Chim Acta, 1235:340536, 2022 : PubMed
In this work, a dual-signal visual biosensor was designed for organophosphorus pesticides (OPs) detection using DNA functionalized Ag/Au bimetallic nanoparticles (Ag/Au NPs) as multifunctional nanoprobe. The dual-signal detection strategy was based on the inhibition of enzyme-induced H(2)O(2) generation by OPs in the detection solution containing acetylcholinesterase (AChE), choline oxidase (CHO), acetylcholine (ACh) and nanoprobe. H(2)O(2) produced by enzyme-catalyzed reaction could trigger the etching of Ag and dissociation of carboxyfluorescein (FAM)-labeled aptamer from the nanoprobe, resulting in significant localized surface plasmon resonance (LPRR) and fluorescence (FL) signal responses. In the presence of OPs, AChE activity was inhibited to disrupt the enzymatic generation of H(2)O(2), which allowed to simultaneous quantitative measure OPs through the LSPR peak shifts and FL intensity variations of the nanoprobe. The LSPR/FL dual-signal biosensor showed great selectivity and sensitivity for OPs detection. In addition, two distinct colour changes were visually observed to match the LSPR/FL spectra signal responses, which was a feasible means for visual analysis of OPs. Consequently, the work provided a dual-signal visual biosensor via the combination of multifunctional nanoprobe, and had significant potential to monitor pesticide residue with high anti-interference capability and detection accuracy.
Title: From tryptamine to the discovery of efficient multi-target directed ligands against cholinesterase-associated neurodegenerative disorders Wu J, Zhang H, Wang Y, Yin G, Li Q, Zhuo L, Chen H, Wang Z Ref: Front Pharmacol, 13:1036030, 2022 : PubMed
A novel class of benzyl-free and benzyl-substituted carbamylated tryptamine derivatives (CDTs) was designed and synthesized to serve as effective building blocks for the development of novel multi-target directed ligands (MTDLs) for the treatment of neurological disorders linked to cholinesterase (ChE) activity. The majority of them endowed butyrylcholinesterase (BuChE) with more substantial inhibition potency than acetylcholinesterase (AChE), according to the full study of ChE inhibition. Particularly, hybrids with dibenzyl groups (2b-2f, 2j, 2o, and 2q) showed weak or no neuronal toxicity and hepatotoxicity and single-digit nanomolar inhibitory effects against BuChE. Through molecular docking and kinetic analyses, the potential mechanism of action on BuChE was first investigated. In vitro H(2)O(2)-induced HT-22 cells assay demonstrated the favorable neuroprotective potency of 2g, 2h, 2j, 2m, 2o, and 2p. Besides, 2g, 2h, 2j, 2m, 2o, and 2p endowed good antioxidant activities and COX-2 inhibitory effects. This study suggested that this series of hybrids can be applied to treat various ChE-associated neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD), as well as promising building blocks for further structure modification to develop efficient MTDLs.
BACKGROUND & AIMS: Non-invasive stratification of the liver decompensation risk remains unmet in people with compensated cirrhosis. This study aimed to develop a non-invasive tool (NIT) to predict hepatic decompensation. METHODS: This retrospective study recruited 689 people with compensated cirrhosis (median age, 54 years; 441 men) from 5 centres from January 2016 to June 2020. Baseline abdominal computed tomography (CT), clinical features, and liver stiffness were collected, and then the first decompensation was registered during the follow-up. The spleen-based model was designed for predicting decompensation based on a deep learning segmentation network to generate the spleen volume and least absolute shrinkage and selection operator (LASSO)-Cox. The spleen-based model was trained on the training cohort of 282 individuals (Institutions I-III) and was validated in 2 external validation cohorts (97 and 310 individuals from Institutions IV and V, respectively) and compared with the conventional serum-based models and the Baveno VII criteria. RESULTS: The decompensation rate at 3 years was 23%, with a 37.6-month median (IQR 21.1-52.1 months) follow-up. The proposed model showed good performance in predicting decompensation (C-index <=0.84) and outperformed the serum-based models (C-index comparison test p <0.05) in both the training and validation cohorts. The hazard ratio (HR) for decompensation in individuals with high risk was 7.3 (95% CI 4.2-12.8) in the training and 5.8 (95% CI 3.9-8.6) in the validation (log-rank test, p <0.05) cohorts. The low-risk group had a negligible 3-year decompensation risk (>=1%), and the model had a competitive performance compared with the Baveno VII criteria. CONCLUSIONS: This spleen-based model provides a non-invasive and user-friendly method to help predict decompensation in people with compensated cirrhosis in diverse healthcare settings where liver stiffness is not available. LAY SUMMARY: People with compensated cirrhosis with larger spleen volume would have a higher risk of decompensation. We developed a spleen-based model and validated it in external validation cohorts. The proposed model might help predict hepatic decompensation in people with compensated cirrhosis when invasive tools are unavailable.
Title: Water-soluble non-conjugated polymer dots with strong green fluorescence for sensitive detection of organophosphate pesticides Zhang C, Li S, Duan Z, Li Q, Zhao M, Chen Y, Zhai X, Mao G, Wang H Ref: Anal Chim Acta, 1206:339792, 2022 : PubMed
Water-soluble non-conjugated polymer dots (PDs) have been synthesized using hyperbranched polyethyleneimine (PEI) and dihydroxybenzaldehyde (DHB) for the first time via the Schiff base reaction at room temperature. The yielded non-conjugated PDs of PEI-DHB could display the well-defined spheric structure and good water solubility. In contrast to the common PDs otherwise showing blue emission, the PEI-DHB PDs could give out strong green fluorescence in aqueous media. Especially, the fluorescence of the PEI-DHB PDs could be specifically quenched by MnO(2) nanosheets through the inner filter effects and further restored by the thiocholine that could reduce MnO(2) nanosheets into Mn(2+). Herein, thiocholine could be produced in hydrolysis reaction of acetylthiocholine catalyzed by the acetylcholinesterase (AChE), of which the catalytic activity could be irreversibly inhibitted by the introduction of organophosphates. A highly selective fluorimetric method was thereby been developed for the detection of organophosphorus pesticides using dimethyl-dichloro-vinyl phosphate as a model. The linear concentrations ranges from 0.050 to 2.5 microM. Importantly, the non-conjugated PDs probes with strong green fluorescence and high water solubility may promise the extensive applications in the environmental, food, and clinical analysis fields.
Title: Transcriptomic and metabolomic analyses reveal the antifungal mechanism of the compound phenazine-1-carboxamide on Rhizoctonia solani AG1IA Zhang Y, Li Q, Wang C, Liu S Ref: Front Plant Sci, 13:1041733, 2022 : PubMed
To explore the molecular mechanisms of the antifungal compound phenazine-1-carboxamide (PCN) inhibits Rhizoctonia solani and discover potential targets of action, we performed an integrated analysis of transcriptome and metabolome in R. solani mycelium by whether PCN treating or not. A total of 511 differentially expressed genes (DEGs) were identified between the PCN treatment and control groups. The fluorescence-based quantitative PCR (qPCR) got the accordant results of the gene expression trends for ten randomly selected DEGs. The Gene Ontology (GO) enrichment analysis revealed that fatty acid metabolic process, fatty acid oxidation, and lipid oxidation were among the most enriched in the biological process category, while integral component of membrane, plasma membrane, and extracellular region were among the most enriched in the cellular component category and oxidoreductase activity, cofactor binding, and coenzyme binding were among the most enriched in the molecular function category. KEGG enrichment analysis revealed the most prominently enriched metabolic pathways included ATP-binding cassette (ABC) transporters, nitrogen metabolism, aminobenzoate degradation. The DEGs related functions of cellular structures, cell membrane functions, cellular nutrition, vacuole-mitochondrion membrane contact site and ATPase activity, pH, anti-oxidation, were downregulated. A total of 466 differential metabolites were found between the PCN treatment and control groups after PCN treatment. KEGG enrichment found purine, arachidonic acid, and phenylpropanoid biosynthesis pathways were mainly affected. Further results proved PCN decreased the mycelial biomass and protein content of R. solani, and superoxide dismutase (SOD) activity reduced while peroxidase (POD) and cytochrome P450 activities increased. The molecule docking indicted that NADPH nitrite reductase, ATP-binding cassette transporter, alpha/beta hydrolase family domain-containing protein, and NADPH-cytochrome P450 reductase maybe the particular target of PCN. In conclusion, the mechanisms via which PCN inhibits R. solani AG1IA may be related to cell wall damage, cell membrane impairment, intracellular nutrient imbalance, disturbed antioxidant system, and altered intracellular pH, which laid foundation for the further new compound designing to improve antifungal efficacy.
TfCa, a promiscuous carboxylesterase from Thermobifida fusca, was found to hydrolyze polyethylene terephthalate (PET) degradation intermediates such as bis(2-hydroxyethyl) terephthalate (BHET) and mono-(2-hydroxyethyl)-terephthalate (MHET). In this study, we elucidated the structures of TfCa in its apo form, as well as in complex with a PET monomer analogue and with BHET. The structurefunction relationship of TfCa was investigated by comparing its hydrolytic activity on various ortho- and para-phthalate esters of different lengths. Structure-guided rational engineering of amino acid residues in the substrate-binding pocket resulted in the TfCa variant I69W/V376A (WA), which showed 2.6-fold and 3.3-fold higher hydrolytic activity on MHET and BHET, respectively, than the wild-type enzyme. TfCa or its WA variant was mixed with a mesophilic PET depolymerizing enzyme variant [Ideonella sakaiensis PETase (IsPETase) PM] to degrade PET substrates of various crystallinity. The dual enzyme system with the wild-type TfCa or its WA variant produced up to 11-fold and 14-fold more terephthalate (TPA) than the single IsPETase PM, respectively. In comparison to the recently published chimeric fusion protein of IsPETase and MHETase, our system requires 10% IsPETase and one-fourth of the reaction time to yield the same amount of TPA under similar PET degradation conditions. Our simple dual enzyme system reveals further advantages in terms of cost-effectiveness and catalytic efficiency since it does not require time-consuming and expensive cross-linking and immobilization approaches.
Benzoylecgonine (BZE) is the major toxic metabolite of cocaine, and is responsible for the long-term cocaine-induced toxicity due to its long residence time in humans. BZE is also the main contaminant following cocaine consumption, representing a risk to our environment and non-target organisms. Here, we identified the bacterial cocaine esterase (CocE) as a BZE-metabolizing enzyme (BZEase), which can degrade BZE into biological inactive metabolites (ecgonine and benzoic acid). CocE was redesigned by a reactant-state-based enzyme design theory. An encouraging mutant denoted as BZEase2, presented a >400-fold improved catalytic efficiency against BZE compared with wild-type (WT) CocE. In vivo , a single dose of BZEase2 (1 mg/kg, IV) could eliminate nearly all BZE within only two minutes, suggesting the enzyme have the potential for cocaine overdose treatment and BZE elimination in the environment by accelerating BZE clearance. The crystal structure of a designed BZEase was determined, providing additional insights in support of our simulation results.
Title: Risk Factors and a Nomogram Model Establishment for Postoperative Delirium in Elderly Patients Undergoing Arthroplasty Surgery: A Single-Center Retrospective Study Chen D, Li Y, Li Q, Gao W, Li J, Wang S, Cao J Ref: Biomed Res Int, 2021:6607386, 2021 : PubMed
OBJECTIVE: To explore the related risk factors of postoperative delirium (POD) after hip or knee arthroplasty in elderly orthopedic patients and the predictive value of related risk factors. Material and Methods. In total, 309 patients (<=60 years) who received knee and hip arthroplasty between January 2017 and May 2020 were consecutively selected into the POD and nonpostoperative delirium (NPOD) groups. Group bias was eliminated through propensity score matching. Univariate and multivariable logistic analysis was used to determine the risk factors for POD. The nomogram was made by R. RESULTS: 58 patients were included in each group after propensity score matching; multivariable analysis demonstrated that LDH (OR = 4.364, P = 0.017), CHE (OR = 4.640, P = 0.004), Cystatin C (OR = 5.283, P = 0.006), arrhythmia (OR = 5.253, P = 0.002), and operation duration (OR = 1.017, P = 0.050) were independent risk factors of POD. LDH, CHE, Cystatin C, and arrhythmia were used to construct a nomogram to predict the POD. The nomogram was well calibrated and had moderate discriminative ability (AUC = 0.821, 95% CI: 0.760~0.883). Decision curve analysis demonstrated that the nomogram was clinically useful. CONCLUSIONS: Our study revealed that arrhythmia, operation duration, the increase of lactate dehydrogenase and Cystatin C, and the decrease of cholinesterase were reliable factors for predicting postoperative delirium after elderly hip and knee arthroplasty. Meanwhile, the nomogram we developed can assist the clinician to filtrate potential patients with postoperative delirium.
Burkholderia pseudomallei is the etiological agent of melioidosis, which is an emerging infectious disease endemic to many tropical regions. Autophagy is an intrinsic cellular process that degrades cytoplasmic components and plays an important role in protecting the host against pathogens. Like many intracellular pathogens, B. pseudomallei can evade the autophagy-dependent cellular clearance. However, the underlying mechanism remains unclear. In this study, we applied a combination of multiple assays to monitor autophagy processes and found that B. pseudomallei induced an incomplete autophagic flux and eliminate autophagy clearance in macrophages by blocking autophagosome-lysosome fusion. Based on a high-throughput microarray screening, we found that LIPA (lysosomal acid LIPAse A) was downregulated during B. pseudomallei infection. MiR-146a was then identified to be specifically upregulated upon infection with B. pseudomallei and further regulated LIPA expression by interacting with 3'UTR of LIPA. Furthermore, overexpression of miR-146a contributed to the defect of autophagic flux caused by B. pseudomallei and was beneficial for the survival of B. pseudomallei in macrophages. Therefore, our findings suggest that miR-146a inhibits autophagy via posttranscriptional suppression of LIPA expression to maintain B. pseudomallei survival in macrophages.
PubChem (https://pubchem.ncbi.nlm.nih.gov) is a popular chemical information resource that serves the scientific community as well as the general public, with millions of unique users per month. In the past two years, PubChem made substantial improvements. Data from more than 100 new data sources were added to PubChem, including chemical-literature links from Thieme Chemistry, chemical and physical property links from SpringerMaterials, and patent links from the World Intellectual Properties Organization (WIPO). PubChem's homepage and individual record pages were updated to help users find desired information faster. This update involved a data model change for the data objects used by these pages as well as by programmatic users. Several new services were introduced, including the PubChem Periodic Table and Element pages, Pathway pages, and Knowledge panels. Additionally, in response to the coronavirus disease 2019 (COVID-19) outbreak, PubChem created a special data collection that contains PubChem data related to COVID-19 and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Butyrylcholinesterase (BChE) has been considered as a potential therapeutic target for Alzheimer's disease (AD) because of its compensation capacity to hydrolyze acetylcholine (ACh) and its close association with Abeta deposit. Here, we identified S06-1011 (hBChE IC(50) = 16 nM) and S06-1031 (hBChE IC(50) = 25 nM) as highly effective and selective BChE inhibitors, which were proved to be safe and long-acting. Candidate compounds exhibited neuroprotective effects and the ability to improve cognition in scopolamine- and Abeta(1-42) peptide-induced cognitive deficit models. The best candidate S06-1011 increased the level of ghrelin, a substrate of BChE, which can function as improving the mental mood appetite. The weight gain of the S06-1011-treated group remarkably increased. Hence, BChE inhibition not only plays a protective role against dementia but also exerts a great effect on treating and nursing care.
Title: pH and Redox Dual-Response Disulfide Bond-Functionalized Red-Emitting Gold Nanoclusters for Monitoring the Contamination of Organophosphorus Pesticides in Foods Li Q, Wu J, Yang Q, Li H, Li F Ref: Analytical Chemistry, 93:7362, 2021 : PubMed
Most of the fluorescence sensors require choline oxidase or quenchers to detect organophosphorus pesticides (OPs) based on a single hydrolysate and suffer from high cost, complex procedures, weak stability, and low sensitivity. Here, we proposed a brand-new fluorescence strategy for highly sensitive detection of OPs based on both hydrolysate-response disulfide bond-functionalized gold nanoclusters (S-S-AuNCs) without additional substances. S-S-AuNCs were synthesized via a facile one-step redox reaction and emitted bright red light with ultrasmall size and high water dispersion. Interestingly, S-S-AuNCs displayed a unique response to thiol compounds and low pH values and were thus pioneered as a high-efficiency sensor for OPs based on acetylcholinesterase (AChE)-catalyzed hydrolysis of acetylthiocholine into thiocholine and CH(3)COOH and OP inhibition of AChE activity. Further, S-S-AuNCs were employed to monitor the residue, distribution, and metabolization of methidathion in pakchoi with acceptable results. We believe that this work supplies a simpler and more highly sensitive approach for OP assay than the known ones and opens a new avenue to development of multistimulus-responsive and high-performance fluorescence substances.
Title: Inorganic Recognizer-Assisted Homogeneous Electrochemiluminescence Determination of Organophosphorus Pesticides via Target-Controlled Emitter Release Li H, Lv W, Yang Q, Li Q, Li F Ref: Journal of Agricultural and Food Chemistry, 69:6087, 2021 : PubMed
Given the relevance of organophosphorus pesticides (OPs) with food safety, it is highly urgent to develop sensitive and reliable sensors for OPs. However, most of the OP sensors are developed based on colorimetric and fluorescent techniques, which are limited to severe interference of color and fluorescence from pigments and organic acids in agricultural crops. Herein, we develop an inorganic recognizer-based homogeneous electrochemiluminescence (ECL) sensor for the highly sensitive and credible determination of OPs based on manganese dioxide and tris(2,2'-bipyridine)ruthenium [Ru(bpy)(3)](2+). Through electrostatic interaction, manganese dioxide nanoflakes-[Ru(bpy)(3)](2+) nanocomposites (MnNFs-Ru) are formed and exhibit a weak ECL signal due to the confinement of [Ru(bpy)(3)](2+) in MnNFs-Ru. Interestingly, MnNFs-Ru are capable of recognizing thiols due to the analyte-initiated reduction of MnNFs into Mn(2+) and release of [Ru(bpy)(3)](2+) from MnNFs-Ru into solution. Further, MnNFs-Ru are employed for the homogeneous ECL determination of OPs, where acetylcholinesterase (AChE) catalyzes the hydrolysis of acetylthiocholine (ATCh) into thiocholine, which in turn decomposes MnNFs of MnNFs-Ru into Mn(2+), and OPs inhibit AChE activity. This study widens the application of inorganic recognizers from colorimetry/fluorescence to homogeneous ECL and effectively avoids the interference of color and fluorescence, opening up a new path to the development of high-performance OP sensors and supplying a promising tool for guaranteed OP-related food safety.
Title: Identification and structure-activity relationship exploration of uracil-based benzoic acid and ester derivatives as novel dipeptidyl Peptidase-4 inhibitors for the treatment of type 2 diabetes mellitus Li Q, Deng X, Jiang N, Meng L, Xing J, Jiang W, Xu Y Ref: Eur Journal of Medicinal Chemistry, 225:113765, 2021 : PubMed
Our previously reported carboxyl-containing DPP-4 inhibitors were highly potent but were poorly bioavailable. Esters of the carboxyl analogs exhibited a significant DPP-4 potency loss albeit with enhanced oral absorption. Herein, we described identification and structure-activity relationship (SAR) exploration of a novel series of benzoic acid and ester derivatives as low single-digit nanomolar DPP-4 inhibitors. Importantly, the esters displayed comparable activities to the acids counterparts. Molecular simulation revealed that ester adopts a similar binding mode to acid. Moreover, the selected esters and acids demonstrated high selectivity and low cytotoxicity, as well as good metabolic stability. And more importantly, the esters possessed excellent pharmacokinetic profiles for oral administration. The best compound ester 19b demonstrated long DPP-4 inhibition in vivo, and robustly improved the glucose tolerance in normal and db/db mice while ensuring glucose-lowering potency in chronic treatment. Our results supported that the compound 19b can be served as a potential candidate for the treatment of type 2 diabetes.
Title: A novel lipase from Aspergillus oryzae WZ007 catalyzed synthesis of brivaracetam intermediate and its enzymatic characterization Li Q, Zhang M, Li X, Zhang Y, Wang Z, Zheng J Ref: Chirality, 33:62, 2021 : PubMed
Brivaracetam is a structural derivative of the chiral drug levetiracetam and has been approved for the adjuvant treatment of partial epilepsy. As a new antiepileptic drug, it is widely used in a variety of epilepsy models. In this study, a novel lipase M16 derived from Aspergillus oryzae WZ007 was cloned, expressed, and used for chiral resolution. Lipase M16 has a high enantioselectivity to the racemic substrate (R,S)-methyl 2-propylsuccinate 4-tert-butyl ester, and the intermediate (R)-2-propylsuccinic acid 4-tert-butyl ester of brivaracetam was obtained efficiently. Under optimal conditions, the enantiomeric excess of substrate was up to 99.26%, and the e.e.(p) was 96.23%. The conversion and apparent E value were 50.63% and 342.48, respectively. This study suggests a new biocatalytic resolution via lipase M16 for preparing the brivaracetam chiral intermediate and its potential application in the pharmaceutical industry.
Title: Design, Synthesis, and Study of the Insecticidal Activity of Novel Steroidal 1,3,4-Oxadiazoles Ma S, Jiang W, Li Q, Li T, Wu W, Bai H, Shi B Ref: Journal of Agricultural and Food Chemistry, :, 2021 : PubMed
A series of novel steroidal derivatives with a substituted 1,3,4-oxadiazole structure was designed and synthesized, and the target compounds were evaluated for their insecticidal activity against five aphid species. Most of the tested compounds exhibited potent insecticidal activity against Eriosoma lanigerum (Hausmann), Myzus persicae, and Aphis citricola. Compounds 20g and 24g displayed the highest activity against E. lanigerum, showing LC(50) values of 27.6 and 30.4 microg/mL, respectively. Ultrastructural changes in the midgut cells of E. lanigerum were detected by transmission electron microscopy, indicating that these steroidal oxazole derivatives might exert their insecticidal activity by destroying the mitochondria and nuclear membranes in insect midgut cells. Furthermore, a field trial showed that compound 20g exhibited effects similar to those of the positive controls chlorpyrifos and thiamethoxam against E. lanigerum, reaching a control rate of 89.5% at a dose of 200 microg/mL after 21 days. We also investigated the hydrolysis and metabolism of the target compounds in E. lanigerum by assaying the activities of three insecticide-detoxifying enzymes. Compound 20g at 50 microg/mL exhibited inhibitory action on carboxylesterase similar to the known inhibitor triphenyl phosphate. The above results demonstrate the potential of these steroidal oxazole derivatives to be developed as novel pesticides.
Poly(ethylene terephthalate) (PET) is used widely by human beings, but is very difficult to degrade. Up to now, the PET degradation effect of PETase from Ideonella sakaiensis 201-F6 (IsPETase) variants with low stability and activity was not ideal. In this study, a mutation design tool, Premuse, was developed to integrate the sequence alignment and quantitative selection of the preferred mutations based on natural sequence evolution. Ten single point mutants were selected from 1486 homologous sequences using Premuse, and then two mutations (W159H and F229Y) with improved stability were screened from them. The derived double point mutant, W159H/F229Y, exhibited a strikingly enhanced enzymatic performance. Its T(m) and catalytic efficiency values (k(cat)/K(m)) respectively increased by 10.4 degreesC and 2.0-fold using p-NPP as the substrate compared with wild type. The degradation activity for amorphous PET was increased by almost 40-fold in comparison with wild type at 40 degreesC in 24 h. Additionally, the variant could catalyze biodegradation of PET bottle preform at a mean rate of 23.4 mg(PET)/h/mg(enzyme). This study allowed us to design the mutation more efficiently, and provides a tool for achieving biodegradation of PET pollution under mild natural environments.
Title: Improved efficiency of lipase-mediated epoxidation of alpha-pinene using H2O2 in single-phase systems Su W, Li Q, Liu Y, Qin Y, Liu H, Tang A Ref: Molecular Catalysis, 508:111585, 2021 : PubMed
Taking advantage of the intersolubility of alcohol and water, we developed an efficient single-phase system for chemoenzymatic epoxidation of (-)-alpha-pinene. Different from traditional methods, it included all substrates, such as (-)-alpha-pinene, acyl donors and oxidants, into one phase. Isopropanol was eventually selected as the epoxidation medium to optimize three controllable parameters. Under the optimal conditions of 3.35 mol/L ethyl acetate and 1.1 mol/L H2O2, the conversion and selectivity reached 92.3% and 86.6% in 90 min, respectively, and the initial reaction rate was 13.58x10-4 mmol.min-1.mg-1 with Novozym435 as a catalyst. Trisodium citrate was screened as an acid-trapping reagent to eliminate the negative impact of acetic acid on (-)-alpha-pinene oxide. The enzyme reusability was at least 6 cycles with a relative activity of 57.5% at the sixth cycle.
Title: Two-Dimensional MnO(2) Nanozyme-Mediated Homogeneous Electrochemical Detection of Organophosphate Pesticides without the Interference of H(2)O(2) and Color Wu J, Yang Q, Li Q, Li H, Li F Ref: Analytical Chemistry, :, 2021 : PubMed
Traditional peroxidase-like nanozyme-based sensors suffer from self-decomposition and high toxicity of H(2)O(2), as well as the interference of color from nanozymes themselves and testing samples. In this work, we adopt nanozymes (two-dimension (2D) MnO(2) sheets, manganese dioxide nanosheets (MnNS)) with oxidase-like and peroxidase-like properties as advanced catalysts to develop a novel homogeneous electrochemical sensor for organophosphate pesticides (OPs) using dissolved O(2) as a coreactant without the interference of H(2)O(2) and color. Owing to the large surface area and unique catalytic activity of MnNS, a large amount of tetramethylbenzidine (TMB) is catalyzed oxidation, leading to a significantly declined differential pulse voltammetry (DPV) current. Obviously, MnNS display an excellent response to thiocholine, deriving from the catalyzing hydrolysis of acetylthiocholine (ATCh) by acetylcholinesterase (AChE), which switches a homogeneous electrochemical OP detection process based on the depressing AChE activity with a limit of detection (LOD) of 0.025 ng mL(-1). The as-proposed strategy on using nanozymes with oxidase-like and peroxidase-like properties to develop a homogeneous electrochemical sensor will provide a new pathway for improving the performance of nanozyme-based sensors, and the established MnNS-based homogeneous electrochemical sensor will find more applications for OP residue determination in food samples.
Title: Synthesis and bio-evaluation of a novel selective butyrylcholinesterase inhibitor discovered through structure-based virtual screening Xing S, Chen Y, Xiong B, Lu W, Li Q, Wang Y, Jiao M, Feng F, Liu W, Sun H Ref: Int J Biol Macromol, 166:1352, 2021 : PubMed
In recent years, butyrylcholinesterase (BChE) has gradually gained worldwide interests as a novel target for treating Alzheimer's disease (AD). Here, two pharmacophore models were generated using Schrodinger suite and used to virtually screen ChemDiv database, from which three hits were obtained. Among them, 2513-4169 displayed the highest inhibitory activity and selectivity against BChE (eeAChE IC(50) > 10 microM, eqBChE IC(50) = 3.73 +/- 1.90 microM). Molecular dynamic (MD) simulation validated the binding pattern of 2513-4169 in BChE, and it could form a various of receptor-ligand interactions with adjacent residues. In vitro cytotoxicity assay proved the safety of 2513-4169 on diverse neural cell lines. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay performed on SH-SY5Y cells proved the neuroprotective effect of 2513-4169 against toxic Abeta(1)(-)(42). In vivo behavioral study further confirmed the great efficacy of 2513-4169 on reversing Abeta(1)(-)(42)-induced cognitive impairment of mice and clearing the toxic Abeta(1)(-)(42) in brains. Moreover, 2513-4169 was proved to be able to cross blood-brain barrier (BBB) through a parallel artificial membrane permeation assay of BBB (PAMPA-BBB). Taken together, 2513-4169 is a promising lead compound for future optimization to discover anti-AD treating agents.
Title: Structure and therapeutic uses of butyrylcholinesterase: Application in detoxification, Alzheimer's disease, and fat metabolism Xing S, Li Q, Xiong B, Chen Y, Feng F, Liu W, Sun H Ref: Med Res Rev, 41:858, 2021 : PubMed
Structural information of butyrylcholinesterase (BChE) and its variants associated with several diseases are discussed here. Pure human BChE has been proved safe and effective in treating organophosphorus (OPs) poisoning and has completed Phase 1 and 2 pharmacokinetic (PK) and safety studies. The introduction of specific mutations into native BChE to endow it a self-reactivating property has gained much progress in producing effective OPs hydrolases. The hydrolysis ability of native BChE on cocaine has been confirmed but was blocked to clinical application due to poor PK properties. Several BChE mutants with elevated cocaine hydrolysis activity were published, some of which have shown safety and efficiency in treating cocaine addiction of human. The increased level of BChE in progressed Alzheimer's disease patients made it a promising target to elevate acetylcholine level and attenuate cognitive status. A variety of selective BChE inhibitors with high inhibitory activity published in recent years are reviewed here. BChE could influence the weight and insulin secretion and resistance of BChE knockout (KO) mice through hydrolyzing ghrelin. The BChE-ghrelin pathway could also regulate aggressive behaviors of BChE-KO mice.
Title: pH-Response Quantum Dots with Orange-Red Emission for Monitoring the Residue, Distribution, and Variation of an Organophosphorus Pesticide in an Agricultural Crop Yang Q, Li Q, Li H, Li F Ref: Journal of Agricultural and Food Chemistry, :, 2021 : PubMed
Development of simple, sensitive, and reliable fluorescence sensors for monitoring the residue, distribution, and variation of organophosphorus pesticides (OPs) in agricultural crops is highly urgent but remains challenging, which is ascribed to deprivation of an ideal fluorophore and ingenious detection strategy. Herein, we report the fabrication of cadmium telluride quantum dots (CdTe QDs) with bright emission, good water dispersion, and long emission wavelength for OP screening based on the unique response of CdTe QDs to pH and the inhibition of OPs on acetylcholinesterase (AChE) activity. AChE catalyzed hydrolysis of acetylcholine (ACh) into CH(3)COOH, which protonated CdTe QDs to decline the fluorescence, whereas target OP impeded AChE from catalyzing hydrolysis of ACh into CH(3)COOH, making little influence in fluorescence of CdTe QDs. On the basis of the change in fluorescence, sensitive detection of OP was acquired, with the limit of detection at 0.027 ng/mL, which was comparable or lower than that of most known OP sensors. Furthermore, the CdTe-QD-based sensor was successfully applied for precisely monitoring the residue, distribution, and variation of methidathion in Chinese cabbage and cultivated soil. Therefore, the proposed sensor was anticipated to supply a promising alternative for food safety guarantee and was an valuable application for OP screening.
Title: Thirteen cyathane diterpenoids with acetylcholinesterase inhibitory effects from the fungus Cyathus africanus Yu M, Kang X, Li Q, Liang Y, Zhang M, Gong Y, Chen C, Zhu H, Zhang Y Ref: Phytochemistry, 193:112982, 2021 : PubMed
Eight undescribed cyathane diterpenoids, representative specialised metabolites of the genus Cyathus, named cyathins Q-X, along with five known congeners, were isolated from the liquid fermentation of Cyathus africanus. Their structures and absolute configurations were elucidated by integrating NMR spectroscopic analyses, electronic circular dichroism (ECD) calculations, and X-ray diffraction. Reasonable correction to the C-12 configuration of cyathin I was corroborated by the crystal data. The structural identification in this research expanded the number of candidates to allow for more bioactivity-screening options. Among them, (12S)-11alpha,14alpha-epoxy-13alpha,14beta,15-trihydroxycyath-3-ene displayed significant acetylcholinesterase (AChE) inhibitory effect with an IC(50) value of 4.60 +/- 0.85 microM. Molecular docking studies were also performed to unravel the underlying modes of interactions with the active sites of AChE for active compounds.
Title: Design, Synthesis, and Evaluation of Acetylcholinesterase and Butyrylcholinesterase Dual-Target Inhibitors against Alzheimer's Diseases Guo Y, Yang H, Huang Z, Tian S, Li Q, Du C, Chen T, Liu Y, Sun H, Liu Z Ref: Molecules, 25:, 2020 : PubMed
A series of novel compounds 6a-h, 8i-1, 10s-v, and 16a-d were synthesized and evaluated, together with the known analogs 11a-f, for their inhibitory activities towards acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The inhibitory activities of AChE and BChE were evaluated in vitro by Ellman method. The results show that some compounds have good inhibitory activity against AChE and BChE. Among them, compound 8i showed the strongest inhibitory effect on both AChE (eeAChE IC50 = 0.39 muM) and BChE (eqBChE IC50 = 0.28 muM). Enzyme inhibition kinetics and molecular modeling studies have shown that compound 8i bind simultaneously to the peripheral anionic site (PAS) and the catalytic sites (CAS) of AChE and BChE. In addition, the cytotoxicity of compound 8i is lower than that of Tacrine, indicating its potential safety as anti-Alzheimer's disease (anti-AD) agents. In summary, these data suggest that compound 8i is a promising multipotent agent for the treatment of AD.
In the present work, a novel series of pyridinethiazole bearing benzylpiperidine hybrids were designed and synthesized as dual-target inhibitors of GSK-3beta/AChE. Among them, GD29 was the most promising candidate, with an IC(50) value of 0.3 M for hAChE and an IC(50) value of 0.003 M for hGSK-3beta, respectively. The compounds exhibited good drug-like properties with optimal inhibitory enzyme activities. Moreover, GD29 showed anti-inflammatory properties at micromolar concentrations and displayed interesting neuroprotective profiles in an in vitro model of oxidative stress-induced neuronal death. Notably, the compounds also exhibited good permeability across the blood-brain-barrier (BBB) both in vitro. Central cholinomimetic activity was confirmed using a scopolamine-induced cognition impairment model in Institute of Cancer Research (ICR) mice upon oral administration. The current work identified optimized compounds and explored the therapeutic potential of glycogen synthase kinase 3/cholinesterase inhibition for the treatment of AD.
Karrikins (KARs) are butenolides found in smoke that can influence germination and seedling development of many plants. The KAR signaling mechanism is hypothesized to be very similar to that of the plant hormone strigolactone (SL). Both pathways require the F-box protein MORE AXILLARY GROWTH2 (MAX2), and other core signaling components have shared ancestry. Putatively, KAR activates the receptor KARRIKIN INSENSITIVE2 (KAI2), triggering its association with the E3 ubiquitin ligase complex SCF(MAX2) and downstream targets SUPPRESSOR OF MAX2 1 (SMAX1) and SMAX1-LIKE2 (SMXL2). Polyubiquitination and proteolysis of SMAX1 and SMXL2 then enable growth responses to KAR. However, many of the assumptions of this model have not been demonstrated. Therefore, we investigated the posttranslational regulation of SMAX1 from the model plant Arabidopsis (Arabidopsis thaliana). We find evidence that SMAX1 is degraded by KAI2-SCF(MAX2) but is also subject to MAX2-independent turnover. We identify SMAX1 domains that are responsible for its nuclear localization, KAR-induced degradation, association with KAI2, and ability to interact with other SMXL proteins. KAI2 undergoes MAX2-independent degradation after KAR treatment, which we propose results from its association with SMAX1 and SMXL2. Finally, we discover an SMXL domain that mediates receptor-target interaction preferences in KAR and SL signaling, laying the foundation for understanding how these highly similar pathways evolved to fulfill different roles.
Title: Immobilized lipase in bio-based metal-organic frameworks constructed by biomimetic mineralization: A sustainable biocatalyst for biodiesel synthesis Li Q, Chen Y, Bai S, Shao X, Jiang L Ref: Colloids Surf B Biointerfaces, 188:110812, 2020 : PubMed
Herein, thermophilic lipase QLM from Alcaligenes sp. has been successfully immobilized in bio-based metal-organic frameworks (MOFs) through biomimetic mineralization, using zinc acetate and adenine as metal ion and organic ligand, respectively. The morphology and structure of lipase@Bio-MOF was systematically characterized by scanning electron microcopy (SEM), transmission electron microcopy (TEM), powder X-ray diffraction (PXRD) and Fourier transform infrared spectra (FT-IR). The enzyme loading in immobilized enzyme was measured to be 15.9 % by thermogravimetric analysis (TGA). Further, it was demonstrated to possess favorable catalytic activity and stability under high temperature and alkaline conditions and in the presence of metal ions, using the hydrolysis of p-nitrophenyl caprylate as a model. Finally, the immobilized enzyme was successfully applied in the preparation of biodiesel through the trans-esterification of sunflower oil with methanol, obtaining a conversion of >60 % at a high oil/methanol ratio of 8:1. Meanwhile, it showed excellent recyclability during the biodiesel production, and no changes of morphology and crystal structure were observed after being used for 3 cycles. Overall, the immobilized lipase in bio-based MOFs provided an economically and environmentally viable biocatalyst for the synthesis of biodiesel.
Neurodegenerative diseases are a variety of debilitating and fatal disorder in central nervous system (CNS). Besides targeting neuronal activity by influencing neurotransmitters or their corresponding receptors, modulating the underlying processes that lead to cell death, such as oxidative stress and mitochondrial dysfunction, should also be emphasized as an assistant strategy for neurodegeneration therapy. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) has been closely verified to be related to anti-inflammation and oxidative stress, rationally regulating its belonging pathway and activating Nrf2 is emphasized to be a potential treatment approach. There have existed multiple Nrf2 activators with different mechanisms and diverse structures, but those applied for neuro-disorders are still limited. On the basis of research arrangement and compound summary, we put forward the limitations of existing Nrf2 activators for neurodegenerative diseases and their future developing directions in enhancing the blood-brain barrier permeability to make Nrf2 activators function in CNS and designing Nrf2-based multi-target-directed ligands to affect multiple nodes in pathology of neurodegenerative diseases.
Title: A safety type of genetically engineered bacterium that degrades chemical pesticides Li Q, Li J, Kang KL, Wu YJ Ref: AMB Express, 10:33, 2020 : PubMed
Chemical pesticides are used widely and their residues are found in the environment. Pesticide pollution has become a global problem. To find an economical, effective and safety way to degrade residues of pesticides in environment, we constructed a genetically engineered bacterium (GEB) having the ability to degrade pesticides, emit green fluorescence and has a containment system by using a dual plasmid expression system. One plasmid contains the genes of enhanced green fluorescent protein (EGFP) and carboxylesterase B1 (CarE B1), which were cloned downstream of lambda PL promoter and expressed constitutively. The gene of CarE B1 encodes an insect-detoxifying enzyme possessing the degradability to organochloride pesticides, organophosphorus pesticides, carbamates, and pyrethoid insecticides. The other is the conditional suicide plasmid for containment system, in which the lethal gene used was the nuclease gene of Serratia marcescens without the leader-coding sequence and was placed downstream of T7 promoter. The GEB has wide prospects of application on cleanup of pesticide residues with its degradability to several pesticides and containment system.
To discover novel BChE inhibitors, a hierarchical virtual screening protocol followed by biochemical evaluation was applied. The most potent compound 8012-9656 (eqBChE IC(50) = 0.18 +/- 0.03 M, hBChE IC(50) = 0.32 +/- 0.07 M) was purchased and synthesized. It inhibited BChE in a noncompetitive manner and could occupy the binding pocket forming diverse interactions with the target. 8012-9656 was proven to be safe in vivo and in vitro and showed comparable performance in ameliorating the scopolamine-induced cognition impairment to tacrine. Additionally, treatment with 8012-9656 could almost entirely recover the Abeta(1-42) (icv)-impaired cognitive function to the normal level and showed better behavioral performance than donepezil. The evaluation of the Abeta(1-42) total amount confirmed its anti-amyloidogenic profile. Moreover, 8012-9656 possessed blood-brain barrier (BBB) penetrating ability, a long T(1/2), and low intrinsic clearance. Hence, the novel potential BChE inhibitor 8012-9656 can be considered as a promising lead compound for further investigation of anti-AD agents.
Title: Reduced insecticide sensitivity of the wheat aphid Sitobion miscanthi after infection by the secondary bacterial symbiont Hamiltonella defensa Li Q, Sun J, Qin Y, Fan J, Zhang Y, Tan X, Hou M, Chen J Ref: Pest Manag Sci, 77:1936, 2020 : PubMed
BACKGROUND: Bacterial symbionts in insects, especially aphids, have a major influence on host adaptation. The authors previously showed that infection with the secondary symbiont Hamiltonella defensa increases the fitness of the wheat aphid Sitobion miscanthi, yielding increases in fitness parameters such as adult weight and offspring number. However, whether H. defensa affects the sensitivity of host aphids to insecticides remains unknown. RESULTS: We tested the effects of H. defensa on host aphid susceptibility to the insecticides chlorpyrifos methyl, imidacloprid, cyantraniliprole and acetamiprid. Our results showed that compared with Hamiltonella-free aphid clones, Hamiltonella-infected aphid clones exhibited lower sensitivity to most of the tested insecticides at low concentrations. Quantitative PCR showed that the density of H. defensa in the infected clones was slightly decreased at 24 h but then sharply increased until the late stage after treatment with the different insecticides. H. defensa in the host aphids was detected by fluorescence in situ hybridization and was localized to the aphid hindgut. The levels of the detoxification enzymes acetylcholinesterase (AChE), glutathione transferase (GST) and carboxylesterase (CarE) were significantly higher in the Hamiltonella-infected clones than in the Hamiltonella-free clones. CONCLUSIONS: The findings indicated that infection with H. defensa reduced aphid sensitivity to the investigated insecticides at low concentrations, potentially by increasing detoxification enzyme activity in the host. Therefore, symbiont-mediated insecticide resistance should be taken into account when performing resistance-monitoring studies. Studies of symbiont-mediated insecticide resistance may enhance our understanding of the emergence of insecticide resistance in agricultural systems. This article is protected by copyright. All rights reserved.
Title: Immobilized angiotensin II type I receptor: A powerful method of high throughput screening for antihypertensive compound identification through binding interaction analysis Liang Q, Fu X, Zhang J, Hao J, Feng G, Wang J, Li Q, Ahmad F, Zhao X Ref: Journal of Chromatography A, :461003, 2020 : PubMed
The enormous growth in drug discovery paradigm has necessitated continuous exploration of new methods for drug-protein interaction analysis. To enhance the role of these methodologies in designing rational drugs, this work extended an immobilized angiotensin II type I receptor (AT1R) based affinity chromatography in antihypertensive compound identification. We fused haloalkane dehalogenase at C-terminus of AT1R and expressed the fusion receptor in E. coli. The expressed receptor was covalently immobilized onto 8.0mum microspheres by mixing the cell lysate with 6-chlorocaproic acid-modified amino polystyrene microspheres. The immobilized AT1R was utilized for thermodynamic and kinetic interaction analysis between the receptor and four specific ligands. Following confirmation of these interactions by molecular docking, we identified puerarin and rosmarinic acid by determining their binding to the receptor. Azilsartan, candesartan, valsartan and olmesartan displayed two kinds of binding sites to AT1R by injection amount-dependent method. By molecular docking, we recognize the driving forces of the interaction as electrostatic interaction, hydrogen bonds and van der Waals force. The dissociation rate constants (kd) of azilsartan, candesartan, valsartan and olmesartan to AT1R were 0.01138 +/- 0.003, 0.05142 +/- 0.003, 0.07547 +/- 0.004 and 0.01310 +/- 0.005 min(-1) by peak profiling assay. Comparing with these parameters, puerarin and rosmarinic acid presented lower affinity (KA: 0.12x10(4) and 1.5x10(4)/M) and slower kinetics (kd: 0.6864 +/- 0.03 and 0.3005 +/- 0.01 min(-1)) to the receptor. These results, taking together, indicated that the immobilized AT1R has the capacity to probe antihypertensive compounds.
Title: Design, synthesis and biological evaluation of novel carboline-cinnamic acid hybrids as multifunctional agents for treatment of Alzheimer's disease Liao Q, Li Q, Zhao Y, Jiang P, Yan Y, Sun H, Liu W, Feng F, Qu W Ref: Bioorg Chem, 99:103844, 2020 : PubMed
Alzheimer's disease (AD) is a complex neurodegenerative disease with multiple pathological features. Multifunctional compounds able to simultaneously interact with several pathological components have been considered as a solution to treat the complex pathologies of neurodegenerative diseases. beta-carboline and cinnamic acid have been extensively studied for their widespread biological effects in treatment of AD, further application is limited due to its poor solubility and high toxicity. Herein, a series of carboline-cinnamic acid hybrids was designed and synthesized to obtain new multifunctional molecules with low toxicity and good physicochemical properties. In particular, e3 and e12 exhibited significant inhibition of Abeta aggregation (inhibitory rate at 25 M: 65% and 72% respectively), moderate BuChE inhibition, excellent neuroprotective effects and low neurotoxicity. Furthermore, in the AD mice model, e3 and e12 could restore learning and memory function to a comparable level to that of the control and did not exhibit any acute toxicity in vivo at a relatively high dose of 600 mg/kg. Thus, these new compounds can be further studied as multifunctional molecules for AD.
Title: Immobilization of thermophilic lipase in inorganic hybrid nanoflower through biomimetic mineralization Liu Y, Shao X, Kong D, Li G, Li Q Ref: Colloids Surf B Biointerfaces, 197:111450, 2020 : PubMed
Thermophilic lipase QLM from Alcaligenes sp. was successfully immobilized in Cu(3)(PO(4))(2)-based inorganic hybrid nanoflower through biomimetic mineralization. The morphology, structure and element composition of immobilized enzyme were systemically characterized to elucidate the successful loading of enzyme molecules. The optimal temperature (65 degreeC) and pH (8.0) of immobilized enzyme were then determined by monitoring the hydrolysis of p-nitrophenyl caprylate. Moreover, compared with free enzyme, immobilized enzyme in inorganic hybrid nanoflower exhibited enhanced stability against thermal, pH and metal ions, attributing to the protective effect of nanoflower shell. Additionally, the immobilized enzyme possessed excellent reusability and long-term storage stability, with slightly decreased activity after being repeatedly used for 8 cycles or stored in water at room temperature for 4 weeks. Overall, the immobilization in inorganic hybrid nanoflower provided a facile and effective approach for the preparation of immobilized enzymes with favorable activity, stability and reusability, and thus the strategy showed great potential in developing ideal catalysts for future biocatalytic applications.
Title: LINC00205 modulates the expression of EPHX1 through the inhibition of miR-184 in hepatocellular carcinoma as a ceRNA Long X, Li Q, Zhi LJ, Li JM, Wang ZY Ref: Journal of Cellular Physiology, 235:3013, 2020 : PubMed
Several studies have shown that low expression of epoxide hydrolase 1 (EPHX1) is closely associated with varying human cancers, including hepatocellular carcinoma (HCC). This study aims to explore the potential mechanism of EPHX1 silencing and revealed a novel regulatory pathway in the pathogenesis of HCC. In this study, micro ribonucleic acid (miR)-184 was predicted and validated to be a regulator of EPHX1 through experiments, and its expression was negatively correlated with the messenger RNA (mRNA) levels of EPHX1 in primary tumors. Elevation of EPHX1 suppressed cell proliferation and migration as well as cell cycle progression, and induced apoptosis, while downregulation of miR-184 exhibited the opposite effect on cellular processes. Moreover, LINC00205 interacted with miR-184 and was markedly downregulated in tumors. The effects of the miR-184 inhibitor on cell proliferation, apoptosis, and migration were reversed in part by the transfection with LINC00205 small interfering RNAs. In addition, LINC00205 acted as a molecular sponge to positively regulate the mRNA and protein levels of EPHX1 via regulating miR-184. The tumorigenicity of HCC cells was enhanced by LINC00205 shRNA but diminished by overexpression of EPHX1 in vivo. Clinically, the EPHX1 expression in patients with HCC was markedly downregulated. Taken together, the results of this study suggest that as a competing endogenous RNA, LINC00205 may regulate EPHX1 by inhibiting miR-184 in the progression of HCC and that targeting the LINC00205/miR-184/EPHX1 axis may provide a treatment protocol for patients.
Title: Correction to Near-Infrared Fluorescence Probe for Evaluating Acetylcholinesterase Activity in PC12 Cells and In Situ Tracing AChE Distribution in Zebrafish Ma J, Si T, Yan C, Li Y, Li Q, Lu X, Guo Y Ref: ACS Sens, :, 2020 : PubMed
Title: Near-Infrared Fluorescence Probe for Evaluating Acetylcholinesterase Activity in PC12 Cells and In Situ Tracing AChE Distribution in Zebrafish Ma J, Si T, Yan C, Li Y, Li Q, Lu X, Guo Y Ref: ACS Sens, 5:83, 2020 : PubMed
Acetylcholinesterase (AChE) plays crucial roles in numerous physiological processes such as cell differentiation, cell apoptosis, and nerve tissue developments. Hence, it is highly necessary to design a fluorescent probe for monitoring AChE activity in complex living organisms. In this work, a near-infrared (NIR) off-on probe (CyN) was developed for AChE detection. CyN was exactly synthesized by introducing an N,N-dimethyl carbamyl moiety to hemicyanine (CyOH). AChE can "light up" strong NIR fluorescence through a cleavage special ester bond and transform CyN into CyOH. Moreover, CyN was qualified for imaging the dynamic change of AChE activity in PC12 cells with retinoic acid or hypoxia stimulation. In particular, the probe has been successfully applied for in situ tracing the intact distribution of AChE in living zebrafish. The observations indicate that major occurrence sites of endogenic AChE on zebrafish are the yolk sac and neuromasts. Overall, CyN shows great potential for use in AChE-related physiological studies.
Title: Rational design of a near-infrared fluorescence probe for highly selective sensing butyrylcholinesterase (BChE) and its bioimaging applications in living cell Ma J, Lu X, Zhai H, Li Q, Qiao L, Guo Y Ref: Talanta, 219:121278, 2020 : PubMed
In the current work, a near-infrared (NIR) fluorescent probe (CyClCP) was developed for fast (35 min), highly sensitive (LOD of 3.75 U/L) and selective response to BChE in vitro and in vivo. Upon the addition of BChE, CyClCP could be efficiently activated with remarkable NIR ((em) = 708 nm) fluorescence enhancement and obvious absorbance red shift (581 nm-687 nm). Specifically, according to the subtle differences structural features and substrate preference between BChE and its sister enzyme AChE, CyClCP was constructed by introducing chlorine atom at the ortho-position of the phenolic hydroxyl in the previous reported probe (CyCP). Fortunately, CyClCP exhibited better selectivity towards BChE over AChE compared with CyCP. This molecular design strategy was further rationalized by docking molecular of fluorescence probes (CyClCP and CyCP) and enzymes (BChE and AChE). Finally, CyClCP was membrane permeable and successfully applied to image endogenous BChE level in HepG2 and LO2 cells. Therefore, CyClCP could serve as a promising tool for BChE-related physiological function studies in complex biological systems.
The production and N-glycosylation of recombinant human butyrylcholinesterase (BChE), a model highly glycosylated therapeutic protein, in a transgenic rice cell suspension culture treated with kifunensine, a strong alpha-mannosidase I inhibitor, was studied in a 5 L bioreactor. A media exchange was performed at day 7 of cultivation by removing spent sugar-rich medium (NB+S) and adding fresh sugar-free (NB-S) medium to induce the rice alpha-amylase 3D (RAmy3D) promoter to produce rice recombinant human BChE (rrBChE). Using a 1.25X-concentrated sugar-free medium together with an 80% reduced working volume during the media exchange led to a total active rrBChE production level of 79 +/- 2 mug (g FW)(-1) or 7.5 +/- 0.4 mg L(-1) in the presence of kifunensine, which was 1.5-times higher than our previous bioreactor runs using normal sugar-free (NB-S) media with no kifunensine treatment. Importantly, the amount of secreted active rrBChE in culture medium was enhanced in the presence of kifunensine, comprising 44% of the total active rrBChE at day 5 following induction. Coomassie-stained SDS-PAGE gel and Western blot analyses revealed different electrophoretic migration of purified rrBChE bands with and without kifunensine treatment, which was attributed to different N-glycoforms. N-Glycosylation analysis showed substantially increased oligomannose glycans (Man5/6/7/8) in rrBChE treated with kifunensine compared to controls. However, the mass-transfer limitation of kifunensine was likely the major reason for incomplete inhibition of alpha-mannosidase I in this bioreactor study.
Cholinesterase inhibitor plays an important role in the treatment of patients with Alzheimer's disease (AD). Herein, we report the medicinal chemistry efforts leading to a new series of 1,3-dimethylbenzimidazolinone derivatives. Among the synthesised compounds, 15b and 15j showed submicromolar IC50 values (15b, eeAChE IC50 = 0.39 +/- 0.11 microM; 15j, eqBChE IC50 = 0.16 +/- 0.04 microM) towards acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Kinetic and molecular modelling studies revealed that 15b and 15j act in a competitive manner. 15b and 15j showed neuroprotective effect against H2O2-induced oxidative damage on PC12 cells. This effect was further supported by their antioxidant activity determined in a DPPH assay in vitro. Morris water maze test confirmed the memory amelioration effect of the two compounds in a scopolamine-induced mouse model. Moreover, the hepatotoxicity of 15b and 15j was lower than tacrine. In summary, these data suggest 15b and 15j are promising multifunctional agents against AD.
Title: Dl-3-n-butylphthalide regulates cholinergic dysfunction in chronic cerebral hypoperfusion rats Sun Y, Zhao Z, Li Q, Wang C, Ge X, Wang X, Wang G, Qin Y Ref: J Internal Medicine Res, 48:300060520936177, 2020 : PubMed
OBJECTIVES: To investigate whether dl-3-n-butylphthalide (NBP) affects cholinergic system function and ameliorates cognitive decline in a rat model of vascular dementia (VaD). METHODS: The VaD rat model was established by bilateral common carotid artery ligation (two-vessel occlusion, 2VO). Rats were divided into five groups: control, sham, 2VO, 2VO+NBP (80 mg/kg; intragastric), and 2VO+donepezil (1 mg/kg; intragastric). Treatments were administered once daily for 2 weeks from day 21 post-surgery. Spatial learning and memory were evaluated by Morris water maze performance. Hippocampal choline acetyltransferase (ChAT), acetylcholinesterase (AChE), vesicular acetylcholine transporter (VAChT), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) expressions were detected using immunohistochemistry, immunofluorescence, and real-time polymerase chain reaction methods. RESULTS: The daily escape latency was significantly longer in 2VO rats than in the sham or control groups, while the time spent in the target quadrant was significantly shorter. The daily escape latency of the 2VO+NBP group was significantly shorter compared with the 2VO group. Following NBP treatment, ChAT, AChE, VAChT, and BDNF expressions were significantly upregulated in the hippocampus. CONCLUSIONS: Central cholinergic dysfunction may be involved in VaD pathogenesis. NBP treatment significantly improved spatial learning and memory in VaD rats, and may enhance cholinergic system function via BDNF-mediated neuroprotection.
Cognitive impairment (CI) refers to dysfunctional cognition, which encompasses a spectrum of disorders, ranging from mild cognitive impairment to dementia. Any factor that results in cortical damage may cause CI. Total flavonoids of Selaginella pulvinata (TFSP), have shown promising antioxidant and protective effects in animal models. In the present study, mice were intraperitoneally treated with scopolamine, sodium nitrite or 45% ethanol to induce memory impairment, and the effects were assessed using a step-down test. After performing the behavioural test, hippocampal sections were collected for anatomical analysis, and the brain and serum levels of memory-related molecules were evaluated. The results showed that TFSP improved memory in a mouse model of CI significantly. Serum data were consistent with the behavioural results: TFSP increased blood acetylcholine levels through modulation of the acetylcholinesterase and choline acetyltransferase levels. It also ameliorated oxidative stress in neurons, increasing superoxide dismutase, glutathione peroxidase and inhibiting nitric oxide synthase levels in the brain. These results suggest that TFSP may exhibit potential as a clinical treatment for neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, and senile dementia.
Title: Directed evolution of Aspergillus oryzae lipase for the efficient resolution of (R,S)-ethyl-2-(4-hydroxyphenoxy) propanoate Zhang M, Li Q, Lan X, Li X, Zhang Y, Wang Z, Zheng J Ref: Bioprocess Biosyst Eng, 43:2131, 2020 : PubMed
Aspergillus oryzae lipase (AOL) is a potential biocatalyst for industrial application. In this study, a mutant lipase AOL-3(F38N/V230R) was screened through two rounds of directed evolution, resulting in a fourfold increase in lipase activity, and threefold in catalytic efficiency (k(cat)/K(m)), while maintaining its excellent stereoselectivity. AOL-3(F38N/V230R) enzyme activity was maximum at pH 7.5 and also at 40 degreesC. And compared with wild-type AOL-3, AOL-3(F38N/V230R) preferentially hydrolyzed the fatty acid ethyl ester carbon chain length from C4 to C6-C10. In the same catalytic reaction conditions, the conversion of (R,S)-ethyl-2-(4-hydroxyphenoxy) propanoate ((R,S)-EHPP) by AOL-3(F38N/V230R) can be increased 169.7% compared to the original enzyme. The e.e.(s) of (R,S)-EHPP achieved 99.4% and conversion about 50.2% with E value being 829.0. Therefore, AOL-3(F38N/V230R) was a potential biocatalyst for obtaining key chiral compounds for aryloxyphenoxy propionate (APP) herbicides.
Title: Discovery of a Selective 6-Hydroxy-1, 4-Diazepan-2-one Containing Butyrylcholinesterase Inhibitor by Virtual Screening and MM-GBSA Rescoring Zhou Y, Hu Y, Lu X, Yang H, Li Q, Du C, Chen Y, Hong KH, Sun H Ref: Dose Response, 18:1559325820938526, 2020 : PubMed
Alzheimer disease (AD) is the most common form of dementia characterized by the loss of cognitive abilities through the death of central neuronal cells. In this study, structure-based virtual screens of 2 central nervous system-targeted libraries followed by molecular mechanics/generalized born surface area rescoring were performed to discover novel, selective butyrylcholinesterase (BChE) inhibitors, which are one of the most effective therapeutic strategies for the treatments in late-stage AD. Satisfyingly, compound 5 was identified as a highly selective low micromolar inhibitor of BChE (BChE IC50 = 1.4 muM). The binding mode prediction and kinetic analysis were performed to obtain detailed information about compound 5. Besides, a preliminary structure-activity relationship investigation of compound 5 was carried out for further development of the series. The present results provided a valuable chemical template with a novel scaffold for the development of selective BChE inhibitors.
Our recently successful identification of benzoic acid-based DPP-4 inhibitors spurs the further quest for in-depth structure-activity relationships (SAR) study in S2' site DPP-4. Thus novel benzamide fragments were designed to target the S2' site to compromise lipophilicity and improve oral activity. Exploring SAR by introduction of a variety of amide and halogen on benzene ring led to identification of several compounds, exerting moderated to excellent DPP-4 activities, in which 4'-chlorine substituted methyl amide 17g showed most potent DPP-4 activity with the IC50 value of 1.6nM. Its activity was superior to reference alogliptin. Docking study ideally verified and interpreted the obtained SAR of designed compounds. As a continuation, DPP-8/9 assays revealed the designed compounds exhibited good selectivity over DPP-8 and DPP-9. Subsequent cell-based test indicated compound 17g displayed low toxicity toward the LO2 cell line up to 100muM. In vivo evaluation showed compound 17g robustly improved the glucose tolerance in normal mice. Importantly, 17g exhibited reasonable pharmacokinetic (PK) profiles for oral delivery. Overall, compound 17g has the potential to a safe and efficacious DPP-4 inhibitor for T2DM treatment.
Title: Study on the Multitarget Synergistic Effects of Kai-Xin-San against Alzheimer's Disease Based on Systems Biology Guo S, Wang J, Wang Y, Zhang Y, Bi K, Zhang Z, Li Q Ref: Oxid Med Cell Longev, 2019:1707218, 2019 : PubMed
Kai-Xin-San (KXS), a classical Chinese traditional prescription, was widely applied in the treatment of Alzheimer's disease (AD), while its functional mechanisms still remain unclear. By using systems biology approaches at animal, cellular, and molecular levels, the improvement of KXS on cognitive impairment was achieved by inhibiting abnormal acetylcholinesterase. The function on the nerve skeleton was performed by regulating the Tau phosphorylation pathway. Its antioxidant, anti-inflammatory, and antiapoptotic effects by modulating the aberrant upregulation of ROS, proinflammatory factors, and apoptosis-related proteins in the brain were studied to reveal the synergistic therapeutic efficacy of KXS. Then, formula dismantling in vitro indicated that ginseng was the principal herb, whereas three other herbs served adjuvant roles to achieve the best effect. After that, the in vivo analysis of components into plasma and brain of AD rats showed that 8 of 23 components in blood and 4 of 10 components in brain were from ginseng, respectively, further verifying the principal status of ginseng and the synergistic effects of the formula. Thus, the anti-AD effects of KXS were achieved by multitargets and multichannels. The systems biology approaches presented here provide a novel way in traditional herbal medicine research.
Alzheimer's disease (AD) is a chronic, fatal and complex neurodegenerative disorder, which is characterized by cholinergic system dysregulation, metal dyshomeostasis, amyloid-beta (Abeta) aggregation, etc. Therefore in most cases, single-target or single-functional agents are insufficient to achieve the desirable effect against AD. Multi-Target-Directed Ligand (MTDL), which is rationally designed to simultaneously hit multiple targets to improve the pharmacological profiles, has been developed as a promising approach for drug discovery against AD. To identify the multifunctional agents for AD, we developed an innovative method to successfully conceal the metal chelator into acetylcholinesterase (AChE) inhibitor. Briefly, the "hidden" agents first cross the Blood Brain Barrier (BBB) to inhibit the function of AChE, and the metal chelator will then be released via the enzymatic hydrolysis by AChE. Therefore, the AChE inhibitor, in this case, is not only a single-target agent against AD, but also a carrier of the metal chelator. In this study a total of 14 quinoline derivatives were synthesized and biologically evaluated. Both in vitro and in vivo results demonstrated that compound 9b could cross the BBB efficiently, then release 8a, the metabolite of 9b, into brain. In vitro, 9b had a potent AChE inhibitory activity, while 8a displayed a significant metal ion chelating function, therefore in combination, both 9b and 8a exhibited a considerable inhibition of Abeta aggregation, one of the observations that plays important roles in the pathogenesis of AD. The efficacy of 9b against AD was further investigated in both a zebrafish model and two different mice models.
Dipeptidyl Peptidase-IV (DPP-4) is a validated therapeutic target for type 2 diabetes. Aiming to interact with both residues Try629 and Lys554 in S2' site, a series of novel uracil derivatives 1a-l and 2a-i incorporating benzoic acid moieties at the N3 position were designed and evaluated for their DPP-4 inhibitory activity. Structure-activity relationships (SAR) study led to the identification of the optimal compound 2b as a potent and selective DPP-4 inhibitor (IC50=1.7nM). Docking study revealed the additional salt bridge formed between the carboxylic acid and primary amine of Lys554 has a key role in the enhancement of the activity. Furthermore, compound 2b exhibited no cytotoxicity in human hepatocyte LO2 cells up to 50muM. Subsequent in vivo evaluations revealed that the ester of 2b robustly improves the glucose tolerance in normal mice. The overall results have shown that compound 2b has the potential to a safe and efficacious treatment for T2DM.
BACKGROUND AND PURPOSE: Low-density-lipoprotein-receptor-associated protein 4 (LRP4) autoantibodies have recently been detected in myasthenia gravis (MG), but little is known about the clinical characteristics associated with this serological type. In this study, the clinical features of Chinese patients with anti-LRP4 antibody-positive MG were characterized. METHODS: A total of 2172 MG serum samples were collected from patients in various parts of China. An enzyme-linked immunosorbent assay was used to detect acetylcholine receptor (AChR) antibody and titin antibody, and cell-based assays were used to detect muscle-specific kinase antibody and LRP4 antibody. Clinical data for patients with MG were collected from different provinces in China. RESULTS: In total, 16 (0.8%) patients with LRP4-MG were found amongst 2172 total patients, including three patients with AChR/LRP4-MG. Additionally, 13 (2.9%) patients with LRP4-MG were found amongst 455 patients with double seronegative MG. The ratio of males to females for these 13 patients was 1:1.6, and 53.8% patients were children. A total of 91.7% of cases exhibited initial ocular involvement, and 58.3% of cases exhibited simple eye muscle involvement. Responses to acetylcholinesterase inhibitors and prednisone were observed. CONCLUSION: The expanded sample confirmed that the positive rate of LRP4 antibodies in China is lower than that in western countries. Our results highlighted the differences between LRP4-MG and other antibody groups. Children and female patients with LRP4-MG have a higher prevalence, often involving the ocular muscles and limb muscles. The clinical symptoms are mild, and satisfactory responses to treatment are often achieved.
Title: Expansion of the scaffold diversity for the development of highly selective butyrylcholinesterase (BChE) inhibitors: Discovery of new hits through the pharmacophore model generation, virtual screening and molecular dynamics simulation Lu X, Yang H, Li Q, Chen Y, Zhou Y, Feng F, Liu W, Guo Q, Sun H Ref: Bioorg Chem, 85:117, 2018 : PubMed
Butyrylcholinesterase (BChE) is recently considered as a new target for the treatment of Alzheimer's disease (AD). There is an increasing interest in the development of BChE inhibitors. In the present study, a set of pharmacophore models for BChE was developed and validated. Based on the models, virtual screening was performed on five compound collections, from which seventeen potential hits were retained for biological investigation. In total, eight of these seventeen potential hits showed selective BChE inhibitory activity. Moreover, four compounds displayed IC50 values in sub-micromolar range on eqBChE and three displayed IC50 values <2muM on huBChE. The diverse scaffolds of the active compounds provided good starting point further development of selective BChE inhibitors. As far as we concerned, here we disclose the first selective pharmacophore model targeting BChE. The high rate of the model in the identification of active hits indicates it is a valuable tool for the development of selective BChE inhibitors, which may benefit the treatment of AD.
A series of quinoline-ferulic acid hybrids has been designed, synthesized, and evaluated as cholinesterase inhibitors. Most of the compounds showed good inhibitory activities toward both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Among them, 10f was found to be the most potent inhibitor against AChE (IC50=0.62+/-0.17mum), and 14 was the most potent inhibitor against BChE (IC50=0.10+/-0.01mum). Representative compounds, such as 10f and 12g, act in a competitive manner when they inhibit AChE or BChE. Molecular docking and dynamic simulation revealed that the synthesized compounds bind to the target by simultaneously interacting with the catalytic active site (CAS) and the peripheral anionic site (PAS) of both AChE and BChE. The U-shaped confirmation was preferred when 12g bound to BChE, which was different from the linear conformation of 10f bound to AChE. Cell-based assays have confirmed the moderate neuroprotective effects of compounds 10f and 12g against H2O2-induced oxidative damage towards PC12 cells. Moreover, the hepatotoxicity of 12g was lower than that of tacrine, indicating its potential safety as an anti-Alzheimer's agent. In summary, we report a new chemotype of multifunctional hybrid, which may be further modified to develop new anti-Alzheimer's agents.
Title: Bioactivity-guided identification of flavonoids with cholinesterase and beta-amyloid peptide aggregation inhibitory effects from the seeds of Millettia pachycarpa Tu Y, Wu C, Kang Y, Li Q, Zhu C, Li Y Ref: Bioorganic & Medicinal Chemistry Lett, 29:1194, 2019 : PubMed
Millettia pachycarpa Benth, a widely used anthelminthic drug in folk, is rich in flavonoids with various bioactivities. This study aimed to identify active flavonoids with anti-Alzheimer's disease (AD) effect from its seeds by a bioassay-guided isolation. A novel rotenoid with unusual oxidative ring-opening skeleton (10) and nine known flavonoids (1-9) were obtained, and their structures were elucidated by NMR and HR-ESIMS analysis. Among all isolates, 7 and 8 showed selective butyrylcholinesterase (BChE) inhibitory activities (IC50=2.34 and 11.49muM, respectively), while 3 was classified as a dual-action inhibitor against acetylcholinesterase (AChE) and BChE (IC50 AChE=17.14muM, IC50 BChE=5.68muM). Further kinetic study revealed that 3, 7, and 8 were mixed-type BChE inhibitors, but 3 was a competitive AChE inhibitor. Their strong binding affinities to BChE were confirmed by fluorescence quenching analysis. Additionally, 3 and 8 exhibited potent inhibitory effects against beta-amyloid peptide aggregation. These results revealed M. pachycarpa could be a valuable source for anti-AD leads development, and compounds 3, 7 and 8 were worthy of further study as multifunctional or specific agents for AD treatment.
Title: Purification and biochemical characterization of FrsA protein from Vibrio vulnificus as an esterase Wang X, Li ZM, Li Q, Shi M, Bao L, Xu D, Li Z Ref: PLoS ONE, 14:e0215084, 2019 : PubMed
Fermentation-respiration switch protein (FrsA) was thought to play an important role in controlling the metabolic flux between respiration and fermentation pathways, whereas the biochemical function of FrsA was unclear yet. A gene coding for FrsA protein from Vibrio vulnificus was chemically synthesized. The recombinant VvFrsA was expressed as a soluble protein and purified by Ni-NTA affinity chromatography. The protein had a subunit molecular weight of ca. 45 kDa by SDS-PAGE and preferred short-chain esters when p-nitrophenyl alkanoate esters were used as substrates. Optimum condition for VvFrsA was found to be at pH 9.0 and 50 degrees C. The protein retained high esterase activity at alkaline condition and would denature slowly at over 50 degrees C. With p-nitrophenyl acetate as the substrate, the Km and kcat were determined to be 18.6 mM and 0.67 s-1, respectively, by steady-state kinetic assay. Molecular dynamics simulation and docking model structure revealed that p-nitrophenyl acetate could be the substrate of VvFrsA. In conclusion our results demonstrated that the protein was able to catalyze the hydrolysis of esters, especially p-nitrophenyl acetate, for the first time.
Title: Discovery, molecular dynamic simulation and biological evaluation of structurally diverse cholinesterase inhibitors with new scaffold through shape-based pharmacophore virtual screening Yang H, Du C, Li Q, Chen T, Lu X, Feng F, Chen Y, Liu W, Sun H Ref: Bioorg Chem, 92:103294, 2019 : PubMed
Designing small molecule inhibitors targeting cholinesterases (ChEs) is considered as an efficient strategy for the treatment of Alzheimer's disease (AD). In the present study, based on a shaped-based pharmacophore (SBP) model that we reported previously, virtual screening was performed on four commercial compound databases, from which eight small molecules containing new structurally scaffolds were retained and evaluated. In general, six of these potential hits were identified to be selective ChEs inhibitors. Three compounds exhibited IC50 values and Ki values in micromolar range on acetylcholinesterase (AChE), the most active compound 4 showed IC50 value of 6.31+/-2.68muM and Ki value of 4.76muM. Other three compounds displayed IC50 values and Ki values in micromolar range on butyrylcholinesterase (BChE) with high target selectivity, the most active compound 1 showed IC50 value of 3.87+/-2.48muM and Ki value of 1.52muM. Multiple biological evaluations were performed to determine their cytotoxicity, cyto-protective effects, antioxidant effect as well as druglike properties. These compounds provide new cores for the further design and optimization, with the aim to discover new ChEs inhibitors for the treatment of AD.
Title: Insecticidal and Acetylcholinesterase Inhibition Activity of Veratrum nigrum Alkaloidal Extract against the German Cockroach (Blattella germanica) Cai X, Li Q, Xiao L, Lu H, Tang J, Huang J, Yuan J Ref: J Arthropod Borne Dis, 12:414, 2018 : PubMed
Background: Veratrum nigrum (Liliaceae) is perennial medicinal plant widely used to treat various conditions. To determine its insecticidal properties against the German cockroach (Blattella germanica), several laboratory tests were carried out. Methods: A 4kg dry sample of V. nigrum root was purchased from the medicinal material market in Yunnan Province in 2015, China. In contact toxicity tests, V. nigrum alkaloidal extract was topically applied to the abdomen of cockroaches using a micro-applicator. In vitro acetylcholinesterase (AChE) activity tests were performed using a modified Ellman method. Results: Veratrum nigrum alkaloidal extract was toxic to male adults and 4(th) nymphs cockroaches, with median lethal dose (LD50) values of 14.90mug/insect, 14.21mug/insect for adults and 41.45mug/insect, 39.01mug/insect for 4(th) nymphs after 24h and 48h exposure, respectively. There was a significant difference between adults and nymphs in terms of tolerance to V. nigrum alkaloidal extract. There was no significant difference in mortalities at 24h and 48h, the lethal effect of V. nigrum alkaloidal extract on German cockroach was quick. AChE activity tests showed that V. nigrum alkaloidal extract had an excellent inhibitory effect on AChE: inhibition in the 4(th) nymphs and male adults had 50% inhibiting concentration (IC50) values of 3.56mg/ml and 5.78mg/ml respectively. The inhibitory effect of AChE activity was positively correlated with inhibitory time (0-20min), at a concentration of 1mg/ml, inhibition of nymph and adult AChE activity had 50% inhibiting time (IT50) values of 8.34min and 16.75min, respectively. Conclusion: V. nigrum may be explored as a potential natural insecticide for control of the German cockroach.
Title: The HindIII and PvuII polymorphisms of lipoprotein lipase (LPL) gene reduce the risk of ischemic stroke (IS): A meta-analysis Cao L, Li Q, Chen X Ref: Medicine (Baltimore), 97:e0483, 2018 : PubMed
BACKGROUND: Lipoprotein lipase (LPL) polymorphisms were suggested to be the risk factor for ischemic stroke (IS). However, controversial results were obtained. Our objective was to investigate the association of LPL polymorphisms at Ser447Ter, HindIII (+/-), and PvuII (+/-) with IS risk. METHODS: Literatures search were carried out on databases: PubMed, Web of science, the Cochrane database of system reviews, Chinese National Knowledge Infrastructure, and Embase. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated to detect the relationship between LPL polymorphisms and the risk of IS. RESULTS: No significant association was detected between LPL Ser447Ter and IS in allelic, dominant, or recessive models (P > .05). Significant lower frequencies of allelic and dominant models of LPL HindIII (+/-) and PvuII (+/-) in cases were detected (HindIII (+/-): allelic model: P = .0002, OR[95%CI] = 0.80 [0.71, 0.90]; dominant model: P = 0.003, OR[95%CI] = 0.80 [0.69, 0.92]; PvuII (+/-): allelic model: P < 0.0001, OR[95%CI] = 0.75[0.65-0.86]; dominant model: P = 0.02, OR[95%CI] = 0.67[0.48-0.93]). And the recessive model of PvuII (+/-) was significantly associated with the IS risk (P = .01, OR[95%CI] = .71[0.55-0.93]). Subgroup analysis stratified by ethnicity showed that the frequencies of allelic, dominant, and recessive models of HindIII (+/-), as well as dominant model of PvuII (+/-) were significant lower in Asian cases (HindIII (+/-): allelic model: P < .00001, OR[95%CI] = 0.69 [0.59, 0.79]; dominant model: P < .0001, OR[95%CI] = 0.69 [0.58, 0.83]; recessive model: P = .005, OR[95%CI] = 0.66 [0.50, 0.89]; PvuII (+/-): dominant model: P = .0008, OR[95%CI] = 0.66 [0.51-0.84]), but not in Caucasian cases (P > .05). In addition, the frequencies of allelic and recessive models of PvuII (+/-) significantly decreased in Caucasian cases (P < .05). CONCLUSION: the HindIII (+/-) and PvuII (+/-), but not the Ser447Ter might be the protective factors for IS.
Infection by the Middle East respiratory syndrome coronavirus (MERS-CoV) causes respiratory illness and has a high mortality rate (~35%). The requirement for the virus to be manipulated in a biosafety level three (BSL-3) facility has impeded development of urgently-needed antiviral agents. Here, we established anovel mouse model by inserting human dipeptidyl peptidase 4 (hDPP4) into the Rosa26 locus using CRISPR/Cas9, resulting in global expression of the transgene in a genetically stable mouse line. The mice were highly susceptible to infection by MERS-CoV clinical strain hCoV-EMC, which induced severe diffuse pulmonary disease in the animals, and could also be infected by an optimized pseudotyped MERS-CoV. Administration of the neutralizing monoclonal antibodies, H111-1 and m336, as well as a fusion inhibitor peptide, HR2P-M2, protected mice from challenge with authentic and pseudotyped MERS-CoV. These results confirmed that the hDPP4-knockin mouse is a novel model for studies of MERS-CoV pathogenesis and anti-MERS-CoV antiviral agents in BSL-3 and BSL-2facilities, respectively.
Title: Combined transcriptomic/proteomic analysis of salivary gland and secreted saliva in three planthopper species Huang HJ, Lu JB, Li Q, Bao YY, Zhang CX Ref: J Proteomics, 172:25, 2018 : PubMed
The planthoppers are piercing-sucking pests that continuously inject saliva into host plants using specialized stylets. However, knowledge on the constituent and function of planthopper saliva proteins was still limited. In this study, the transcriptomic and proteomic approach were adopted to characterize the composition of salivary glands and their secreted saliva in three planthoppers, respectively. Gene repertoires of salivary glands in brown planthopper (Nilaparvata lugens, BPH), white-backed planthopper (Sogatella furcifera, WBPH) and small brown planthopper (Laodelphax striatellus, SBPH) were very similar, which actively involved in protein synthesis and energy metabolism. Comparative analysis of saliva proteome was performed among three planthoppers and other reported insect species. The saliva composition in three planthoppers was diverse, with 55 saliva proteins commonly identified in more than two species. A few proteins, including serine protease, carboxylesterase, aminopeptidase N, lipophorin, elongation factor, carbonic anhydrase, and calcium binding protein were ubiquitous distributed in different insects, indicating conserved function of saliva. While, the majority of saliva proteins were specifically identified in planthoppers, which might be the evolutional adaptation of insects to different hosts. Our work gained insight into the interaction between insect and host plant through salivary approach, and provided a good resource for functional characterization of effectors. BIOLOGICAL SIGNIFICANCE: Secreted saliva from insects is attracting immense research interest on the global level due to the crucial roles in determining the compatibility between the insects and their hosts. The three planthoppers: brown planthopper (Nilaparvata lugens, BPH), small brown planthopper (Laodelphax striatellus, SBPH), and white-backed planthopper (Sogatella furcifera, WBPH) caused serious damage to rice plants throughout Asia. However, knowledge on the composition and function of their secreted saliva proteins was limited. Our study characterizes the global gene expression of salivary glands and their secreted saliva by Illumina sequencing technology and LC-MS/MS analysis, respectively. By comparative analysis, the ubiquitous and specific saliva compounds in different insects were unveiled.
Title: Design, synthesis and biological evaluation of new coumarin-dithiocarbamate hybrids as multifunctional agents for the treatment of Alzheimer's disease Jiang N, Huang Q, Liu J, Liang N, Li Q, Xie SS Ref: Eur Journal of Medicinal Chemistry, 146:287, 2018 : PubMed
A series of new coumarin-dithiocarbamate hybrids were designed, synthesized and evaluated as multifunctional agents for the treatment of Alzheimer's Disease (AD). The biological assays indicated that most of them showed potent inhibition and excellent selectivity towards acetylcholinesterase (AChE), and could inhibit self-induced beta-amyloid (Abeta) aggregation. Especially, compound 4n presented the highest ability to inhibit AChE (IC50, 0.027muM for hAChE) and good inhibition of Abeta aggregation (40.19% at 25muM). Kinetic and molecular modeling studies revealed that 4n was a mixed-type inhibitor, which could interact simultaneously with the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. In addition, it also possessed specific metal-chelating ability, good BBB permeability and low toxicity on SH-SY5Y neuroblastoma cells. Moreover, compound 4n did not exhibit any acute toxicity in mice at doses up to 1000mg/kg, and could reverse the cognitive dysfunction of scopolamine-induced AD mice. As far as we know, 4n was the first reported dithiocarbamate derivative with multifunctional activity. Its excellent profiles in vitro and effectivity in vivo highlight this structurally distinct compound as a potential lead compound in the research of innovative multifunctional drugs for AD.
Title: Donepezil-based multi-functional cholinesterase inhibitors for treatment of Alzheimer's disease Li Q, He S, Chen Y, Feng F, Qu W, Sun H Ref: Eur Journal of Medicinal Chemistry, 158:463, 2018 : PubMed
Alzheimer's disease (AD) is one of the most common neurodegenerative disorders in elderly people. Considering the multifactorial nature of AD, the concept of multi-target-directed ligands (MTDLs) has recently emerged as a new strategy for designing therapeutic agents on AD. MTDLs are confirmed to simultaneously affect diverse targets which contribute to etiology of AD. As the most potent approved drug, donepezil affects various events of AD, like inhibiting cholinesterases activities, anti-Abeta aggregation, anti-oxidative stress et al. Modifications of donepezil or hybrids with pharmacophores of donepezil in recent five years are summarized in this article. On the basis of case studies, our concerns and opinions about development of donepezil derivatives, designing of MTDLs, and perspectives for AD treatments are discussed in final part.
Title: Biosynthetic and antimicrobial potential of actinobacteria isolated from bulrush rhizospheres habitat in Zhalong Wetland, China Li Y, Li Q, Gao J, Wang J, Luo Y, Fan X, Gu P Ref: Arch Microbiol, 200:695, 2018 : PubMed
The wetland ecosystem is known to possess unique vegetation and serves multiple functions within the environment. In this study, bacterial bioprospecting of bulrush rhizospheres in the Zhalong Wetland, China, was performed using comprehensive methods, including strain isolation and phylogenetic analysis, PCR detection of biosynthetic gene clusters, assessment of antimicrobial activity, metabolite profiling and genome analysis. A total of 27 actinobacterial strains were isolated, and their biosynthetic gene clusters (NRPS, PKS-I and PKS-II) were investigated; all of the tested strains had at least one of the three aforementioned biosynthetic gene clusters. Furthermore, fermentation broth extracts produced by these strains showed antimicrobial activities against certain pathogens, and ten of the extracts exhibited broad-spectrum antimicrobial activity. Liquid chromatography-mass spectrometry (LC-MS) analysis indicated chemical diversity of secondary metabolites from these extracts. Among these strains, ZLSD-24 generated the largest amounts and types of secondary metabolites. Subsequent genome analysis showed that 41 secondary metabolite biosynthetic gene clusters were present in the strain ZLSD-24, which was in accordance with the LC-MS data. Taken together, the results of this study reveal that bulrush rhizosphere habitat in the Zhalong wetland is a promising source of novel natural products.
In our endeavor towards the development of potent multi-target ligands for the treatment of Alzheimer's disease, miconazole was identified to show BuChE-IDO1 dual-target inhibitory effects. Morris water maze test indicated that miconazole obviously ameliorated the cognitive function impaired by scopolamine. Furthermore, it showed good safety in primary hepatotoxicity evaluation. Based on these results, we designed, synthesized, and evaluated a series of miconazole derivatives as BuChE-IDO1 dual-target inhibitors. Out of the 12 compounds, 5i and 5j exhibited the best potency in enzymatic evaluation, thus were selected for subsequent behavioral study, in which the two compounds exerted much improved effect than tacrine. Meanwhile, 5i and 5j displayed no apparent hepatotoxicity. The results suggest that miconazole analogue offers an attractive starting point for further development of new BuChE-IDO1 dual-target inhibitors against Alzheimer's disease.
Title: Ultra-thin bimetallic alloy nanowires with porous architecture/monolayer MoS2 nanosheet as a highly sensitive platform for the electrochemical assay of hazardous omethoate pollutant Song D, Li Q, Lu X, Li Y, Wang Y, Gao F Ref: J Hazard Mater, 357:466, 2018 : PubMed
A novel electrochemical biosensor was designed for sensitive detection of organophosphate pesticides based on three-dimensional porous bimetallic alloy architecture with ultrathin nanowires (PdCo NWs, PdCu NWs, PdNi NWs) and monolayer MoS2 nanosheet (m-MoS2). The bimetallic alloy NWs/m-MoS2 nanomaterials were used as a sensing platform for electrochemical analysis of omethoate, a representative organophosphate pesticide, via acetylcholinesterase inhibition pathway. We demonstrated that all three bimetallic alloy NWs enhanced electrochemical responses of enzymatic biosensor, benefited from bimetallic synergistic action and porous structure. In particular, PdNi NWs outperformed other two bimetallic alloy. Moreover, PdNi NWs/m-MoS2 as an electronic transducer is superior to the corresponding biosensor in the absence of monolayer MoS2 nanosheet, which arise from synergistic signal amplification effect between different components. Under optimized conditions, the developed biosensor on the basis of PdNi NWs/m-MoS2 shows outstanding performance for the electrochemical assay of omethoate, such as a wide linear range (10(-13) M approximately 10(-7) M), a low detection limit of 0.05pM at a signal-to-noise ratio of 3, high sensitivity and long-time stability. The results demonstrate that bimetallic alloy NWs/m-MoS2 nanocomposites could be excellent transducers to promote electron transfer for the electrochemical reactions, holding great potentials in the construction of current and future biosensing devices.
Draft genomes of the species Annulohypoxylon stygium, Aspergillus mulundensis, Berkeleyomyces basicola (syn. Thielaviopsis basicola), Ceratocystis smalleyi, two Cercospora beticola strains, Coleophoma cylindrospora, Fusarium fracticaudum, Phialophora cf. hyalina and Morchella septimelata are presented. Both mating types (MAT1-1 and MAT1-2) of Cercospora beticola are included. Two strains of Coleophoma cylindrospora that produce sulfated homotyrosine echinocandin variants, FR209602, FR220897 and FR220899 are presented. The sequencing of Aspergillus mulundensis, Coleophoma cylindrospora and Phialophora cf. hyalina has enabled mapping of the gene clusters encoding the chemical diversity from the echinocandin pathways, providing data that reveals the complexity of secondary metabolism in these different species. Overall these genomes provide a valuable resource for understanding the molecular processes underlying pathogenicity (in some cases), biology and toxin production of these economically important fungi.
Title: One-step methodology for the direct covalent capture of GPCRs from complex matrices onto solid surfaces based on the bioorthogonal reaction between haloalkane dehalogenase and chloroalkanes Zeng K, Li Q, Wang J, Yin G, Zhang Y, Xiao C, Fan T, Zhao X, Zheng X Ref: Chem Sci, 9:446, 2018 : PubMed
Protein immobilization techniques play an important role in the development of assays for disease diagnosis and drug discovery. However, many of these approaches are not applicable to transmembrane proteins. G protein-coupled receptors (GPCRs) are the largest protein superfamily encoded by the human genome and are targeted by a quarter of all prescription drugs. GPCRs are highly dynamic and sensitive to changes in the ambient environment, and current immobilization methodologies are not suitable for GPCRs. We used haloalkane dehalogenase (Halo) as an immobilization tag fused to the beta2-adrenoceptor (beta2-AR), angiotensin II type 1 (AT1) and angiotensin II type 2 (AT2) receptors. The engineered Halo-tag covalently binds to a specific substrate chloroalkane through Asp 106 in the catalytic pocket. The Halo-tagged GPCRs were expressed in Escherichia coli at a suitable yield. Accordingly, we loaded cell lysate containing Halo-tagged GPCRs onto a macroporous silica gel coated with chloroalkane. Morphological characterization indicated a homogeneous monolayer of immobilized Halo-tagged GPCRs on the silica gel surface. The immobilized receptors proved to be surrounded by specific bound phospholipids including PG C18:1/C18:1. We observed a radio-ligand binding ability and ligand-induced conformational changes in the immobilized GPCRs, suggesting the preservation of bioactivity. This method is a one-step approach for the specific immobilization of GPCRs from cell lysates and validates that immobilized receptors retain canonical ligand binding capacity. Our immobilization strategy circumvents labor-intensive purification procedures and minimizes loss of activity. The immobilized receptors can be applied to high-throughput drug and interaction partner screening for GPCRs.
Title: Pharmacological Inhibition of Soluble Epoxide Hydrolase Ameliorates Chronic Ethanol-Induced Cardiac Fibrosis by Restoring Autophagic Flux Zhou C, Huang J, Li Q, Zhan C, He Y, Liu J, Wen Z, Wang DW Ref: Alcohol Clin Exp Res, 42:1970, 2018 : PubMed
BACKGROUND: Chronic drinking leads to myocardial contractile dysfunction and dilated cardiomyopathy, and cardiac fibrosis is a consequence of these alcoholic injuries. Soluble epoxide hydrolase (sEH) hydrolyzes epoxyeicosatrienoic acids (EETs) to less bioactive diols, and EETs have cardioprotective properties. However, the effects of sEH inhibition in ethanol (EtOH)-induced cardiac fibrosis are unknown. METHODS: This study was designed to investigate the role and underlying mechanisms of sEH inhibition in chronic EtOH feeding-induced cardiac fibrosis. C57BL/6J mice were fed a 4% Lieber-DeCarli EtOH diet for 8 weeks, and the sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) was administered throughout the experimental period. RESULTS: The results showed that chronic EtOH intake led to cardiac dilatation, collagen deposition, and autophagosome accumulation, while TPPU administration ameliorated these effects. In vitro, treating primary cardiac fibroblasts (CFs) with EtOH resulted in CF activation, including alpha smooth muscle actin overexpression, collagen synthesis, and cell migration. Moreover, EtOH disturbed CF autophagic flux, as evidenced by the increased LC3 II/I ratio and SQSTM1 expression, and by the enhanced autophagosome accumulation. TPPU treatment prevented the activation of CF induced by EtOH and restored the impaired autophagic flux by suppressing mTOR activation. CONCLUSIONS: Taken together, these findings suggest that sEH pharmacological inhibition may be a unique therapeutic strategy for treating EtOH-induced cardiac fibrosis.
Title: Synthesis, pharmacology and molecular docking on multifunctional tacrine-ferulic acid hybrids as cholinesterase inhibitors against Alzheimer's disease Zhu J, Yang H, Chen Y, Lin H, Li Q, Mo J, Bian Y, Pei Y, Sun H Ref: J Enzyme Inhib Med Chem, 33:496, 2018 : PubMed
The cholinergic hypothesis has long been a "polar star" in drug discovery for Alzheimer's disease (AD), resulting in many small molecules and biological drug candidates. Most of the drugs marketed for AD are cholinergic. Herein, we report our efforts in the discovery of cholinesterases inhibitors (ChEIs) as multi-target-directed ligands. A series of tacrine-ferulic acid hybrids have been designed and synthesised. All these compounds showed potent acetyl-(AChE) and butyryl cholinesterase(BuChE) inhibition. Among them, the optimal compound 10g, was the most potent inhibitor against AChE (electrophorus electricus (eeAChE) half maximal inhibitory concentration (IC50) = 37.02 nM), it was also a strong inhibitor against BuChE (equine serum (eqBuChE) IC50 = 101.40 nM). Besides, it inhibited amyloid beta-protein self-aggregation by 65.49% at 25 muM. In subsequent in vivo scopolamine-induced AD models, compound 10g obviously ameliorated the cognition impairment and showed preliminary safety in hepatotoxicity evaluation. These data suggest compound 10g as a promising multifunctional agent in the drug discovery process against AD.
Title: Efficient kinetic resolution of (+/-)-menthol by a lipase from Thermomyces lanuginosus De Yan H, Li Q, Wang Z Ref: Biotechnol Appl Biochem, 64:87, 2017 : PubMed
A lipase from Thermomyces lanuginosus (Lipozyme TL IM) exhibited high enantioselectivity for kinetic resolution of (+/-)-menthol in organic solvent. The various reaction parameters affecting the conversion and enantioselectivity were studied. The optimum reaction conditions for the transesterification reaction were found with vinyl acetate in the solvent of methyl tert-butyl ether with a vinyl acetate:(+/-)-menthol molar ratio of 5:1 and an enzyme concentration of 200 g/L at 30 degreeC. In these conditions, (-)-menthyl acetate with 99.3% enantiomeric excess was obtained, whereas the conversion was 34.7% with the reaction time of 12 H at the substrate concentration of 0.5 M. In addition, the enzyme allowed the substrate loading to be increased up to 1.5 M without the decrease of the enantioselectivity. These results indicated that Lipozyme TL IM was a promising biocatalyst in the resolution of (+/-)-menthol.
Title: Discovery of triazole-based uracil derivatives bearing amide moieties as novel dipeptidyl peptidase-IV inhibitors Deng X, Han L, Zhou J, Zhang H, Li Q Ref: Bioorg Chem, 75:357, 2017 : PubMed
Dipeptidyl peptidase-IV (DPP-4) is a validated target for T2DM treatment. We previously reported a novel series of triazole-based uracil derivatives bearing aliphatic carboxylic acids with potent DPP-4 inhibitory activities in vitro, but these compounds showed poor hypoglycemic effects in vivo. Herein we further optimized the triazole moiety by amidation of the carboxylic acid to improve in vivo activities. Two series of compounds 3a-f and 4a-g were designed and synthesized. By screening in DPP-4, compound 4c was identified as a potent DPP-4 inhibitor with the IC(50) value of 28.62 nM. Docking study revealed compound 4c has a favorable binding mode and interpreted the SAR of these analogs. DPP-8 and DPP-9 tests indicated compound 4c had excellent selectivity over DPP-8 and DPP-9. Further in vivo evaluations revealed that compound 4c showed more potent hypoglycemic activity than its corresponding carboxylic acid in ICR mice and dose-dependently reduced glucose levels in type 2 diabetic C57BL/6 mice. The overall results have shown that compound 4c could be a promising lead for further development of novel DPP-4 agents treating T2DM.
Title: Characterization and function of Mycobacterium tuberculosis H37Rv Lipase Rv1076 (LipU) Li C, Li Q, Zhang Y, Gong Z, Ren S, Li P, Xie J Ref: Microbiol Res, 196:7, 2017 : PubMed
Lipids and lipases/esterases are essential for Mycobacterium tuberculosis (Mtb) survival and persistence, even virulence. Mycobacterium tuberculosis H37Rv Rv1076 (LipU), a member of lipase family, is homologous to the human Hormone Sensitive Lipase (HSL) based on the presence of conserved motif 'GXSXG'. To define the enzymatic characteristics of rv1076, the gene was cloned, and expressed in Escherichia coli. The protein was purified for enzymatic characterization. LipU showed high specific activity for the hydrolysis of short carbon chain substrates with optimal activity at 40 degrees C/pH 8.0 and stability at low temperature and near-neutral pH. The specific activity, Km and Vmax of LipU was calculated to 176.7U/mg, 1.73muM and 62.24muM/min respectively. Ionic detergents can inhibit its activity. The active-site residues of LipU were determined to be Ser140, Asp244 and His269 by site-directed mutagenesis. The upregulation of Mycobacterium tuberculosis rv1076 under nutritive stress implicates a role in starvation.
Title: Recent progress in the identification of selective butyrylcholinesterase inhibitors for Alzheimer's disease Li Q, Yang H, Chen Y, Sun H Ref: Eur Journal of Medicinal Chemistry, 132:294, 2017 : PubMed
Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders with notable factor of dysfunction in cholinergic system. Low ACh level can be observed in the pathogenesis of AD. Several AChE inhibitors have already been used for clinical treatments. However, other than normal conditions, ACh is mostly hydrolyzed by BuChE in progressed AD. Account for an increased level of BuChE and decreased level of AChE in the late stage of AD, development of selective BuChE inhibitor is of vital importance. Up till now, compounds with various scaffolds have been discovered to selectively inhibit BuChE. Different effective anti-BuChE molecules are concluded in this review.
Title: Mycobacterium tuberculosis rv1400c encodes functional lipase/esterase Lin Y, Li Q, Xie L, Xie J Ref: Protein Expr Purif, 129:143, 2017 : PubMed
Lipases catalyze the hydrolysis of triglycerides (TAG). Open reading frames (ORF) predicted to encode enzymes involved in fatty acids breakdown are abundant in Mycobacterium tuberculosis genome. To define the function of M. tuberculosis rv1400c (LipI), a putative Hormone Sensitive Lipase (HSL) subfamily ORF, the rv1400c was cloned, expressed and purified in Escherichia coli as fusion protein. The purified LipI preferred short carbon chain substrates with an optimal activity at 37 degrees C/pH 8.0 and stable between pH 6.0 to 9.0. Its specific activity was calculated to 35.71 U/mg with pNP-butyrate as a preferred substrate. SDS, CTAB and Zn2+ can inhibit this enzyme. The conserved residues Ser165 and His291 were shown to be important for the catalysis activity of Rv1400c by site-directed mutagenesis. The biochemical and genetical data showed M. tuberculosis LipI might be a good candidate catalyst for polyunsaturated fatty acids.
Title: Therapeutic Agents in Alzheimer's Disease Through a Multi-targetdirected Ligands Strategy: Recent Progress Based on Tacrine Core Lin H, Li Q, Gu K, Zhu J, Jiang X, Chen Y, Sun H Ref: Curr Top Med Chem, 17:3000, 2017 : PubMed
Alzheimer's Disease (AD) is one of the most common forms of dementia in elderly people. To date, efficacious therapeutic agent for the treatment of AD is still very limited, so it has long been a challenging and attractive task to discover new anti-AD drugs. Considering the multifactorial nature of AD, recently, the concept of Multi-Target-Directed Ligands (MTDLs) has emerged as a new strategy for designing therapeutic agents on AD. MTDLs are believed to exert their effects through simultaneously affecting multiple targets which contribute to etiology of AD. Therefore, MTDLs are considered to be more efficacious than mono-target agents. Tacrine is the first drug approved by Food and Drug Administration (FDA). Although the clinical use of tacrine is restricted because of its hepatotoxicity, the high Ligand Efficiency (LE) of this compound makes it an ideal component for designing MTDLs. This article provides an update review of the advances on the development of MTDLs based on tacrine. Case studies are carefully selected to show the detailed strategy on medicinal modification of Tacrine-Based MTDLs. Finally, several concerns and opinions on designing new MTDLs are discussed as well.
Title: Chemical composition and insecticidal property of Myrsine stolonifera (Koidz.) walker (Family: Myrsinaceae) on Musca domestica (Diptera: Muscidae) Wang XG, Li Q, Jiang SR, Li P, Yang JZ Ref: Acta Trop, 170:70, 2017 : PubMed
Musca domestica is one of the most important pests of human health, and has developed strong resistance to many chemicals used for its control. One important approach for creating new pesticides is the exploration of novel compounds from plants. During a wide screening of plants with insecticidal properties that grow in southern China, we found that the methanolic extracts of Myrsine stolonifera had insecticidal activity against the adults of M. domestica. However, the insecticidal constituents and mechanisms of the M. stolonifera extracts remain unclear. The insecticidal components of the methanolic extracts of M. stolonifera were isolated with activity-guided fractionation. From the spectra of nuclear magnetic resonance (NMR) and mass spectrometry (MS), the compounds were identified as syringing (1), 2,6-dimethoxy-4-hydroxyphenol-1-O-beta-d-glu (2), kaempferol-3-O-glu-rha-glu (3), and quercetin-3-O-glu-rha-glu (4). This study is the first to report the spectral data for compounds 3 and 4, and their LC50 values were 0.52mg/g sugar and 0.36mg/g sugar 24h after treatment of the adults of M. domestica, respectively. Compounds 3 and 4 (LC25) also inhibited the activities of the enzymes carboxylesterase, glutathione S-transferase, mixed function oxidase, and acetylcholine esterase of adult M. domestica, particularly mixed function oxidase and acetylcholine esterase. The cytotoxic effects of compounds 3 and 4 on cell proliferation, mitochondrial membrane potentials (MMP) and reactive oxygen species (ROS) were demonstrated on SL-1 cells. From the extracts of M. stolonifera, quercetin-3-O-glu-rha-glu and kaempferol-3-O-glu-rha-glu have displayed comparable toxicities to rotenone on M. domestica and also exhibited cytotoxic effects on SL-1 cells; therefore, the extracts of M. stolonifera and their compounds have potential as botanical insecticides to control M. domestica.
Coconut palm (Cocos nucifera,2n = 32), a member of genus Cocos and family Arecaceae (Palmaceae), is an important tropical fruit and oil crop. Currently, coconut palm is cultivated in 93 countries, including Central and South America, East and West Africa, Southeast Asia and the Pacific Islands, with a total growth area of more than 12 million hectares [1]. Coconut palm is generally classified into 2 main categories: "Tall" (flowering 8-10 years after planting) and "Dwarf" (flowering 4-6 years after planting), based on morphological characteristics and breeding habits. This Palmae species has a long growth period before reproductive years, which hinders conventional breeding progress. In spite of initial successes, improvements made by conventional breeding have been very slow. In the present study, we obtained de novo sequences of the Cocos nucifera genome: a major genomic resource that could be used to facilitate molecular breeding in Cocos nucifera and accelerate the breeding process in this important crop. A total of 419.67 gigabases (Gb) of raw reads were generated by the Illumina HiSeq 2000 platform using a series of paired-end and mate-pair libraries, covering the predicted Cocos nucifera genome length (2.42 Gb, variety "Hainan Tall") to an estimated x173.32 read depth. A total scaffold length of 2.20 Gb was generated (N50 = 418 Kb), representing 90.91% of the genome. The coconut genome was predicted to harbor 28 039 protein-coding genes, which is less than in Phoenix dactylifera (PDK30: 28 889), Phoenix dactylifera (DPV01: 41 660), and Elaeis guineensis (EG5: 34 802). BUSCO evaluation demonstrated that the obtained scaffold sequences covered 90.8% of the coconut genome and that the genome annotation was 74.1% complete. Genome annotation results revealed that 72.75% of the coconut genome consisted of transposable elements, of which long-terminal repeat retrotransposons elements (LTRs) accounted for the largest proportion (92.23%). Comparative analysis of the antiporter gene family and ion channel gene families between C. nucifera and Arabidopsis thaliana indicated that significant gene expansion may have occurred in the coconut involving Na+/H+ antiporter, carnitine/acylcarnitine translocase, potassium-dependent sodium-calcium exchanger, and potassium channel genes. Despite its agronomic importance, C. nucifera is still under-studied. In this report, we present a draft genome of C. nucifera and provide genomic information that will facilitate future functional genomics and molecular-assisted breeding in this crop species.
A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 x 10(-20)), ER-negative BC (P=1.1 x 10(-13)), BRCA1-associated BC (P=7.7 x 10(-16)) and triple negative BC (P-diff=2 x 10(-5)). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 x 10(-3)) and ABHD8 (P<2 x 10(-3)). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3'-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk.
Fourteen metabolites with various structure types were isolated from endophytic Chaetomium globosum. Five compounds were separated from genus Chaetomium for the first time. Some compounds exhibited remarkable inhibition against phytopathogenic fungi causing root rot of Panax notoginseng. Compounds 1-5 had significant DPPH-free radical-scavenging activity. Compounds 3 and 5 indicated significant inhibitions against the acetylcholinesterase (AChE). From preliminary structure-activity relationship, it was found that the oxygenic five-membered ring of 3 and 5 was crucial in the anti-AChE activity. These structures provide new templates for the potential treatment and management of plant diseases and Alzheimer disease.
Title: Synthesis and biological evaluation of triazole based uracil derivatives as novel DPP-4 inhibitors Li Q, Han L, Zhang B, Zhou J, Zhang H Ref: Org Biomol Chem, 14:9598, 2016 : PubMed
A series of triazole based uracil derivatives were designed and synthesized as novel DPP-4 inhibitors. Compound A01 was identified as a lead compound for SAR studies focused on the structural modification at the S(2') subsite of DPP-4. The novel analogues A02-A25 were obtained by modifying the substituents at the phenyl group, and B01-B09, by introducing the carbonyl group. On screening in DPP-4, compounds B03, B04 and B08 showed a significant improvement in DPP-4 inhibitory activities compared to compound A01 and showed comparable activities to the marketed DPP-4 inhibitor, alogliptin. Docking studies revealed new favorable binding modes of designed compounds in the S(2') subsite and proved that structural modifications in the S(2') subsite were an effective option to increase the inhibition of DPP-4. In vitro DPP-8 and DPP-9 tests indicated that all compounds showed excellent selectivity against DPP-8 and DPP-9. Further in vivo evaluation showed that compound B04 could significantly improve oral glucose tolerance in ICR mice and dose-dependently reduced glucose levels in type 2 diabetic C57BL/6 mice. These data suggest that compound B04 could be a promising DPP-4 inhibitor for future treatment of T2DM.
Title: A New Flavonoid Glycoside from Lysionotus pauciflorus Luo W, Wen Y, Tu Y, Du H, Li Q, Zhu C, Li Y Ref: Nat Prod Commun, 11:621, 2016 : PubMed
Ten flavonoids (1-10), including a new glycoside (nevadensin-7-sambubioside, 7), together with a phenylpropanoid glycoside (11) were isolated from Lysionotus pauciflorus. Their structures were elucidated by a combination of spectroscopic methods and comparing with literature data. Five compounds (1, 3, 4, 8, and 9) were obtained from the family Gesneriaceae for the first time. The new compound was evaluated in vitro for anticholinesterase activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), but was found to be inactive.
The enzyme ZHD101 from Clonostachys rosea hydrolyzes and deactivates the mycotoxin zearalenone (ZEN) and its zearalenol (ZOL) derivatives. ZHD101 prefers ZEN to ZOL as its substrate, but ZOL, especially the -form, shows higher estrogenic toxicity than ZEN. To enhance alpha-ZOL selectivity, we solved the complex structures of ZHD101 with both ZOLs and modified several lactone-surrounding residues. Among the mutants, V153H maintained activity for ZEN but showed a 3.7-fold increase in specific activity against alpha-ZOL, with an 2.7-fold reduction in substrate affinity but a 5.2-fold higher turnover rate. We then determined two V153H/ZOL complex structures. Here, the alpha-ZOL lactone ring is hydrogen-bonded to the H153 side chain, yielding a larger space for H242 to reconstitute the catalytic triad. In conclusion, structure-based engineering was successfully employed to improve the ZHD101 activity toward the more toxic alpha-ZOL, with great potential in further industrial applications.
Long noncoding RNAs (lncRNAs) play vital roles in tumorigenesis. However, the diagnostic values of most lncRNAs are largely unknown. To investigate whether gastric juice lncRNA-ABHD11-AS1 can be a potential biomarker in the screening of gastric cancer, 173 tissue samples and 130 gastric juice from benign lesion, gastric dysplasia, gastric premalignant lesions, and gastric cancer were collected. ABHD11-AS1 levels were detected by reverse transcription-polymerase chain reaction. Then, the relationships between ABHD11-AS1 levels and clinicopathological factors of patients with gastric cancer were investigated. The results showed that ABHD11-AS1 levels in gastric cancer tissues were significantly higher than those in other tissues. Its levels in gastric juice from gastric cancer patients were not only significantly higher than those from cases of normal mucosa or minimal gastritis, atrophic gastritis, and gastric ulcers but also associated with gender, tumor size, tumor stage, Lauren type, and blood carcinoembryonic antigen (CEA) levels. More importantly, when using gastric juice ABHD11-AS1 as a marker, the positive detection rate of early gastric cancer patients was reached to 71.4 %. Thanks to the special origin of gastric juice, these results indicate that gastric juice ABHD11-AS1 may be a potential biomarker in the screening of gastric cancer.
Title: New chemiluminescent substrates of paraoxonase 1 with improved specificity: synthesis and properties Abulimite Z, Mu X, Xiao S, Liu M, Li Q, Chen G Ref: Appl Biochem Biotechnol, 176:301, 2015 : PubMed
Paraoxonase 1 (PON1) is an important hydrolase, and the enzyme activity decreases in patients with liver disease, diabetes, coronary heart disease, etc. Phenyl acetate and organophosphates are usually employed as substrates for serum PON1 activity assay. However, phenyl acetate for arylesterase activity assay exhibits disadvantage of high background. According to properties of PON1, four new chemiluminescent acridinium esters were designed, prepared through three steps, and characterized with (1)H NMR and mass spectrometry (MS) data, and their properties as PON1 substrates were investigated. The hydrolyses of the four compounds catalyzed by recombinant human PON1 (rhPON1) (or serum) followed first-order kinetics within 22 min. The PON1 activator (NaCl, 0.10 mol L(-1)) could boost the rhPON1-mediated and serum-mediated hydrolyses of the acridinium esters to 2.01 ~ 2.26 folds, but 1.0 mol L(-1) NaCl decreased the serum arylesterase activity. RhPON1 showed selectivity over other serum esterases such as lipase, acetylcholinesterase, and esterase D more than 300 folds. By using ethylene diamine tetraacetic acid (EDTA) inhibitor, the specificities of the four substrates toward serum PON1 were determined as 78.3 ~ 92.9 %, which is improved than that of the model compound 9-(4-chloro-phenoxycarbonyl)-10-methylacridinium ester triflate. Due to low toxicity, high specificity, and sensitivity of the substrates, they are useful for serum PON1 activity assay.
The large yellow croaker Larimichthys crocea (L. crocea) is one of the most economically important marine fish in China and East Asian countries. It also exhibits peculiar behavioral and physiological characteristics, especially sensitive to various environmental stresses, such as hypoxia and air exposure. These traits may render L. crocea a good model for investigating the response mechanisms to environmental stress. To understand the molecular and genetic mechanisms underlying the adaptation and response of L. crocea to environmental stress, we sequenced and assembled the genome of L. crocea using a bacterial artificial chromosome and whole-genome shotgun hierarchical strategy. The final genome assembly was 679 Mb, with a contig N50 of 63.11 kb and a scaffold N50 of 1.03 Mb, containing 25,401 protein-coding genes. Gene families underlying adaptive behaviours, such as vision-related crystallins, olfactory receptors, and auditory sense-related genes, were significantly expanded in the genome of L. crocea relative to those of other vertebrates. Transcriptome analyses of the hypoxia-exposed L. crocea brain revealed new aspects of neuro-endocrine-immune/metabolism regulatory networks that may help the fish to avoid cerebral inflammatory injury and maintain energy balance under hypoxia. Proteomics data demonstrate that skin mucus of the air-exposed L. crocea had a complex composition, with an unexpectedly high number of proteins (3,209), suggesting its multiple protective mechanisms involved in antioxidant functions, oxygen transport, immune defence, and osmotic and ionic regulation. Our results reveal the molecular and genetic basis of fish adaptation and response to hypoxia and air exposure. The data generated by this study will provide valuable resources for the genetic improvement of stress resistance and yield potential in L. crocea.
Alzheimer's disease (AD) is characterized by amyloid beta (Abeta) peptide aggregation and cholinergic neurodegeneration. Therefore, in this paper, we examined silibinin, a flavonoid extracted from Silybum marianum, to determine its potential as a dual inhibitor of acetylcholinesterase (AChE) and Abeta peptide aggregation for AD treatment. To achieve this, we used molecular docking and molecular dynamics simulations to examine the affinity of silibinin with Abeta and AChE in silico. Next, we used circular dichroism and transmission electron microscopy to study the anti-Abeta aggregation capability of silibinin in vitro. Moreover, a Morris Water Maze test, enzyme-linked immunosorbent assay, immunohistochemistry, 5-bromo-2-deoxyuridine double labeling, and a gene gun experiment were performed on silibinin-treated APP/PS1 transgenic mice. In molecular dynamics simulations, silibinin interacted with Abeta and AChE to form different stable complexes. After the administration of silibinin, AChE activity and Abeta aggregations were down-regulated, and the quantity of AChE also decreased. In addition, silibinin-treated APP/PS1 transgenic mice had greater scores in the Morris Water Maze. Moreover, silibinin could increase the number of newly generated microglia, astrocytes, neurons, and neuronal precursor cells. Taken together, these data suggest that silibinin could act as a dual inhibitor of AChE and Abeta peptide aggregation, therefore suggesting a therapeutic strategy for AD treatment.
Title: Discovery of a new family of Dieckmann cyclases essential to tetramic acid and pyridone-based natural products biosynthesis Gui C, Li Q, Mo X, Qin X, Ma J, Ju J Ref: Org Lett, 17:628, 2015 : PubMed
Bioinformatic analyses indicate that TrdC, SlgL, LipX2, KirHI, and FacHI belong to a group of highly homologous proteins involved in biosynthesis of actinomycete-derived tirandamycin B, streptolydigin, alpha-lipomycin, kirromycin, and factumycin, respectively. However, assignment of their biosynthetic roles has remained elusive. Gene inactivation and complementation, in vitro biochemical assays with synthetic analogues, point mutations, and phylogenetic tree analyses reveal that these proteins represent a new family of Dieckmann cyclases that drive tetramic acid and pyridone scaffold biosynthesis.
Title: Identification of carboxylesterase genes and their expression profiles in the Colorado potato beetle Leptinotarsa decemlineata treated with fipronil and cyhalothrin Lu FG, Fu KY, Li Q, Guo WC, Ahmat T, Li GQ Ref: Pestic Biochem Physiol, 122:86, 2015 : PubMed
Based on the Leptinotarsa decemlineata transcriptome dataset and the GenBank sequences, 70 novel carboxylesterases and 2 acetylcholinesterases were found. The 72 members belong to a multifunctional carboxylesterase/cholinesterase superfamily (CCE). A phylogenetic tree including the 72 LdCCEs and the CCEs from Tribolium castaneum, Drosophila melanogaster and Apis mellifera revealed that all CCEs fell into three main phylogenetic groups: dietary/detoxification, hormone/semiochemical processing, and neurodevelopmental classes. Numbers of L. decemlineata CCEs in the three classes were 52, 12 and 8, respectively. The dietary/detoxification class includes two clades: coleopteran xenobiotic metabolizing and alpha-esterase type CCEs. CCEs in the two clades have independently expanded in L. decemlineata. The hormone/semiochemical processing class has three clades: integument CCEs, beta- and pheromone CCEs and juvenile hormone CCEs. Integument CCEs in L. decemlineata have also expanded. The neurodevelopmental CCEs are implicated the most ancient class, containing acetylcholinesterase, neuroligin, neurotactin, glutactin, gliotactin and others. Among the 70 novel CCE genes, KM220566, KM220530, KM220576, KM220527 and KM220541 were fipronil-inducible, and KM220578, KM220566, KM220542, KM220564, KM220561, KM220554, KM220527, KM220538 and KM220541 were cyhalothrin-inducible. They were the candidates involving in insecticide detoxification. Moreover, our results also provided a platform to understand the functions and evolution of L. decemlineata CCE genes.
OBJECTIVE: To characterize pathogenic effects of antibodies to dipeptidyl-peptidase-like protein 6 (DPPX), a subunit of Kv4.2 potassium channels, on gut and brain neurons. METHODS: We identified a new patient with anti-DPPX encephalitis and analyzed the effects of the patient's serum and purified immunoglobulin G (IgG), and of serum of a previous patient with anti-DPPX encephalitis, on the activity of enteric neurons by voltage-sensitive dye imaging in guinea pig myenteric and human submucous plexus preparations. We studied the subcellular localization of DPPX by immunocytochemistry in cultured murine hippocampal neurons using sera of 4 patients with anti-DPPX encephalitis. We investigated the influence of anti-DPPX-containing serum and purified IgG on neuronal surface expression of DPPX and Kv4.2 by immunoblots of purified murine hippocampal neuron membranes. RESULTS: The new patient with anti-DPPX encephalitis presented with a 2-month episode of diarrhea, which was followed by tremor, disorientation, and mild memory impairment. Anti-DPPX-IgG-containing sera and purified IgG increased the excitability and action potential frequency of guinea pig and human enteric nervous system neurons. Patient sera revealed a somatodendritic and perisynaptic neuronal surface staining that colocalized with the signal of commercial anti-DPPX and Kv4.2 antibodies. Incubation of hippocampal neurons with patient serum and purified IgG resulted in a decreased expression of DPPX and Kv4.2 in neuronal membranes. CONCLUSIONS: Hyperexcitability of enteric nervous system neurons and downregulation of DPPX and Kv4.2 from hippocampal neuron membranes mirror the clinical phenotype of patients with anti-DPPX encephalitis and support a pathogenic role of anti-DPPX antibodies in anti-DPPX encephalitis.
The anticholinesterase and antioxidant effects of five different extracts of Piper nigrum were evaluated. Twenty-one known alkamides were isolated from active ethyl acetate extract and investigated for their cholinesterase inhibitory and antioxidant effects. Among them, piperine (2), piperettine (5) and piperettyline (20) exhibited dual inhibition against AChE and BChE, and feruperine (18) was the most potent selective inhibitor of BChE. Molecular docking simulation was performed to get insight into the binding interactions of the ligands and enzymes. In addition, N-trans-feruloyltyramine (3) contributed to the strongest DPPH radical-scavenging activity. The self-induced Abeta aggregation inhibition of 2, 5 and 18 was further evaluated. Results indicated that some alkamides could be multifunctional lead candidates for Alzheimer's disease therapy.
Title: Transgenic mouse milk expressing human bile salt-stimulated lipase improves the survival and growth status of premature mice Wang Y, Sheng Z, Li Q, Gao Y, Dai Y, Liu G, Zhao Y, Li N Ref: Mol Biotechnol, 57:287, 2015 : PubMed
The lactating human mammary gland and the pancreas both produce bile salt-stimulated lipase (BSSL), a lipolytic enzyme acting on a wide range of substrates, including triglyceride, cholesterol esters, and fat-soluble vitamins esters. Breast milk BSSL has a particularly important role in the digestion of milk fat by newborn infants. We report the generation of transgenic mice that harbored a human BSSL gene controlled by a mammary gland-specific promoter. BSSL levels in transgenic mouse milk were raised to 376.8 mug/ml, corresponding to an activity of 9.15 U/ml. Premature wild-type neonates nursed by transgenic dams exhibited significantly higher survival rate than did the control neonates nursed by wild dams (95 vs. 83.3 % and, P < 0.05). They also showed 43.8 % greater body weight gain and 33.3 % lesser fecal crude fat levels than did the controls. This study provides significant evidence that increased levels of BSSL in milk may reduce mortality and improve the growth and fat absorption in premature mice during neonatal development.
Title: Death receptor and mitochondria-mediated hepatocyte apoptosis underlies liver dysfunction in rats exposed to organic pollutants from drinking water Yang G, Zhou Z, Cen Y, Gui X, Zeng Q, Ao Y, Li Q, Wang S, Li J, Zhang A Ref: Drug Des Devel Ther, 9:4719, 2015 : PubMed
Persistent organic pollutants in drinking water impose a substantial risk to the health of human beings, but the evidence for liver toxic effect and the underlying mechanism is scarce. This study aimed to examine the liver toxicity and elucidate the molecular mechanism of organic pollutants in drinking water in normal human liver cell line L02 cells and rats. The data showed that organic extraction from drinking water remarkably impaired rat liver function, evident from the increase in the serum level of alanine aminotransferase, aspartate aminotransferase, and cholinesterase, and decrease in the serum level of total protein and albumin. Organic extraction dose-dependently induced apoptotic cell death in rat liver and L02 cells. Administration of rats with organic extraction promoted death receptor signaling pathway through the increase in gene and protein expression level of Fas and FasL. Treatment of rats with organic extraction also induced mitochondria-mediated apoptosis via increasing the expression level of proapoptotic protein, Bax, but decreasing the expression level of antiapoptotic protein, Bcl-2, resulting in an upregulation of cytochrome c and activation of caspase cascade at both transcriptional and post-transcriptional levels. Moreover, organic extraction enhanced rat liver glutathione S-transferases activity and reactive oxygen species generation, and upregulated aryl hydrocarbon receptor and glutathione S-transferase A1 at both transcriptional and translational levels. Collectively, the results indicate that organic extraction from drinking water impairs liver function, with the involvement of death receptor and mitochondria-mediated apoptosis in rats. The results provide evidence and molecular mechanisms for organic pollutants in drinking water-induced liver dysfunction, which may help prevent and treat organic extraction-induced liver injury.
Title: Anti-neurotoxicity effects of oxoisoaporphine-lipoic acid hybrids Chen W, Wu Y, Zhong S, Cheng L, Li Q, Tang H Ref: Chemico-Biological Interactions, 223C:45, 2014 : PubMed
Four oxoisoaporphine-lipoic acid hybrids were designed, synthesized, and investigated in this study. To develop the hybrids, the oxoisoaporphine fragment was used for its inhibition of cholinesterases and beta-amyloid (Abeta) aggregation, while the unit of lipoic acid was used for its radical-capturing and neuroprotective effects. The hybrids exhibited moderate inhibitory effects on the activity of acetylcholinesterase (AChE), with IC50 values in the micromolar range and low toxicity in SH-SY5Y cells. Moreover, the learning and memory abilities, climbing capability, and average life expectancy of the Abeta42 transgenic Drosophila were all significantly improved by the hybrids. They also enhanced the intracephalic antioxidant activity, the metabolism, and the activity cholinesterase in the flies. More strikingly, Abeta42 aggregation in the hybrids-treated Drosophila was attenuated with effective neuroprotection. Our results indicate the potential of using these oxoisoaporphine-lipoic acid hybrids in AD treatments.
Genetic sex determination by W and Z chromosomes has developed independently in different groups of organisms. To better understand the evolution of sex chromosomes and the plasticity of sex-determination mechanisms, we sequenced the whole genomes of a male (ZZ) and a female (ZW) half-smooth tongue sole (Cynoglossus semilaevis). In addition to insights into adaptation to a benthic lifestyle, we find that the sex chromosomes of these fish are derived from the same ancestral vertebrate protochromosome as the avian W and Z chromosomes. Notably, the same gene on the Z chromosome, dmrt1, which is the male-determining gene in birds, showed convergent evolution of features that are compatible with a similar function in tongue sole. Comparison of the relatively young tongue sole sex chromosomes with those of mammals and birds identified events that occurred during the early phase of sex-chromosome evolution. Pertinent to the current debate about heterogametic sex-chromosome decay, we find that massive gene loss occurred in the wake of sex-chromosome 'birth'.
Title: Construction of genetically engineered bacteria that degrades organophosphorus pesticide residues and can be easily detected by the fluorescence Li Q, Wang P, Chen R, Li W, Wu YJ Ref: Environ Technol, 35:556, 2014 : PubMed
Organophosphorus compounds (OPs) are widely used in agriculture and industry and there is increased concern about their toxicological effects in the environment. Bioremediation can offer an efficient and cost-effective option for the removal of OPs. Herein, we describe the construction of a genetically engineered microorganism (GEM) that can degrade OPs and be directly detected and monitored in the environment using an enhanced green fluorescent protein (EGFP) fusion strategy. The coding regions of EGFP, a reporter protein that can fluoresce by itself, and organophosphorus hydrolase (OPH), which has a broad substrate specificity and is able to hydrolyse a number of organophosphorus pesticides, were cloned into the expression vector pET-28b. The fusion protein of EGFP-OPH was expressed in E. coli BL21 (DE3) and the protein expression reached the highest level at 11 h after isopropyl beta-D-thiogalactopyranoside induction. The fluorescence of the GEM was detected by fluorescence spectrophotometry and microscopy, and its ability to degrade OPs was determined by OPH activity assay. Those GEM that express the fusion protein (EGFP and OPH) exhibited strong fluorescence intensity and also potent hydrolase activity, which could be used to degrade organophosphorus pesticide residues in the environment and can also be directly monitored by fluorescence.
Title: Genome Sequence of the Polycyclic Aromatic Hydrocarbon-Degrading Bacterium Strain Marinobacter nanhaiticus D15-8WT Cui Z, Gao W, Li Q, Xu G, Zheng L Ref: Genome Announc, 1:, 2013 : PubMed
Marinobacter nanhaiticus strain D15-8W(T) was isolated from a phenanthrene-degrading consortium, enriched from sediment of the South China Sea. Here, we present the draft genome of strain D15-8W(T), which contains 5,358,309 bp with a G+C content of 58.53% and contains 4,829 protein-coding genes and 47 tRNA genes.
Current pharmacotherapies for Alzheimer's disease (AD) are focused on improving performance of daily activities, personal care, and management of problematic behaviors. Both memantine, a noncompetitive N-methyl-D-aspartate channel blocker and galantamine, a selective acetylcholinesterase inhibitor, are currently prescribed as symptomatic therapies for AD. However, drugs that progressed directly from testing in rodent models to testing in AD patients in clinical trials failed to demonstrate consistent effects on cognitive symptoms. Considering the lack of nonhuman primate data on the effects of memantine and galantamine alone or in combination on cognitive dysfunction in aged nonhuman primates, the present study examined how closely data derived from aged nonhuman primates reflects data obtained in humans. Mild beneficial effects on aspects of cognitive performance in aged primates were found, in general agreement with the human clinical experience with these drugs but in contrast to the more positive effects reported in the rodent literature. These data suggest that the nonhuman primate might have more predictive validity for drug development in this area than comparable rodent assays.
Title: Cell debris self-immobilized thermophilic lipase: a biocatalyst for synthesizing aliphatic polyesters Sun Y, Yang Y, Wang C, Liu J, Shi W, Zhu X, Lu L, Li Q Ref: Appl Biochem Biotechnol, 170:399, 2013 : PubMed
The paper explored the catalytic activity of a cell debris self-immobilized thermophilic lipase for polyester synthesis, using the ring-opening polymerization of sigma-caprolactone as model. Effects of biocatalyst concentration, temperature, and reaction medium on monomer conversion and product molecular weight were systematically evaluated. The biocatalyst displayed high catalytic activity at high temperatures (70-90 degreesC), with 100 % monomer conversion. High monomer conversion values (>90 %) were achieved in both hydrophobic and hydrophilic solvents, and also in solvent-free system, with the exception of dichloromethane. Poly(sigma-caprolactone) was obtained in 100 % monomer conversion, with a number-average molecular weight of 1,680 g/mol and a polydispersity index of 1.35 in cyclohexane at 70 degreesC for 72 h. Furthermore, the biocatalyst exhibited excellent operational stability, with monomer conversion values exceeding 90 % over the course of 15 batch reactions.
The unique anatomical features of turtles have raised unanswered questions about the origin of their unique body plan. We generated and analyzed draft genomes of the soft-shell turtle (Pelodiscus sinensis) and the green sea turtle (Chelonia mydas); our results indicated the close relationship of the turtles to the bird-crocodilian lineage, from which they split approximately 267.9-248.3 million years ago (Upper Permian to Triassic). We also found extensive expansion of olfactory receptor genes in these turtles. Embryonic gene expression analysis identified an hourglass-like divergence of turtle and chicken embryogenesis, with maximal conservation around the vertebrate phylotypic period, rather than at later stages that show the amniote-common pattern. Wnt5a expression was found in the growth zone of the dorsal shell, supporting the possible co-option of limb-associated Wnt signaling in the acquisition of this turtle-specific novelty. Our results suggest that turtle evolution was accompanied by an unexpectedly conservative vertebrate phylotypic period, followed by turtle-specific repatterning of development to yield the novel structure of the shell.
Rhizoctonia solani is a major fungal pathogen of rice (Oryza sativa L.) that causes great yield losses in all rice-growing regions of the world. Here we report the draft genome sequence of the rice sheath blight disease pathogen, R. solani AG1 IA, assembled using next-generation Illumina Genome Analyser sequencing technologies. The genome encodes a large and diverse set of secreted proteins, enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, which probably reflect an exclusive necrotrophic lifestyle. We find few repetitive elements, a closer relationship to Agaricomycotina among Basidiomycetes, and expand protein domains and families. Among the 25 candidate pathogen effectors identified according to their functionality and evolution, we validate 3 that trigger crop defence responses; hence we reveal the exclusive expression patterns of the pathogenic determinants during host infection.
The ambient resting dopamine (DA) concentration in brain regulates cognition and motivation. Despite its importance, resting DA level in vivo remains elusive. Here, by high-frequency stimulation of the medial forebrain bundle and immediately following the stimulus-induced DA overflow, we recorded a DA "undershoot" which is a temporal reduction of DA concentration to a level below the baseline. Based on the DA undershoot, we predicted a resting DA concentration of approximately 73nM in rat striatum in vivo. Simulation studies suggested that removing basal DA by DAT during the post-stimulation inhibition of tonic DA release caused the DA undershoot, and the resting concentration of DA modulated the kinetics of the evoked DA transient. The DA undershoot was eliminated by either blocking D2 receptors with haloperidol or blocking the DA transporter (DAT) with cocaine. Therefore, the impulse-dependent resting DA concentration is in the tens of nanomolar range and is modulated by the presynaptic D2 receptors and the DAT in vivo.
Title: Biocatalytic Synthesis of Poly(delta-Valerolactone) Using a Thermophilic Esterase from Archaeoglobus fulgidus as Catalyst Cao H, Han H, Li G, Yang J, Zhang L, Yang Y, Fang X, Li Q Ref: Int J Mol Sci, 13:12232, 2012 : PubMed
The ring-opening polymerization of delta-valerolactone catalyzed by a thermophilic esterase from the archaeon Archaeoglobus fulgidus was successfully conducted in organic solvents. The effects of enzyme concentration, temperature, reaction time and reaction medium on monomer conversion and product molecular weight were systematically evaluated. Through the optimization of reaction conditions, poly(delta-valerolactone) was produced in 97% monomer conversion, with a number-average molecular weight of 2225 g/mol, in toluene at 70 degrees C for 72 h. This paper has produced a new biocatalyst for the synthesis of poly(delta-valerolactone), and also deeper insight has been gained into the mechanism of thermophilic esterase-catalyzed ring-opening polymerization.
Melioidosis, caused by Burkholderia pseudomallei, is considered to be endemic to Northern Australia and Southeast Asia, with high mortality and relapse rates, regardless of powerful antibiotic therapy. Here we report the first genome sequence of Burkholderia pseudomallei strain BPC006, obtained from a melioidosis patient in Hainan, China. The genome sizes of the 2 chromosomes were determined to be 4,001,777 bp and 3,153,284 bp.
Bacillus thuringiensis is an important microbial insecticide used in the control of agricultural pests. Here we report the finished, annotated genome sequence of Bacillus thuringiensis serovar Sichuansis strain MC28, which can form parasporal crystals consisting of Cry4Cc1, Cry30Fa1, Cry53Ab1, Cry54Aa1, Cry54Ab1, Cry68Aa1, Cry69Aa1, Cry69Aa2, Cry70Ba1, Cyt1Da1, and Cyt2Aa3. It is also highly toxic to lepidopterous and dipterous insects.
Bactrian camels serve as an important means of transportation in the cold desert regions of China and Mongolia. Here we present a 2.01 Gb draft genome sequence from both a wild and a domestic bactrian camel. We estimate the camel genome to be 2.38 Gb, containing 20,821 protein-coding genes. Our phylogenomics analysis reveals that camels shared common ancestors with other even-toed ungulates about 55-60 million years ago. Rapidly evolving genes in the camel lineage are significantly enriched in metabolic pathways, and these changes may underlie the insulin resistance typically observed in these animals. We estimate the genome-wide heterozygosity rates in both wild and domestic camels to be 1.0 x 10(-3). However, genomic regions with significantly lower heterozygosity are found in the domestic camel, and olfactory receptors are enriched in these regions. Our comparative genomics analyses may also shed light on the genetic basis of the camel's remarkable salt tolerance and unusual immune system.
Title: Expression of APP, BACE1, AChE and ChAT in an AD model in rats and the effect of donepezil hydrochloride treatment Li Q, Chen M, Liu H, Yang L, Yang G Ref: Mol Med Rep, 6:1450, 2012 : PubMed
The aim of this study was to investigate the pathological changes in a rat model of Alzheimer's disease (AD) and the effect of donepezil hydrochloride (HCl) treatment. The rat model of AD was established by the bilateral injection of amyloid beta1-40 (Abeta1-40) into the hippocampus. Changes in spatial learning and memory functions were examined using the Morris water maze test and changes in catalase (CAT) and glutathione peroxidase (GSH-Px) activities were determined using chemical colorimetry. Moreover, the changes in acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) expression were analyzed using immunohistochemical staining. The mRNA expression levels of the amyloid precursor protein (APP) and beta-secreted enzyme 1 (BACE1) were evaluated using RT-PCR. The effects of donepezil HCl on the aforementioned indices were also observed. The rat memories of the platform quadrants in the blank, sham and donepezil HCl groups were improved compared with those of the rats in the model group. The ratio of swim distance in the fourth platform quadrant (l4) to the total swim distance (l total) for the model group rats (l4/l total) was significantly decreased compared with that for the blank and sham group rats. Following donepezil HCl treatment, the ratio of l4/l total significantly increased. AD modeling caused a significant decrease in the CAT and GSH-Px activities in the brain tissues of the rats. The CAT and GSH-Px activities in the AD model rats significantly increased following donepezil HCl treatment. Moreover, donepezil HCl treatment significantly decreased the AChE, APP and BACE1 mRNA expression levels and increased the ChAT expression levels. Therefore, donepezil HCl was able to significantly decrease learning and memory damage in a rat model of AD.
Title: Draft genome sequence of Streptomyces globisporus C-1027, which produces an antitumor antibiotic consisting of a nine-membered enediyne with a chromoprotein Wang L, Wang S, He Q, Yu T, Li Q, Hong B Ref: Journal of Bacteriology, 194:4144, 2012 : PubMed
Streptomyces globisporus C-1027 is the producer of antitumor antibiotic C-1027, a nine-membered enediyne-containing compound. Here we present a draft genome sequence of S. globisporus C-1027 containing the intact biosynthetic gene cluster for this antibiotic. The genome also carries numerous sets of genes for the biosynthesis of diverse secondary metabolites.
OBJECTIVES: This study was conducted to evaluate the effects of exposure to pioglitazone, a peroxisome proliferator-activated receptor agonist, on cognitive impairment induced by scopolamine, a muscarinic antagonist, in mice. METHODS: Pioglitazone (9mg/kg, 18mg/kg) was orally administered for 9 days at 30min before intraperitoneal injection with scopolamine (0.8mg/kg, i.p.). Cognitive function was evaluated by the passive avoidance test and the Morris water maze test on the 10th day after treatment. Changes in cholinergic system reactivity were also examined by measuring the acetylcholine, acetylcholinesterase and choline acetyltransferase in the hippocampus and cortex. KEY FINDINGS: Scopolamine injection induced impaired performance in the passive avoidance test and the water maze test and severe decrease of cholinergic system reactivity, as indicated by reduced acetylcholine levels, decreased choline acetyltransferase activity and increased acetylcholinesterase activity. Daily administration of pioglitazone significantly increased step-through latency in passive avoidance test, and significantly decreased the escape latency, and increased the time spent in the platform quadrant in the Morris water maze test. Pioglitazone also protected against scopolamine-induced cholinergic system deficit, including reduced acetylcholine levels, decreased choline acetyltransferase activity and increased acetylcholinesterase activity in the hippocampus or cortex. CONCLUSIONS: Pioglitazone demonstrates a significant neuroprotective effect against scopolamine-induced cholinergic system deficit and cognitive impairment.
Pseudomonas mendocina NK-01 can synthesize medium-chain-length polyhydroxyalkanoate (PHA(MCL)) and alginate oligosaccharides (AO) simultaneously from glucose under conditions of limited nitrogen. Here, we report the complete sequence of the 5.4-Mbp genome of Pseudomonas mendocina NK-01, which was isolated from farmland soil in Tianjin, China.
The naked mole rat (Heterocephalus glaber) is a strictly subterranean, extraordinarily long-lived eusocial mammal. Although it is the size of a mouse, its maximum lifespan exceeds 30 years, making this animal the longest-living rodent. Naked mole rats show negligible senescence, no age-related increase in mortality, and high fecundity until death. In addition to delayed ageing, they are resistant to both spontaneous cancer and experimentally induced tumorigenesis. Naked mole rats pose a challenge to the theories that link ageing, cancer and redox homeostasis. Although characterized by significant oxidative stress, the naked mole rat proteome does not show age-related susceptibility to oxidative damage or increased ubiquitination. Naked mole rats naturally reside in large colonies with a single breeding female, the 'queen', who suppresses the sexual maturity of her subordinates. They also live in full darkness, at low oxygen and high carbon dioxide concentrations, and are unable to sustain thermogenesis nor feel certain types of pain. Here we report the sequencing and analysis of the naked mole rat genome, which reveals unique genome features and molecular adaptations consistent with cancer resistance, poikilothermy, hairlessness and insensitivity to low oxygen, and altered visual function, circadian rythms and taste sensing. This information provides insights into the naked mole rat's exceptional longevity and ability to live in hostile conditions, in the dark and at low oxygen. The extreme traits of the naked mole rat, together with the reported genome and transcriptome information, offer opportunities for understanding ageing and advancing other areas of biological and biomedical research.
Mycoplasma hyopneumoniae strain 168, a pathogenic strain prevalent in China, was isolated in 1974. Although this strain has been widespread for a long time, the genome sequence had not been determined. Here, we announce the complete genome sequence of M. hyopneumoniae strain 168.
The nonhuman primates most commonly used in medical research are from the genus Macaca. To better understand the genetic differences between these animal models, we present high-quality draft genome sequences from two macaque species, the cynomolgus/crab-eating macaque and the Chinese rhesus macaque. Comparison with the previously sequenced Indian rhesus macaque reveals that all three macaques maintain abundant genetic heterogeneity, including millions of single-nucleotide substitutions and many insertions, deletions and gross chromosomal rearrangements. By assessing genetic regions with reduced variability, we identify genes in each macaque species that may have experienced positive selection. Genetic divergence patterns suggest that the cynomolgus macaque genome has been shaped by introgression after hybridization with the Chinese rhesus macaque. Macaque genes display a high degree of sequence similarity with human disease gene orthologs and drug targets. However, we identify several putatively dysfunctional genetic differences between the three macaque species, which may explain functional differences between them previously observed in clinical studies.
We present here the analysis of the whole-genome sequence of Pseudomonas stutzeri strain DSM4166, a diazotrophic isolate from the rhizosphere of a Sorghum nutans cultivar. To our knowledge, this is the second genome to be sequenced for P. stutzeri. The availability and analysis of the genome provide insight into the evolution of the nitrogen fixation property and identification of rhizosphere competence traits required in interactions with host plants.
The organized societies of ants include short-lived worker castes displaying specialized behavior and morphology and long-lived queens dedicated to reproduction. We sequenced and compared the genomes of two socially divergent ant species: Camponotus floridanus and Harpegnathos saltator. Both genomes contained high amounts of CpG, despite the presence of DNA methylation, which in non-Hymenoptera correlates with CpG depletion. Comparison of gene expression in different castes identified up-regulation of telomerase and sirtuin deacetylases in longer-lived H. saltator reproductives, caste-specific expression of microRNAs and SMYD histone methyltransferases, and differential regulation of genes implicated in neuronal function and chemical communication. Our findings provide clues on the molecular differences between castes in these two ants and establish a new experimental model to study epigenetics in aging and behavior.
Title: Identification of the G994T polymorphism in exon 9 of plasma platelet-activating factor acetylhydrolase gene as a risk factor for polycystic ovary syndrome Fan P, Liu Hw, Wang XS, Zhang F, Song Q, Li Q, Wu HM, Bai H Ref: Hum Reprod, 25:1288, 2010 : PubMed
BACKGROUND: Low-grade chronic inflammation and greater risks of cardiovascular diseases are often present in patients with polycystic ovary syndrome (PCOS). Platelet-activating factor (PAF) acetylhydrolase (PAF-AH) hydrolyzes and inactivates PAF and PAF-like oxidized phospholipids that are potent lipid mediators involved in inflammation and atherosclerosis. Deficiency of this enzyme is caused by a missense mutation (G994 --> T) in exon 9 of the plasma PAF-AH gene. The aim of the study was to investigate a possible association of this polymorphism with the risk of PCOS and to evaluate the effects of the genotype on the activity and distribution of PAFAH in Chinese patients. METHODS: A total of 661 subjects (346 patients with PCOS and 315 healthy control women) from a population of Chinese Han nationality in Chengdu area were included in this study. PAFAH G994T genotype was studied using PCR and restriction fragment length polymorphism analysis. Total plasma PAF-AH, high-density lipoprotein (HDL)-associated PAF-AH (H-PAF-AH) and low-density lipoprotein (LDL)-associated PAF-AH (L-PAF-AH) activities were measured by the trichloroacetic acid precipitation procedure using [(3)H-acetyl] PAF and PAF C-16 as a substrate. RESULTS: The prevalence of the mutant genotype (GT + TT) was significantly more frequent in patients with PCOS than in control subjects (12.7 versus 6.0%, P = 0.003). Genotype (GT + TT) remained a significant predictor for PCOS (P = 0.020) in prognostic models including age, body mass index, insulin resistance index, triglyceride, HDL and LDL as covariates. There was a significant difference in plasma PAF-AH, L-PAF-AH and H-PAF-AH activities between GG and GT genotypes in both the patient and control groups. The ratio of L-PAF-AH to H-PAF-AH activities was significantly higher after adjustment for multiple variables in patients with GT genotype compared with patients with GG genotype (P = 0.003). There were no significant differences in clinical, biochemical and metabolic parameters according to PAFAH G994T genotyping in patients with PCOS and control women. CONCLUSIONS: The G994T polymorphism in PAFAH gene may be one of the genetic determinants for PCOS in Chinese Han women.
Using next-generation sequencing technology alone, we have successfully generated and assembled a draft sequence of the giant panda genome. The assembled contigs (2.25 gigabases (Gb)) cover approximately 94% of the whole genome, and the remaining gaps (0.05 Gb) seem to contain carnivore-specific repeats and tandem repeats. Comparisons with the dog and human showed that the panda genome has a lower divergence rate. The assessment of panda genes potentially underlying some of its unique traits indicated that its bamboo diet might be more dependent on its gut microbiome than its own genetic composition. We also identified more than 2.7 million heterozygous single nucleotide polymorphisms in the diploid genome. Our data and analyses provide a foundation for promoting mammalian genetic research, and demonstrate the feasibility for using next-generation sequencing technologies for accurate, cost-effective and rapid de novo assembly of large eukaryotic genomes.
Title: Effects of galantamine on beta-amyloid release and beta-site cleaving enzyme 1 expression in differentiated human neuroblastoma SH-SY5Y cells Li Q, Wu D, Zhang L, Zhang Y Ref: Experimental Gerontology, 45:842, 2010 : PubMed
Galantamine (Gal) is an acetylcholinesterase inhibitor and used to treat the symptoms of Alzheimer's disease (AD). Recent studies show that Gal may affect amyloid precursor protein (APP) metabolism and increase release of secretory APPalpha (sAPPalpha). However the effect of Gal on amyloid-beta peptide (Abeta) release and beta-site cleaving enzyme 1 (BACE1) expression is still unknown. Consequently, we investigated the effect of Gal on the level of Abeta and BACE1. In a differentiated human neuroblastoma cell line (SH-SY5Y), Gal (0.3 muM) was found to significantly decrease Abeta release and BACE1 expression following treatment for 6, 12, and 24h. Increasing Gal to 0.9 muM or 10 muM had no further effect. The effect of Gal (0.3 muM for 18h) was maximal on BACE1 expression but not on Abeta secretion. At higher concentration (0.9 muM and 10 muM), Gal had no effect on the level of full-length APP but could still stimulate further decrease in Abeta secretion and release of sAPPalpha. These observations suggested that 0.3 muM Gal exerts its effect on Abeta production by inhibiting BACE1 expression, while 0.9 muM or 10 muM Gal mainly reduces Abeta production by stimulating the non-amyloidogenic pathway to decrease the amount of APP substrate available for beta-secretase cleavage. In addition, alpha7 nicotinic acetylcholine receptor (alpha7nAChR) and multiple second messengers (including PKC, MEK, and p38MAPK) were found to be involved in the regulation of Gal-inhibited Abeta release and BACE1 expression.
Mycoplasma hyorhinis is generally considered a swine pathogen yet is most commonly found infecting laboratory cell lines. An increasing body of evidence suggests that chronic infections with M. hyorhinis may cause oncogenic transformation. Here, we announce the complete genome sequence of M. hyorhinis strain HUB-1.
MOTIVATION: Unraveling the structure and behavior of the brain and central nervous system (CNS) has always been a major goal of neuroscience. Understanding the wiring diagrams of the neuromuscular junction connectomes (full connectivity of nervous system neuronal components) is a starting point for this, as it helps in the study of the organizational and developmental properties of the mammalian CNS. The phenomenon of synapse elimination during developmental stages of the neuronal circuitry is such an example. Due to the organizational specificity of the axons in the connectomes, it becomes important to label and extract individual axons for morphological analysis. Features such as axonal trajectories, their branching patterns, geometric information, the spatial relations of groups of axons, etc. are of great interests for neurobiologists in the study of wiring diagrams. However, due to the complexity of spatial structure of the axons, automatically tracking and reconstructing them from microscopy images in 3D is an unresolved problem. In this article, AxonTracker-3D, an interactive 3D axon tracking and labeling tool is built to obtain quantitative information by reconstruction of the axonal structures in the entire innervation field. The ease of use along with accuracy of results makes AxonTracker-3D an attractive tool to obtain valuable quantitative information from axon datasets. AVAILABILITY: The software is freely available for download at http://www.cbi-tmhs.org/AxonTracker/.
Title: Genomic characterization of the Guillain-Barre syndrome-associated Campylobacter jejuni ICDCCJ07001 Isolate Zhang M, He L, Li Q, Sun H, Gu Y, You Y, Meng F, Zhang J Ref: PLoS ONE, 5:e15060, 2010 : PubMed
Campylobacter jejuni ICDCCJ07001 (HS:41, ST2993) was isolated from a Guillain-Barre syndrome (GBS) patient during a 36-case GBS outbreak triggered by C. jejuni infections in north China in 2007. Sequence analysis revealed that the ICDCCJ07001 genome consisted of 1,664,840 base pairs (bp) and one tetracycline resistance plasmid of 44,084 bp. The GC content was 59.29% and 1,579 and 37 CDSs were identified on the chromosome and plasmid, respectively. The ICDCCJ07001 genome was compared to C. jejuni subsp. jejuni strains 81-176, 81116, NCTC11168, RM1221 and C. jejuni subsp. doylei 269.97. The length and organization of ICDCCJ07001 was similar to that of NCTC11168, 81-176 and 81-116 except that CMLP1 had a reverse orientation in strain ICDCCJ07001. Comparative genomic analyses were also carried out between GBS-associated C. jejuni strains. Thirteen common genes were present in four GBS-associated strains and 9 genes mapped to the LOS cluster and the ICDCCJ07001_pTet (44 kb) plasmid was mosaic in structure. Thirty-seven predicted CDS in ICDCCJ07001_pTet were homologous to genes present in three virulence-associated plasmids in Campylobacter: 81-176_pTet, pCC31 and 81-176_pVir. Comparative analysis of virulence loci and virulence-associated genes indicated that the LOS biosynthesis loci of ICDCCJ07001 belonged to type A, previously reported to be associated with cases of GBS. The polysaccharide capsular biosynthesis (CPS) loci and the flagella modification (FM) loci of ICDCCJ07001 were similar to corresponding sequences of strain 260.94 of similar serotype as strain ICDCCJ07001. Other virulence-associated genes including cadF, peb1, jlpA, cdt and ciaB were conserved between the C. jejuni strains examined.
Title: Clinicopathologic features between multicentric occurence and intrahepatic metastasis of multiple hepatocellular carcinomas related to HBV Wang J, Li Q, Sun Y, Zheng H, Cui Y, Li H, Zhou H, Hao X Ref: Surg Oncol, 18:25, 2009 : PubMed
AIMS: To clarify the incidence of multicentric occurrence (MO) and intrahepatic metastasis (IM) for hepatocellular carcinoma (HCC) related to hepatitis B virus (HBV) in China and to identify the differences between them. PATIENTS AND METHODS: Histopathologic features of multiple tumors in 82 cases with HCC were analyzed. The two groups, the origin was determinable as of multicentric occurrence or as of intrahepatic metastasis, were analyzed for their survival rate, disease-free survival and clinicopathologic differences. RESULTS: According to histological findings, 19.5% and 69.5% patients were considered to be MO and IM, respectively. In total 73 cases from the histopathological method were selected and divided into group MO (16 cases) and the group IM (57 cases). Analysis of stepwise regression identified that: Child's stage, cholinesterase (host factors), tumor size, histological grade and positive portal vein invasion (tumor factors) were the most important discriminating factors between MO and IM (p<0.05). As for their prognosis, Kaplan-Meier and Log rank test showed the survival rate in group MO was significantly better than that in the group IM (p=0.003). No statistical significance was found between the disease-free survival in group MO and that in group IM (p=0.141). The analysis of Cox's proportional hazards model showed that tumor type (MO or IM) and Child's stage were the important prognostic factors (p=0.002 and 0.014, respectively). CONCLUSIONS: The incidence of MO in patients with multiple HCCs related to HBV is only about 20%, which is lower than that of Japan. Child's stage, cholinesterase (host factors), tumor size, histological grade and positive portal vein invasion (tumor factors) are the most important discriminating factors between MO and IM. The prognosis of patients with MO compared to IM is significantly better and tumor type (MO or IM) and Child's stage are important prognostic factors.
Title: Paeonol attenuates neurotoxicity and ameliorates cognitive impairment induced by d-galactose in ICR mice Zhong SZ, Ge QH, Qu R, Li Q, Ma SP Ref: Journal of Neurology Sci, 277:58, 2009 : PubMed
In the present study, we examined the supplementation of paeonol extracted from Moutan cortex of Paeonia suffruticosa Andrews (MC) or the root of Paeonia lactiflora Pall (PL) on reducing oxidative stress, cognitive impairment and neurotoxicity in d-galactose (D-gal)-induced aging mice. The ICR mice were subcutaneously injected with D-gal (50 mg/(kg day)) for 60 days and administered with paeonol (50, 100 mg/(kg day)) simultaneously. The results showed that paeonol significantly improved the learning and memory ability in Morris water maze test and step-down passive avoidance test in D-gal-treated mice. Further investigation showed that the effect of paeonol on improvement of cognitive deficit was related to its ability to inhibit the biochemical changes in brains of D-gal-treated mice. Paeonol increased acetylcholine (Ach) and glutathione (GSH) levels, restored superoxide dismutase (SOD) and Na(+), K(+)-adenosine triphosphatase (Na(+), K(+)-ATPase) activities, but decreased cholinesterase AChe activity and malondialdehyde (MDA) level in D-gal-treated mice. Furthermore, paeonol ameliorated neuronal damage in both hippocampus and temporal cortex in D-gal-treated mice. These results suggest that paeonol possesses anti-aging efficacy and may have potential in treatment of neurodegenerative diseases.
Bacillus sphaericus strain C3-41 is an aerobic, mesophilic, spore-forming bacterium that has been used with great success in mosquito control programs worldwide. Genome sequencing revealed that the complete genome of this entomopathogenic bacterium is composed of a chromosomal replicon of 4,639,821 bp and a plasmid replicon of 177,642 bp, containing 4,786 and 186 potential protein-coding sequences, respectively. Comparison of the genome with other published sequences indicated that the B. sphaericus C3-41 chromosome is most similar to that of Bacillus sp. strain NRRL B-14905, a marine species that, like B. sphaericus, is unable to metabolize polysaccharides. The lack of key enzymes and sugar transport systems in the two bacteria appears to be the main reason for this inability, and the abundance of proteolytic enzymes and transport systems may endow these bacteria with exclusive metabolic pathways for a wide variety of organic compounds and amino acids. The genes shared between B. sphaericus C3-41 and Bacillus sp. strain NRRL B-14905, including mobile genetic elements, membrane-associated proteins, and transport systems, demonstrated that these two species are a biologically and phylogenetically divergent group. Knowledge of the genome sequence of B. sphaericus C3-41 thus increases our understanding of the bacilli and may also offer prospects for future genetic improvement of this important biological control agent.
Title: Prognostic factors for chronic severe hepatitis and construction of a prognostic model Li Q, Yuan GY, Tang KC, Liu GW, Wang R, Cao WK Ref: Hepatobiliary Pancreat Dis Int, 7:40, 2008 : PubMed
BACKGROUND: Chronic severe hepatitis is a serious illness with a high mortality rate. Discussion of prognostic judgment criteria for chronic severe hepatitis is of great value in clinical guidance. This study was designed to investigate the clinical and laboratory indices affecting the prognosis of chronic severe hepatitis and construct a prognostic model. METHODS: The clinical and laboratory indices of 213 patients with chronic severe hepatitis within 24 hours after diagnosis were analyzed retrospectively. Death or survival was limited to within 3 months after diagnosis. RESULTS: The mortality of all patients was 47.42%. Compared with the survival group, the age, basis of hepatocirrhosis, infection, degree of hepatic encephalopathy (HE) and the levels of total bilirubin (TBil), total cholesterol (CHO), cholinesterase (CHE), blood urea nitrogen (BUN), blood creatinine (Cr), blood sodium ion (Na), peripheral blood leukocytes (WBC), alpha-fetoprotein (AFP), international normalized ratio (INR) of blood coagulation and prothrombin time (PT) were significantly different in the group who died, but the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB) and hemoglobin (HGB) were not different between the two groups. At the same time, a regression model, Logit (P) =1.573XAge+1.338XHE-1.608XCHO+0.011XCr-0.109XNa+1.298XINR+11.057, was constructed by logistic regression analysis and the prognostic value of the model was higher than that of the MELD score. CONCLUSIONS: Multivariate analysis excels univariate analysis in the prognosis of chronic severe hepatitis, and the regression model is of significant value in the prognosis of this disease.
Various intestinal symptoms or diseases are closely associated with intestinal motility, which may be altered by metabolic disturbances associated with diabetes and obesity. It is therefore important that drugs used in the treatment of metabolic disorders should not have any adverse effects on the intestine. In the present study, we examined whether [4-(4-bromo-2-cyano-phenylcarbamoyl)-benzyl]-phosphonic acid diethyl ester (NO-1886), a lipoprotein lipase activator with anti-diabetic and/or anti-obese activity, affects stimulant-induced intestinal contractility. Administration of NO-1886 to intestinal ring preparations of ileum, rectum and colon isolated from Wistar rats attenuated or relaxed contraction induced by a high K+ environment or acetylcholine (ACh). This effect of NO-1886 was dependent on extracellular Ca(2+) and intracellular myosin light chain kinase activity. Our results also showed that ACh-induced colonic contraction was significantly higher in the obese Otsuka Long-Evans Tokushima Fatty (OLETF) than in the non-obese Long-Evans Tokushima Otsuka (LETO) rats. The hypercontractility observed in the colons of OLETF rats occurred concomitantly with an elevation in muscarinic M3 ACh receptor protein levels. Administration of NO-1886 attenuated the obesity-induced hypercontractility of the colonic rings of OLETF rats. Thus, intestinal contractile system would be a novel pharmacological target of the lipoprotein lipase activator NO-1886.
Bombyx mori, the domesticated silkworm, is a major insect model for research, and the first lepidopteran for which draft genome sequences became available in 2004. Two independent data sets from whole-genome shotgun sequencing were merged and assembled together with newly obtained fosmid- and BAC-end sequences. The remarkably improved new assembly is presented here. The 8.5-fold sequence coverage of an estimated 432 Mb genome was assembled into scaffolds with an N50 size of approximately 3.7 Mb; the largest scaffold was 14.5 million base pairs. With help of a high-density SNP linkage map, we anchored 87% of the scaffold sequences to all 28 chromosomes. A particular feature was the high repetitive sequence content estimated to be 43.6% and that consisted mainly of transposable elements. We predicted 14,623 gene models based on a GLEAN-based algorithm, a more accurate prediction than the previous gene models for this species. Over three thousand silkworm genes have no homologs in other insect or vertebrate genomes. Some insights into gene evolution and into characteristic biological processes are presented here and in other papers in this issue. The massive silk production correlates with the existence of specific tRNA clusters, and of several sericin genes assembled in a cluster. The silkworm's adaptation to feeding on mulberry leaves, which contain toxic alkaloids, is likely linked to the presence of new-type sucrase genes, apparently acquired from bacteria. The silkworm genome also revealed the cascade of genes involved in the juvenile hormone biosynthesis pathway, and a large number of cuticular protein genes.
Title: New mechanism of organophosphorus pesticide-induced immunotoxicity Li Q Ref: J Nippon Med Sch, 74:92, 2007 : PubMed
Organophosphorus pesticides (OPs) are widely used throughout the world as insecticides in agriculture and as eradicating agents for termites around homes. The main toxicity of OPs is neurotoxicity, which is caused by the inhibition of acetylcholinesterase. OPs also affect the immune response, including effects on antibody production, interleukin-2 production, T cell proliferation, decrease of CD5 cells, and increases of CD26 cells and autoantibodies, Th1/Th2 cytokine profiles, and the inhibition of natural killer (NK) cell, lymphokine-activated killer (LAK) cell, and cytotoxic T lymphocyte (CTL) activities. However, there have been few studies of the mechanism of OP-induced immunotoxicity, especially the mechanism of OP-induced inhibition of cytolytic activity of killer cells. This study reviews new mechanisms of OP-induced inhibition of the activities of NK cells, LAK cells, and CTLs. It has been reported that NK cells, LAK cells, and CTLs induce cell death in tumors or virus-infected target cells by two main mechanisms. The first mechanism is direct release of cytolytic granules that contain the pore-forming protein perforin, several serine proteases termed granzymes, and granulysin by exocytosis to kill target cells, which is called the granule exocytosis pathway. The second mechanism is mediated by the Fas ligand (Fas-L)/Fas pathway, in which FasL (CD95 L), a surface membrane ligand of the killer cell cross links with the target cell's surface death receptor Fas (CD95) to induce apoptosis of the target cells. To date, it has been reported that OPs inhibit NK cell, LAK cell, and CTL activities by at least the following three mechanisms: 1) OPs impair the granule exocytosis pathway of NK cells, LAK cells, and CTLs by inhibiting the activity of granzymes, and by decreasing the intracellular levels of perforin, granzyme A, and granulysin, which were mediated by inducing degranulation of NK cells and by inhibiting the transcription of the mRNAs of perforin, granzyme A, and granulysin. 2) OPs impair the FasL/Fas pathway of NK cells, LAK cells, and CTLs, as investigated by using perforin-knockout mice, in which the granule exocytosis pathway of NK cells does not function and only the FasL/Fas pathway remains functional. 3) OPs induce apoptosis of immune cells.
Title: The mechanism of organophosphorus pesticide-induced inhibition of cytolytic activity of killer cells Li Q, Kawada T Ref: Cell Mol Immunol, 3:171, 2006 : PubMed
The main toxicity of organophosphorus pesticides (OPs) is neurotoxicity, which is caused by the inhibition of acetylcholinesterase. OPs also affect immune responses including effects on antibody production, IL-2 production, T cell proliferation, decrease of CD5 cells, and increase of CD26 cells and autoantibodies. However, there have been few papers investigating the mechanism of OP-induced inhibition of cytolytic activity of killer cells. This study reviews the new mechanism of OP-induced inhibition of activities of natural killer (NK), lymphokine-activated killer (LAK) and cytotoxic T lymphocytes (CTL). NK, LAK and CTL induce cell death in tumor or virus-infected target cells by two main mechanisms. The first mechanism is direct release of cytolytic granules that contain perforin, granzymes, and granulysin by exocytosis to kill target cells, which is called the granule exocytosis pathway. The second mechanism is mediated by the Fas ligand (Fas-L)/Fas pathway. To date, it has been reported that OPs inhibit NK, LAK and CTL activities by at least the following three mechanisms: 1) OPs impair the granule exocytosis pathway of NK, LAK and CTL cells by inhibiting the activity of granzymes, and by decreasing the intracellular level of perforin, granzyme A and granulysin, which was mediated by inducing degranulation of NK cells and by inhibiting the transcript of mRNA of perforin, granzyme A and granulysin; 2) OPs impair the FasL/Fas pathway of NK, LAK and CTL cells, as investigated by using perforin-knockout mice, in which the granule exocytosis pathway of NK cells does not function and only the FasL/Fas pathway remains functional; 3) OPs induce apoptosis of immune cells.
Title: [The value of coagulation factors in severity categorization of hepatitis B-related liver cirrhosis] Li Q, Wang BE, Cong YL, Jia JD, Yin ZJ, Qian LX, Ma H Ref: Zhonghua Nei Ke Za Zhi, 44:188, 2005 : PubMed
OBJECTIVE: To investigate the diagnostic value of coagulation factors in assessing the severity degree of liver cirrhosis caused by hepatitis B. METHODS: Fifty-eight patients with liver cirrhosis and twenty healthy persons as control were enrolled. Prothrombin time activity percentage (PTA), activated partial thromboplastin time, coagulation activity of factor II, V, VII, VIII, IX and X were detected with clotting assay. Antithrombin-III (AT-III) was detected with colorimetric assay. The biochemical markers were also detected. RESULTS: The differences of PTA, factor II, VII and AT-III among Child-Pugh A, B, C in patients with liver cirrhosis were statistically significant (P < 0.01). Through receiver operating characteristic curve analysis, when 64% and 50% were used as cut-off values for PTA and factor VII in diagnosing Child-Pugh B, the area under the curve (AUC) was 0.689 and 0.610, the sensitivity was 76.9% and 61.5%, the specificity was 62.2% and 55.6%; when 54% and 39% were used as cut-off values for PTA and factor VII in diagnosing Child-Pugh C, the AUC was 0.924 and 0.942, the sensitivity was 80.0% and 86.7%, the specificity was 88.4% and 90.7%. Stepwise linear regression was done between Child-Pugh grade and coagulation factors. PTA, cholinesterase (Che), total bilirubin (TBil), albumin (Alb), factor VII were included in regression equation, Y = 15.008 - 0.018 x PTA - 0.288 x Che + 0.264 x TBil - 0.988 x Alb - 0.034 x VII, R(2) = 0.871. Patients whose Y was less than 8 were classified as grade "a", between 8 - 10 as grade "b", more than 10 as grade "c", the diagnostic accuracy was 84.5%. CONCLUSION: Coagulation factor VII may serve as a helpful marker in diagnosing the severity degree of liver cirrhosis.
Title: 1H NMR relaxation investigation of acetylcholinesterase inhibitors from huperzine A and derivative Li Y, Li Q, Sun M, Song G, Jiang S, Zhu D Ref: Bioorganic & Medicinal Chemistry Lett, 14:1585, 2004 : PubMed
The binding properties of huperzine A (1) with Torpediniforms Nacline acetylcholinesterase (TnAChE) were investigated by (1)H NMR methods. The noselective, selective and double-selective spin-lattice relaxation rates were acquired in absent and present of TnAChE at a ratio [ligand]/[protein]=1:0.005. The selective relaxation rates shown protons of 1 had dipole-dipole interaction with protein active site protons. The motional correlation time of bound ligand was calculated by double-selective relaxation rate at 1 tau(2,3)=40.5 ns at 298 K, which showed 1 had high affinity with TnAChE. The experiments give a possible method to use TnAChE to locate the new huperzine A derivatives as AChE inhibitors.
Title: Elevated frequency of sister chromatid exchanges of lymphocytes in sarin-exposed victims of the Tokyo sarin disaster 3 years after the event Li Q, Hirata Y, Kawada T, Minami M Ref: Toxicology, 201:209, 2004 : PubMed
We previously reported that the frequency of sister chromatid exchanges (SCEs) among victims of the Tokyo subway sarin disaster was significantly higher than that of controls 2-3 months after the disaster. It has been reported that the victims were also exposed to the by-products generated during sarin synthesis, i.e., diisopropyl methylphosphonate (DIMP), diethyl methylphosphonate (DEMP) and N,N-diethylaniline (DEA) during the disaster and we previously found that DIMP, DEMP and DEA induced a significant SCE increase in human lymphocytes in vitro. To monitor the genetic aftereffects of the sarin exposure, SCEs of peripheral blood lymphocytes were measured in fire fighters and police officers involved in the disaster 3 years after the event. We found that the frequency of SCEs was still significantly higher in the exposed subjects than the controls, suggesting a risk of the genetic aftereffects of the sarin exposure. We further found a significant positive correlation between the frequency of SCEs and the inhibition of serum cholinesterase activity in the exposed subjects, suggesting that the elevated frequency of SCEs is related to the sarin exposure. On the other hand, there was no significant difference in natural killer activity between the exposed and the controls.
Title: [Influence of chronic epilepsy on spatial memory retrieval in rats] Zhang LS, Jin CL, Li Q, Sun YC, Chen Z Ref: Zhejiang Da Xue Xue Bao Yi Xue Ban, 33:205, 2004 : PubMed
OBJECTIVE: To investigate the influence of chronic epilepsy on spatial memory retrieval in rats, and to evaluate the effects of TAK-147, an acetylcholinesterase inhibitor, and histidine, the precursor of histamine, on the amnesia induced by epilepsy. METHODS: After successfully trained in the 8-arm (4-arm baited) radial maze, the rats were ip injected with a subconvulsive dose of pentylenetetrazole (PTZ) every 48 h until fully kindled. Memory retrieval was tested at the same maze. RESULT: Impairment of memory retrieval was in a steady state 1 to 18 days after fully kindled, the ability of memory retrieval returned to the control level 31 days after fully kindled. TAK-147 showed an ameliorating effect on memory impairment induced by epilepsy, including reference and working memory in a dose-dependent manner. Histidine only ameliorated reference but not working memory. CONCLUSION: PTZ-kindled seizure impair spatial memory retrieval, which it might be due to a decrease of brain acetylcholine and histamine induced by epilepsy.
In order to develop the specific oligobodies against human brain acetylcholinesterase (AChE) and distinguishes between human erythrocyte and brain AChEs, we applied the strategy of 'target switching' to obtain the specific polyclonal and monoclonal oligobodies. The specificity between human brain AChE and other ChEs was identified by Western blotting, dot blotting and enzyme protein binding assay (EPBA). The results showed that the oligobodies against the human brain AChE specifically immunoreacted with the human brain AChE and Torpedo AChE, not showing significant binding to AChE from human erythrocyte and butyrylcholinesterase (BChE) from human serum.
INTRODUCTION: Mechanisms and drug treatment of serious ventricular arrhythmias in patients with healed myocardial infarction (HMI) are incompletely understood, in part because the electrophysiology and pharmacology of myocytes from noninfarcted regions of HMI hearts are not well characterized. METHODS AND RESULTS: We studied the delayed rectifier potassium current (I(K)) and quinidine responsiveness of single left ventricular subendocardial myocytes isolated from the region remote to the border zone of healed infarct myocardium (4 to 6 mm from scar edge) in cat hearts 2 months after coronary artery occlusion. Subendocardial cells isolated from corresponding regions of normal cat hearts provided controls. I(K) activation and tail currents were recorded using whole cell, voltage clamp techniques. Membrane capacitance of cells remote to HMI (187 +/- 7 pF) was significantly greater than normal (155 +/- 6 pF; P < 0.001). Action potential durations (APDs) recorded from myocytes in remote regions were prolonged (APD90 = 247 +/- 10 msec) compared to normal (214 +/- 11 msec; P < 0.05). Quinidine (1 microM) significantly prolonged APD90 in normal cells but not in remote cells. Density of I(K) (tail current) was significantly decreased in remote cells (3.1 +/- 0.3 pA/pF) compared to normal (3.9 +/- 0.3 pA/pF; P < 0.05), and voltage-dependent activation of I(K) was shifted in the positive direction. Quinidine had significantly less incremental blocking effect on I(K) already blunted by regional hypertrophy compared to its effect on normal cells in remote cells. IC50 shifted to 0.95 microM in remote cells compared with 0.50 microM in normal cells. CONCLUSION: Cells in noninfarct region remote from the scar are hypertrophied and display altered electrophysiology. Their reduced I(K) responsiveness to quinidine may explain, in part, failure of quinidine to prolong APD in such cells. Moreover, dispersion of repolarization may be decreased by the effect of quinidine on normal cells.
Title: Lack of nucleotide-promoted second messenger signaling responses in 1321N1 cells expressing the proposed P2Y receptor, p2y7 Herold CL, Li Q, Schachter JB, Harden TK, Nicholas RA Ref: Biochemical & Biophysical Research Communications, 235:717, 1997 : PubMed
A recently cloned G protein-coupled receptor (named the p2y7 receptor) with relatively low sequence identity to previously cloned P2Y receptors was proposed to be a member of this family of receptors on the basis of both a radioligand binding assay with [35S]dATP alphaS and an inositol phosphate response to ATP in COS-7 cells transiently transfected with receptor cDNA. Previous work in our laboratory has shown that [35S]dATP alphaS is not a general radioligand for the identification of P2Y receptors and that COS-7 cells express an endogenous P2Y receptor (P2Y2) that complicates the analysis of nucleotide-promoted inositol phosphate responses. Thus, data supporting inclusion of the p2y7 receptor in the P2Y family of receptors are equivocal. To determine unambiguously whether the p2y7 receptor is a P2Y receptor subtype, a p2y7 receptor bearing an epitope-tag at its NH2-terminus was expressed in 1321N1 cells and cell surface expression of the receptor was demonstrated by an intact cell-based ELISA. Cells shown to express epitope-tagged p2y7 receptors by ELISA were examined for their second messenger signaling properties in response to a range of nucleotides. ATP, UTP, ADP, UDP, and dATP alphaS had no effect on phospholipase C or adenylyl cyclase activities in cells expressing the p2y7 receptor. Experimental controls utilizing expression of other G protein-coupled receptors showed that 1321N1 cells displayed robust responses for each of these signaling pathways. These data, together with the low sequence identity of the p2y7 receptor to other P2Y receptors, indicate that the p2y7 is not a member of the P2Y family of signaling molecules.
