Title: Population performance and detoxifying and protective enzyme activities of four thrips species feeding on flowers of Magnolia grandiflora (Ranunculales: Magnolia) Cao Y, Qi G, Jiang F, Meng Y, Wang C, Gu Z, Gao Y, Reitz SR, Li C Ref: Pest Manag Sci, :, 2023 : PubMed
BACKGROUND: Different thrips species can co-occur on the same flowers with different dominance degrees. To accurately evaluate the population performance on different thrips species on Magnolia grandiflora flowers, we investigated the diversity of thrips species and their population dynamics both in the field and laboratory. In addition, the activities of detoxifying and protective enzymes in thrips were also measured. RESULTS: Field investigations revealed that four thrips species (Thrips hawaiiensis, Thrips flavidulus, Frankliniella occidentalis, and Thrips coloratus) were coexisted on M. grandiflora flowers. They were ranked, from highest population density to lowest, as follows: T. hawaiiensis > T. flavidulus > F. occidentalis > T. coloratus. In laboratory investigations, the species were ranked, from fastest developmental rates to slowest, as follows: F. occidentalis > T. hawaiiensis > T. flavidulus > T. coloratus; and from largest population size to smallest, as follows: T. hawaiiensis > F. occidentalis > T. flavidulus > T. coloratus. Biochemistry assays showed that the four species differed in their activities of detoxifying enzymes (carboxylesterase, glutathione-S-transferase, and cytochrome P450) and protective enzymes (superoxide dismutase, peroxidase) in both laboratory and field strains. CONCLUSION: Differences in population performance among these four thrips on M. grandiflora may be related to their activity levels of physiological enzymes. The variations in thrips population performance between the field and the laboratory could be due to differences in environmental conditions. T. hawaiiensis showed a strong host preference for M. grandiflora, and thus it has the potential to be a dangerous pest in horticultural plants. This article is protected by copyright. All rights reserved.
AIM: To assess the efficacy and safety of the dipeptidyl peptidase-4 inhibitor, cetagliptin, as monotherapy in Chinese patients with type 2 diabetes (T2D) and inadequate glycaemic control. MATERIALS AND METHODS: In total, 504 eligible patients with T2D were enrolled and randomized to cetagliptin 50 mg once daily, cetagliptin 100 mg once daily or placebo at a ratio of 2:2:1 for 24 weeks of double-blind treatment, then all patients received cetagliptin 100 mg once daily for 28 weeks of open-label treatment. The primary efficacy endpoint was the change in HbA1c level from baseline at week 24. RESULTS: After 24 weeks, HbA1c from baseline was significantly reduced with cetagliptin 50 mg (-1.08%) and cetagliptin 100 mg (-1.07%) compared with placebo (-0.35%). The placebo-subtracted HbA1c reduction was -0.72% with cetagliptin 50 mg and 100 mg. Patients with a baseline HbA1c of 8.5% or higher had a greater HbA1c reduction with cetagliptin than those patients with a baseline HbA1c of less than 8.5%. Both doses studied led to a significantly higher proportion of patients (42.3% with 100 mg and 45.0% with 50 mg) achieving an HbA1c of less than 7.0% compared with placebo (12.9%). Cetagliptin also significantly lowered fasting plasma glucose and 2-hour postmeal plasma glucose relative to placebo. The incidence of adverse experiences was similar between cetagliptin and placebo. No drug-related hypoglycaemia was reported. CONCLUSIONS: Cetagliptin monotherapy was effective and well tolerated in Chinese patients with T2D who had inadequate glycaemic control on exercise and diet.
        
Title: Characterization of the metabolism of eupalinolide A and B by carboxylesterase and cytochrome P450 in human liver microsomes Li Y, Liu X, Li L, Zhang T, Gao Y, Zeng K, Wang Q Ref: Front Pharmacol, 14:1093696, 2023 : PubMed
Eupalinolide A (EA; Z-configuration) and eupalinolide B (EB; E-configuration) are bioactive cis-trans isomers isolated from Eupatorii Lindleyani Herba that exert anti-inflammatory and antitumor effects. Although one pharmacokinetic study found that the metabolic parameters of the isomers were different in rats, metabolic processes relevant to EA and EB remain largely unknown. Our preliminary findings revealed that EA and EB are rapidly hydrolyzed by carboxylesterase. Here, we investigated the metabolic stability and enzyme kinetics of carboxylesterase-mediated hydrolysis and cytochrome P450 (CYP)-mediated oxidation of EA and EB in human liver microsomes (HLMs). We also explored differences in the hydrolytic stability of EA and EB in human liver microsomes and rat liver microsomes (RLMs). Moreover, cytochrome P450 reaction phenotyping of the isomers was performed via in silico methods (i.e., using a quantitative structure-activity relationship model and molecular docking) and confirmed using human recombinant enzymes. The total normalized rate approach was considered to assess the relative contributions of five major cytochrome P450s to EA and EB metabolism. We found that EA and EB were eliminated rapidly, mainly by carboxylesterase-mediated hydrolysis, as compared with cytochrome P450-mediated oxidation. An inter-species difference was observed as well, with faster rates of EA and EB hydrolysis in rat liver microsomes. Furthermore, our findings confirmed EA and EB were metabolized by multiple cytochrome P450s, among which CYP3A4 played a particularly important role.
Hepatotoxicity induced by bioactive constituents in traditional Chinese medicines or herbs, such as bavachin (BV) in Fructus Psoraleae, has a prolonged latency to overt drug-induced liver injury in the clinic. Several studies have described BV-induced liver damage and underlying toxicity mechanisms, but little attention has been paid to the deciphering of organisms or cellular responses to BV at no-observed-adverse-effect level, and the underlying molecular mechanisms and specific indicators are also lacking during the asymptomatic phase, making it much harder for early recognition of hepatotoxicity. Here, we treated mice with BV for 7 days and did not detect any abnormalities in biochemical tests, but found subtle steatosis in BV-treated hepatocytes. We then profiled the gene expression of hepatocytes and non-parenchymal cells at single-cell resolution and discovered three types of hepatocyte subsets in the BV-treated liver. Among these, the hepa3 subtype suffered from a vast alteration in lipid metabolism, which was characterized by enhanced expression of apolipoproteins, carboxylesterases, and stearoyl-CoA desaturase 1 (Scd1). In particular, increased Scd1 promoted monounsaturated fatty acids (MUFAs) synthesis and was considered to be related to BV-induced steatosis and polyunsaturated fatty acids (PUFAs) generation, which participates in the initiation of ferroptosis. Additionally, we demonstrated that multiple intrinsic transcription factors, including Srebf1 and Hnf4a, and extrinsic signals from niche cells may regulate the above-mentioned molecular events in BV-treated hepatocytes. Collectively, our study deciphered the features of hepatocytes in response to BV insult, decoded the underlying molecular mechanisms, and suggested that Scd1 could be a hub molecule for the prediction of hepatotoxicity at an early stage.
        
Title: Neuroligins facilitate the development of bone cancer pain via regulating synaptic transmission: an experimental study Xie X, Li Y, Su S, Li X, Xu X, Gao Y, Peng M, Ke C Ref: Braz J Anesthesiol, :, 2023 : PubMed
BACKGROUND: The underlying mechanism of chronic pain involves the plasticity in synaptic receptors and neurotransmitters. This study aimed to investigate potential roles of Neuroligins (NLs) within the spinal dorsal horn of rats in a newly established Bone Cancer Pain (BCP) model. The objective was to explore the mechanism of neuroligin involved in the occurrence and development of bone cancer pain. METHODS: Using our rat BCP model, we assessed pain hypersensitivity over time. Quantitative real-time polymerase chain reaction and Western blot analysis were performed to investigate NL expression, and NLs were overexpressed in the rat spinal cord using lentiviral vectors. Immunofluorescence staining and whole-cell patch-clamp recordings were deployed to investigate the role of NLs in the development of BCP. RESULTS: We observed reduced expression levels of NL1 and NL2, but not of NL3, within the rat spinal cord, which were found to be associated with and essential for the development of BCP in our model. Accordingly, NL1 or NL2 overexpression in the spinal cord alleviated mechanical hypersensitivity of rats. Electrophysiological experiments indicated that NL1 and NL2 are involved in BCP via regulating gamma-aminobutyric acid-ergic interneuronal synapses and the activity of glutamatergic interneuronal synapses, respectively. CONCLUSIONS: Our observations unravel the role of NLs in cancer-related chronic pain and further suggest that inhibitory mechanisms are central features of BCP in the spinal dorsal horn. These results provide a new perspective and basis for subsequent studies elucidating the onset and progression of BCP.
Esterases are a class of enzymes that split esters into an acid and an alcohol in a chemical reaction with water, having high potential in pharmaceutical, food and biofuel industrial applications. To advance the understanding of esterases, we have identified and characterized E53, an alkalophilic esterase from a marine bacterium Erythrobacter longus. The crystal structures of wild type E53 and three variants were solved successfully using the X-ray diffraction method. Phylogenetic analysis classified E53 as a member of the family IV esterase. The enzyme showed highest activity against p-nitrophenyl butyrate substrate at pH 8.5 9.5 and 40 C. Based on the structural feature, the catalytic pocket was defined as R1 (catalytic center), R2 (pocket entrance), and R3 (end area of pocket) regions. Nine variants were generated spanning R1-R3 and thorough functional studies were performed. Detailed structural analysis and the results obtained from the mutagenesis study revealed that mutations in the R1 region could regulate the catalytic reaction in both positive and negative directions; expanding the bottleneck in R2 region has improved the enzymatic activity; and R3 region was associated with the determination of the pH pattern of E53. N166A in R3 region showed reduced activity only under alkaline conditions, and structural analysis indicated the role of N166 in stabilizing the loop by forming a hydrogen bond with L193 and G233. In summary, the systematic studies on E53 performed in this work provide structural and functional insights into alkaliphilic esterases and further our knowledge of these enzymes.
        
Title: Similarities and differences among the responses to three chlorinated organophosphate esters in earthworm: Evidences from biomarkers, transcriptomics and metabolomics Gao Y, Wang L, Zhang X, Shi C, Ma L, Wang G Ref: Sci Total Environ, 815:152853, 2022 : PubMed
The wide use of chlorinated organophosphate esters (Cl-OPEs) as additive flame retardants has aroused concern about their potential risks on ecosystem and human health. However, knowledge about the toxicity of Cl-OPEs on soil organisms remains limited. In this study, earthworms, Eisenia fetida, were exposed to three representative Cl-OPEs, i.e., tris(2-chloroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP) in artificial soil. Using a combination of biochemical indicators (biomarkers), transcriptomics, and metabolomics, we compared the Cl-OPE-induced toxicity to E. fetida and provide new insight into the related molecular mechanism. All three Cl-OPEs elicited immune defense by the earthworms, as evidenced by increased acid phosphatase and alkaline phosphatase activities, and the genes involved in immune-related pathways (e.g., lysosomal and interleukin-17 signaling pathways). Furthermore, no effects on acetylcholinesterase activity were observed among the three Cl-OPEs. However, the TCPP and TDCPP treatments significantly decreased the neurotransmitter serotonin, suggesting the potential neurotoxicity of Cl-OPEs. Although TCEP affected the genes involved in carbohydrate and amino acid metabolism, the changes in the corresponding metabolites were not statistically significant. In contrast, exposure to TCPP and TDCPP induced oxidative stress, and affected xenobiotic metabolism and energy metabolism, leading to the decreased body weight in E. fetida. Based on these toxic effects, TCPP and TDCPP were more severely toxic than TCEP, despite their structural similarity. Given that the use of TCEP has been tightly regulated, our results suggest the potentially toxic effects of TCPP and TDCPP should not be ignored in future risk assessments of flame retardants.
Pyrethroid pesticides, with low toxicity to birds and mammals and short persistence in the environment, are widely used now. With the development of intensive poultry farming, pesticide application leads to residues in poultry products and pollution in ecological environment. The aim of the present study was to examine deltamethrin subchronic toxicity in laying chickens. One hundred and twelve laying chickens were randomly assigned to 14 groups including 13 groups medicated with deltamethrin (n = 8) and one unmedicated group used as control (n = 8). Tissue samples were collected during and after administration for weighing and histopathological analysis. A single dose of deltamethrin (20 mg.kg(-1).BW.d) was administered orally to laying chickens for 14 days. The results showed that deltamethrin has no significant effect on the relative organ weight of laying chickens (p > 0.05). The activities of aspartate aminotransferase and cholinesterase in the plasma gradually decreased over time in the medicated group (p < 0.05). Plasma concentrations of urea nitrogen, uric acid, cholesterol, triglycerides, and creatinine significantly increased during treatment (p < 0.05), and significant liver damage and loss of intestinal villous epithelium were observed. The intestinal wall thickness, villus height, and crypt depth of laying chickens were altered by deltamethrin treatment. During treatment was withdrawn, the intestinal repair was more extensive than the liver repair.
        
Title: The Relationship Between Zinc Deficiency and Hepatocellular Carcinoma Associated with Hepatitis B Liver Cirrhosis: A 10-year Follow-up Study Wang S, Fan X, Gao Y, Zuo L, Hong M, Xu Y Ref: Biol Trace Elem Res, :, 2022 : PubMed
Our aim is to evaluate the serum zinc levels in Hepatitis B liver cirrhosis patients and clarify the relationship between the serum zinc levels and the development of hepatocellular carcinoma (HCC). From January 2009 to December 2019, 295 included patients diagnosed with Hepatitis B liver cirrhosis received nucleos(t)ide analogues (NUCs) therapy at China-Japan Union Hospital of Jilin University. Their comprehensive medical records were retrospectively analyzed, and to analyze the relationship between hypozincemia and hepatitis B-related HCC. Twenty-eight of 295 patients (9.49%) developed HCC during an observation period of the median follow-up time was 42 months. Compared with the non-zinc deficiency group, the zinc deficiency group is older, has a higher proportion of hepatic encephalopathy, higher levels of aspartate aminotransferase(AST), international normalized ratio(INR) and TB, and lower levels of cholinesterase (CHE), creatinine, and platelet counts (P< 0.05). Multivariate analysis showed that zine (HR=0.854, 95%CI 0.725-1.007; P=0.061), zinc is not significant for reducing the incidence of HCC, as liver disease progresses, the proportion of zinc deficiency is getting higher and higher, Child-Pugh C. The proportion of grade zinc deficiency accounted for 64.86%. Child-Pugh grade C was more than Child-Pugh grade B and A, p<0.001. Zinc deficiency is associated with hepatic encephalopathy, and other complications related to hepatitis B and liver cirrhosis. But the relationship with hepatocellular carcinoma still needs further study.
        
Title: Adeno-associated virus-mediated in vivo suppression of expression of EPHX2 gene modulates the activity of paraventricular nucleus neurons in spontaneously hypertensive rats Zhu X, Li K, Gao Y Ref: Biochemical & Biophysical Research Communications, 606:121, 2022 : PubMed
BACKGROUND: Hypertension can be attributed to increased sympathetic activities. Presympathetic neurons in the paraventricular nucleus (PVN) of the hypothalamus are capable of modulating sympathetic outflow, thus contributing to the pathogenesis of neurogenic hypertension. Epoxyeicosatrienoic acids (EETs) were reported to have anti-hypertensive effects, which could be degraded by soluble epoxide hydrolase (sEH), encoded by EPHX2. However, the potential effect of EETs on PVN neuron activity and the underlying molecular mechanism are largely unknown. METHODS: Knockdown of EPHX2 in spontaneously hypertensive rats (SHRs) was achieved by tail-intravenous injection of AAV plasmid containing shRNA targeting EPHX2. Whole-cell patch clamp was used to record action potentials of PVN neurons. An LC-MS/MS System was employed to determine 14,15-EET levels in rat cerebrospinal fluid. qPCR and western blotting were applied to examine the expression level of EPHX2 in various tissues. ELISA and immunofluorescence staining were applied to examine the levels of ATP, D-serine and glial fibrillary acidic protein (GFAP) in isolated astrocytes. RESULTS: The expression level of EPHX2 was higher, while the level of 14,15-EET was lower in SHRs than normotensive Wistar-Kyoto rats (WKY) rats. The spike firing frequency of PNV neurons in SHRs was higher than in WKY rats at a given stimulus current, which could be reduced by either EPHX2 downregulation or 14,15-EET administration. In isolated hypothalamic astrocytes, the elevated intracellular ATP or D-serine induced by Angiotensin II (Ang II) treatment could be rescued by 14,15-EET addition or 14,15-EET combing serine racemase (SR) downregulation by siRNA, respectively. Furthermore, 14,15-EET treatment reduced the Ang II-induced elevation of GFAP immunofluorescence. CONCLUSIONS: The elevation of EET levels by EPHX2 downregulation reduced presympathetic neuronal activity in the PVN of SHRs, leading to a reduced sympathetic outflow in hypertension rats. The ATP/SR/D-serine pathway of astrocytes is involved in EET-mediated neuroprotection.
Pyrethroids are the third widespread used insecticides globally which have been extensively applied in agricultural or household environments. Due to continuous applications, pyrethroids have been detected both in living cells and environments. The permanent exposure to pyrethroids have caused substantial health risks and ecosystem concerns. In this work, a lambda-cyhalothrin (one kind of pyrethroid insecticides) degrading bacterium Bacillus velezensis sd was isolated and a carboxylesterase gene, CarCB2 was characterized. A whole cell biocatalyst was developed for lambda-cyhalothrin biodegradation by displaying CarCB2 on the surface of Escherichia coli cells. CarCB2 was successfully displayed and functionally expressed on E. coli cells with optimal pH and temperature of 7.5 and 30 degreesC, using p-NPC(4) as substrate, respectively. The whole cell biocatalyst exhibited better stability than the purified CarCB2, and approximately 120%, 60% or 50% of its original activity at 4 degreesC, 30 degreesC or 37 degreesC over a period of 35 d was retained, respectively. No enzymatic activity was detected when incubated the purified CarCB2 at 30 degreesC for 120 h, or 37 degreesC for 72 h, respectively. Additionally, 30 mg/L of lambda-cyhalothrin was degraded in citrate-phosphate buffer by 10 U of the whole cell biocatalyst in 150 min. This work reveals that the whole cell biocatalyst affords a promising approach for efficient biodegradation of lambda-cyhalothrin, and might have the potential to be applied in further environmental bioremediation of other different kinds of pyrethroid insecticides.
        
Title: Effects of elevated CO(2) on activities of protective and detoxifying enzymes in Frankliniella occidentalis and Frankliniella intonsa under spinetoram stress1 Fan Z, Qian L, Chen Y, Fan R, He S, Gao Y, Gui F Ref: Pest Manag Sci, :, 2021 : PubMed
BACKGROUND: Elevated CO(2) can directly affect toxicity of insecticides to insects and the physiological response of insects to insecticides. Frankliniella occidentalis and Frankliniella intonsa are highly destructive pests that target horticultural crops. Spinetoram is an effective pesticide against thrips. This study sought to explore the effect of elevated CO(2) on efficacy of spinetoram against F. occidentalis and F. intonsa and effect of the spinetoram on activities of protective and detoxifying enzymes under elevated CO(2) . Notably, these enzymes can be exploited in further studies to develop interventions for thrips resistance management. RESULTS: Toxicity bioassay showed that the LC(50) values of F. occidentalis and F. intonsa exposed to spinetoram at elevated CO(2) (800 microL.L(-1) concentration) for 48 h was 0.08 and 0.006 mg.L(-1) , respectively, they are 0.62 and 0.75 times of those at ambient CO(2) (400 microL.L(-1) concentration). The findings showed that elevated CO(2) decreased activities of the superoxide dismutase and acetylcholinesterase in thrips, while increased the activities of carboxylesterase and glutathione-S-transferase. However, spinetoram increased activities of protective and detoxifying enzymes in both thrips under the two CO(2) levels. It has synergistic effect of elevated CO(2) and spinetoram treatment on the physiological enzyme activity of thrips, and the activities of analyzed enzymes were generally higher in F. occidentalis than those in F. intonsa. CONCLUSION: Elevated CO(2) amplifies the efficacy of spinetoram on thrips, F. intonsa is more susceptibility to spinetoram than F. occidentalis, and the latter showed better adaptation to adverse conditions than the former. This article is protected by copyright. All rights reserved.
Tannases are a family of esterases that catalyze the hydrolysis of ester and depside bonds present in hydrolyzable tannins to release gallic acid. Here, a novel tannase from Lachnospiraceae bacterium (TanA(Lb)) was characterized. The recombinant TanA(Lb) exhibited maximal activity at pH 7.0 and 50 degreesC, and it maintained more than 70% relative activity from 30 degreesC to 55 degreesC. The activity of TanA(Lb) was enhanced by Mg(2+) and Ca(2+), and was dramatically reduced by Cu(2+) and Mn(2+). TanA(Lb) is capable of degrading esters of phenolic acids with long-chain alcohols, such as lauryl gallate as well as tannic acid. The Km value and catalytic efficiency (k (cat) /Km) of TanA(Lb) toward five substrates showed that tannic acid (TA) was the favorite substrate. Homology modeling and structural analysis indicated that TanA(Lb) contains an insertion loop (residues 341-450). Based on the moleculer docking and molecular dynamics (MD) simulation, this loop was observed as a flap-like lid to interact with bulk substrates such as tannic acid. TanA(Lb) is a novel bacterial tannase, and the characteristics of this enzyme make it potentially interesting for industrial use.
        
Title: Changes of embryonic development, locomotor activity, and metabolomics in zebrafish co-exposed to chlorpyrifos and deltamethrin Hu Y, Hu J, Li W, Gao Y, Tian Y Ref: J Appl Toxicol, 41:1345, 2021 : PubMed
Organophosphates (OPs) and pyrethroids (PYRs) are extensively used pesticides and often occur in the form of mixture, whereas little was known about their joint toxicities. We aim to investigate the individual and joint effects of OPs and PYRs exposure on zebrafish embryo by employing chlorpyrifos (CPF) and deltamethrin (DM) as representatives. Zebrafish embryos at 2 hours post fertilization (hpf) were exposed to CPF (4.80, 39.06, and 78.13 microg/L), DM exposure (0.06, 1.60, and 3.19 microg/L), and CPF + DM (4.80 + 0.06, 39.06 + 1.60, and 78.13 + 3.19 microg/L) until 144 hpf. Embryonic development, locomotor activity, and metabolomic changes were recorded and examined. Results displayed that individual exposure to CPF and DM significantly increased the mortality and malformation rate of zebrafish embryos, but decreased hatching rate was only found in CPF + DM co-exposure groups (p < .05). Meanwhile, individual CPF exposure had no detrimental effect on locomotor activity, high dose of individual CPF exposure decreased the swimming speed but had adaptability to the conversion from dark to light, whereas high dose of CPF + DM co-exposure exhibited not only significant decline in swimming speed but also no adaptability to the repeated stimulations, suggesting deficit in learning and memory function. In metabolomic analysis, individual CPF exposure mainly influenced the metabolism of glycerophospholipids and amino acids, individual DM exposure mainly influenced glycerophospholipids, and CPF + DM co-exposure mainly influenced glycerophospholipids and amino acids. Taken together, our findings suggested the embryonic toxicities and neurobehavioral changes caused by CPF and/or DM exposure. The disorder metabolomics of glycerophospholipids and amino acids might be involved in the underlying mechanism of those toxicities.
        
Title: Inhibiting Monoacylglycerol Lipase Suppresses RANKL-Induced Osteoclastogenesis and Alleviates Ovariectomy-Induced Bone Loss Liu H, Zhou C, Qi D, Gao Y, Zhu M, Tao T, Sun X, Xiao J Ref: Front Cell Developmental Biology, 9:640867, 2021 : PubMed
Osteoporosis is a common chronic metabolic bone disease characterized by reduced trabecular bone and increased bone fragility. Monoacylglycerol lipase (MAGL) is a lipolytic enzyme to catalyze the hydrolysis of monoglycerides and specifically degrades the 2-arachidonoyl glycerol (2-AG). Previous studies have identified that 2-AG is the mainly source for arachidonic acid and the most abundant endogenous agonist of cannabinoid receptors. Considering the close relationship between inflammatory mediators/cannabinoid receptors and bone metabolism, we speculated that MAGL may play a role in the osteoclast differentiation. In the present study, we found that MAGL protein expression increased during osteoclast differentiation. MAGL knockdown by adenovirus-mediated shRNA in bone marrow-derived macrophages demonstrated the suppressive effects of MAGL on osteoclast formation and bone resorption. In addition, pharmacological inhibition of MAGL by JZL184 suppressed osteoclast differentiation, bone resorption, and osteoclast-specific gene expression. Activation of the Mitogen-activated protein kinase (MAPK) and nuclear factor kappaB (NF-kappaB) pathways was inhibited by JZL184 and deletion of MAGL. Our in vivo study indicated that JZL184 ameliorated bone loss in an ovariectomized mouse model. Furthermore, overexpressing H1 calponin partially alleviated the inhibition caused by JZL184 or MAGL deletion on osteoclastogenesis. Therefore, we conclude that targeting MAGL may be a novel therapeutic strategy for osteoporosis.
The natural product harmine, a representative beta-carboline alkaloid from the seeds of Peganum harmala L. (Zygophyllaceae), possesses a broad spectrum of biological activities. In this study, a novel series of harmine derivatives containing N-benzylpiperidine moiety were identified for the treatment of Alzheimer's disease (AD). The results showed that all the derivatives possessed significant anti-acetylcholinesterase (AChE) activity and good selectivity over butyrylcholinesterase (BChE). In particular, compound ZLWH-23 exhibited potent anti-AChE activity (IC(50) = 0.27 microM) and selective BChE inhibition (IC(50) = 20.82 microM), as well as acceptable glycogen synthase kinase-3 (GSK-3beta) inhibition (IC(50) = 6.78 microM). Molecular docking studies and molecular dynamics simulations indicated that ZLWH-23 could form stable interaction with AChE and GSK-3beta. Gratifyingly, ZLWH-23 exhibited good selectivity for GSK-3beta over multi-kinases and very low cytotoxicity towards SH-SY5Y, HEK-293T, HL-7702, and HepG2 cell lines. Importantly, ZLWH-23 displayed efficient reduction against tau hyperphosphorylation on Ser-396 site in Tau (P301L) 293T cell model. Collectively, harmine-based derivatives could be considered as possible drug leads for the development of AD therapies.
        
Title: Novel insights into host receptors and receptor-mediated signaling that regulate arbuscular mycorrhizal symbiosis Nasir F, Bahadur A, Lin X, Gao Y, Tian C Ref: J Exp Bot, 72:1546, 2021 : PubMed
More than 80% of land plant species benefit from symbiotic partnerships with arbuscular mycorrhizal (AM) fungi, which assist in nutrient acquisition and enhance the ability of host plants to adapt to environmental constraints. Host-generated plasma membrane-residing receptor-like kinases and the intracellular alpha/beta-hydrolase DWARF14-LIKE, a putative karrikin receptor, detect the presence of AM fungi before physical contact between the host and fungus. Detection induces appropriate symbiotic responses, which subsequently enables a favorable environment for AM symbiosis to occur. To prevent hyper-colonization and maintain a mutually beneficial association, the host plant precisely monitors and controls AM colonization by receptor-like kinases, such as SUPER NUMERIC NODULES. Previous studies have elucidated how host plant receptors and receptor-mediated signaling regulate AM symbiosis, but the underlying molecular mechanisms remain poorly understood. The identification of a rice CHITIN ELICITOR RECEPTOR KINASE 1 interaction partner, MYC FACTOR RECEPTOR 1, and new insights into DWARF14-LIKE receptor- and SUPER NUMERIC NODULES receptor-mediated signaling have expanded our understanding of how host plant receptors and their corresponding signals regulate AM symbiosis. This review summarizes these and other recent relevant findings. The identified receptors and/or their signaling components could be manipulated to engineer crops with improved agronomic traits by conferring the ability to precisely control AM colonization.
Tau accumulation and cholinergic impairment are characteristic pathologies in Alzheimer's disease (AD). However, the causal role of tau accumulation in cholinergic lesion is elusive. Here, we observed an aberrant tau accumulation in the medial septum (MS) of 3xTg and 5xFAD mice, especially in their cholinergic neurons. Overexpressing hTau in mouse MS (MS(hTau) ) for 6 months but not 3 months induced spatial memory impairment without changing object recognition and anxiety-like behavior, indicating a specific and time-dependent effect of MS-hTau accumulation on spatial cognitive functions. With increasing hTau accumulation, the MS(hTau) mice showed a time-dependent cholinergic neuron loss with reduced cholinergic projections to the hippocampus. Intraperitoneal administration of donepezil, a cholinesterase inhibitor, for 1 month ameliorated the MS-hTau-induced spatial memory deficits with preservation of MS-hippocampal cholinergic pathway and removal of tau load; and the beneficial effects of donepezil was more prominent at low dose. Proteomics revealed that MS-hTau accumulation deregulated multiple signaling pathways with numerous differentially expressed proteins (DEPs). Among them, the vacuolar protein sorting-associated protein 37D (VP37D), an autophagy-related protein, was significantly reduced in MS(hTau) mice; the reduction of VP37D was restored by donepezil, and the effect was more significant at low dose than high dose. These novel evidences reveal a causal role of tau accumulation in linking MS cholinergic lesion to hippocampus-dependent spatial cognitive damages as seen in the AD patients, and the new tau-removal and autophagy-promoting effects of donepezil may extend its application beyond simple symptom amelioration to potential disease modification.
        
Title: A highly sensitive acetylcholinesterase electrochemical biosensor based on Au-Tb alloy nanospheres for determining organophosphate pesticides Yang Y, Zhao Y, Liu Q, You T, Gao Y, Chen H, Yin P Ref: Nanotechnology, :, 2021 : PubMed
Accurately detect the residues of organophosphate pesticides(OPs) in food and environment is critical to our daily lives. In this study, we developed a novel acetylcholinesterase (AChE) biosensor based on Au-Tb alloy nanospheres (NSs) for rapid and sensitive detection of OPs for the first time. Au-Tb alloy nanospheres that with good conductivity and biocompatibility were produced with a mild hydrothermal. Under optimal conditions, the AChE biosensor was obtained by a simple assembly process, with a big linear range (10-13 M - 10-7 M) and the limit of detection was 2.51 x 10-14 M for the determination of methyl parathion. Moreover, the determination of methyl parathion with the prepared biosensor presented a high sensitivity, outstanding repeatability and superior stability compared with other reported biosensors. Through the determination of tap water and Yanming lake samples, it was proved that the modified biosensor with satisfactory recoveries (96.76 %-108.6 %), and are realizable in the determination of OPs in real samples.
        
Title: Characterization of a novel lipase from Bacillus licheniformis NCU CS-5 for applications in detergent industry and biodegradation of 2,4-D butyl ester Zhao J, Liu S, Gao Y, Ma M, Yan X, Cheng D, Wan D, Zeng Z, Yu P, Gong D Ref: Int J Biol Macromol, :, 2021 : PubMed
Enzymatic degradation has become the most promising approach to degrading organic ester compounds. In this study, Bacillus licheniformis NCU CS-5 was isolated from the spoilage of Cinnamomum camphora seed kernel, and its extracellular lipase was purified, with a specific activity of 192.98 U/mg. The lipase was found to be a trimeric protein as it showed a single band of 27 kDa in SDS-PAGE and 81 kDa in Native-PAGE. It was active in a wide range of temperatures (5-55 degreesC) and pH values (6.0-9.0), and the optimal temperature and pH value were 40 degreesC and 8.0, respectively. The enzyme was active in the presence of various organic solvents, metal ions, inhibitors and surfactants. Both crude and purified lipase retained more than 80% activity after 5 h in the presence of commercial detergents, suggesting its great application potential in detergent industry. The highest activity was found to be towards medium- and long-chain fatty acids (C(6)-C(18)). Peptide mass spectrometric analysis of the purified lipase showed similarity to the lipase family of B. licheniformis. Furthermore, it degraded more than 90% 2,4-D butyl ester to its hydrolysate 2,4-D within 24 h, indicating that the novel lipase may be applied to degrade organic ester pesticides.
A recently discovered bisubstrate inhibitor of Nicotinamide N-methyltransferase (NNMT) was found to be highly potent in biochemical assays with a single digit nanomolar IC(50) value but lacking in cellular activity. We, here, report a prodrug strategy designed to translate the observed potent biochemical inhibitory activity of this inhibitor into strong cellular activity. This prodrug strategy relies on the temporary protection of the amine and carboxylic acid moieties of the highly polar amino acid side chain present in the bisubstrate inhibitor. The modification of the carboxylic acid into a range of esters in the absence or presence of a trimethyl-lock (TML) amine protecting group yielded a range of candidate prodrugs. Based on the stability in an aqueous buffer, and the confirmed esterase-dependent conversion to the parent compound, the isopropyl ester was selected as the preferred acid prodrug. The isopropyl ester and isopropyl ester-TML prodrugs exhibit improved cell permeability, which also translates to significantly enhanced cellular activity as established using assays designed to measure the enzymatic activity of NNMT in live cells.
        
Title: Characterization of EstZY: A new acetylesterase with 7-aminocephalosporanic acid deacetylase activity from Alicyclobacillus tengchongensis Ding J, Zhou Y, Zhu H, Deng M, Gao Y, Yang Y, Huang Z Ref: Int J Biol Macromol, 148:333, 2020 : PubMed
Deacetyl-7-aminocephalosporanic acid (D-7-ACA) is required for producing of many semisynthetic beta-lactam antibiotics; therefore, enzymes capable of converting 7-aminocephalosporanic acid (7-ACA) to D-7-ACA present a valuable resource to the pharmaceutical industry. In the present study, a putative acetylesterase, EstZY, was identified and characterized from a thermophilic bacterium Alicyclobacillus tengchongensis. Sequence alignment showed that EstZY was an acetylesterase which belonged to carbohydrate esterase family 7 (CE7), with substrate preference for short-chain acyl esters p-NPC(2) to p-NPC(8). Maximum enzyme activity was recorded at pH 9.0 and 50 degreesC, where K(m) and V(max) were calculated as 1.9 +/- 0.23 mM and 258 +/- 18.5 microM min(-)(1), respectively. The residues Ser185, Asp274, and His303 were identified as the putative catalytic triad by homology modelling, site-directed mutagenesis and molecular docking. Moreover, EstZY can remove the acetyl group at C3' position of 7-ACA to form D-7-ACA; this is the first report of a 7-ACA deacetylase from CE7 family in A. tengchongensis and may represent a new enzyme with industrial values.
        
Title: Ecological risk assessment of heavy metals in fish from the Dianchi Lake, China using the integrated biomarker response approach Gao Y, Fang L, Xiang QQ, Wang D, Ding LY, Ding CZ, Chen LQ Ref: Environ Sci Pollut Res Int, 27:45712, 2020 : PubMed
This study used the integrated biomarker response (IBR) index approach to assess the ecological risks of heavy metals in different regions of Dianchi Lake, combined with active monitoring and passive monitoring. The contents of five heavy metals (Cu, As, Cd, Hg, and Pb) and six biomarkers (acetylcholinesterase, sodium-potassium ATPase, metallothionein, superoxide dismutase, glutathione peroxidase, and malondialdehyde) in the muscles of crucians (Carassius auratus) were measured to calculate the IBR value. The results indicate that the contents of heavy metal in the fish under active monitoring and passive monitoring were rather low and did not exceed the National Food Safety Standards of China. The IBR value of day 14 of active monitoring correlated with the heavy metal Cd content in the fish, suggesting a potential risk of Cd pollution in the aquatic environment of Dianchi Lake. The IBR values obtained for different regions of the lake on day 14 can be arranged in the following order: West S3 (9.24) > East S1 (3.97) > South S2 (2.39) > North S4 (0.36). These results suggest a potential risk of heavy metal contamination in the western part of Dianchi Lake.
        
Title: Decreased T-cell mediated hepatic injury in concanavalin A-treated PLRP2-deficient mice Ge W, Gao Y, Zhao Y, Yang Y, Sun Q, Yang X, Xu X, Zhang J Ref: Int Immunopharmacol, 85:106604, 2020 : PubMed
Concanavalin A (Con A) activates innate immunity and causes liver damage mediated by cytotoxic T lymphocytes (CTL) in mice. The Pancreatic lipase-related protein 2 (PLRP2) is induced by interleukin (IL)-4 in vitro in CTLs and associated with CTL functions. We examined the role of PLRP2 in a mouse model of Con A-induced T cell-mediated hepatitis. PLRP2-knockout and wild-type (WT) mice were inoculated with 20 mg/kg Con A. Mice lacking PLRP2 reduced Con A-induced hepatitis, which was manifested by a decrease in serum aminotransferase and histopathological assessment. The expression and secretion of cytokines including tumor necrosis factor-alpha (TNF-alpha), interferon (IFN)-gamma, IL-6, and IL-1beta were suppressed in Con A-treated PLRP2-knockout mice. In PLRP2 knockout mice, Con A-induced liver chemokines and adhesion molecules (such as MIP-1alpha, MIP-1beta, ICAM-1 and MCP-1) were also down regulated. In the WT liver treated with Con A, the number of T cells (CD4(+) and CD8(+)) and macrophages (CD11b(+) F4/80(+)) increased significantly, while the lack of PLRP2 reduced the number of T cells in the liver, but had no effect on macrophages. The shift of the metabolic profiles was impaired in Con A-treated PLRP2-knockout mice compared to WT mice. In conclusion, these results indicate that PLRP2 deficiency reduces T-cell mediated Con A-induced hepatitis, and suggest PLRP2 is a potential target of anti-inflammatory and immunomodulatory drugs to treat immune-mediated hepatitis.
Cystic echinococcosis (CE) is a worldwide zoonotic disease. At present, the treatment options of CE are limited. The main drugs used in clinical chemotherapy of echinococcosis are albendazole and mebendazole, but they mainly exert longterm antiparasitic effects based on high doses. Therefore, there is an urgent need for effective and safe anti-CE drugs. Previous studies have identified harmine (HM) as a new anti-CE drug. In this study, the efficacy of harmine derivatives was evaluated in vitro and in vivo. The harmine derivatives were tested against E. granulosus protoscoleces (PSC) in vitro. The effect of harmine derivatives was time and concentration dependent at different concentrations, and the anti-CE effect was better than that of harmine. The mortality rate of PSC reached 100% on the 5th day after exposure to harmine derivatives at a concentration of 100 mol . L (-1). Compared with the untreated model control mice, the weight of the cyst was significantly reduced in infected mice treated with harmine derivatives. The effect of harmine derivatives was better than that of harmine, and there was significant difference between harmine derivatives and albendazole (P <0.001). Histopathological examination of experimental mice organs (liver, spleen, lung, brain and small intestine) showed that there was no change in the tissues except for mild inflammation in the liver. The neurotoxicity test in Caenorhabditis elegans showed that the derivative inhibited the movement, feeding, perceptual behavior and acetylcholinesterase activity of C. elegans , and its effect was lower than that of harmine. In addition, intervention with HM derivatives was preliminarily proved to cause DNA damage. This study reveals the potential of HM derivatives as a new class of anti-CE agents and indicates that Topo2a may be a promising target for the development of anti-CE drugs.
        
Title: Directed Evolution of Pseudomonas fluorescens Lipase Variants With Improved Thermostability Using Error-Prone PCR Guan L, Gao Y, Li J, Wang K, Zhang Z, Yan S, Ji N, Zhou Y, Lu S Ref: Front Bioeng Biotechnol, 8:1034, 2020 : PubMed
Lipases catalyze the hydrolysis of fats and oils, and have been widely used in various industrial fields. However, bacterial lipases have a lower thermostability in industrial processes, which was a limiting factor in their industrial application. In this study, we obtained an improve variant of Pseudomonas fluorescens lipase (PFL) with enhanced thermostability using classical error-prone PCR. Wild-type PFL showed an optimal temperature and pH of 50degC and pH 7.5, respectively. Due to the low thermostability of PFL, a library containing over 3000 individual mutants as constructed using error-prone PCR. Screening for thermotolerance yielded the mutants L218P and P184C/M243C with T (m) values of 62.5 and 66.0degC, which was 2.5 and 6degC higher than that of the WT, respectively. The combination of the two mutants (P184C/M243C/L218P) resulted in an approximately additive effect with a T (m) value of 68.0degC. Although the increase of T (m) was not substantial, the mutant also had dramatically increased methanol tolerance. Structural analysis revealed that the introduction of a disulfide bond between P184C and M243C and the substitution of Pro to reduce the flexibility of a loop increased the thermostability of PFL, which provides a theoretical foundation for improving the thermostability and methanol tolerance of lipase family I.1 to resist the harsh conditions of industrial processes.
        
Title: Detoxification enzymes associated with butene-fipronil resistance in Epacromius coerulipes Jin Y, Gao Y, Zhang H, Wang L, Yang K, Dong H Ref: Pest Manag Sci, 76:227, 2020 : PubMed
BACKGROUND: Epacromius coerulipes is a widely distributed locust pest species. Chemical control is the main method used to kill locusts; however, this can result in the selection of locusts with resistance to chemical pesticides. Therefore, the study of resistance is of great significance for the sustainable management of locusts. RESULTS: In this study, to investigate the relationship between detoxification enzymes and butene-fipronil resistance in E. coerulipes, resistant strains of the locust were compared with sensitive strains. The synergism of synergistic agents was significantly enhanced, and the activities of multifunctional oxidase, carboxylesterase, and glutathione sulfur transferase were significantly increased. Transcriptome sequencing revealed 226 detoxification enzyme genes and 23 upregulated genes. Neighbor-joining was used to construct a phylogenetic tree of related gene families, which included 59 P450 genes, 52 carboxylesterases (CarE) genes, and 25 glutathione S-transferase (GST) genes. Reverse transcription polymerase chain reaction (RT-PCR) analysis results of overexpressed genes in the resistant population combined with a phylogenetic tree showed that four P450 genes belonged to the CYP6, CYP4, CYP18 and CYP302 families, two CarE genes belonged to Clade A families, and one GST gene belonged to the Sigma family. These family members were annotated as detoxification enzyme genes of metabolic insecticide in the transcriptome databases. CONCLUSIONS: This study showed that P450, CarE and GST together resulted in moderate resistance to butene-fipronil in locusts. The analysis revealed several overexpressed detoxification enzyme genes that will be the focus of future studies on the mechanism of resistance to butene-fipronil. (c) 2019 Society of Chemical Industry.
        
Title: Ultrasensitive detection of butyrylcholinesterase activity based on the inner filter effect of MnO(2) nanosheets on sulfur nanodots Li T, Gao Y, Li H, Zhang C, Xing Y, Jiao M, Shi YE, Li W, Zhai Y, Wang Z Ref: Analyst, 145:5206, 2020 : PubMed
Butyrylcholinesterase (BChE) activity is an important index for a variety of diseases. In this work, a "turn-on" assay is proposed based on controlling the inner filter effect (IFE) of MnO(2) nanosheets (NSs) on sulfur nanodots (S-dots). The fluorescence of S-dots is effectively quenched by the MnO(2) NSs, due to the wide overlap of the emission spectrum of S-dots and absorption spectrum of MnO(2) NSs, together with the superior light absorption capability of MnO(2) NSs. BChE can catalyze acetylthiocholine and produce thiocholine, which effectively decomposes the MnO(2) NSs into Mn(2+), resulting in the disappearance of the IFE and recovery of fluorescence of S-dots. Two-stage linear relationships between the ratio of fluorescence intensity and concentration of BChE are observed from 0.05 to 10 and from 10 to 500 U L(-1). A limit of detection of 0.035 U L(-1) is achieved, which is the best performance so far. The as-proposed assay is robust enough for practical detection in human serum, and it can avoid interference from its sister enzyme (acetylcholinesterase) and glutathione at the micromolar level. The presented results provide a clue for the functionalization of S-dots, and offer a powerful tool as an analytic technique for nanomedicine and environmental science.
        
Title: Enzymology, Histological and Ultrastructural Effects of Ar-Turmerone on Culex pipiens pallens Larvae Liu J, Fernandez D, Gao Y, Pierre S, Dai G Ref: Insects, 11:, 2020 : PubMed
Our previous article demonstrated that ar-turmerone ((6S)-2-methyl-6-(4-methylphenyl)-2-hepten-4-one) extracted from Curcuma longa L. has a significant larvicidal activity against the fourth instar larvae of Culex pipiens pallens. To reveal the effects of ar-turmerone on C. pipiens pallens larvae, light microscopy and transmission electron microscopy were used to observe the histological and ultrastructure changes in muscle and digestive tissues of fourth instar larvae. It was also revealed by detecting the activity of the acetylcholinesterase (AChE) enzyme and three detoxifying enzymes, including carboxylesterase (CarE), glutathione-S-transferase (GST) and Cytochrome P450 monooxidases (P450). The observation under the light microscope showed that the larvae displayed a disruption of myofibril in ventral muscle cells, the disappearance of nucleolus in the malpighian tubule cells, and the exfoliation of the brush border in midgut epithelial cells, 24 h after treatment. The observation under the transmission electron microscope displayed disorganized Z-lines in the ventral muscle cells, and dissolved membrane of mitochondria, nuclear and endoplasmic reticulum in abdominal cells. The enzymatic activity results showed that ar-turmerone significantly increased the level of detoxifying enzymes, while the activity of AChE was not obviously affected. All the results suggest that the larvicidal mechanism of ar-turmerone is estimated to be stomach poison and the active sites might be the muscle and digestive tissues, and the mode of action of ar-turmerone may be unrelated to AChE.
        
Title: Design, synthesis and biological evaluation of acridone glycosides as selective BChE inhibitors Ma W, Bi J, Zhao C, Gao Y, Zhang G Ref: Carbohydr Res, 491:107977, 2020 : PubMed
Based on structure analyses of butyrylcholinesterase (BChE), a series of 21 acridone glycosides were designed, synthesized and evaluated in vitro for their BChE and acetylcholinesterase (AChE) inhibitory activities. d-ribose derivative 6f exhibited the greatest inhibitory activity on BChE (IC50 = 6.95 muM), and was the most selective inhibitor of BChE with the IC50 ratio of AChE/BChE was 20.59. d-glucose and d-galactose derivatives 6a and 6b showed inhibitory activities against both AChE and BChE. Moreover, compounds 6a, 6b, 6f and 5t were found nontoxic on SHSY5Y neuroblastoma and HepG2 cell and exhibited remarkable neuroprotective activity. Besides, compound 6f showed mixed-type inhibition against BChE (Ki = 1.76 muM), which renders 6f a potential agent for the treatment of Alzheimer's disease. These novel acridone hybrids might be used as efficient probes to reveal the relationship between ligands and BChE and pave the way for developing selective BChE inhibitors to further study the pathogenesis of alzheimer's disease.
        
Title: Donepezil promotes neurogenesis via Src signaling pathway in a rat model of chronic cerebral hypoperfusion Man J, Cui K, Fu X, Zhang D, Lu Z, Gao Y, Yu L, Li N, Wang J Ref: Brain Research, 1736:146782, 2020 : PubMed
Donepezil, a selective acetylcholinesterase (AchE) inhibitor, enhances stroke-induced neurogenesis within subventricular zone (SVZ). Src/Pyk-2 is one of the downstream pathways of acetylcholine receptors (AchRs), and has been shown to participate in the activation of fibroblast growth factor receptor (FGFR)/epidermal growth factor receptor (EGFR) signaling in cancer cells. In this study, we investigated whether donepezil could promote SVZ neurogenesis in chronic cerebral hypoperfusion (CCH) injury via Src signaling pathway. In the bilateral carotid artery occlusion (2VO) rat model, we observed more nestin/5-bromo-2'-deoxyuridine (BrdU)-positive cells and doublecortin (DCX)/BrdU-positive cells in the SVZ than that in the sham group. Further, donepezil obviously improved neurologic function after 2VO, induced the greater number of SVZ proliferative NSCs and neuroblasts, and elevated levels of Src, p-FGFR1, p-EGFR, p-Akt and p-Raf in ipsilateral SVZ. Lastly, Src inhibitor KX-01 abolished the beneficial effects of donepezil in 2VO rats. These results suggest that donepezil could upregulate Src signaling pathway to enhance CCH-induced SVZ neurogenesis.
INTRODUCTION: Myasthenia gravis (MG) is an autoimmune disease in which antibodies directly target components of the neuromuscular junction, causing neuromuscular conduction damage that leads to muscle weakness. The current pharmaceutical treatment for MG is still not ideal to address the problems of disease progression, high recurrence rate, and drug side effects. Clinical observations suggest that traditional Chinese medicine (TCM) can strengthen immunity and improve symptoms of MG patients, delay the progression of the disease, reduce or even prevent the need for immunosuppressive therapy when used in combination with acetylcholinesterase inhibitors or low-dose prednisone, as well as improve the quality of life of patients. The Qiangji Jianli Capsule (QJC) is a combination of medicinal herbs which is used in traditional Chinese medicine. Since MG is a rare disorder, randomized controlled trials comparing large cohorts are difficult to conduct. Therefore, we proposed to aggregate data from a small series of N-of-1 trials to assess the effect of the Chinese medical prescription QJC, which strengthens the spleen and nourishes Qi, as an add-on treatment for MG with spleen and stomach Qi deficiency syndrome. METHODS AND ANALYSIS: Single-center, randomized, double-blind, multiple crossover N-of-1 studies will compare QJC versus placebo in 5 adult MG patients with spleen and stomach Qi deficiency syndrome. Patients will undergo 3 cycles of two 4-week intervention periods. According to the treatment schedule, patients will continue to be treated with pyridine bromide tablets, prednisone acetate, tablets and/or tacrolimus capsules throughout the entire trial. Each period consisting of 4-week oral add-on treatment with QJC will be compared with 4-week add-on treatment with a placebo. The primary endpoints are quantitative myasthenia gravis (QMG) test; measurement of the amount of Treg cells and cytokines such as interferon-gamma (IFN-gamma), interleukin-4 (IL-4), interleukin-17A (IL-17A), and transforming growth factor-beta (TGF-beta); and corticosteroid or immunosuppressive agent dosage. Secondary outcome measures: Clinical: Evaluation of the effect of TCM syndromes; MG-activities of daily living (MG-ADL) scales; adverse events. ETHICS AND DISSEMINATION: This study was approved by The First Affiliated Hospital of Guangzhou University of Chinese Medicine (GZUCM), No. ZYYECK[2019]038. The results will be published in a peer-reviewed publication. Regulatory stakeholders will comment on the suitability of the trial for market authorization and reimbursement purposes. Trial registration: Chinese Clinical Trial Register, ID: ChiCTR2000033516. Registered on 3 June 2020, http://www.chictr.org.cn/showprojen.aspx?proj=54618.
        
Title: Structure and Catalytic Mechanism of a Pyrethroid Carboxylesterase PytH from Sphingobium faniae JZ-2 Xu D, Gao Y, Sun B, Ran T, Zeng L, He J, Wang W Ref: Applied Environmental Microbiology, :, 2020 : PubMed
Carboxylesterase PytH, isolated from a pyrethroid degrading bacterium Sphingobium faniae JZ-2, could rapidly hydrolyze the ester bond of a wide range of pyrethroid pesticides, including permethrin, fenpropathrin, cypermethrin, fenvalerate, deltamethrin, cyhalothrin and bifenthrin. To elucidate the catalytic mechanism of PytH, here we report the crystal structures of PytH with bifenthrin (BIF) and phenylmethylsulfonyl fluoride (PMSF) and two PytH mutants. Though PytH shares low sequence identity with reported alpha/beta-hydrolase fold proteins, the typical triad catalytic center with Ser-His-Asp triad (Ser78, His230 and Asp202) is present and vital for the hydrolase activity. However, no contact was found between Ser78 and His230 in the structures we solved, which may be due to the fact that the PytH structures we determined are in their inactive or low activity forms. The structure of PytH is composed of a core domain and a lid domain; some hydrophobic amino acid residues surrounding the substrate from both domains form a deeper and wider hydrophobic pocket than its homologous structures. This indicates that the larger hydrophobic pocket makes PytH fit for its larger substrates binding; both lid and core domains are involved in substrate binding and the lid domain induced core domain movement may make the active center correctly positioned with substrates.IMPORTANCE Pyrethroid pesticides are widely applied in agriculture and household, however, extensive use of these pesticides also causes serious environmental and health problems. The hydrolysis of pyrethroids by carboxylesterases is the major pathway of microbial degradation of pyrethroids, but the structure of carboxylesterases and its catalytic mechanism are still unknown. Carboxylesterase PytH from Sphingobium faniae JZ-2 could effectively hydrolyze a wide range of pyrethroid pesticides. The crystal structures of PytH are solved in this study. It showed that it belongs to the alpha/beta-hydrolase fold proteins with typical catalytic Ser-His-Asp triad though PytH has a low sequence identity (about 20%) with them. The special large hydrophobic binding pocket endowed PytH binding bigger pyrethroids family substrates. Our structures shed light on the substrate selectivity and the future application of PytH and deeper the understanding of alpha/beta-hydrolase members.
Abnormal metabolism is one of the hallmarks of cancer cells. Monoacylglycerol lipase (MGLL), a key enzyme in lipid metabolism, has emerged as an important regulator of tumor progression. In this study, we aimed to characterize the role of MGLL in the development of lung adenocarcinoma (LUAD). To this end, we used tissue microarrays to evaluate the expression of MGLL in LUAD tissue and assessed whether the levels of this protein are correlated with clinicopathological characteristics of LUAD. We found that the expression of MGLL is higher in LUAD samples than that in adjacent non-tumor tissues. In addition, elevated MGLL expression was found to be associated with advanced tumor progression and poor prognosis in LUAD patients. Functional studies further demonstrated that stable short hairpin RNA (shRNA)-mediated knockdown of MGLL inhibits tumor proliferation and metastasis, both in vitro and in vivo, and mechanistically, our data indicate that MGLL regulates Cyclin D1 and Cyclin B1 in LUAD cells. Moreover, we found that knockdown of MGLL suppresses the expression of matrix metalloproteinase 14 (MMP14) in A549 and H322 cells, and in clinical samples, expression of MMP14 is significantly correlated with MGLL expression. Taken together, our results indicate that MGLL plays an oncogenic role in LUAD progression and metastasis and may serve as a potential biomarker for disease prognosis and as a target for the development of personalized therapies.
        
Title: The relationship of lipoprotein-associated phospholipase A2 activity with the seriousness of coronary artery disease Zhang H, Gao Y, Wu D, Zhang D Ref: BMC Cardiovasc Disord, 20:295, 2020 : PubMed
BACKGROUND: The level of lipoprotein-associated phospholipase A2 (LP-PLA2) in serum is independently correlated to coronary artery diseases (CAD). The aim of the study was to determine whether LP-PLA2 activity is positively associated with the seriousness of CAD. METHODS: Amount to 1056 patients suspected of having CAD underwent coronary angiography (CAG) to determine the seriousness of CAD. According to the amount of diseased coronary branches, the 1056 patients were split into three groups: single-vessel stenosis group, multiple-vessels stenosis group (> or = 2 diseased coronary branches),and control group (no diseased coronary branches). According to CAG results, electrocardiography, cardiac biomarker, and clinical presentation, all patients were split into four groups: acute myocardial infarction (AMI), unstable angina (UA), stable angina (SA), and control groups (excluding CAD). The activity of LP-PLA2 was compared statistically among the subgroups. Receiver operating characteristic analysis was applied to investigate the role of LP-PLA2 in evaluating the presence and seriousness of CAD. RESULTS: The level of LP-PLA2 increased in line with the number of diseased coronary branches. The levels of LP-PLA2 in the AMI and UA groups were observably higher when compared with the control and SA groups. LP-PLA2 had 75.6% sensitivity and 67.3% specificity for recognizing CAD, and 53.0% sensitivity and 80.3% specificity for recognizing severe coronary artery lesions. CONCLUSION: The activity of LP-PLA2 is positively correlated to the seriousness of CAD.
        
Title: Biomarkers responses in Manila clam, Ruditapes philippinarum after single and combined exposure to mercury and benzo[a]pyrene Jiang W, Fang J, Gao Y, Du M, Wang X, Li F, Lin F, Jiang Z Ref: Comparative Biochemistry & Physiology C Toxicol Pharmacol, 220:1, 2019 : PubMed
Physiological and biochemical responses in bivalves exposed to pollutants have proved a valuable tool to assess the health of organisms in aquatic ecosystems. The single and combined effects of mercury (Hg(2+), 2 and 10mug/L) and benzo[a]pyrene (BaP, 3mug/L) on physiological and biochemical biomarkers in Manila clam, Ruditapes philippinarum were evaluated. Results showed that significant higher oxygen consumption (OR) and ammonia-N excretion rates (NR) together with significant lower ingestion rates (IR) were observed for the 10mug/L Hg(2+) or 3mug/L BaP treatments compared to controls (P<0.05). However, clam NR decreased significantly in response to the binary mixtures of 10mug/L Hg(2+) and 3mug/L BaP (P<0.05). Moreover, the levels of superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferases (GSTs), glutathione (GSH), acetylcholinesterase (AChE) and malondialdehyde (MDA) in the hepatopancreas of clams were induced substantially, whereas glycogen (GLY) contents were suppressed dramatically after Hg(2+) and BaP exposure. Additionally, the integrated biomarker response (IBR) values measured showed significant increases in combination treatments and they were much higher than that in the Hg(2+) treatment. This study will provide further information on the defense mechanism in the Manila clam after exposure to marine pollutants and may help evaluate the quality of the aquatic environment.
Rapid and precise profiling of acetylcholine (ACh) has become important for diagnosing diseases and safeguarding health care because of its pivotal role in the central nervous system. Herein, we developed a new colorimetric sensor based on protein-inorganic hybrid nanoflowers as artificial peroxidase, comprising a test kit and a smartphone reader, which sensitively quantifies ACh in human serum. In this sensor, ACh indirectly triggered the substrate reaction with the help of a multienzyme system including acetylcholinesterase, choline oxidase, and mimic peroxidase (nanoflowers), accompanying the enhancement of absorbance intensity at 652 nm. Therefore, the multienzyme platform can be used to detect ACh via monitoring the change of the absorbance in a range from 0.0005 to 6.0 mmol L(-1). It is worth mentioning that the platform was used to prepare a portable agarose gel-based kit for rapid qualitative monitoring of ACh. Coupling with ImageJ program, the image information of test kits can be transduced into the hue parameter, which provides a directly quantitative tool to identify ACh. Based on the advantages of simple operation, good selectivity, and low cost, the availability of a portable kit for point-of-care testing will achieve the needs of frequent screening and diagnostic tracking.
        
Title: Genome sequence of Isaria javanica and comparative genome analysis insights into family S53 peptidase evolution in fungal entomopathogens Lin R, Zhang X, Xin B, Zou M, Gao Y, Qin F, Hu Q, Xie B, Cheng X Ref: Applied Microbiology & Biotechnology, 103:7111, 2019 : PubMed
The fungus Isaria javanica is an important entomopathogen that parasitizes various insects and is effective for pest control. In this study, we sequenced and assembled the genomes (IJ1G and IJ2G) of two I. javanica strains isolated from different insects. The genomes were approximately 35 Mb in size with 11,441 and 11,143 protein-coding genes, respectively. Using a phylogenomic approach, we evaluated genome evolution across five entomopathogenic fungi in Cordycipitaceae. By comparative genome analysis, it was found that family S53 serine peptidases were expanded in Cordycipitaceae entomopathogens, particularly in I. javanica. Gene duplication events were identified based on phylogenetic relationships inferred from 82 S53 peptidases within six entomopathogenic fungal genomes. Moreover, we found that carbohydrate-active enzymes and proteinases were the largest secretory protein groups encoded in the I. javanica genome, especially chitinases (GH18), serine and aspartic peptidases (S53, S08, S10, A01). Pathogenesis-related genes and genes for bacterial-like toxins and secondary metabolites were also identified. By comparative transcriptome analysis, differentially expressed genes in response to insect nutrients (in vitro) were identified. Moreover, most S53 peptidases were detected to be significantly upregulated during the initial fungal infection process in insects (in vivo) by RT-qPCR. Our results provide new clues about understanding evolution of pathogenic proteases and may suggest that abundant S53 peptidases in the I. javanica genome may contribute to its effective parasitism on various insects.
The management of medications in persons with frailty presents challenges. There is evidence of inappropriate prescribing and a lack of consensus among healthcare professionals on the judicious use of medications, particularly for patients with more severe frailty. This study reviews the evidence on the use of commonly prescribed pharmacological treatments in advanced frailty based on a questionnaire of prescribing practices and attitudes of healthcare professionals at different stages in their careers, in different countries. A convenience sample of those attending hospital grand rounds in Ireland, Canada and Australia/New Zealand (ANZ) were surveyed on the management of 18 medications in advanced frailty using a clinical vignette (man with severe dementia, Clinical Frailty Scale 7/9). Choices were to continue or discontinue (stop now or later) medications. In total, 298 respondents from Ireland (n = 124), Canada (n = 110), and ANZ (n = 64) completed the questionnaire, response rate 97%, including 81 consultants, 40 non-consultant hospital doctors, 134 general practitioners and 43 others (nurses, pharmacists, and medical students). Most felt that statins (88%), bisphosphonates (77%) and cholinesterase inhibitors (76%) should be discontinued. Thyroid replacement (88%), laxatives (83%) and paracetamol (81%) were most often continued. Respondents with experience in geriatric, palliative and dementia care were significantly more likely to discontinue medications. Age, gender and experience working in nursing homes did not contribute to the decision. Reflecting the current literature, there was no clear consensus on inappropriate prescribing, although respondents preferentially discontinued medications for secondary prevention. Experience significantly predicted the number and type discontinued, suggesting that education is important in reducing inappropriate prescribing for people in advanced states of frailty.
        
Title: Comparative transcriptome profiling reveals candidate genes related to insecticide resistance of Glyphodes pyloalis Su H, Gao Y, Liu Y, Li X, Liang Y, Dai X, Xu Y, Zhou Y, Wang H Ref: Bull Entomol Res, :1, 2019 : PubMed
Glyphodes pyloalis Walker (Lepidoptera: Pyralididae) is a common pest in sericulture and has developed resistance to different insecticides. However, the mechanisms involved in insecticide resistance of G. pyloalis are poorly understood. Here, we present the first whole-transcriptome analysis of differential expression genes in insecticide-resistant and susceptible G. pyloalis. Clustering and enrichment analysis of DEGs revealed several biological pathways and enriched Gene Ontology terms were related to detoxification or insecticide resistance. Genes involved in insecticide metabolic processes, including cytochrome P450, glutathione S-transferases and carboxylesterase, were identified in the larval midgut of G. pyloalis. Among them, CYP324A19, CYP304F17, CYP6AW1, CYP6AB10, GSTs5, and AChE-like were significantly increased after propoxur treatment, while CYP324A19, CCE001c, and AChE-like were significantly induced by phoxim, suggesting that these genes were involved in insecticide metabolism. Furthermore, the sequence variation analysis identified 21 single nucleotide polymorphisms within CYP9A20, CYP6AB47, and CYP6AW1. Our findings reveal many candidate genes related to insecticide resistance of G. pyloalis. These results provide novel insights into insecticide resistance and facilitate the development of insecticides with greater specificity to G. pyloalis.
        
Title: Catalpol prevents denervated muscular atrophy related to the inhibition of autophagy and reduces BAX/BCL2 ratio via mTOR pathway Wang Y, Shao Y, Gao Y, Wan G, Wan D, Zhu H, Qiu Y, Ye X Ref: Drug Des Devel Ther, 13:243, 2019 : PubMed
Aim: To investigate the effects of catalpol on muscular atrophy induced by sciatic nerve crush injury (SNCI). Methods: Seventy male Kunming mice were randomized into five groups (n=10): model, sham, catalpol (Cat), rapamycin (Rapa), and catalpol+rapamycin (Rapa+Cat). The ratio of gastrocnemius muscle wet weight (right/left, R/L) between the operated leg (right) and the normal leg (left) was calculated, and acetylcholinesterase (AChE) immunohistochemistry assays were performed to observe the change of motor end plate (MEP), along with the sizes of denervated and innervated muscle fibers. The expression levels of LC3II, TUNEL, BAX/BCL-2, LC3II/LC3I and P62, Beclin1, mTOR, and p-mTOR (ser2448) proteins in muscle were examined by fluorescence immunohistochemistry or Western blotting. Results: Results show that catalpol improved the results of the grid walking tests by reducing the percentage of foot slips, which increased the gastrocnemius muscle wet weight (R/L), enhanced AChE expression at the MEP, and enlarged the section area of the muscle. The expression of LC3II and TUNEL was significantly inhibited by catalpol. The BAX/BCL-2 ratio was significantly increased in muscles of denervated and control groups. Lower LC3II/LC3I and BAX/BCL-2 ratios in denervated muscles were also detected after catalpol treatment. Conclusion: These results indicated that apoptosis and autophagy play a role in the regulation of denervation-induced muscle atrophy after SNCI, and catalpol alleviates muscle atrophy through the regulation of muscle apoptosis and autophagy via the mTOR signaling pathway.
        
Title: Efficacy and outcomes of lipid resuscitation on organophosphate poisoning patients: A systematic review and meta-analysis Yu S, Zhang L, Gao Y, Walline J, Lu X, Ma Y, Zhu H, Yu X, Li Y Ref: Am J Emerg Med, 37:1611, 2019 : PubMed
OBJECTIVE: Organophosphate (OP) pesticides are still widely available in developing countries, leading to numerous accidental or suicidal poisonings every year. Lipid emulsion treatments are commonly used in resuscitating OP poisoning patients but few studies regarding their use have been reported. Our meta-analysis aimed to analyze the efficacy and outcomes of lipid resuscitation on OP poisoning patients. METHODS: A systematic search for associated studies was conducted in Pubmed, EMBASE, MEDLINE, the Cochrane Library and the Chinese National Knowledge Infrastructure. Collected data was pooled using Revman v5.3. Outcomes included prognosis (cured vs. mortality rates), hepatic function (serum ALT, AST, Total Bilirubin (TBIL) level), serum acetylcholinesterase (AchE) level and respiratory function (rate of respiratory muscular paralysis). RESULTS: Seven randomized controlled studies consisting of 630 patients meeting inclusion criteria were identified. Lipid emulsion helped to improve the cure rate [OR=2.54, 95% CI (1.33, 4.86), p=0.005] and lower the mortality rate [OR=0.31, 95% CI (0.13, 0.74), p=0.009]. Serum ALT, AST and TBIL in patients undergoing lipid resuscitation were lower than those in the control groups [ALT, SMD=-1.52, 95% CI (-2.64, 0.40), p=0.008; AST, SMD=-1.66, 95% CI (-3.15, 0.16), p=0.03; TBIL, SMD=-1.26, 95% CI (-2.32, 0.20), p=0.02]. Serum AchE level were increased in patients treated with lipid emulsion [SMD=2.15, 95% CI (1.60, 2.71), p<0.00001]. Rate of respiratory muscular paralysis was lower in patients undergoing lipid resuscitation than those in the control groups [OR=0.19, 95% CI (0.05, 0.71), p=0.01]. CONCLUSION: Based on our meta-analysis of included RCT reports, lipid resuscitation seems likely to help improve prognosis and liver function of OP poisoning patients. However, larger multi-center RCTs are still recommended.
        
Title: Treating Cocaine Addiction, Obesity, and Emotional Disorders by Viral Gene Transfer of Butyrylcholinesterase Brimijoin S, Gao Y, Geng L, Chen VP Ref: Front Pharmacol, 9:112, 2018 : PubMed
Butyrylcholinesterase (BChE), a plasma enzyme that hydrolyses the neurotransmitter, acetylcholine relatively well, with far lower efficiency than acetylcholinesterase (AChE) but with the capability to degrade a broad range of bioactive esters. AChE is universally understood as essential to cholinergic neurotransmission, voluntary muscle performance, and cognition, among other roles, and its catalytic impact is essential for life. A total absence of BChE activity, whether by enzyme inhibition or simple lack of enzyme protein is not only compatible with life, but does not lead to obvious physiologic disturbance. However, very recent studies at Mayo Clinic have amassed support for the concept that BChE does have a true physiological role as a "ghrelin hydrolase" and, pharmacologically, as a cocaine hydrolase. Human subjects and animal mutations that lack functional BChE show higher than normal levels of ghrelin, an acylated peptide that drives hunger and feeding, along with certain emotional behaviors. Mice treated by viral gene transfer of BChE show higher plasma levels of enzyme and lower levels of ghrelin. Ghrelin is acknowledged as a driver of food-seeking and stress. This brief review examines some key phenomena and considers means of modulating BChE as treatments for cocaine addiction, anxiety, aggression, and obesity.
        
Title: Effect of Telmisartan on Preventing Learning and Memory Deficits Via Peroxisome Proliferator-Activated Receptor-gamma in Vascular Dementia Spontaneously Hypertensive Rats Gao Y, Li W, Liu Y, Wang Y, Zhang J, Li M, Bu M Ref: J Stroke Cerebrovasc Dis, 27:277, 2018 : PubMed
BACKGROUND: This study aimed to explore the effect of telmisartan (TEL), as a partial peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist, in vascular dementia (VaD) rats induced by middle cerebral artery occlusion (MCAO). METHODS: Spontaneously hypertensive rats were divided into 6 groups: the sham group, model group, TEL-treated groups (1, 5, and 10 mg/kg), and TEL + GW9662 (10 mg/kg + 1 mg/kg). Using the MCAO method established the VaD rat model. Cognitive function was detected through the Morris water maze test, and matrix metalloproteinase 2 (MMP2) or matrix metalloproteinase 9 (MMP9), acetylcholinesterase (AChE), choline acetyltransferase (ChAT), and synaptophysin (SYN) in the hippocampus of rats were measured by the immunohistochemical method. RESULTS: In the Morris water maze test, the spatial memory ability was significantly impaired in the model group and improved in the TEL groups (1, 5, and 10 mg/kg), but the improvement effect of TEL on spatial memory was inhibited by GW9662, a PPAR-gamma antagonist. Compared with the sham group, the expression levels of MMP2, MMP9, and AChE increased and the expression levels of ChAT and SYN decreased significantly in the model group. Interestingly, TEL (1, 5, and 10 mg/kg) significantly reduced the expression levels of MMP2, MMP9, and AChE and significantly improved the expression levels of ChAT and SYN in a dose-dependent manner. However, cotreatment with GW9662 inhibited the TEL-mediated improvement effects on MMPs, the cholinergic system, and SYN. CONCLUSION: This study suggested that TEL had improvement effects in VaD rats via the PPAR-gamma pathway.
Two novel ent-aromadendrane derivatives, plagiochianin A (1), possessing an unprecedented 2,3:6,7-di- seco-6,8-cyclo-aromadendrane carbon scaffold conjugated with three cyclic acetals, and plagiochianin B (2), an exceptional pyridine type aromadendrane alkaloid, were isolated from the Chinese liverwort Plagiochila duthiana. Their structures were established by comprehensive spectroscopic analysis coupled with single-crystal X-ray diffraction and electronic circular dichroism calculations. A plausible biogenetic pathway of these two compounds is presented, and their acetylcholinesterase inhibitory activities are preliminarily tested using TLC-bioautographic assays.
        
Title: Bushen recipe and its disassembled prescriptions inhibit inflammation of liver injury associated with Concanavalin A through Tolllike receptor 3/9 signaling pathway Nie H, Mei Z, Wang R, Zhao B, Gao Y, Chen J, Wang L Ref: Mol Med Rep, 18:1682, 2018 : PubMed
The aim of the present study was to explore the effect of Bushen recipe and its disassembled prescriptions on liver injury and chronic hepatitis B. Liver injury was induced in normal and hepatitis B virus (HBV)transgenic mice through injection of Concanavalin A, followed by treatment with Bushen recipe and its disassembled prescriptions including the Bushenyang, the Bushenyin and the QingHua groups as well as the GanYanLing group (positive control). Subsequently, their liver function indexes were investigated by a microplate method and liver sections were blindly evaluated using an optical microscope by a pathologist. Subsequently, the activation state of Tolllike receptor (TLR)3/9 signaling pathway in liver tissues was analyzed by western blotting. Additionally, the inflammatory factors produced following liver injury in peripheral blood were detected via ELISA. Following intervention with the Bushen recipe and its disassembled prescriptions, the liver function indexe alanine aminotransferase had declined, whereas cholinesterase increased. The pathological alterations of liver tissue in HBV transgenic mice were reversed by Bushen recipe and its disassembled prescriptions. In addition, the TLR3/9 signaling pathway in liver tissues of HBV transgenic mice was inhibited and inflammatory factors such as interleukin (IL)6, IL1, tumor necrosis factoralpha and interferongamma were reduced significantly. In conclusion, the present study demonstrated that Bushen recipe and its disassembled prescriptions repaired liver injury induced by Concanavalin A through inhibition of TLR3/9 signaling pathway.
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.
We report herein the design and synthesis of a series of 11 novel tacrine-1,2,3-triazole derivatives via a Cu(i)-catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC) reaction. The newly synthesized compounds were evaluated for their inhibition activity against Electrophorus electricus acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BChE) as potential drug targets for Alzheimer's disease (AD). Among the designed compounds, compound 8a2 exhibited potent inhibition against AChE and BChE with IC50 values of 4.89 muM and 3.61 muM, respectively. Further structure-activity relationship (SAR) and molecular modeling studies may provide valuable insights into the design of better tacrine-triazole analogues with potential therapeutic applications for AD.
        
Title: Responses of Antioxidant Defense and Immune Gene Expression in Early Life Stages of Large Yellow Croaker (Pseudosciaena crocea) Under Methyl Mercury Exposure Wu F, Huang W, Liu Q, Xu X, Zeng J, Cao L, Hu J, Gao Y, Jia S Ref: Front Physiol, 9:1436, 2018 : PubMed
Early life stages of marine organisms are the most sensitive stages to environment stressors including pollutants. In order to understand the toxicological effects induced by MeHg exposure on juveniles of large yellow croaker (Pseudosciaena crocea), a toxicity test was performed wherein fish were exposed to sub-lethal concentrations of MeHg under laboratory conditions (18 +/- 1 degrees C; 26 +/- 1 in salinity). After 30 days of 0-4.0 mug L(-1) MeHg exposure, SOD activity was significantly decreased in the 0.25, 1.0, and 4.0 mug L(-1) treatments; while CAT activity was significantly increased in the 4.0 mug L(-1) treatments; GSH level, GPx activity were significantly elevated in the 4.0 mug L(-1) treatments, respectively. Meanwhile, malondialdehyde content was also significantly increased in the 1.0 and 4.0 mug L(-1) treatments with respect to the control. Acetylcholinesterase activity was significantly decreased by 18.3, 25.2, and 21.7% in the 0.25, 1.0, and 4.0 mug L(-1) treatments, respectively. The expression of TCTP, GST3, Hsp70, Hsp27 mRNA were all up-regulated in juveniles with a dose-dependent manner exposed to MeHg. These results suggest that large yellow croaker juveniles have the potential to regulate the levels of antioxidant enzymes and initiate immune response in order to protect fish to some extent from oxidative stress induced by MeHg.
        
Title: Controllable Growth of Core-Shell Nanogels via Esterase-Induced Self-Assembly of Peptides for Drug Delivery Wu C, Hu W, Wei Q, Qiao L, Gao Y, Lv Y, Liu M, Li C, Wang X, Wang Q Ref: J Biomed Nanotechnol, 14:354, 2018 : PubMed
In this work, we developed an unexplored enzyme-responsive core-shell nanogel via the assembly of hydrogelators at the surface of silicon nanoparticles. The immobilized carboxylesterase at the surface of silicon nanoparticles can catalyse precursors into hydrogelators, self-assembling around the surface of silicon nanoparticles owing to its surface confinement effect. These novel phenomena can be confirmed by observation of their morphology and increased diameters through scanning electron microscopy, transmission electron microscopy and dynamic light scattering. Moreover, these resulting core-shell nanogels can achieve controlled growth of the gel layer by means of changing the concentrations of precursors. Because of their good biocompatibility, these nanogels can realize applications in enzyme-specific drug delivery as nanocarriers.
        
Title: Rapid Screening and Characterization of Acetylcholinesterase Inhibitors from Yinhuang Oral Liquid Using Ultrafiltration-liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry Zhang H, Guo Y, Meng L, Sun H, Yang Y, Gao Y, Sun J Ref: Pharmacogn Mag, 14:248, 2018 : PubMed
Background: At present, approximately 17-25 million people in the world suffer from Alzheimer's disease (AD). The most efficacious and acceptable therapeutic drug clinically are the acetylcholinesterase inhibitors (AChEIs). Yinhuang oral liquid is a Chinese medicine preparation which contains AChEIs according to the literatures. However, no strategy has been presented for rapid screening and identification of AChEIs from Yinhuang oral liquid. Objective: To develop a method for rapid screening and identification of AChEIs from Yinhuang oral liquid using ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry (UF-LC-ESI-MS/MS). Materials and Methods: In this study, UF incubation conditions such as enzyme concentration, incubation time, and incubation temperature were optimized so as to get better screening results. The AChEIs from Yinhuang oral liquid were identified by high-performance liquid chromatography-ESI-MS and the improved Ellman method was used for the AChE inhibitory activity test in vitro. Results: The results showed that Yinhuang oral liquid can inhibit the activity of AChE. We screened and identified seven compounds with potential AChE inhibitory activity from Yinhuang oral liquid, which provided experimental basis for the treatment and prevention of AD. Conclusion: The current technique was used to directly screen the active ingredients with acetylcholinesterase inhibition from complex traditional Chinese medicine, which was simple, rapid, accurate, and suitable for high-throughput screening of AChEI from complex systems. SUMMARY: A UF-LC-ESI-MS/MS method for rapid screening and identification of AChEIs from Yinhuang oral liquid was developedSeven compounds were screened and identified with potential AChE inhibitory activity from Yinhuang oral liquidIt provided experimental basis of Yinhuang oral liquid for the treating and preventing AD. Abbreviations used: (AD): Alzheimer's disease; (UF-LC-ESI-MS/MS): ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry; (AChEIs): acetylcholinesterase inhibitors.
        
Title: Glycyrrhetinic Acid Liposomes Containing Mannose-Diester Lauric Diacid-Cholesterol Conjugate Synthesized by Lipase-Catalytic Acylation for Liver-Specific Delivery Chen J, Chen Y, Cheng Y, Gao Y Ref: Molecules, 22:, 2017 : PubMed
Mannose-diester lauric diacid-cholesterol (Man-DLD-Chol), as a liposomal target ligand, was synthesized by lipase catalyzed in a non-aqueous medium. Its chemical structure was confirmed by mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Glycyrrhetinic acid (GA) liposomes containing Man-DLD-Chol (Man-DLD-Chol-GA-Lp) were prepared by the film-dispersion method. We evaluated the characterizations of liposomes, drug-release in vitro, the hemolytic test, cellular uptake, pharmacokinetics, and the tissue distributions. The cellular uptake in vitro suggested that the uptake of Man-DLD-Chol-modified liposomes was significantly higher than that of unmodified liposomes in HepG2 cells. Pharmacokinetic parameters indicated that Man-DLD-Chol-GA-Lp was eliminated more rapidly than GA-Lp. In tissue distributions, the targeting efficiency (Te) of Man-DLD-Chol-GA-Lp on liver was 54.67%, relative targeting efficiency (RTe) was 3.39, relative uptake rate (Re) was 4.78, and peak concentration ratio (Ce) was 3.46. All these results supported the hypothesis that Man-DLD-Chol would be an efficient liposomal carrier, and demonstrated that Man-DLD-Chol-GA-Lp has potential as a drug delivery for liver-targeting therapy.
        
Title: Butyrylcholinesterase gene transfer in obese mice prevents postdieting body weight rebound by suppressing ghrelin signaling Chen VP, Gao Y, Geng L, Brimijoin S Ref: Proc Natl Acad Sci U S A, 114:10960, 2017 : PubMed
The worldwide prevalence of obesity is increasing at an alarming rate but treatment options remain limited. Despite initial success, weight loss by calorie restriction (CR) often fails because of rebound weight gain. Postdieting hyperphagia along with altered hypothalamic neuro-architecture appears to be one direct cause of this undesirable outcome. In response to calorie deficiency the circulating levels of the appetite-promoting hormone, acyl-ghrelin, rise sharply. We hypothesize that proper modulation of acyl-ghrelin and its receptor's sensitivity will favorably impact energy intake and reprogram the body weight set point. Here we applied viral gene transfer of the acyl-ghrelin hydrolyzing enzyme, butyrylcholinesterase (BChE), in a mouse model of diet-induced obesity. Our results confirmed that BChE overexpression decreased circulating acyl-ghrelin levels, suppressed CR-provoked ghrelin signaling, and restored central ghrelin sensitivity. In addition to maintaining healthy body weights, BChE treated mice had modest postdieting food intake and showed normal glucose homeostasis. Spontaneous activity and energy expenditure did not differ significantly between treated and untreated mice after body weight rebound, suggesting that BChE gene transfer did not alter energy expenditure in the long term. These findings indicate that combining BChE treatment with CR could be an effective approach in treating human obesity and aiding lifelong weight management.
        
Title: Butyrylcholinesterase regulates central ghrelin signaling and has an impact on food intake and glucose homeostasis Chen VP, Gao Y, Geng L, Brimijoin S Ref: Int J Obes (Lond), 41:1413, 2017 : PubMed
BACKGROUND: Ghrelin is the only orexigenic hormone known to stimulate food intake and promote obesity and insulin resistance. We recently showed that plasma ghrelin is controlled by butyrylcholinesterase (BChE), which has a strong impact on feeding and weight gain. BChE knockout (KO) mice are prone to obesity on high-fat diet, but hepatic BChE gene transfer rescues normal food intake and obesity resistance. However, these mice lack brain BChE and still develop hyperinsulinemia and insulin resistance, suggesting essential interactions between BChE and ghrelin within the brain. METHODS: To test the hypothesis we used four experimental groups: (1) untreated wild-type mice, (2) BChE KO mice with LUC delivered by adeno-associated virus (AAV) in combined intravenous (i.v.) and intracerebral (i.c.) injections, (3) KO mice given AAV for mouse BChE (i.v. only) and (4) KO mice given the same vector both i.v. and i.c. All mice ate a 45% calorie high-fat diet from the age of 1 month. Body weight, body composition, daily caloric intake and serum parameters were monitored throughout, and glucose tolerance and insulin tolerance tests were performed at intervals. RESULTS: Circulating ghrelin levels dropped substantially in the KO mice after i.v. AAV-BChE delivery, which led to normal food intake and healthy body weight. BChE KO mice that received AAV-BChE through i.v. and i.c. combined treatments not only resisted weight gain on high-fat diet but also retained normal glucose and insulin tolerance. CONCLUSIONS: These data indicate a central role for BChE in regulating both insulin and glucose homeostasis. BChE gene transfer could be a useful therapy for complications linked to diet-induced obesity and insulin resistance.
        
Title: Therapeutic Delivery of Butyrylcholinesterase by Brain-Wide Viral Gene Transfer to Mice Gao Y, Geng L, Chen VP, Brimijoin S Ref: Molecules, 22:, 2017 : PubMed
Recent research shows that butyrylcholinesterase (BChE) is not simply a liver enzyme that detoxifies bioactive esters in food and medications. In fact, in pursuing other goals, we recently found that it has an equally important role in regulating the peptide hormone ghrelin and its impact on hunger, obesity, and emotions. Here, we present and examine means of manipulating brain BChE levels by viral gene transfer, either regionally or globally, to modulate ghrelin signaling for long-term therapeutic purposes and to set the stage for exploring the neurophysiological impact of such an intervention.
The mechanisms of post-stroke neurogenesis in the subventricular zone (SVZ) are unclear. However, neural stem cell-intrinsic and neurogenic niche mechanisms, as well as neurotransmitters, have been shown to play important roles in SVZ neurogenesis. Recently, a previously unknown population of choline acetyltransferase (ChAT)+ neurons residing in rodent SVZ were identified to have direct control over neural stem cell proliferation by indirectly activating fibroblast growth factor receptor (FGFR). This finding revealed possible neuronal control over SVZ neurogenesis. In this study, we assessed whether these ChAT+ neurons also participate in stroke-induced neurogenesis. We used a permanent middle cerebral artery occlusion (MCAO) model produced by transcranial electrocoagulation in mice, atropine (muscarinic cholinergic receptor [mAchR] antagonist), and donepezil (acetylcholinesterase inhibitor) to investigate the role of ChAT+ neurons in stroke-induced neurogenesis. We found that mAchRs, phosphorylated protein kinase C (p-PKC), and p-38 levels in the SVZ were upregulated in mice on day 7 after MCAO. MCAO also significantly increased the number of BrdU/doublecortin-positive cells and protein levels of phosphorylated-neural cell adhesion molecule and mammalian achaete scute homolog-1. FGFR was activated in the SVZ, and doublecortin-positive cells increased in the peri-infarction region. These post-stroke neurogenic effects were enhanced by donepezil and partially decreased by atropine. Neither atropine nor donepezil affected peri-infarct microglial activation or serum concentrations of TNF-alpha, IFN-gamma, or TGF-beta on day 7 after MCAO. We conclude that ChAT+ neurons in the SVZ may participate in stroke-induced neurogenesis, suggesting a new mechanism for neurogenesis after stroke.
Apart from sharing common ancestry with chordates, sea cucumbers exhibit a unique morphology and exceptional regenerative capacity. Here we present the complete genome sequence of an economically important sea cucumber, A. japonicus, generated using Illumina and PacBio platforms, to achieve an assembly of approximately 805 Mb (contig N50 of 190 Kb and scaffold N50 of 486 Kb), with 30,350 protein-coding genes and high continuity. We used this resource to explore key genetic mechanisms behind the unique biological characters of sea cucumbers. Phylogenetic and comparative genomic analyses revealed the presence of marker genes associated with notochord and gill slits, suggesting that these chordate features were present in ancestral echinoderms. The unique shape and weak mineralization of the sea cucumber adult body were also preliminarily explained by the contraction of biomineralization genes. Genome, transcriptome, and proteome analyses of organ regrowth after induced evisceration provided insight into the molecular underpinnings of visceral regeneration, including a specific tandem-duplicated prostatic secretory protein of 94 amino acids (PSP94)-like gene family and a significantly expanded fibrinogen-related protein (FREP) gene family. This high-quality genome resource will provide a useful framework for future research into biological processes and evolution in deuterostomes, including remarkable regenerative abilities that could have medical applications. Moreover, the multiomics data will be of prime value for commercial sea cucumber breeding programs.
        
Title: Physiological Roles for Butyrylcholinesterase: A BChE-Ghrelin Axis Brimijoin S, Chen VP, Pang YP, Geng L, Gao Y Ref: Chemico-Biological Interactions, 259:271, 2016 : PubMed
Butyrylcholinesterase (BChE) has long been regarded as an "orphan enzyme" with no specific physiological role other than to metabolize exogenous bioactive esters in the diet or in medicines. Human beings with genetic mutations that eliminate all BChE activity appear completely normal, and BChE-knockout mice have been described as "lacking a phenotype" except for faster weight gain on high-fat diets. However, our recent studies with viral gene transfer of BChE in mice reveal that BChE hydrolyses the so-called "hunger hormone," ghrelin, at a rate which strongly affects the circulating levels of this peptide hormone. This action has important consequences for weight gain and fat metabolism. Surprisingly, it also impacts emotional behaviors such as aggression. Overexpression of BChE leads to low ghrelin levels in the blood stream and reduces aggression and social stress in mice. Under certain circumstances these combined effects contribute to increased life-span in group-housed animals. These findings may generalize to humans, as recent clinical studies by multiple investigators indicate that, among patients with severe cardiovascular disease, longevity correlates with increasing levels of plasma BChE activity.
        
Title: Immobilization of Candida antarctica lipase B onto SBA-15 and their application in glycerolysis for diacylglycerols synthesis Cai C, Gao Y, Liu Y, Zhong N, Liu N Ref: Food Chem, 212:205, 2016 : PubMed
In this study, Candida antarctica lipase B (CALB) was immobilized on SBA-15 with three pore diameters. CALB loading was found increased with CALB concentration increasing from 20.3 to 80.12mug/ml. Higher CALB loading was observed from SBA-15 with pore diameters at 8.1nm (SBA-15(8.1)), yet highest hydrolytic activity was found at SBA-15(12.5). Thermal stability of the immobilized CALB (SBA-15-CALB) samples was greatly influenced by their water content, after 4h storage at 70 degrees C, 8.93 and 67.4% of the initial activity was observed from SBA-15-CALB samples with water content at 9.23 and 3.22% respectively. The SBA-15-CALB samples were then used in glycerolysis of corn oil, and 53.6wt% of diacylglycerols was obtained after optimization. The operational stability was tested, and after 5 consecutive applications, 92.5 and 80.3% of the initial glycerolysis activity was remained respectively from SBA-15(6.6)-CALB and SBA-15(12.5)-CALB.
        
Title: Butyrylcholinesterase deficiency promotes adipose tissue growth and hepatic lipid accumulation in male mice on high-fat diet Chen VP, Gao Y, Geng L, Stout MB, Jensen MD, Brimijoin S Ref: Endocrinology, :en20161166, 2016 : PubMed
Despite numerous reports of relationships between weight-gain and butyrylcholinesterase (BChE), this enzyme's role in the genesis of obesity remains unclear, but recent research points to strong links with ghrelin, the "hunger hormone." The availability of BChE knockout mice (KO) provides an opportunity to clarify the causal relationship between BChE and obesity onset. We now find that young KO mice have abnormally high plasma ghrelin levels that slowly decline during long-term high fat feeding and ultimately drop below those in wild type mice. On such a diet, the KO mice gained notably more weight, more white fat, and more hepatic fat than wild-type animals. In addition to a greater burden of hepatic triglycerides, the livers of these KO mice show distinctly higher levels of inflammatory markers. Finally, their energy expenditure proved to be lower than in wild type mice despite similar activity levels and increased caloric intake. A gene transfer of mouse BChE with adeno-associated virus vector restored nearly all aspects of the normal phenotype. Our results indicate that BChE strongly affects fat metabolism, has an important impact on fat accumulation, and may be a promising tool for combating obesity.
Monoglyceride lipase (MGL) is required for efficient hydrolysis of the endocannabinoid 2-arachidonoylglyerol (2-AG) in the brain generating arachidonic acid (AA) and glycerol. This metabolic function makes MGL an interesting target for the treatment of neuroinflammation, since 2-AG exhibits anti-inflammatory properties and AA is a precursor for pro-inflammatory prostaglandins. Astrocytes are an important source of AA and 2-AG, and highly express MGL. In the present study, we dissected the distinct contribution of MGL in astrocytes on brain 2-AG and AA metabolism by generating a mouse model with genetic deletion of MGL specifically in astrocytes (MKO(GFAP)). MKO(GFAP) mice exhibit moderately increased 2-AG and reduced AA levels in brain. Minor accumulation of 2-AG in the brain of MKO(GFAP) mice does not cause cannabinoid receptor desensitization as previously observed in mice globally lacking MGL. Importantly, MKO(GFAP) mice exhibit reduced brain prostaglandin E2 and pro-inflammatory cytokine levels upon peripheral lipopolysaccharide (LPS) administration. These observations indicate that MGL-mediated degradation of 2-AG in astrocytes provides AA for prostaglandin synthesis promoting LPS-induced neuroinflammation. The beneficial effect of astrocyte-specific MGL-deficiency is not fully abrogated by the inverse cannabinoid receptor 1 agonist SR141716 (Rimonabant) suggesting that the anti-inflammatory effects are rather caused by reduced prostaglandin synthesis than by activation of cannabinoid receptors. In conclusion, our data demonstrate that MGL in astrocytes is an important regulator of 2-AG levels, AA availability, and neuroinflammation.
        
Title: Cocaine Hydrolase Gene Transfer Demonstrates Cardiac Safety and Efficacy against Cocaine-Induced QT Prolongation in Mice Murthy V, Reyes S, Geng L, Gao Y, Brimijoin S Ref: Journal of Pharmacology & Experimental Therapeutics, 356:720, 2016 : PubMed
Cocaine addiction is associated with devastating medical consequences, including cardiotoxicity and risk-conferring prolongation of the QT interval. Viral gene transfer of cocaine hydrolase engineered from butyrylcholinesterase offers therapeutic promise for treatment-seeking drug users. Although previous preclinical studies have demonstrated benefits of this strategy without signs of toxicity, the specific cardiac safety and efficacy of engineered butyrylcholinesterase viral delivery remains unknown. Here, telemetric recording of electrocardiograms from awake, unrestrained mice receiving a course of moderately large cocaine doses (30 mg/kg, twice daily for 3 weeks) revealed protection against a 2-fold prolongation of the QT interval conferred by pretreatment with cocaine hydrolase vector. By itself, this prophylactic treatment did not affect QT interval duration or cardiac structure, demonstrating that viral delivery of cocaine hydrolase has no intrinsic cardiac toxicity and, on the contrary, actively protects against cocaine-induced QT prolongation.
        
Title: Long-Term Blockade of Cocaine Self-Administration and Locomotor Activation in Rats by an Adenoviral Vector-Delivered Cocaine Hydrolase Smethells JR, Swalve N, Brimijoin S, Gao Y, Parks RJ, Greer A, Carroll ME Ref: Journal of Pharmacology & Experimental Therapeutics, 357:375, 2016 : PubMed
A promising approach in treating cocaine abuse is to metabolize cocaine in the blood using a mutated butyrylcholinesterase (BChE) that functions as a cocaine hydrolase (CocH). In rats, a helper-dependent adenoviral (hdAD) vector-mediated delivery of CocH abolished ongoing cocaine use and cocaine-primed reinstatement of drug-seeking for several months. This enzyme also metabolizes ghrelin, an effect that may be beneficial in maintaining healthy weights. The effect of a single hdAD-CocH vector injection was examined in rats on measures of anxiety, body weight, cocaine self-administration, and cocaine-induced locomotor activity. To examine anxiety, periadolescent rats were tested in an elevated-plus maze. Weight gain was then examined under four rodent diets. Ten months after CocH-injection, adult rats were trained to self-administer cocaine intravenously and, subsequently, cocaine-induced locomotion was tested. Viral gene transfer produced sustained plasma levels of CocH for over 13 months of testing. CocH-treated rats did not differ from controls in measures of anxiety, and only showed a transient reduction in weight gain during the first 3 weeks postinjection. However, CocH-treated rats were insensitive to cocaine. At 10 months postinjection, none of the CocH-treated rats initiated cocaine self-administration, unlike 90% of the control rats. At 13 months postinjection, CocH-treated rats showed no cocaine-induced locomotion, whereas control rats showed a dose-dependent enhancement of locomotion. CocH vector produced a long-term blockade of the rewarding and behavioral effects of cocaine in rats, emphasizing its role as a promising therapeutic intervention in cocaine abuse.
Ongoing mouse studies of a proposed therapy for cocaine abuse based on viral gene transfer of butyrylcholinesterase (BChE) mutated for accelerated cocaine hydrolysis have yielded surprising effects on aggression. Further investigation has linked these effects to a reduction in circulating ghrelin, driven by BChE at levels approximately 100-fold above normal. Tests with human BChE showed ready ghrelin hydrolysis at physiologic concentrations, and multiple low-mass molecular dynamics simulations revealed that ghrelin's first five residues fit sterically and electrostatically into BChE's active site. Consistent with in vitro results, male BALB/c mice with high plasma BChE after gene transfer exhibited sharply reduced plasma ghrelin. Unexpectedly, such animals fought less, both spontaneously and in a resident/intruder provocation model. One mutant BChE was found to be deficient in ghrelin hydrolysis. BALB/c mice transduced with this variant retained normal plasma ghrelin levels and did not differ from untreated controls in the aggression model. In contrast, C57BL/6 mice with BChE gene deletion exhibited increased ghrelin and fought more readily than wild-type animals. Collectively, these findings indicate that BChE-catalyzed ghrelin hydrolysis influences mouse aggression and social stress, with potential implications for humans.
        
Title: Radiometric assay of ghrelin hydrolase activity and (3)H-ghrelin distribution into mouse tissues Chen VP, Gao Y, Geng L, Brimijoin S Ref: Biochemical Pharmacology, 98:732, 2015 : PubMed
A high-throughput radiometric assay was developed to characterize enzymatic hydrolysis of ghrelin and to track the peptide's fate in vivo. The assay is based on solvent partitioning of [(3)H]-octanoic acid liberated from [(3)H]-octanoyl ghrelin during enzymatic hydrolysis. This simple and cost-effective method facilitates kinetic analysis of ghrelin hydrolase activity of native and mutated butyrylcholinesterases or carboxylesterases from multiple species. In addition, the assay's high sensitivity facilitates ready evaluation of ghrelin's pharmacokinetics and tissue distribution in mice after i.v. bolus administration of radiolabeled peptide.
Butyrylcholinesterase (BChE) gene therapy is emerging as a promising concept for treatment of cocaine addiction. BChE levels after gene transfer can rise 1000-fold above those in untreated mice, making this enzyme the second most abundant plasma protein. For months or years, gene transfer of a BChE mutated into a cocaine hydrolase (CocH) can maintain enzyme levels that destroy cocaine within seconds after appearance in the blood stream, allowing little to reach the brain. Rapid enzyme action causes a sharp rise in plasma levels of two cocaine metabolites, benzoic acid (BA) and ecgonine methyl ester (EME), a smooth muscle relaxant that is mildly hypotensive and, at best, only weakly rewarding. The present study, utilizing Balb/c mice, tested reward effects and cardiovascular effects of administering EME and BA together at molar levels equivalent to those generated by a given dose of cocaine. Reward was evaluated by conditioned place preference. In this paradigm, cocaine (20 mg/kg) induced a robust positive response but the equivalent combined dose of EME + BA failed to induce either place preference or aversion. Likewise, mice that had undergone gene transfer with mouse CocH (mCocH) showed no place preference or aversion after repeated treatments with a near-lethal 80 mg/kg cocaine dose. Furthermore, a single administration of that same high cocaine dose failed to affect blood pressure as measured using the noninvasive tail-cuff method. These observations confirm that the drug metabolites generated after CocH gene transfer therapy are safe even after a dose of cocaine that would ordinarily be lethal.
        
Title: Solid phase synthesis of 1,3,4-oxadiazin-5 (6R)-one and 1,3,4-oxadiazol-2-one scaffolds from acyl hydrazides Sarma BK, Liu X, Wu H, Gao Y, Kodadek T Ref: Org Biomol Chem, 13:59, 2015 : PubMed
Solid phase synthesis of 1,3,4-oxadiazin-5(6R)-one and 1,3,4-oxadiazol-2-one scaffolds from resin-bound acyl hydrazides is described. We demonstrate here that the reactions of resin-bound aryl or hetero-aromatic acyl hydrazides with 2-substituted-2-bromoacetic acids and 4-nitrophenyl chloroformate and subsequent treatment with DIEA lead to intramolecular cyclization reactions to produce six-membered 1,3,4-oxadiazin-5(6R)-ones and five-membered 1,3,4-oxadiazol-2-ones, respectively. We also show that acyl hydrazide-derived 1,3,4-oxadiazol-2-ones may be useful serine hydrolase inhibitors.
AT-1001 [N-(2-bromophenyl)-9-methyl-9-azabicyclo[3.3.1] nonan-3-amine] is a high-affinity and highly selective ligand at alpha3beta4 nicotinic cholinergic receptors (nAChRs) that was reported to decrease nicotine self-administration in rats. It was initially reported to be an antagonist at rat alpha3beta4 nAChRs heterologously expressed in HEK293 cells. Here we compared AT-1001 actions at rat and human alpha3beta4 and alpha4beta2 nAChRs similarly expressed in HEK 293 cells. We found that, as originally reported, AT-1001 is highly selective for alpha3beta4 receptors over alpha4beta2 receptors, but its binding selectivity is much greater at human than at rat receptors, because of a higher affinity at human than at rat alpha3beta4 nAChRs. Binding studies in human and rat brain and pineal gland confirmed the selectivity of AT-1001 for alpha3beta4 nAChRs and its higher affinity for human compared with rat receptors. In patch-clamp electrophysiology studies, AT-1001 was a potent partial agonist with 65-70% efficacy at both human and rat alpha3beta4 nAChRs. It was also a less potent and weaker (18%) partial agonist at alpha4beta2 nAChRs. Both alpha3beta4 and alpha4beta2 nAChRs are upregulated by exposure of cells to AT-1001 for 3 days. Similarly, AT-1001 desensitized both receptor subtypes in a concentration-dependent manner, but it was 10 and 30 times more potent to desensitize human alpha3beta4 receptors than rat alpha3beta4 and human alpha4beta2 receptors, respectively. After exposure to AT-1001, the time to recovery from desensitization was longest for the human alpha3beta4 nAChR and shortest for the human alpha4beta2 receptor, suggesting that recovery from desensitization is primarily related to the dissociation of the ligand from the receptor.
        
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: Comprehensive characterization of a time-course transcriptional response induced by autotoxins in Panax ginseng using RNA-Seq Wu B, Long Q, Gao Y, Wang Z, Shao T, Liu Y, Li Y, Ding W Ref: BMC Genomics, 16:1010, 2015 : PubMed
BACKGROUND: As a valuable medicinal plant, the yield of Panax ginseng is seriously affected by autotoxicity, which is a common phenomenon due to continuous cropping. However, the mechanism of autotoxicity in P. ginseng is still unknown. RESULTS: In total, high throughput sequencing of 18 RNA-Seq libraries produced 996,000 000 100-nt reads that were assembled into 72,732 contigs. Compared with control, 3697 and 2828 genes were significantly up- and down-regulated across different tissues and time points, respectively. Gene Ontology enrichment analysis showed that 'enzyme inhibitor activity', 'carboxylesterase activity', 'pectinesterase activity', 'centrosome cycle and duplication' and 'mitotic spindle elongation' were enriched for the up-regulated genes. Transcription factors including AP2s/ERFs, MYBs, and WRKYs were up-regulated in roots after benzoic acid treatment. Moreover, reactive oxygen species, peroxidases and superoxide dismutase contigs were up-regulated in roots after benzoic acid treatment. Physiological and biochemical indexes showed that the proline and malondialdehyde content were restored to lower levels at a later stage after benzoic acid treatment. Benzoic acid inhibited the root hair development in a dose-dependent manner, and several differential expressed genes potentially involved in hair development were identified. Several key contigs in the flavonoid and ginsenoside biosynthesis pathways were repressed. Finally, 58,518 alternative splicing (AS) events from 12,950 genes were found after benzoic acid treatment. Interestingly, contigs in the ginsenoside biosynthetic pathway underwent AS, providing useful information about post-transcriptional regulation in P. ginseng. CONCLUSIONS: This study revealed the stress-response molecular mechanisms in P. ginseng induced by benzoic acid.
        
Title: Expression of DPP6 in Meckel's cartilage and tooth germs during mouse facial development Du J, Fan Z, Ma X, Wu Y, Liu S, Gao Y, Shen Y, Fan M, Wang S Ref: Biotech Histochem, 89:14, 2014 : PubMed
Dipeptidyl peptidase-like protein 6 (DPP6), a member of the dipeptidyl aminopeptidase family, plays distinct roles in brain development, but its expression in embryonic Meckel's cartilage and tooth germs development is unknown. We analyzed the expression pattern of DPP6 in Meckel's cartilage and tooth germs development using in situ hybridization. DPP6 was detected in different patterns in Meckel's cartilage and tooth germs during mouse facial development from 11.5 to 13.5 days post-coitus (dpc) embryos. The expression pattern of DPP6 suggests that it may be involved in mandible and tooth development.
The alpha7-nicotinic cholinergic receptor (alpha7-nAChR) is a key mediator of brain communication and has been implicated in a wide variety of central nervous system disorders. None of the currently available PET radioligands for alpha7-nAChR are suitable for quantitative PET imaging, mostly because of insufficient specific binding. The goal of this study was to evaluate the potential of (18)F-ASEM ((18)F-JHU82132) as an alpha7-nAChR radioligand for PET. METHODS: The inhibition binding assay and receptor functional properties of ASEM were assessed in vitro. The brain regional distribution of (18)F-ASEM in baseline and blockade were evaluated in DISC1 mice (dissection) and baboons (PET). RESULTS: ASEM is an antagonist for the alpha7-nAChR with high binding affinity (Ki = 0.3 nM). (18)F-ASEM readily entered the baboon brain and specifically labeled alpha7-nAChR. The in vivo specific binding of (18)F-ASEM in the brain regions enriched with alpha7-nAChRs was 80%-90%. SSR180711, an alpha7-nAChR-selective partial agonist, blocked (18)F-ASEM binding in the baboon brain in a dose-dependent manner, suggesting that the binding of (18)F-ASEM was mediated by alpha7-nAChRs and the radioligand was suitable for drug evaluation studies. In the baboon baseline studies, the brain regional volume of distribution (VT) values for (18)F-ASEM were 23 (thalamus), 22 (insula), 18 (hippocampus), and 14 (cerebellum), whereas in the binding selectivity (blockade) scan, all regional VT values were reduced to less than 4. The range of regional binding potential values in the baboon brain was from 3.9 to 6.6. In vivo cerebral binding of (18)F-ASEM and alpha7-nAChR expression in mutant DISC1 mice, a rodent model of schizophrenia, was significantly lower than in control animals, which is in agreement with previous postmortem human data. CONCLUSION: (18)F-ASEM holds promise as a radiotracer with suitable imaging properties for quantification of alpha7-nAChR in the human brain.
In continuing efforts to develop gene transfer of human butyrylcholinesterase (BChE) as therapy for cocaine addiction, we conducted wide-ranging studies of physiological and metabolic safety. For that purpose, mice were given injections of adeno-associated virus (AAV) vector or helper-dependent adenoviral (hdAD) vector encoding human or mouse BChE mutated for optimal cocaine hydrolysis. Age-matched controls received saline or AAV-luciferase control vector. At times when transduced BChE was abundant, physiologic and metabolic parameters in conscious animals were evaluated by non-invasive Echo-MRI and an automated "Comprehensive Laboratory Animal Monitoring System" (CLAMS). Despite high vector doses (up to 10(13) particles per mouse) and high levels of transgene protein in the plasma ( approximately 1500-fold above baseline), the CLAMS apparatus revealed no adverse physiologic or metabolic effects. Likewise, body composition determined by Echo-MRI, and glucose tolerance remained normal. A CLAMS study of vector-treated mice given 40mg/kg cocaine showed none of the physiologic and metabolic fluctuations exhibited in controls. We conclude that neither the tested vectors nor great excesses of circulating BChE affect general physiology directly, while they protect mice from disturbance by cocaine. Hence, viral gene transfer of BChE appears benign and worth exploring as a therapy for cocaine abuse and possibly other disorders as well.
        
Title: Preclinical studies on neurobehavioral and neuromuscular effects of cocaine hydrolase gene therapy in mice Murthy V, Gao Y, Geng L, LeBrasseur NK, White TA, Brimijoin S Ref: Journal of Molecular Neuroscience, 53:409, 2014 : PubMed
Cocaine hydrolase gene transfer of mutated human butyrylcholinesterase (BChE) is evolving as a promising therapy for cocaine addiction. BChE levels after gene transfer can be 1,500-fold above those in untreated mice, making this enzyme the second most abundant plasma protein. Because mutated BChE is approximately 70 % as efficient in hydrolyzing acetylcholine as wild-type enzyme, it is important to examine the impact on cholinergic function. Here, we focused on memory and cognition (Stone T-maze), basic neuromuscular function (treadmill endurance and grip strength), and coordination (Rotarod). BALB/c mice were given adeno-associated virus vector or helper-dependent adenoviral vector encoding mouse or human BChE optimized for cocaine. Age-matched controls received saline or luciferase vector. Despite high doses (up to 10(13) particles per mouse) and high transgene expression (1,000-fold above baseline), no deleterious effects of vector treatment were seen in neurobehavioral functions. The vector-treated mice performed as saline-treated and luciferase controls in maze studies and strength tests, and their Rotarod and treadmill performance decreased less with age. Thus, neither the viral vectors nor the large excess of BChE caused observable toxic effects on the motor and cognitive systems investigated. This outcome justifies further steps toward an eventual clinical trial of vector-based gene transfer for cocaine abuse.
Strigolactones (SLs) are a novel class of plant hormones that inhibit shoot branching. Currently, two proteins in rice are thought to play crucial roles in SL signal transduction. DWARF14 (D14), an alpha/beta hydrolase, is responsible for SL perception, while DWARF3 (D3), an F-box protein with leucine-rich repeats, is essential for SL signal transduction. However, how these two proteins transmit SL signals to downstream factors remains unclear. Here, we characterized a high-tillering dwarf rice mutant, gsor300097, which is insensitive to GR24, a synthetic analog of SL. Mapping and sequencing analysis showed that gsor300097 is a novel allelic mutant of D3, in which a nonsense mutation truncates the protein from 720 to 527 amino acids. The D3 gene was strongly expressed in root, leaf, shoot base and panicle. Nuclear-localized F-box protein D3 played a role in the SCF complex by interacting with OSK1, OSK5 or OSK20 and OsCullin1. In addition, D3 associated with D14 in a GR24-dependent manner in vivo. Taken together, our findings suggested that D3 assembled into an SCF(D3) complex and associated with D14 to suppress rice shoot branching.
        
Title: Long-term reduction of cocaine self-administration in rats treated with adenoviral vector-delivered cocaine hydrolase: evidence for enzymatic activity Zlebnik NE, Brimijoin S, Gao Y, Saykao AT, Parks RJ, Carroll ME Ref: Neuropsychopharmacology, 39:1538, 2014 : PubMed
A new pharmacokinetic approach treating cocaine addiction involves rapidly metabolizing cocaine before it reaches brain reward centers using mutated human butyrylcholinesterase (BChE) or cocaine hydrolase (CocH). Recent work has shown that helper-dependent adenoviral (hdAD) vector-mediated plasma CocH reduced the locomotor-activating effects of cocaine and prevented reinstatement of cocaine-seeking behavior up to 6 months in rats. The present study investigated whether hdAD-CocH could decrease ongoing intravenous cocaine (0.4 mg/kg) self-administration. The hdAD-CocH vector was injected into self-administering rats, and after accumulation of plasma CocH, there was a dramatic reduction in cocaine infusions earned under a fixed ratio 1 schedule of reinforcement that lasted for the length of the study (>2 months). Pretreatment with the selective BChE and CocH inhibitor iso-OMPA (1.5 mg/kg) restored cocaine intake; therefore, the decline in self-administration was likely due to rapid CocH-mediated cocaine metabolism. Direct measurements of cocaine levels in plasma and brain samples taken after the conclusion of behavioral studies provided strong support for this conclusion. Further, rats injected with hdAD-CocH did not experience a deficit in operant responding for drug reinforcement and self-administered methamphetamine (0.05 mg/kg) at control levels. Overall, these outcomes suggest that viral gene transfer can yield plasma CocH levels that effectively diminish long-term cocaine intake and may have potential treatment implications for cocaine-dependent individuals seeking to become and remain abstinent.
        
Title: Anti-cocaine antibody and butyrylcholinesterase-derived cocaine hydrolase exert cooperative effects on cocaine pharmacokinetics and cocaine-induced locomotor activity in mice Brimijoin S, Orson FM, Kosten TR, Kinsey B, Shen XY, White SJ, Gao Y Ref: Chemico-Biological Interactions, 203:212, 2013 : PubMed
We are investigating treatments for cocaine abuse based on viral gene transfer of a cocaine hydrolase (CocH) derived from human butyrylcholinesterase, which can reduce cocaine-stimulated locomotion and cocaine-primed reinstatement of drug-seeking behavior in rats for many months. Here, in mice, we explored the possibility that anti-cocaine antibodies can complement the actions of CocH to reduce cocaine uptake in brain and block centrally-evoked locomotor stimulation. Direct injections of test proteins showed that CocH (0.3 or 1mg/kg) was effective by itself in reducing drug levels in plasma and brain of mice given cocaine (10mg/kg, s.c., or 20mg/kg, i.p). Administration of cocaine antibody per se at a low dose (8mg/kg, i.p.) exerted little effect on cocaine distribution. However, a higher dose of antibody (12mg/kg) caused peripheral trapping (increased plasma drug levels), which led to increased cocaine metabolism by CocH, as evidenced by a 6-fold rise in plasma benzoic acid. Behavioral tests with small doses of CocH and antibody (1 and 8mg/kg, respectively) showed that neither agent alone reduced mouse locomotor activity triggered by a very large cocaine dose (100mg/kg, i.p.). However, dual treatment completely suppressed the locomotor stimulation. Altogether, we found cooperative and possibly synergistic actions that warrant further exploration of dual therapies for treatment of cocaine abuse.
        
Title: Effects of anti-cocaine vaccine and viral gene transfer of cocaine hydrolase in mice on cocaine toxicity including motor strength and liver damage Gao Y, Geng L, Orson FM, Kinsey B, Kosten TR, Shen X, Brimijoin S Ref: Chemico-Biological Interactions, 203:208, 2013 : PubMed
In developing an vivo drug-interception therapy to treat cocaine abuse and hinder relapse into drug seeking provoked by re-encounter with cocaine, two promising agents are: (1) a cocaine hydrolase enzyme (CocH) derived from human butyrylcholinesterase and delivered by gene transfer; (2) an anti-cocaine antibody elicited by vaccination. Recent behavioral experiments showed that antibody and enzyme work in a complementary fashion to reduce cocaine-stimulated locomotor activity in rats and mice. Our present goal was to test protection against liver damage and muscle weakness in mice challenged with massive doses of cocaine at or near the LD50 level (100-120mg/kg, i.p.). We found that, when the interceptor proteins were combined at doses that were only modestly protective in isolation (enzyme, 1mg/kg; antibody, 8mg/kg), they provided complete protection of liver tissue and motor function. When the enzyme levels were approximately 400-fold higher, after in vivo transduction by adeno-associated viral vector, similar protection was observed from CocH alone.
        
Title: Derivatives of dibenzothiophene for positron emission tomography imaging of alpha7-nicotinic acetylcholine receptors Gao Y, Kellar KJ, Yasuda RP, Tran T, Xiao Y, Dannals RF, Horti AG Ref: Journal of Medicinal Chemistry, 56:7574, 2013 : PubMed
A new series of derivatives of 3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)dibenzo[b,d]thiophene 5,5-dioxide with high binding affinities and selectivity for alpha7-nicotinic acetylcholine receptors (alpha7-nAChRs) (Ki = 0.4-20 nM) has been synthesized for positron emission tomography (PET) imaging of alpha7-nAChRs. Two radiolabeled members of the series [(18)F]7a (Ki = 0.4 nM) and [(18)F]7c (Ki = 1.3 nM) were synthesized. [(18)F]7a and [(18)F]7c readily entered the mouse brain and specifically labeled alpha7-nAChRs. The alpha7-nAChR selective ligand 1 (SSR180711) blocked the binding of [(18)F]7a in the mouse brain in a dose-dependent manner. The mouse blocking studies with non-alpha7-nAChR central nervous system drugs demonstrated that [(18)F]7a is highly alpha7-nAChR selective. In agreement with its binding affinity the binding potential of [(18)F]7a (BPND = 5.3-8.0) in control mice is superior to previous alpha7-nAChR PET radioligands. Thus, [(18)F]7a displays excellent imaging properties in mice and has been chosen for further evaluation as a potential PET radioligand for imaging of alpha7-nAChR in non-human primates.
Cocaine addiction affects millions of people with disastrous personal and social consequences. Cocaine is one of the most reinforcing of all drugs of abuse, and even those who undergo rehabilitation and experience long periods of abstinence have more than 80% chance of relapse. Yet there is no FDA-approved treatment to decrease the likelihood of relapse in rehabilitated addicts. Recent studies, however, have demonstrated a promising potential treatment option with the help of the serum enzyme butyrylcholinesterase (BChE), which is capable of breaking down naturally occurring (-)-cocaine before the drug can influence the reward centers of the brain or affect other areas of the body. This activity of wild-type (WT) BChE, however, is relatively low. This prompted the design of variants of BChE which exhibit significantly improved catalytic activity against (-)-cocaine. Plants are a promising means to produce large amounts of these cocaine hydrolase variants of BChE, cheaply, safely with no concerns regarding human pathogens and functionally equivalent to enzymes derived from other sources. Here, in expressing cocaine-hydrolyzing mutants of BChE in Nicotiana benthamiana using the MagnICON virus-assisted transient expression system, and in reporting their initial biochemical analysis, we provide proof-of-principle that plants can express engineered BChE proteins with desired properties.
        
Title: Solvent-free enzymatic synthesis of 1, 3-diacylglycerols by direct esterification of glycerol with saturated fatty acids Zhong N, Gui Z, Xu L, Huang J, Hu K, Gao Y, Zhang X, Xu Z, Su J, Li B Ref: Lipids Health Dis, 12:65, 2013 : PubMed
BACKGROUND: Pure 1, 3-diacylglycerols (1, 3-DAG) have been considered to be significant surfactants in food, cosmetics and pharmaceutical industries, as well as the effect on obesity prevention. METHODS: In this study, a vacuum-driven air bubbling operation mode was developed and evaluated for the enzymatic synthesis of 1, 3-DAG of saturated fatty acids, by direct esterification of glycerol with fatty acids in a solvent-free system. The employed vacuum-driven air bubbling operation mode was comparable to vacuum-driven N2 bubbling protocol, in terms of lauric acid conversion and 1, 3-dilaurin content. RESULTS: Some operation parameters were optimized, and 95.3% of lauric acid conversion and 80.3% of 1, 3-dilaurin content was obtained after 3-h reaction at 50 degC, with 5 wt% of Lipozyme RM IM (based on reactants) amount. Of the lipases studied, both Lipozyme RM IM and Novozym 435 exhibited good performance in terms of lauric acid conversion. Lipozyme TL IM, however, showed low activity. Lipozyme RM IM showed good operational stability in this operation protocol, 80.2% of the original catalytic activity remained after 10 consecutive batch applications. Some other 1, 3-DAG were prepared and high content was obtained after purification: 98.5% for 1, 3-dicaprylin, 99.2% for 1, 3-dicaprin, 99.1% for 1, 3-dilaurin, 99.5 for 1, 3-dipalmitin and 99.4% for 1, 3-disterin. CONCLUSION: The established vacuum-driven air bubbling operation protocol had been demonstrated to be a simple-operating, cost-effective, application practical and efficient methodology for 1, 3-DAG preparation.
BACKGROUND: Cocaine dependence is a pervasive disorder with high rates of relapse. In a previous study, direct administration of a quadruple mutant albumin-fused butyrylcholinesterase that efficiently catalyzes hydrolysis of cocaine to benzoic acid and ecgonine methyl ester acutely blocked cocaine seeking in an animal model of relapse. In the present experiments, these results were extended to achieve a long-duration blockade of cocaine seeking with a gene transfer paradigm using a related butyrylcholinesterase-based cocaine hydrolase (CocH). METHODS: Male and female rats were allowed to self-administer cocaine under a fixed-ratio 1 schedule of reinforcement for approximately 14 days. Following the final self-administration session, rats were injected with CocH vector or a control injection (empty vector or saline), and their cocaine solutions were replaced with saline for 14 days to allow for extinction of lever pressing. Subsequently, they were tested for drug-primed reinstatement by administering intraperitoneal injections of saline (S), cocaine (C) (5, 10, and 15 mg/kg), and d-amphetamine according to the following sequence: S, C, S, C, S, C, S, d-amphetamine. Rats then received cocaine-priming injections once weekly for 4 weeks and, subsequently, once monthly for up to 6 months. RESULTS: Administration of CocH vector produced substantial and sustained CocH activity in plasma that corresponded with diminished cocaine-induced (but not amphetamine-induced) reinstatement responding for up to 6 months following treatment (compared with high-responding control animals). CONCLUSIONS: These results demonstrate that viral transfer of CocH may be useful in promoting long-term resistance to relapse to cocaine addiction.
        
Title: Cocaine hydrolase gene therapy for cocaine abuse Brimijoin S, Gao Y Ref: Future Med Chem, 4:151, 2012 : PubMed
Rapid progress in the past decade with re-engineering of human plasma butyrylcholinesterase has led to enzymes that destroy cocaine so efficiently that they prevent or interrupt drug actions in the CNS even though confined to the blood stream. Over the same time window, improved gene-transfer technology has made it possible to deliver such enzymes by endogenous gene transduction at high levels for periods of a year or longer after a single treatment. This article reviews recent advances in this field and considers prospects for development of a robust therapy aimed at aiding recovering drug users avoid addiction relapse.
Mice and rats were tested for reduced sensitivity to cocaine-induced hyper-locomotion after pretreatment with anti-cocaine antibody or cocaine hydrolase (CocH) derived from human butyrylcholinesterase (BChE). In Balb/c mice, direct i.p. injection of CocH protein (1 mg/kg) had no effect on spontaneous locomotion, but it suppressed responses to i.p. cocaine up to 80 mg/kg. When CocH was injected i.p. along with a murine cocaine antiserum that also did not affect spontaneous locomotion, there was no response to any cocaine dose. This suppression of locomotor activity required active enzyme, as it was lost after pretreatment with iso-OMPA, a selective BChE inhibitor. Comparable results were obtained in rats that developed high levels of CocH by gene transfer with helper-dependent adenoviral vector, and/or high levels of anti-cocaine antibody by vaccination with norcocaine hapten conjugated to keyhole limpet hemocyanin (KLH). After these treatments, rats were subjected to a locomotor sensitization paradigm involving a "training phase" with an initial i.p. saline injection on day 1 followed by 8 days of repeated cocaine injections (10 mg/kg, i.p.). A 15-day rest period then ensued, followed by a final "challenge" cocaine injection. As in mice, the individual treatment interventions reduced cocaine-stimulated hyperactivity to a modest extent, while combined treatment produced a greater reduction during all phases of testing compared to control rats (with only saline pretreatment). Overall, the present results strongly support the view that anti-cocaine vaccine and cocaine hydrolase vector treatments together provide enhanced protection against the stimulatory actions of cocaine in rodents. A similar combination therapy in human cocaine users might provide a robust therapy to help maintain abstinence.
        
Title: Effects of cocaine hydrolase on cocaine self-administration under a PR schedule and during extended access (escalation) in rats Carroll ME, Gao Y, Brimijoin S, Anker JJ Ref: Psychopharmacology (Berl), 213:817, 2011 : PubMed
RATIONALE AND OBJECTIVES: Previously, Albu-CocH, a cocaine hydrolase derived from human butyrylcholinesterase, blocked cocaine-induced reinstatement of drug seeking in rats. In the present study, rats were treated with Albu-CocH while self-administering cocaine under a progressive ratio (PR) schedule during 2-h sessions and under a fixed-ratio 1 (FR 1) schedule during 6-h sessions. METHODS: In experiment 1, rats were treated with saline or Albu-CocH (2 or 4 mg/kg) before a single 2-h cocaine (0.2 mg/kg) self-administration (PR) session. In experiment 2, rats were treated with Albu-CocH or saline for the first seven of the 21-day 6-h sessions prior to cocaine (0.2 or 0.4 mg/kg) self-administration sessions (FR 1). RESULTS: In experiment 1, Albu-CocH (vs saline) reduced cocaine infusions immediately following treatment compared with sessions pretreatment and posttreatment. In experiment 2, the Albu-CocH-treated groups (vs saline) showed an initial twofold to threefold increase in 0.2 and 0.4 mg/kg cocaine infusions over the 7 days of treatment, but they decreased to the infusion levels of saline controls by day 7. Cocaine (0.4 mg/kg) intake in the saline-treated group was elevated during the last 3 days of 6-h access compared with the first 3 days, indicating an escalation effect. Responding for 0.4 mg/kg (but not 0.2 mg/kg) cocaine during 2-h sessions after the 21 days of 6-h access was elevated in the saline groups (compared with 2-h sessions before long access) but not in the Albu-CocH-treated groups. CONCLUSIONS: Albu-CocH decreased cocaine infusions under the PR schedule, indicating a reduced reward value of cocaine (experiment 1). However, Albu-CocH, compared with saline, temporarily increased cocaine infusions during long access. The post-long access 2-h cocaine intake was not increased in the Albu-CocH-treated groups as it was in the saline-treated groups. Albu-CocH is an effective agent for reducing cocaine reward under conditions of low cocaine exposure and chronic treatment.
Oxidative stress-induced apoptosis plays a critical role in the pathogenesis of various neurodegenerative disorders. In this study, the neuroprotective properties of bis(12)-hupyridone (B12H), a novel dimeric acetylcholinesterase (AChE) inhibitor modified from a naturally occurring monomeric analogue, huperzine A, on H(2)O(2)-induced neurotoxicity were investigated in cerebellar granule neurons (CGNs). Exposure of CGNs to H(2)O(2) resulted in apoptosis which could be attenuated by the pre-treatment of B12H (0.3-5 nM) in a concentration-dependent manner. Moreover, tacrine and neostigmine failed to prevent neurotoxicity, indicating that the neuroprotection of B12H might not be due to its inhibitory property of AChE enzymatic activity. Increased activation of extracellular signal-regulated kinase (ERK) and decreased activation of glycogen synthase kinase (GSK) 3beta were observed after H(2)O(2) exposure, and B12H reversed the altered activation of GSK3beta, but not that of ERK. Furthermore, using vascular endothelial growth factor (VEGF), phospho-VEGF receptor-2 (VEGFR-2) antibody, a specific VEGFR-2 inhibitor (PTK787/ZK222584) and specific phosphoinositide 3-kinase inhibitors (LY294002 and wortmannin), it was found that VEGF prevented H(2)O(2)-induced neuronal loss from activating the VEGF/VEGFR-2 system and that the observed B12H neuroprotective effects might share the same signaling pathway. These findings strongly suggest that B12H prevents H(2)O(2)-induced neuronal apoptosis independent of inhibiting AChE, but through regulating VEGFR-2/Akt/GSK3beta signaling pathway.
Dipeptidyl-peptidase-like protein 6 (DPP6), a member of the dipeptidyl aminopeptidase family, plays distinct roles in brain development, but its expression in embryonic craniofacial development is unknown. The expression pattern of Dpp6 in the maxillofacial region during mouse embryonic craniofacial development was analyzed by whole-mount in situ hybridization on sections and by real-time PCR analysis. Dpp6 expression was detected during mouse embryonic craniofacial development in embryos 11-13.5 days post-coitum (dpc). Real-time PCR showed high Dpp6 expression present in 11.5-13.5dpc, and this then decreased as development of maxillofacial region progressed. The expression pattern of Dpp6 suggests that Dpp6 may be involved in embryonic craniofacial development.
        
Title: Complete genome sequence of Lactococcus lactis subsp. lactis CV56, a probiotic strain isolated from the vaginas of healthy women Gao Y, Lu Y, Teng KL, Chen ML, Zheng HJ, Zhu YQ, Zhong J Ref: Journal of Bacteriology, 193:2886, 2011 : PubMed
Lactic acid bacteria that exist in the urinogenital system play an important role in maintaining the health of the host. Here, we report the finished and annotated genome of a Lactococcus strain that was isolated from the vaginas of healthy women and shows probiotic properties, including nisin A production and adhesion to vaginal epithelial cells.
        
Title: Population pharmacokinetic-pharmacodynamic analysis of vernakalant hydrochloride injection (RSD1235) in atrial fibrillation or atrial flutter Mao Z, Wheeler JJ, Townsend R, Gao Y, Kshirsagar S, Keirns JJ Ref: J Pharmacokinet Pharmacodyn, 38:541, 2011 : PubMed
Vernakalant hydrochloride is a novel, relatively atrial-selective antiarrhythmic agent that rapidly converts atrial fibrillation (AF) to sinus rhythm (SR). This analysis integrates pharmacokinetic (PK) and safety data from 5 clinical trials of patients with AF or atrial flutter (AFL). Patients were initially given a 10-min intravenous (IV) infusion of vernakalant 3 mg/kg or placebo. If SR was not evident after a 15-min observation, then a second 10-min IV infusion of vernakalant 2 mg/kg or placebo was given. Population pharmacokinetic/pharmacodynamic (PK/PD) models were constructed for QT interval prolongation corrected for heart rate by Fridericia's formula (QTcF) and for changes in systolic blood pressure (SBP). The exposure-response relationships for QTcF and SBP were best described by sigmoidal maximum-effect (E (max)) models. For QTcF, the model was characterized by a typical E (max) of 20.3 ms, and by a vernakalant median effective concentration dependent (EC(5)(0)) on conversion status (4,222 ng/ml for patients converting to SR and 2,276 ng/ml for those remaining in AF/AFL). For SBP, the model was characterized by E (max) of 3.05 mmHg and EC(5)(0) of 1,141 ng/ml. Risk of hypotension (SBP <90 mmHg) was primarily associated with low baseline SBP and to a smaller extent with a history of congestive heart failure (CHF); plasma vernakalant concentrations showed a small contribution to the risk of hypotension (relative risk = 1.4 at 4,000 ng/ml), which may be significant with a baseline SBP of <105 mmHg. These results show that vernakalant had a smaller effect on QTcF in patients who demonstrated conversion to SR than those remaining in AF or AFL, and it had a relatively small effect on SBP.
        
Title: Complete genome sequences of Brucella melitensis strains M28 and M5-90, with different virulence backgrounds Wang F, Hu S, Gao Y, Qiao Z, Liu W, Bu Z Ref: Journal of Bacteriology, 193:2904, 2011 : PubMed
Brucella melitensis is a Gram-negative coccobacillus bacteria belonging to the Alphaproteobacteria subclass. It is an important zoonotic pathogen that causes brucellosis, a disease affecting sheep, cattle, and sometimes humans. The B. melitensis strain M5-90, a live attenuated vaccine cultured from the B. melitensis virulent strain M28, has been an effective tool to control brucellosis in goats and sheep in China. Here we report the complete genome sequences of B. melitensis M28 and M5-90, strains with different virulence backgrounds, which will serve as a valuable reference for future studies.
Endocannabinoids are lipid molecules that serve as natural ligands for the cannabinoid receptors CB1 and CB2. They modulate a diverse set of physiological processes such as pain, cognition, appetite, and emotional states, and their levels and functions are tightly regulated by enzymatic biosynthesis and degradation. 2-Arachidonoylglycerol (2-AG) is the most abundant endocannabinoid in the brain and is believed to be hydrolyzed primarily by the serine hydrolase monoacylglycerol lipase (MAGL). Although 2-AG binds and activates cannabinoid receptors in vitro, when administered in vivo, it induces only transient cannabimimetic effects as a result of its rapid catabolism. Here we show using a mouse model with a targeted disruption of the MAGL gene that MAGL is the major modulator of 2-AG hydrolysis in vivo. Mice lacking MAGL exhibit dramatically reduced 2-AG hydrolase activity and highly elevated 2-AG levels in the nervous system. A lack of MAGL activity and subsequent long-term elevation of 2-AG levels lead to desensitization of brain CB1 receptors with a significant reduction of cannabimimetic effects of CB1 agonists. Also consistent with CB1 desensitization, MAGL-deficient mice do not show alterations in neuropathic and inflammatory pain sensitivity. These findings provide the first genetic in vivo evidence that MAGL is the major regulator of 2-AG levels and signaling and reveal a pivotal role for 2-AG in modulating CB1 receptor sensitization and endocannabinoid tone.
Endocannabinoids (eCBs) function as retrograde signaling molecules at synapses throughout the brain, regulate axonal growth and guidance during development, and drive adult neurogenesis. There remains a lack of genetic evidence as to the identity of the enzyme(s) responsible for the synthesis of eCBs in the brain. Diacylglycerol lipase-alpha (DAGLalpha) and -beta (DAGLbeta) synthesize 2-arachidonoyl-glycerol (2-AG), the most abundant eCB in the brain. However, their respective contribution to this and to eCB signaling has not been tested. In the present study, we show approximately 80% reductions in 2-AG levels in the brain and spinal cord in DAGLalpha(-/-) mice and a 50% reduction in the brain in DAGLbeta(-/-) mice. In contrast, DAGLbeta plays a more important role than DAGLalpha in regulating 2-AG levels in the liver, with a 90% reduction seen in DAGLbeta(-/-) mice. Levels of arachidonic acid decrease in parallel with 2-AG, suggesting that DAGL activity controls the steady-state levels of both lipids. In the hippocampus, the postsynaptic release of an eCB results in the transient suppression of GABA-mediated transmission at inhibitory synapses; we now show that this form of synaptic plasticity is completely lost in DAGLalpha(-/-) animals and relatively unaffected in DAGLbeta(-/-) animals. Finally, we show that the control of adult neurogenesis in the hippocampus and subventricular zone is compromised in the DAGLalpha(-/-) and/or DAGLbeta(-/-) mice. These findings provide the first evidence that DAGLalpha is the major biosynthetic enzyme for 2-AG in the nervous system and reveal an essential role for this enzyme in regulating retrograde synaptic plasticity and adult neurogenesis.
        
Title: The concept of pharmacologic cocaine interception as a treatment for drug abuse Gao Y, Orson FM, Kinsey B, Kosten T, Brimijoin S Ref: Chemico-Biological Interactions, 187:421, 2010 : PubMed
Cocaine access to brain tissue and associated cocaine-induced behaviors are substantially reduced in rats and mice by significant plasma levels of an enzyme that rapidly metabolizes the drug. Similar results have been obtained in rodents and humans with therapeutic anti-cocaine antibodies, which sequester the drug and prevent its entry into the brain. We show that an efficient cocaine hydrolase can lead to rapid unloading of anti-cocaine antibodies saturated with cocaine, and we provide a theoretical basis for the hypothesis that dual therapy with antibody and hydrolase enzyme may be especially effective.
        
Title: Genetic study of capsular switching between Neisseria meningitidis sequence type 7 serogroup A and C strains Wang Q, Shao Z, Wang X, Gao Y, Li M, Xu L, Xu J, Wang L Ref: Infect Immun, 78:3883, 2010 : PubMed
Neisseria meningitidis is a leading cause of septicemia and meningitis worldwide. N. meningitidis capsular polysaccharides have been classified into 13 distinct serogroups which are defined by antibody reactivity and structural analysis, and the capsule plays an important role in virulence. Serogroups A, B, C, W135, and Y have been reported to be clinically important. Several newly identified serogroup C isolates belonging to the unique sequence type 7 (ST-7) were identified in China. Since most ST-7 isolates from China belonged to serogroup A, the newly identified ST-7 serogroup C strains were proposed to have arisen from those belonging to ST-7 serogroup A. In this study, six ST-7 serogroup C and three ST-7 serogroup A isolates were analyzed by pulsed-field gel electrophoresis to confirm their sequence type. In order to clarify the genetic basis of capsular switching between ST-7 serogroup A and C strains, the whole capsular gene clusters and surrounding genes of the two representative ST-7 strains belonging to serogroups A and C, respectively, were sequenced and compared. Potential recombination sites were analyzed using the RDP3 beta software, and recombination-related regions in two other ST-7 serogroup A and five ST-7 serogroup C strains were also sequenced and compared to the representative ST-7 serogroup A and C strain sequences.
        
Title: Lasting reduction of cocaine action in neostriatum--a hydrolase gene therapy approach Gao Y, Brimijoin S Ref: Journal of Pharmacology & Experimental Therapeutics, 330:449, 2009 : PubMed
We previously found that a quadruple mutant cocaine hydrolase derived from human butyrylcholinesterase [termed cocaine esterase (CocE)] can suppress or reverse cocaine toxicity and abolish drug-primed reinstatement in rats. Here, we examined whether gene transfer of CocE reduces cocaine actions in brain reward centers. Early experiments used a standard, early region 1-deleted adenoviral vector, which, after intravenous delivery of 10(10) plaque-forming units, caused plasma cocaine hydrolase activity to rise 25,000-fold between day 4 and day 7. During this period, under a protocol that typically induces FosB expression in the caudate nucleus, these rats and unprotected controls given only empty vector or saline were subjected to repeated twice-daily injections of cocaine (30 mg/kg i.p.). Immunohistochemistry of the neostriatum on day 7 showed many FosB-reactive nuclei in unprotected rats but few if any in rats pretreated with active vector, which resembled rats never exposed to cocaine. Western blots confirmed this result. In contrast there was a more localized protection against cocaine-elicited FosB induction when hydrolase vector was injected directly into the ventral striatum, which generated high transgene expression in many neurons of the target area. Similar results were obtained with systemic and local injection of a more efficient helper-dependent adenoviral vector, which transduced high levels of hydrolase for at least 2 months, with lesser expression continued up to 1 year. Behavioral tests are now warranted to determine whether such effects can reduce drug-seeking behavior and lower the probability of relapse.
Aphids, among the most destructive insects to world agriculture, are mainly controlled by organophosphate insecticides that disable the catalytic serine residue of acetylcholinesterase (AChE). Because these agents also affect vertebrate AChEs, they are toxic to non-target species including humans and birds. We previously reported that a cysteine residue (Cys), found at the AChE active site in aphids and other insects but not mammals, might serve as a target for insect-selective pesticides. However, aphids have two different AChEs (termed AP and AO), and only AP-AChE carries the unique Cys. The absence of the active-site Cys in AO-AChE might raise concerns about the utility of targeting that residue. Herein we report the development of a methanethiosulfonate-containing small molecule that, at 6.0 microM, irreversibly inhibits 99% of all AChE activity extracted from the greenbug aphid (Schizaphis graminum) without any measurable inhibition of the human AChE. Reactivation studies using beta-mercaptoethanol confirm that the irreversible inhibition resulted from the conjugation of the inhibitor to the unique Cys. These results suggest that AO-AChE does not contribute significantly to the overall AChE activity in aphids, thus offering new insight into the relative functional importance of the two insect AChEs. More importantly, by demonstrating that the Cys-targeting inhibitor can abolish AChE activity in aphids, we can conclude that the unique Cys may be a viable target for species-selective agents to control aphids without causing human toxicity and resistance problems.
New insecticides are urgently needed because resistance to current insecticides allows resurgence of disease-transmitting mosquitoes while concerns for human toxicity from current compounds are growing. We previously reported the finding of a free cysteine (Cys) residue at the entrance of the active site of acetylcholinesterase (AChE) in some insects but not in mammals, birds, and fish. These insects have two AChE genes (AP and AO), and only AP-AChE carries the Cys residue. Most of these insects are disease vectors such as the African malaria mosquito (Anopheles gambiae sensu stricto) or crop pests such as aphids. Recently we reported a Cys-targeting small molecule that irreversibly inhibited all AChE activity extracted from aphids while an identical exposure caused no effect on the human AChE. Full inhibition of AChE in aphids indicates that AP-AChE contributes most of the enzymatic activity and suggests that the Cys residue might serve as a target for developing better aphicides. It is therefore worth investigating whether the Cys-targeting strategy is applicable to mosquitocides. Herein, we report that, under conditions that spare the human AChE, a methanethiosulfonate-containing molecule at 6 microM irreversibly inhibited 95% of the AChE activity extracted from An. gambiae s. str. and >80% of the activity from the yellow fever mosquito (Aedes aegypti L.) or the northern house mosquito (Culex pipiens L.) that is a vector of St. Louis encephalitis. This type of inhibition is fast ( approximately 30 min) and due to conjugation of the inhibitor to the active-site Cys of mosquito AP-AChE, according to our observed reactivation of the methanethiosulfonate-inhibited AChE by 2-mercaptoethanol. We also note that our sulfhydryl agents partially and irreversibly inhibited the human AChE after prolonged exposure (>4 hr). This slow inhibition is due to partial enzyme denaturation by the inhibitor and/or micelles of the inhibitor, according to our studies using atomic force microscopy, circular dichroism spectroscopy, X-ray crystallography, time-resolved fluorescence spectroscopy, and liquid chromatography triple quadrupole mass spectrometry. These results support our view that the mosquito-specific Cys is a viable target for developing new mosquitocides to control disease vectors and to alleviate resistance problems with reduced toxicity toward non-target species.
        
Title: Cholinesterase inhibition and acetylcholine accumulation following intracerebral administration of paraoxon in rats Ray A, Liu J, Karanth S, Gao Y, Brimijoin S, Pope C Ref: Toxicol Appl Pharmacol, 236:341, 2009 : PubMed
We evaluated the inhibition of striatal cholinesterase activity following intracerebral administration of paraoxon assaying activity either in tissue homogenates ex vivo or by substrate hydrolysis in situ. Artificial cerebrospinal fluid (aCSF) or paraoxon in aCSF was infused unilaterally (0.5 microl/min for 2 h) and ipsilateral and contralateral striata were harvested for ChE assay ex vivo. High paraoxon concentrations were needed to inhibit ipsilateral striatal cholinesterase activity (no inhibition at <0.1 mM; 27% at 0.1 mM; 79% at 1 mM paraoxon). With 3 mM paraoxon infusion, substantial ChE inhibition was also noted in contralateral striatum. ChE histochemistry generally confirmed these concentration- and side-dependent effects. Microdialysates collected for up to 4 h after paraoxon infusion inhibited ChE activity when added to striatal homogenate, suggesting prolonged efflux of paraoxon. Since paraoxon efflux could complicate acetylcholine analysis, we evaluated the effects of paraoxon (0, 0.03, 0.1, 1, 10 or 100 microM, 1.5 microl/min for 45 min) administered by reverse dialysis through a microdialysis probe. ChE activity was then monitored in situ by perfusing the colorimetric substrate acetylthiocholine through the same probe and measuring product (thiocholine) in dialysates. Concentration-dependent inhibition was noted but reached a plateau of about 70% at 1 microM and higher concentrations. Striatal acetylcholine was below the detection limit at all times with 0.1 microM paraoxon but was transiently elevated (0.5-1.5 h) with 10 microM paraoxon. In vivo paraoxon (0.4 mg/kg, sc) in adult rats elicited about 90% striatal ChE inhibition measured ex vivo, but only about 10% inhibition measured in situ. Histochemical analyses revealed intense AChE and glial fibrillary acidic protein staining near the cannula track, suggesting proliferation of inflammatory cells/glia. The findings suggest that ex vivo and in situ cholinesterase assays can provide very different views into enzyme-inhibitor interactions. Furthermore, the proliferation/migration of cells containing high amounts of cholinesterase just adjacent to a dialysis probe could affect the recovery and thus detection of extracellular acetylcholine in microdialysis studies.
Successive rational mutations of human butyrylcholinesterase (BChE) followed by fusion to human serum albumin have yielded an efficient hydrolase that offers realistic options for therapy of cocaine overdose and abuse. This albumin-BChE prevented seizures in rats given a normally lethal cocaine injection (100 mg/kg, i.p.), lowered brain cocaine levels even when administered after the drug, and provided rescue after convulsions commenced. Moreover, it selectively blocked cocaine-induced reinstatement of drug seeking in rats that had previously self-administered cocaine. The enzyme treatment was well tolerated and may be worth exploring for clinical application in humans.
Several isomers of 7-methyl-2-exo-([(18)F]fluoropyridinyl-5'-pyridinyl)-7-azabicyclo[2.2.1]heptane have been developed as radioligands with optimized brain kinetics for PET imaging of nAChR. The binding assay demonstrated that all isomers are beta-nAChR selective ligands with Ki = 0.02-0.3 nM. The experimental lipophilicity values of all isomers were in the optimal range for the cerebral radioligands (log D7.4= 0.67-0.99). The isomers with higher binding affinity manifested slow baboon brain kinetics, whereas the isomer with the lowest binding affinity (Ki = 0.3 nM) ((-)-7-methyl-2- exo-[3'-(6-[(18)F]fluoropyridin-2-yl)-5'-pyridinyl]-7-azabicyclo[2.2.1]heptane, [(18)F](-)-6c) and greatest lipophilicity (log D 7.4 = 0.99) exhibited optimal brain kinetics. [(18)F](-)-6c manifests a unique combination of the optimally rapid brain kinetics, high BP and brain uptake, and favorable metabolic profile. Pharmacological studies showed that (-)-6c is an alpha4beta2-nAChR antagonist with low side effects in mice. This combination of imaging properties suggests that [(18)F]-(-)- 6c is a potentially superior replacement for 2-[(18)F]fluoro-A-85380 and 6-[(18)F]fluoro-A-85380, the only available nAChR PET radioligands for humans.
        
Title: An albumin-butyrylcholinesterase for cocaine toxicity and addiction: catalytic and pharmacokinetic properties Gao Y, Lafleur D, Shah R, Zhao Q, Singh M, Brimijoin S Ref: Chemico-Biological Interactions, 175:83, 2008 : PubMed
Butyrylcholinesterase (BChE, EC 3.1.1.8) is important in human cocaine metabolism despite its limited ability to hydrolyze this drug. Efforts to improve the catalytic efficiency of this enzyme have led to a quadruple mutant cocaine hydrolase, "CocH", that in animal models of addiction appears promising for treatment of overdose and relapse. We incorporated the CocH mutations into a BChE-albumin fusion protein, "Albu-CocH", and evaluated the pharmacokinetics of the enzyme after i.v. injection in rats. As assessed from the time course of cocaine hydrolyzing activity in plasma, Albu-CocH redistributed into extracellular fluid (16% of estimated total body water) with a t(1/2) of 0.66h and it underwent elimination with a t(1/2) of 8h. These results indicate that the enzyme has ample stability for short-term applications and may be suitable for longer-term treatment as well. Present data also confirm the markedly enhanced power of Albu-CocH for cocaine hydrolysis and they support the view that Albu-CocH might prove valuable in treating phenomena associated with cocaine abuse.
        
Title: [Immobilization of lipase by chemical modification of chitosan] Hu WJ, Tan TW, Wang F, Gao Y Ref: Sheng Wu Gong Cheng Xue Bao, 23:667, 2007 : PubMed
Lipase (EC3.1.1.3) from Candida sp. 99-125 was immobilized on chitosan by chemical covalence. Lipase was first immobilized to chitosan beads by activating its hydroxyl groups with carbodiimide followed by cross-linking more lipase to the amino groups with glutaraldehyde. In this article, different factors that influenced the immobilization were investigated, and the optimum conditions were ascertained. Comparative studies of organic solvent and thermal stability between free lipase and immobilized lipase were conducted. Immobilization enhanced the lipase stability against changes of temperature and organic solvent. Immobilization lipase can be reused in the synthesis system of palmitate hexadecyl. Operational stability tests indicated that the immobilized lipase occurs after 16 consecutive batches, the conversion rate remained 85%. Such results revealed good potential for recycling under esterification system.
        
Title: Viral transduction of cocaine hydrolase in brain reward centers Gao Y, Brimijoin S Ref: Cellular Molecular Neurobiology, 26:357, 2006 : PubMed
1. Site-directed mutagenesis of human plasma butyrylcholinesterase has led to novel hydrolases that rapidly destroy cocaine. We are investigating whether viral gene transfer of such enzymes might reduce addiction liability by blocking cocaine from its sites of action. 2. As groundwork for a possible gene therapy, we previously studied adenoviral transduction of cocaine hydrolases in the rat. Systemically injected vectors raised plasma cocaine hydrolase activity greatly, reduced pressor responses to cocaine, and lowered cocaine's tissue burden. 3. In the present study, to reduce cocaine's brain access still further, vectors were injected directly into the nucleus accumbens. Six days later, medium sized neurons gained dramatic butyrylcholinesterase activity. Species-selective immunohistochemistry proved that the transgene accounted for this activity. 4. Since the transgene product is so efficient with cocaine as a substrate, it is now reasonable to begin testing gene therapy in rodent models of cocaine addiction.
We previously found that injection of a cocaine hydrolase (CocE) engineered from human butyrylcholinesterase will transiently accelerate cocaine metabolism in rats while reducing physiological and behavioral responses. To investigate more extended therapeutic effects, CocE cDNA was incorporated into a replication-incompetent type-5 adenoviral vector with a cytomegalovirus promoter. In rats dosed with this agent (2.2 x 10(9) plaque-forming units), the time course of expression was characterized by reverse transcription polymerase chain reaction for CocE mRNA and by radiometric assay for enzyme activity. Liver and plasma showed comparable expression, beginning 2 days after vector administration and peaking between 5 and 7 days. Plasma CocE content was up to 100 mU/ml, with total cocaine hydrolyzing activity 3000-fold greater than in "empty vector" or untreated controls. This level of expression approximated that found immediately after i.v. injection of purified hydrolase, 3 mg/kg, a dose that shortened cocaine halflife and blunted cardiovascular effects. Sucrose density gradient analysis showed that 96% of the circulating CocE activity was associated with tetrameric enzyme forms, expected to be stable in vivo. Consistent with this expectation, CocE from vector-treated rats showed a plasma t(1/2) of 33 h when reinjected into naive rats. Transduction of another mutant butyrylcholinesterase, Applied Molecular Evolution mutant 359 (AME(359)), caused plasma cocaine hydrolase activity to rise 50,000-fold. At the point of peak AME(359) expression, cocaine was cleared from the blood too rapidly for accurate measurement, and pressor responses to the injection of drug were greatly impaired.
        
Title: Visualizing viral transduction of a cocaine-hydrolyzing, human butyrylcholinesterase in rats Gao Y, Brimijoin S Ref: Chemico-Biological Interactions, 157-158:97, 2005 : PubMed
Human plasma butyrylcholinesterase (BChE) is essential for cocaine detoxification even though its catalytic efficiency for that substrate is relatively poor. Site-directed mutagenesis of this protein has recently been used to obtain much-improved cocaine esterases, one of which we designate CocE. We previously showed that adenoviral transduction of such esterases caused up to 50,000-fold increases in circulating cocaine hydrolase activity, led to drastically shortened cocaine half-life, and blunted the cardiovascular responses to cocaine in rats. In those experiments, gene transduction of cocaine esterase was sustained at high levels for up to 1 week but then declined steeply. Our eventual goal is to use long-term esterase expression as a means of reducing drug reward and extinguishing intake in models of cocaine-addiction. Therefore, we investigated the site of enzyme transduction for clues to the local reactions that may limit the duration of CocE expression. Histological and immunohistochemical observations demonstrated that hepatocytes were the primary focus for transduction of modified human BChE. Rats were administered 2.2 x 10(10) plaque forming units of a replication-incompetent, type-5 adenoviral vector incorporating CocE cDNA. Within days the livers showed intense thiocholine staining for BChE activity. Selective immunohistochemistry for human BChE proved that this activity represented CocE transgene. By 5 days, however, pockets of mononuclear cells had invaded the hepatic parenchyma, and a meshwork of IgM-like immunoreactivity had lined the hepatic sinusoids. These phenomena probably represent early responses of the immune system, either to the transduced CocE or to the hepatocytes producing this protein.
        
Title: Molecularly imprinted polymer for monocrotophos and its binding characteristics for organophosphorus pesticides Zhu X, Yang J, Su Q, Cai J, Gao Y Ref: Ann Chim, 95:877, 2005 : PubMed
In this study, molecular imprinting was used to develop a method based on noncovalent interaction for the synthesis of a monocrotophos-specific polymer. The selective binding characteristics of the template polymer were evaluated by 1H NMR study. The result was consistent with the existence of multi-molecular complexes formed by hydrogen-bonding interactions. Batch rebinding studies in acetonitrile were undertaken to quantitatively evaluate the affinity of the polymer for monocrotophos. The experimental binding isotherms were fitted to the Freundlich isotherm and the total number of binding sites of the polymer can be calculated to be 4.046 micromol g(-1). The induced affinity and selectivity by imprinting were examined chromatographically. The polymer gave more than 15 times longer retention for monocrotophos than the nonimprinted polymer with the same chemical composition. Other organophosphorus pesticides under study were eluted close to the void volume on the polymer column.
        
Title: An engineered cocaine hydrolase blunts and reverses cardiovascular responses to cocaine in rats Gao Y, Brimijoin S Ref: Journal of Pharmacology & Experimental Therapeutics, 310:1046, 2004 : PubMed
There is increasing evidence that human plasma butyrylcholinesterase can lower the toxicity of cocaine overdose. Recently, with structure-based protein engineering, we converted this enzyme into a more efficient cocaine hydrolase (CocE). When tested in rats, CocE shortened cocaine's plasma half-life and decreased drug accumulation in heart and brain. Here, we have investigated the potential of CocE to antagonize cardiovascular responses to cocaine. Anesthetized rats were instrumented for continuous recording of blood pressure from the femoral artery. Cocaine (7 mg/kg i.v.) caused blood pressure to rise within 30 s by 25 to 37 mmHg, but pressure returned to baseline within 60 s. These transient pressor responses were prolonged up to 5 min when vagal reflexes were blocked with atropine (1 mg/kg). Under such conditions, pretreatment with CocE (3 mg/kg i.v.) reduced cocaine's pressor effect, whereas delayed treatment with CocE rapidly restored normal mean blood pressure. CocE had no hemodynamic effects in control animals not treated with cocaine. The finding that CocE can oppose pre-established physiologic actions of cocaine suggests that similar or improved hydrolases might help rescue patients from the life-threatening toxicity of drug overdose.
Here, we report our effort in generating an ORFeome collection for the Arabidopsis transcription factor (TF) genes. In total, ORFeome clones representing 1,282 Arabidopsis TF genes have been obtained in the Gateway high throughput cloning pENTR vector, including 411 genes whose annotation lack cDNA support. All the ORFeome inserts have also been mobilized into a yeast expression destination vector, with an estimated 85% rate of expressing the respective proteins. Sequence analysis of these clones revealed that 34 of them did not match with either the reported cDNAs or current predicted open-reading-frame sequences. Among those, novel alternative splicing of TF gene transcripts is responsible for the observed differences in at least five genes. However, those alternative splicing events do not appear to be differentially regulated among distinct Arabidopsis tissues examined. Lastly, expression of those TF genes in 17 distinct Arabidopsis organ types and the cultured cells was profiled using a 70-mer oligo microarray.
        
Title: Huperzine A, a promising anti-Alzheimer?s agent, reduces staurosporine-induced apoptosis in NG108-15 cells. Xiao XQ, Wu DC, Gao Y, Fu Y, Lee NT, Ho WL, Tsim KWK, Han YF Ref: Cholinergic Mechanisms, CRC Press, :733, 2004 : PubMed
It has been well established that the formation of reactive metabolites of drugs is associated with drug toxicity. Similarly, there are accumulating data suggesting the role of the formation of reactive metabolites/intermediates through bioactivation in herbal toxicity and carcinogenicity. It has been hypothesized that the resultant reactive metabolites following herbal bioactivation covalently bind to cellular proteins and DNA, leading to toxicity via multiple mechanisms such as direct cytotoxicity, oncogene activation, and hypersensitivity reactions. This is exemplified by aristolochic acids present in Aristolochia spp, undergoing reduction of the nitro group by hepatic cytochrome P450 (CYP1A1/2) or peroxidases in extrahepatic tissues to reactive cyclic nitrenium ion. The latter was capable of reacting with DNA and proteins, resulting in activation of H-ras oncogene, gene mutation and finally carcinogenesis. Other examples are pulegone present in essential oils from many mint species; and teucrin A, a diterpenoid found in germander (Teuchrium chamaedrys) used as an adjuvant to slimming diets. Extensive pulegone metabolism generated p-cresol that was a glutathione depletory, and the furan ring of the diterpenoids in germander was oxidized by CYP3A4 to reactive epoxide which reacts with proteins such as CYP3A and epoxide hydrolase. On the other hand, some herbal/dietary constituents were shown to form reactive intermediates capable of irreversibly inhibiting various CYPs. The resultant metabolites lead to CYP inactivation by chemical modification of the heme, the apoprotein, or both as a result of covalent binding of modified heme to the apoprotein. Some examples include bergamottin, a furanocoumarin of grapefruit juice; capsaicin from chili peppers; glabridin, an isoflavan from licorice root; isothiocyanates found in all cruciferous vegetables; oleuropein rich in olive oil; dially sulfone found in garlic; and resveratrol, a constituent of red wine. CYPs have been known to metabolize more than 95% therapeutic drugs and activate a number of procarcinogens as well. Therefore, mechanism-based inhibition of CYPs may provide an explanation for some reported herb-drug interactions and chemopreventive activity of herbs. Due to the wide use and easy availability of herbal medicines, there is increasing concern about herbal toxicity. The safety and quality of herbal medicine should be ensured through greater research, pharmacovigilance, greater regulatory control and better communication between patients and health professionals.
We have sequenced the genome of Shigella flexneri serotype 2a, the most prevalent species and serotype that causes bacillary dysentery or shigellosis in man. The whole genome is composed of a 4 607 203 bp chromosome and a 221 618 bp virulence plasmid, designated pCP301. While the plasmid shows minor divergence from that sequenced in serotype 5a, striking characteristics of the chromosome have been revealed. The S.flexneri chromosome has, astonishingly, 314 IS elements, more than 7-fold over those possessed by its close relatives, the non-pathogenic K12 strain and enterohemorrhagic O157:H7 strain of Escherichia coli. There are 13 translocations and inversions compared with the E.coli sequences, all involve a segment larger than 5 kb, and most are associated with deletions or acquired DNA sequences, of which several are likely to be bacteriophage-transmitted pathogenicity islands. Furthermore, S.flexneri, resembling another human-restricted enteric pathogen, Salmonella typhi, also has hundreds of pseudogenes compared with the E.coli strains. All of these could be subjected to investigations towards novel preventative and treatment strategies against shigellosis.
        
Title: [Neurotoxicity of antibody against motoneuron on cultured rat cortical neurons] Gao Y, Li Y, Lin J, Li L, Wan X Ref: Zhongguo Yi Xue Ke Xue Yuan Xue Bao, 20:296, 1998 : PubMed
OBJECTIVE In order to determine the role of antibody against motoneuron in the process of neuronal death.
METHODS:
Cultured rat cortical neurons growing in serum-free medium, were employed to observe the effects of antibody against motoneuron (anti-SMN) on the survival of these cultured neurons.
RESULTS:
(1) Exposure of the cultures in serum-free medium to anti-SMN with dilution of 1:50 results in death of 31%-41% of neurons for 24 hours incubation, 50%-67% for 48 hours and above 90% after 72 hours. The neurotoxicity induced by anti-SMN was accompanied by concentration-dependent release of lactate dehydrogenase into the culture medium. Cultures exposed to normal rat IgG as controls exhibited no such sign. (2) The cultured neurons exposed to anti-SMN (1:200) expressed markedly higher levels of immunoreactive Calbindin-D28k especially after 48 hours incubation with it. There was a reduction in the number of acetylcholinesterase-positive neurons compared to the normal control.
CONCLUSIONS:
The anti-SMN could directly initiate the process of cortical neuronal death and this effect was independent of complement. The alteration of Calbindin-D28k immunoreactivity implied that calcium may be involved in the neurotoxicity induced by anti-SMN.