Imine reductases(IREDs)have been extensively used for the imine reduction and reductive amination to access various amines.However,poor activity and severe substrate/product inhibition limit their widespread applicati...Imine reductases(IREDs)have been extensively used for the imine reduction and reductive amination to access various amines.However,poor activity and severe substrate/product inhibition limit their widespread application in industry.Herein,an engineered IRED from Streptomyces viridochromogenes was developed through four rounds of directed evolution.The engineered SvIRED displayed a significant increase in specific activity to 136.8 U mg^(-1),the highest reported for an IRED to date.Molecular dynamics simulations elucidated the surge in specific activity during mutations.The best mutant can also catalyse the reductive coupling of aldehyde homologs and primary amines with up to 66.9 U mg^(-1).Additionally,we established an in-situ product adsorption system using resin,which significantly alleviated substrate/product inhibition and enhanced substrate loading to 100 g L^(-1).Under optimal conditions,a wide range of chiral 2-aryl-pyrrolidines were successfully produced at high substrate loadings(50-100 g L^(-1))with enantiomeric excess over 99%.The usefulness of this biocatalytic system was further demonstrated by preparation of pharmaceutically relevant chiral 2-aryl pyrrolidines,particularly the decagram-scale synthesis of the key chiral aticaprant intermediate with 90%isolated yield,>99%ee,and 438 g L^(-1) d^(-1) space-time yield.展开更多
An investigation of the mangrove-derived fungus Penicillium sp.DM27 led to the isolation of 19 new compounds,including three pairs of piperidinone enantiomers(±)-1,(±)-2,and(±)-3,two pairs of pyrrolidin...An investigation of the mangrove-derived fungus Penicillium sp.DM27 led to the isolation of 19 new compounds,including three pairs of piperidinone enantiomers(±)-1,(±)-2,and(±)-3,two pairs of pyrrolidinone enantiomers(±)-4 and(±)-5,and nine pyrrolidine derivatives 6−14.The structures of 1−14 were elucidated through NMR and HRESIMS analysis,coupled with experimental and calculated ECD spectroscopy and the modified Mosher method.Quantitative real time PCR and Western bolt analyses revealed that 11 blocked EMT in TGF-β1-treated HK-2 cells and suppressed fibroblast activation in TGF-β1-stimulated NIH-3T3 cells.Molecular simulations demonstrated that compound 11 could dock ADAM17,showing a high negative binding affinity.Additionally,the overexpression of ADAM17 by lentiviral infection triggered renal tubular EMT,while compound 11 suppressed this process.Overall,our research suggests that pyrrolidine derivatives may be potential therapeutic agents for the treatment of fibrotic kidney disease.展开更多
An efficient methodology for the stereoselective synthesis of cis-2,5-disubstituted pyrrolidines using copper catalyst was developed. The corresponding cis-2,5-disubstituted pyrrolidines could be obtained in reasonabl...An efficient methodology for the stereoselective synthesis of cis-2,5-disubstituted pyrrolidines using copper catalyst was developed. The corresponding cis-2,5-disubstituted pyrrolidines could be obtained in reasonable yields and with good stereoselectivities in the presence of 4,4＇-di-tert-butyl-2,2＇-bipyridine as ligand and l-methyl-2-pyrrolidinone as solvent.展开更多
The discovery of the novel reactivity of conjugated enynes,mediated by readily available halogenation reagents,opens a broad range of mechanistically unique pathways for the synthesis of highly functionalized chiral a...The discovery of the novel reactivity of conjugated enynes,mediated by readily available halogenation reagents,opens a broad range of mechanistically unique pathways for the synthesis of highly functionalized chiral allene derivatives.Bromoallenyl pyrrolidines can be synthesized via 1,4-addition of sulfonamide nitrogen nucleophiles and halogens to conjugated enynes.This process can lead to simultaneous formation of a highly functionalized axially chiral allene and a stereogenic center under economical and environmentally friendly reaction conditions.展开更多
Asymmetric 1,3-dipolar cycloaddition of methyl a-fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stere...Asymmetric 1,3-dipolar cycloaddition of methyl a-fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stereogenic cen- ters has been achieved with Cu（CH3CN）4BF4/TF-BiphamPhos complexes for the first time. This catalytic system performs well over a broad scope of substrates, providing the synthetically useful adducts in good yields and excel- lent diastereoselectivities and good to high enantioselectivities.展开更多
Four novel [60]fullerene pyrrolidines containing trifluoromethyl （--CF3） group have been synthesized via 1,3-dipolar cycloaddition reaction, which have been characterized by UV-Vis spectroscopy, fourier transform in...Four novel [60]fullerene pyrrolidines containing trifluoromethyl （--CF3） group have been synthesized via 1,3-dipolar cycloaddition reaction, which have been characterized by UV-Vis spectroscopy, fourier transform in- frared spectroscopy, matrix-assisted laser desorption ionization-time of flight mass spectroscopy, and IH, 13C, 19F nuclear magnetic resonance spectrometer （IH NMR, 13C NMR, 19F NMR）. Their optical and electrochemical prop- erties have been studied, and the results show that those fulleropyrrolidines containing --CF3 group have good fluo- rescence and electrochemical properties. Compared with C60, they have negative shifts in varying degrees for half-wave potentials, and may have potential applications for photovoltaic conversion materials since their lowest unoccupied molecular orbital （LUMO） levels are close to that of [6,6]-phenyl-C6：butyric acid methyl ester.展开更多
Two series of stable and soluble fulleropyrrolidines have been prepared from the reactions of C60, glycine or its N-arylated derivatives and aliphatic aldehydes or ketones in refluxing toluene or chlorobenzene. The ne...Two series of stable and soluble fulleropyrrolidines have been prepared from the reactions of C60, glycine or its N-arylated derivatives and aliphatic aldehydes or ketones in refluxing toluene or chlorobenzene. The new C60 derivatives represent new useful building blocks for further preparation of more funcionalized C60 derivatives.展开更多
OBJECTIVE:To evaluate the therapeutic effectiveness of salidroside(Sal)and pyrrolidine dithiocarbamate(PDTC)against severe acute pancreatitis(SAP)in a rat model.METHODS:Rat models of SAP were established by retrograde...OBJECTIVE:To evaluate the therapeutic effectiveness of salidroside(Sal)and pyrrolidine dithiocarbamate(PDTC)against severe acute pancreatitis(SAP)in a rat model.METHODS:Rat models of SAP were established by retrograde infusion of sodium taurocholate solution.SAP rats were randomly divided into 6 groups:SAP 3 h group,SAP 24 h group,low-dose Sal treatment group(Sal L+S),middle-dose Sal treatment group(Sal M+S),high-dose Sal treatment group(Sal H+S)and PDTC treatment group(PDTC+S).The serum amylase,tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and interleukin-10(IL-10)levels were determined by optical turbidimetry and enzyme-linked immunosorbent assay.The expression of Beclin-1,microtubule-associated protein light chain 3Ⅱ(LC3Ⅱ),lysosome associated membrane protein 2(LAMP2),interleukin-1 receptor associated kinase 1(IRAK1),inhibitorαof nuclear transcription factor-κB(IκBα),nuclear transcription factor-κB 65(p65)in the pancreas tissues were detected by quantitative real-time polymerase chain reaction and Western blot,while the pIκBαand p-p65 levels were detected by Western blot.Pathological changes of the pancreas and all the other indexes were observed at 3 and 24 h after operation.RESULTS:The serum IL-10 level,IκBαand LAMP2 levels in Sal M+S,Sal H+S and PDTC+S groups were higher than those in SAP 24 h group,while all the other indexes in these three groups were all lower significantly than those in SAP 24 h group.There was no significant difference in all indexes between Sal H+S and PDTC+S groups.CONCLUSION:High-dose Sal has an effectively therapeutic effect on SAP in rats,which was similar to PDTC.展开更多
AIM:To investigate the pathway(s)mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent,bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction...AIM:To investigate the pathway(s)mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent,bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction. METHODS:Circular smooth muscle strips from the antrum of Sprague-Dawley rats were mounted in muscle baths in Krebs buffer.Isometric tension was recorded.Cumulative concentration-response curves were obtained for(+)-cis- dioxolane(cD),a nonspecific muscarinic agonist,at 10^(-8)- 10^(-4)mol/L,in the presence of tetrodotoxin(TTX,10^(-7)mol/L). Results were normalized to cross sectional area.A repeat concentration-response curve was obtained after incubation of the muscle for 90 min with antagonists for M1(pirenzepine), M2(methoctramine)and M3(darifenadn)muscarinic receptor subtypes.The sensitivity to PTX was tested by the ip injection of 100 mg/kg of PTX 5 d before the experiment.The antral circular smooth muscles were removed from PTX-treated and non-treated rats as strips and dispersed smooth muscle cells to identify whether PTX-linked pathway mediated the contractility to bethanechol. RESULTS:A dose-dependent contractile response observed with bethanechol,was not affected by TTx.The pretreatment of rats with pertussis toxin decreased the contraction induced by bethanechol.Lack of calcium as well as the presence of the L-type calcium channel blocker,nifedipine,also inhibited the cholinergic contraction,with a reduction in response from 2.5±0.4 g/mm^2 to 1.2±0.4 g/mm^2(P<0.05).The dose- response curves were shifted to the right by muscarinic antagonists in the following order of affinity:darifenacin (M_3)>methocramine(M_2)>pirenzepine(M_1). CONCLUSION:The muscarinic receptors-dependent contraction of rat antral circular smooth muscles was linked to the signal transduction pathway(s)involving pertussis-toxin sensitive GTP-binding proteins and to extracellular calcium via L-type voltage gated calcium channels.The presence of the residual contractile response after the treatment with nifedipine,suggests that an additional pathway could mediate the cholinergic contraction.The involvement of more than one muscarinic receptor(functionally predominant type 3 over type 2)also suggests more than one pathway mediating the cholinergic contraction in rat antrum.展开更多
Intramolecular cyclization of N-alkoxyl amines are studied for the stereoselective preparation of 2, 4-disubstituted pyrrolidine derivatives. Reduction of oximes under acidic conditions by NaBH3CN afforded the corres...Intramolecular cyclization of N-alkoxyl amines are studied for the stereoselective preparation of 2, 4-disubstituted pyrrolidine derivatives. Reduction of oximes under acidic conditions by NaBH3CN afforded the corresponding nucleophilic hydroxylamine derivatives, which subsequently cyclized via SN2' mechanism to give the desired N-alkoxyl pyrrolidines.展开更多
（1S、2R、3R、5R、7aR）-1,2-Dihydroxy-3-hydroxy methyl-5-methylpyrrolizidine（hyacinthacine A6, I） was synthesized by Wittig＇s methodology via the reaction of aldehyde 6, prepared from the partially protected deriva...（1S、2R、3R、5R、7aR）-1,2-Dihydroxy-3-hydroxy methyl-5-methylpyrrolizidine（hyacinthacine A6, I） was synthesized by Wittig＇s methodology via the reaction of aldehyde 6, prepared from the partially protected derivative of polyhydroxylated pyrrolidine, with appropriated ylides, followed by cyclization through the intemal reductive amination process of the resulting a,B-unsaturated ketone 7, and total deprotection.展开更多
AIM: To evaluate the effect of pyrrolidine dithio- carbamate (PDTC; an NF-κB inhibitor) administered at low (50 mg/kg) and high (100 mg/kg) doses in suppressing colitis in mice with dextran sodium sulfate (DSS)-induc...AIM: To evaluate the effect of pyrrolidine dithio- carbamate (PDTC; an NF-κB inhibitor) administered at low (50 mg/kg) and high (100 mg/kg) doses in suppressing colitis in mice with dextran sodium sulfate (DSS)-induced colitis. METHODS: Mice were divided into a DSS-untreated group (normal group), DSS-treated control group, DSS+PDTC-treated groupⅠ(low-dose group), and DSS+PDTC-treated groupⅡ (high-dose group). In each group, the disease activity index score (DAI score), intestinal length, histological score, and the levels of activated NF-κB and inflammatory cytokines (IL-1β and TNF-α) in tissue were measured. RESULTS: The DSS+PDTC-treated groupⅡ exhibited suppression of shortening of intestinal length and reduction of DAI score. Activated NF-κB level and IL-1β and TNF-α levels were significantly lower in DSS+PDTC- treated groupⅡ. CONCLUSION: These findings suggest that PDTC is useful for the treatment of ulcerative colitis.展开更多
Objective:To investigate the effects of NF-κB inhibitor pyrrolidine dithiocarbamate hydrochloride(PDTC) on vascular endothelial growth factor(VEGF) and endostatin expression in mice with Lewis lung cance;and its mech...Objective:To investigate the effects of NF-κB inhibitor pyrrolidine dithiocarbamate hydrochloride(PDTC) on vascular endothelial growth factor(VEGF) and endostatin expression in mice with Lewis lung cance;and its mechanism.Methods:Mice survival rate and anti-tumor effects were observed in different concentrations of NF-κB inhibitor PDTC after the Lewis lung cancer mice model was established.VEGF and endostatin expressions were detected by immunohistochemical assay.Results:Lewis lung cancer was be inhibited by 0.5 mg/kg.1.5 mg/kg and 3.0 mg/kg of NF-κB inhibitor PDTC(P<0.05).Microvessel density(MVD) in 0.5 mg/kg.1.5 mg/kg and 3.0 mg/kg NF-κB inhibitor PDTC groups were significantly lower than the control group(P<0.05).Immunohistochemical assay results showed that VEGF and endostatin expressions in the 0.5 mg/kg.1.5 mg/kg and 3.0 mg/kg NF-κB inhibitor PDTC groups were significantly lower than the control group(P<0.05).Western blot results also showed that NF-κB inhibitor PDTC could inhibit VEGF and endostatin expressions in tumor tissues.Conclusions:NF-κB inhibitor PDTC can inhibit tumor formation and reduce tumor angiogenesis in mice with Lewis lung cancer;and its mechanism maybe associated to VEGF and endostatin down-regulation.展开更多
AIM: To explore the changes of nuclear factor-kappa B (NF-κB) DNA-binding activity, the expression of intercellular adhesion molecule-1(ICAM-1) regulated by IMF-κB at various times and to evaluate the effects of pyr...AIM: To explore the changes of nuclear factor-kappa B (NF-κB) DNA-binding activity, the expression of intercellular adhesion molecule-1(ICAM-1) regulated by IMF-κB at various times and to evaluate the effects of pyrrolidine dithiocarbamate (PDTC) on trinitrobenzene sulfonic acid (TNBS)-induced rat colitis. METHODS: TNBS of 0.6 mL was mixed with ethanol of 0.3 mL solution and instilled into the lumen of the rat colon. The rat models were divided into 6 groups, which were killed at 24 h, 3, 7,14, and 21 d after enema. Colonic inflammation and damage were assessed by macroscopical and histological criteria. Activity of NF-κB DNA-binding was analyzed by electrophoresis mobility shift assays (EMSA). Expression of ICAM-1 was detected by in situ hybridization (ISH) and immunohistochemistry (IH). Then various doses of PDTC were injected into rat abdomen 30 min before enema with TNBS/ethanol as pretreatment. The rats were killed 4 h after enema and the colonic inflammation, myeloperoxidase (MPO) activity, malondialdehyde (MDA) level, and DNA-binding activity of NF-κB were assessed. Finally, PDTC was injected intraperitoneally after colitis was induced. Changes of morphology were assayed. RESULTS: During the first week, hyperemia, hemorrhage, edema and ulceration of the colonic mucosa appeared with predominant infiltration of leukocytes. Neutrophils, macrophages, lymphocytes infiltrated in mucosa and submucosa 14 d later. Fibroblasts and granuloma-like structures were also obviously seen. The binding activity of NF-κB began to increase at 24 h time point and reached a peak at 14 d, then decreased but still was higher than control group at 21 d (P<0.01). Levels of ICAM-1 mRNA and protein significantly elevated at 24 h and the peak was at 21 d. Pretreatment with PDTC could attenuate the development of inflammation but not by reducing NF-KB activity. This attenuation of inflammation had a positive relationship with the dose of PDTC. PDTC at the dose of 100 mg/kg had no therapeutic effect after colitis was induced. CONCLUSION: NF-κB activation is an important event that may be involved in acute and chronic inflammation development and may contribute to self-protection against early inflammation damage. NF-κB also regulates ICAM-1 expression during colonic inflammation. Pretreatment of PDTC may attenuate the inflammation development. But PDTC has no therapeutic effect after the colitis is induced.展开更多
Objective:To study the effect of pyrrolidine dithiocarbamate(PDTC) on the anti-tuberculosis drug-induced liver injury and the molecular mechanism. Methods:Clean male SD rats were selected as experimental animals and r...Objective:To study the effect of pyrrolidine dithiocarbamate(PDTC) on the anti-tuberculosis drug-induced liver injury and the molecular mechanism. Methods:Clean male SD rats were selected as experimental animals and randomly divided into normal group,model group,PDTC group and AG490 group. Animal model of anti-tuberculosis drug-induced liver injury was established by intragastric administration isoniazid + rifampicin. PDTC group received intraperitoneal injection of PDTC,and AG490 group received intraperitoneal injection of AG490. Twenty-eight days after intervention,the rats were executed,and the liver injury indexes,inflammation indexes and oxidative stress indexes in serum as well as JAK2/STAT3 expression,liver injury indexes,inflammation indexes and oxidative stress indexes in liver tissue were determined. Results:p-JAK2,p-STAT3,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA expression in liver tissue as well as TBIL,ALT,AST,γ-GT,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA levels in serum of model group were significantly higher than those of normal group while p-JAK2,p-STAT3,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA expression in liver tissu as well as TBIL,ALT,AST,γ-GT,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA levels in serum of PDTC group and AG490 group were significantly lower than those of model group. Conclusions:PDTC can inhibit the inflammation and oxidative stress mediated by JAK2/STAT3 signaling pathway to alleviate the anti-tuberculosis drug-induced liver injury.展开更多
AIM： To evaluate whether pyrrolidine dithiocarbamate （PDTC）, an enhancer of HO production, attenuates intestinal IR injury. METHODS： Eighteen male rats were randomly allocated into three groups： （a） sham; （b）...AIM： To evaluate whether pyrrolidine dithiocarbamate （PDTC）, an enhancer of HO production, attenuates intestinal IR injury. METHODS： Eighteen male rats were randomly allocated into three groups： （a） sham; （b） IR, consisting of 30 min of intestinal ischemia, followed by 2-h period of reperfusion; and （c） PDTC treatment before IR. Intestinal microvascular perfusion （IMP） was monitored continuously by laser Doppler flowmetry. At the end of the reperfusion, serum samples for lactate dehydrogenase （LDH） levels and biopsies of ileum were obtained. HO activity in the ileum was assessed at the end of the reperfusion period. RESULTS： At the end of the reperfusion in the IR group, IMP recovered partially to 42.5% of baseline （P〈0.05 vs sham）, whereas PDTC improved IMP to 67.3% of baseline （P〈0.01 vs IR）. There was a twofold increase in HO activity in PDTC group （2 062.66±106.11） as compared to IR （842.3±85.12） （P〈0.001）. LDH was significantly reduced （P〈0.001） in PDTC group （585.6±102.4） as compared to IR group （1 973.8±306.5）. Histological examination showed that the ileal mucosa was significantly less injured in PDTC group as compared with IR group. CONCLUSION： Our study demonstrates that PDTC improves the IMP and attenuates IR injury of the intestine possibly via HO production. Additional studies are warranted to evaluate the clinical efficacy of PDTC in the prevention of IR injury of the small intestine.展开更多
BACKGROUND: The nuclear translocation of transcription factors may be a critical factor in the intracellular pathway involved in ischemia/reperfusion(I/R) injury. The aim of the study was to evaluate the role of nucle...BACKGROUND: The nuclear translocation of transcription factors may be a critical factor in the intracellular pathway involved in ischemia/reperfusion(I/R) injury. The aim of the study was to evaluate the role of nuclear factor-kappa B (NF-κB) in the pathogenesis of liver injury induced by intestinal ischemia/reperfusion (IIR) and to investigate the effect of pyrrolidine dithiocarbamate (PDTC) on this liver injury. METHODS: Male Wistar rats were divided randomly into three experimental groups (8 rats in each): sham operation group (control group); intestinal/reperfusion group(I/R group): animals received 1-hour of intestinal ischemia and 2-hour reperfusion; and PDTC treatment group (PDTC group): animals that received I/R subject to PDTC treatment (100 mg/kg). The histological changes in the liver and intestine were observed, and the serum levels of tumor necrosis factor-α (TNF-α), alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver superoxide dismutase (SOD), and nitrite/nitrate (NO) were measured. The immunohistochemical expression and Western blot analysis of liver NF-κB and intercellular adhesion molecule-1(ICAM-1) were observed. RESULTS: IIR induced liver injury characterized by the histological changes of liver edema, hemorrhage, polymorphonuclear neutrophil (PMN) infiltration, and elevated serum levels of AST and ALT. The serum TNF-α level was significantly higher than that of the control group(P<0.01) and a high level of liver oxidant product was observed (P<0.01). These changes were parallel to the positive expression of NF-κB and ICAM-1. After the administration of PDTC, the histological changes after liver injury were improved; the levels of SOD and NO in the liver were elevated and reduced, respectively (P<0.01). The expressions of ICAM-1 and NF-κB in the liver were weakened (P<0.01). CONCLUSION: NF-κB plays an important role in the pathogenesis of liver injury induced by HR. PDTC, an agent known to inhibit the activation of NF-κB, can reduce and prevent this injury.展开更多
AIM: To elucidate the mechanism(s) by which S-adenosyl-L-methionine(SAM) decreases hepatitis C virus(HCV) expression.METHODS: We examined the effects of SAM on viral expression using an HCV subgenomic replicon cell cu...AIM: To elucidate the mechanism(s) by which S-adenosyl-L-methionine(SAM) decreases hepatitis C virus(HCV) expression.METHODS: We examined the effects of SAM on viral expression using an HCV subgenomic replicon cell culture system. Huh7 HCV-replicon cells were treated with 1 mmol/L SAM for different times(24-72 h), then total RNA and proteins were isolated. c DNA was synthesized and real time-PCR was achieved to quantify HCV-RNA, superoxide dismutase 1 and 2(SOD-1, SOD-2) catalase, thioredoxin 1, methionine adenosyltransferase 1A and 2A(MAT1A, MAT2A) expression, and GAPDH and RPS18 as endogenous genes. Expression of cellular and viral protein was evaluated by western-blot analysis using antibodies vs HCV-NS5 A, SOD-1, SOD-2, catalase, thioredoxin-1, MAT1 A, MAT2 A, GAPDH and actin. Total glutathione levels were measured at different times by Ellman's recycling method(0-24 h). Reactive oxidative species(ROS) levels were quantified by the dichlorofluorescein assay(0-48 h); Pyrrolidin dithiocarbamate(PDTC) was tested as an antioxidant control and H2O2 as a positive oxidant agent.RESULTS: SAM exposition decreased HCV-RNA levels 50%-70% compared to non-treated controls(24-72 h). SAM induced a synergic antiviral effect with standard IFN treatment but it was independent of IFN signaling. In addition, 1 mmol/L SAM exposition did not modify viral RNA stability, but it needs cellular translation machinery in order to decrease HCV expression. Total glutathione levels increased upon SAM treatment in HCV-replicon cells. Transcriptional antioxidant enzyme expression(SOD-1, SOD-2 and thioredoxin-1) was increased at different times but interestingly, there was no significant change in ROS levels upon SAM treatment, contrary to what was detected with PDTC treatment, where an average 40% reduction was observed in exposed cells. There was a turnover from MAT1A/MAT2 A, since MAT1 A expression was increased(2.5 fold-times at 48 h) and MAT2 A was diminished(from 24 h) upon SAM treatment at both the transcriptional and translational level. CONCLUSION: A likely mechanism(s) by which SAM diminish HCV expression could involve modulating antioxidant enzymes, restoring biosynthesis of glutathione and switching MAT1/MAT2 turnover in HCV expressing cells.展开更多
Objective: To evaluate the antioxidant, immunomodulatory and anti-inflammatory activities of pyrrolidine dithiocarbamate and saxagliptin in rats with thioacetamide-induced ulcerative colitis. Methods: Animals were ora...Objective: To evaluate the antioxidant, immunomodulatory and anti-inflammatory activities of pyrrolidine dithiocarbamate and saxagliptin in rats with thioacetamide-induced ulcerative colitis. Methods: Animals were orally administered with a vehicle, sulfasalazine(500 mg/kg), pyrrolidine dithiocarbamate(100 mg/kg), and saxagliptin(10 mg/kg) for two weeks. Ulcerative colitis was induced by a single intrarectal instillation of thioacetamide on day 8. Colon samples were collected to assess mitogen-activated protein kinase(MAPK), phosphorylated extracellular signal-regulated kinase(ERK), c AMP response element-binding protein(CREB), interleukin-12(IL-12), caspase-3, β-defensin, inducible nitric oxide synthase(i NOS) and glucagon like peptide-1(GLP-1). Moreover, histopathological examination was performed. Results: Rats treated with thioacetamide caused increases in colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin, i NOS, as well as decreases in body weight and GLP-1. In addition, distortion of colonic structure was found by histopathological examination. Pyrrolidine dithiocarbamate and saxagliptin mitigated colitis severity by improving body weight decrease and GLP-1, and reducing colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin and i NOS. Conclusions: Pyrrolidine dithiocarbamate and saxagliptin are efficient against thioacetamide induced colitis through improving inflammatory and oxidative changes.展开更多
Objective： To test whether IL-1 RI/My088-TIR mimic AS-1 can work as a new compound that targeted at blocking MyD88- dependent signaling pathway, we investigated the physical structure and biological function of AS-1....Objective： To test whether IL-1 RI/My088-TIR mimic AS-1 can work as a new compound that targeted at blocking MyD88- dependent signaling pathway, we investigated the physical structure and biological function of AS-1. Methods：The crystallographic structure of AS-1 was examined by 1^H nuclear magnetic resonance. The toxicity of AS-1 was measured with Methyl thiazolyl tetrazolium （MTT） assay. The effect of AS-1 on phosphorylation state of p38 MAPK and IRAK-1 was observed with Western blot. Results：The crystallographic details of AS-1 demonstrated that it was a tri-peptide sequence[（F/Y）-（V/L/I）-（P/G）] of the IL-1R I -TIR domain BBloop. No toxicity of AS-1 was shown to HEK 293A cells. The phosphorylation of p38 MAPK, induced by IL-1β significantly increased from those in the control group. AS-1 significantly reduced the phosphorylation of p38 MAPK induced by IL-1β. IL-1β increased the phosphorylation of IRAK-1 significantly, which was prevented by AS-1. Conclusion：AS-1 is a competitive mimic between IL-1R I-TIR and MyD88-TIR domain, which most likely interferes with MyD88-dependent signaling pathway.展开更多
文摘Imine reductases(IREDs)have been extensively used for the imine reduction and reductive amination to access various amines.However,poor activity and severe substrate/product inhibition limit their widespread application in industry.Herein,an engineered IRED from Streptomyces viridochromogenes was developed through four rounds of directed evolution.The engineered SvIRED displayed a significant increase in specific activity to 136.8 U mg^(-1),the highest reported for an IRED to date.Molecular dynamics simulations elucidated the surge in specific activity during mutations.The best mutant can also catalyse the reductive coupling of aldehyde homologs and primary amines with up to 66.9 U mg^(-1).Additionally,we established an in-situ product adsorption system using resin,which significantly alleviated substrate/product inhibition and enhanced substrate loading to 100 g L^(-1).Under optimal conditions,a wide range of chiral 2-aryl-pyrrolidines were successfully produced at high substrate loadings(50-100 g L^(-1))with enantiomeric excess over 99%.The usefulness of this biocatalytic system was further demonstrated by preparation of pharmaceutically relevant chiral 2-aryl pyrrolidines,particularly the decagram-scale synthesis of the key chiral aticaprant intermediate with 90%isolated yield,>99%ee,and 438 g L^(-1) d^(-1) space-time yield.
基金supported by the National Key Research and Development Program of China(No.2021YFC2100600),the National Natural Science Foundation of China(Nos.81973201,82200773,82370696,82204225,82200807),the Natural Science Foundation of Hubei Province(Nos.2021CFB347,2021CFB061),the Fundamental Research Funds for Central University(2042022kf1140),the Program of Excellent Doctoral(Postdoctoral)of Zhongnan Hospital of Wuhan University(ZNYB2021029),the Hubei Province Health and Family Planning Scientific Research Project(WJ2019MB103),the Clinical Research Project for Wu Jieping Medical Foundation(320.6750.19089-58),and the Research Fund from Medical Sci-Tech Innovation Platform of Zhongnan Hospital,Wuhan University(PTXM2020028,XKJS202035).We thank Dr.Ran Zhang from the Core Facility of Wuhan University and Dr.Xue Zhou from the Core Research Facilities of CCMS(WHU)for their assistance with NMR analysis.
文摘An investigation of the mangrove-derived fungus Penicillium sp.DM27 led to the isolation of 19 new compounds,including three pairs of piperidinone enantiomers(±)-1,(±)-2,and(±)-3,two pairs of pyrrolidinone enantiomers(±)-4 and(±)-5,and nine pyrrolidine derivatives 6−14.The structures of 1−14 were elucidated through NMR and HRESIMS analysis,coupled with experimental and calculated ECD spectroscopy and the modified Mosher method.Quantitative real time PCR and Western bolt analyses revealed that 11 blocked EMT in TGF-β1-treated HK-2 cells and suppressed fibroblast activation in TGF-β1-stimulated NIH-3T3 cells.Molecular simulations demonstrated that compound 11 could dock ADAM17,showing a high negative binding affinity.Additionally,the overexpression of ADAM17 by lentiviral infection triggered renal tubular EMT,while compound 11 suppressed this process.Overall,our research suggests that pyrrolidine derivatives may be potential therapeutic agents for the treatment of fibrotic kidney disease.
基金We gratefully acknowledge the funding support of the State Key Program of National Natural Science Foundation of China （No. 21432009） and the National Natural Science Foundation of China （No. 21372210）. The authors are grateful to Miss Jun Kee Cheng for her careful proofreading of the final manuscript.
文摘An efficient methodology for the stereoselective synthesis of cis-2,5-disubstituted pyrrolidines using copper catalyst was developed. The corresponding cis-2,5-disubstituted pyrrolidines could be obtained in reasonable yields and with good stereoselectivities in the presence of 4,4＇-di-tert-butyl-2,2＇-bipyridine as ligand and l-methyl-2-pyrrolidinone as solvent.
基金the University of Wisconsin-Madison and the American Chemical Society Petroleum Research Fund (48092-G) for funding
文摘The discovery of the novel reactivity of conjugated enynes,mediated by readily available halogenation reagents,opens a broad range of mechanistically unique pathways for the synthesis of highly functionalized chiral allene derivatives.Bromoallenyl pyrrolidines can be synthesized via 1,4-addition of sulfonamide nitrogen nucleophiles and halogens to conjugated enynes.This process can lead to simultaneous formation of a highly functionalized axially chiral allene and a stereogenic center under economical and environmentally friendly reaction conditions.
文摘Asymmetric 1,3-dipolar cycloaddition of methyl a-fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stereogenic cen- ters has been achieved with Cu（CH3CN）4BF4/TF-BiphamPhos complexes for the first time. This catalytic system performs well over a broad scope of substrates, providing the synthetically useful adducts in good yields and excel- lent diastereoselectivities and good to high enantioselectivities.
文摘Four novel [60]fullerene pyrrolidines containing trifluoromethyl （--CF3） group have been synthesized via 1,3-dipolar cycloaddition reaction, which have been characterized by UV-Vis spectroscopy, fourier transform in- frared spectroscopy, matrix-assisted laser desorption ionization-time of flight mass spectroscopy, and IH, 13C, 19F nuclear magnetic resonance spectrometer （IH NMR, 13C NMR, 19F NMR）. Their optical and electrochemical prop- erties have been studied, and the results show that those fulleropyrrolidines containing --CF3 group have good fluo- rescence and electrochemical properties. Compared with C60, they have negative shifts in varying degrees for half-wave potentials, and may have potential applications for photovoltaic conversion materials since their lowest unoccupied molecular orbital （LUMO） levels are close to that of [6,6]-phenyl-C6：butyric acid methyl ester.
文摘Two series of stable and soluble fulleropyrrolidines have been prepared from the reactions of C60, glycine or its N-arylated derivatives and aliphatic aldehydes or ketones in refluxing toluene or chlorobenzene. The new C60 derivatives represent new useful building blocks for further preparation of more funcionalized C60 derivatives.
基金Supported by the Traditional Chinese Medicine Technology Development Plan Project of Jiangsu Province in 2020:Basic and Clinical Study on Salidroside in the Adjuvant Treatment of Severe Acute Pancreatitis(No.YB2020088)the Health Innovation Project of Lvyang Jinfeng Plan of Yangzhou City in 2020:Basic and Clinical Study on Salidroside in the Adjuvant Treatment of Severe Acute Pancreatitis(No.LJ202037)。
文摘OBJECTIVE:To evaluate the therapeutic effectiveness of salidroside(Sal)and pyrrolidine dithiocarbamate(PDTC)against severe acute pancreatitis(SAP)in a rat model.METHODS:Rat models of SAP were established by retrograde infusion of sodium taurocholate solution.SAP rats were randomly divided into 6 groups:SAP 3 h group,SAP 24 h group,low-dose Sal treatment group(Sal L+S),middle-dose Sal treatment group(Sal M+S),high-dose Sal treatment group(Sal H+S)and PDTC treatment group(PDTC+S).The serum amylase,tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and interleukin-10(IL-10)levels were determined by optical turbidimetry and enzyme-linked immunosorbent assay.The expression of Beclin-1,microtubule-associated protein light chain 3Ⅱ(LC3Ⅱ),lysosome associated membrane protein 2(LAMP2),interleukin-1 receptor associated kinase 1(IRAK1),inhibitorαof nuclear transcription factor-κB(IκBα),nuclear transcription factor-κB 65(p65)in the pancreas tissues were detected by quantitative real-time polymerase chain reaction and Western blot,while the pIκBαand p-p65 levels were detected by Western blot.Pathological changes of the pancreas and all the other indexes were observed at 3 and 24 h after operation.RESULTS:The serum IL-10 level,IκBαand LAMP2 levels in Sal M+S,Sal H+S and PDTC+S groups were higher than those in SAP 24 h group,while all the other indexes in these three groups were all lower significantly than those in SAP 24 h group.There was no significant difference in all indexes between Sal H+S and PDTC+S groups.CONCLUSION:High-dose Sal has an effectively therapeutic effect on SAP in rats,which was similar to PDTC.
文摘AIM:To investigate the pathway(s)mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent,bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction. METHODS:Circular smooth muscle strips from the antrum of Sprague-Dawley rats were mounted in muscle baths in Krebs buffer.Isometric tension was recorded.Cumulative concentration-response curves were obtained for(+)-cis- dioxolane(cD),a nonspecific muscarinic agonist,at 10^(-8)- 10^(-4)mol/L,in the presence of tetrodotoxin(TTX,10^(-7)mol/L). Results were normalized to cross sectional area.A repeat concentration-response curve was obtained after incubation of the muscle for 90 min with antagonists for M1(pirenzepine), M2(methoctramine)and M3(darifenadn)muscarinic receptor subtypes.The sensitivity to PTX was tested by the ip injection of 100 mg/kg of PTX 5 d before the experiment.The antral circular smooth muscles were removed from PTX-treated and non-treated rats as strips and dispersed smooth muscle cells to identify whether PTX-linked pathway mediated the contractility to bethanechol. RESULTS:A dose-dependent contractile response observed with bethanechol,was not affected by TTx.The pretreatment of rats with pertussis toxin decreased the contraction induced by bethanechol.Lack of calcium as well as the presence of the L-type calcium channel blocker,nifedipine,also inhibited the cholinergic contraction,with a reduction in response from 2.5±0.4 g/mm^2 to 1.2±0.4 g/mm^2(P<0.05).The dose- response curves were shifted to the right by muscarinic antagonists in the following order of affinity:darifenacin (M_3)>methocramine(M_2)>pirenzepine(M_1). CONCLUSION:The muscarinic receptors-dependent contraction of rat antral circular smooth muscles was linked to the signal transduction pathway(s)involving pertussis-toxin sensitive GTP-binding proteins and to extracellular calcium via L-type voltage gated calcium channels.The presence of the residual contractile response after the treatment with nifedipine,suggests that an additional pathway could mediate the cholinergic contraction.The involvement of more than one muscarinic receptor(functionally predominant type 3 over type 2)also suggests more than one pathway mediating the cholinergic contraction in rat antrum.
文摘Intramolecular cyclization of N-alkoxyl amines are studied for the stereoselective preparation of 2, 4-disubstituted pyrrolidine derivatives. Reduction of oximes under acidic conditions by NaBH3CN afforded the corresponding nucleophilic hydroxylamine derivatives, which subsequently cyclized via SN2' mechanism to give the desired N-alkoxyl pyrrolidines.
基金the National Basic Research Program(973 Program)of China(No.2007CB108903)the National Natural Science Foundation of China(No.20621091)
文摘（1S、2R、3R、5R、7aR）-1,2-Dihydroxy-3-hydroxy methyl-5-methylpyrrolizidine（hyacinthacine A6, I） was synthesized by Wittig＇s methodology via the reaction of aldehyde 6, prepared from the partially protected derivative of polyhydroxylated pyrrolidine, with appropriated ylides, followed by cyclization through the intemal reductive amination process of the resulting a,B-unsaturated ketone 7, and total deprotection.
文摘AIM: To evaluate the effect of pyrrolidine dithio- carbamate (PDTC; an NF-κB inhibitor) administered at low (50 mg/kg) and high (100 mg/kg) doses in suppressing colitis in mice with dextran sodium sulfate (DSS)-induced colitis. METHODS: Mice were divided into a DSS-untreated group (normal group), DSS-treated control group, DSS+PDTC-treated groupⅠ(low-dose group), and DSS+PDTC-treated groupⅡ (high-dose group). In each group, the disease activity index score (DAI score), intestinal length, histological score, and the levels of activated NF-κB and inflammatory cytokines (IL-1β and TNF-α) in tissue were measured. RESULTS: The DSS+PDTC-treated groupⅡ exhibited suppression of shortening of intestinal length and reduction of DAI score. Activated NF-κB level and IL-1β and TNF-α levels were significantly lower in DSS+PDTC- treated groupⅡ. CONCLUSION: These findings suggest that PDTC is useful for the treatment of ulcerative colitis.
基金supported by Natural Science Fund Project of Liaoning Province.No.:201102050
文摘Objective:To investigate the effects of NF-κB inhibitor pyrrolidine dithiocarbamate hydrochloride(PDTC) on vascular endothelial growth factor(VEGF) and endostatin expression in mice with Lewis lung cance;and its mechanism.Methods:Mice survival rate and anti-tumor effects were observed in different concentrations of NF-κB inhibitor PDTC after the Lewis lung cancer mice model was established.VEGF and endostatin expressions were detected by immunohistochemical assay.Results:Lewis lung cancer was be inhibited by 0.5 mg/kg.1.5 mg/kg and 3.0 mg/kg of NF-κB inhibitor PDTC(P<0.05).Microvessel density(MVD) in 0.5 mg/kg.1.5 mg/kg and 3.0 mg/kg NF-κB inhibitor PDTC groups were significantly lower than the control group(P<0.05).Immunohistochemical assay results showed that VEGF and endostatin expressions in the 0.5 mg/kg.1.5 mg/kg and 3.0 mg/kg NF-κB inhibitor PDTC groups were significantly lower than the control group(P<0.05).Western blot results also showed that NF-κB inhibitor PDTC could inhibit VEGF and endostatin expressions in tumor tissues.Conclusions:NF-κB inhibitor PDTC can inhibit tumor formation and reduce tumor angiogenesis in mice with Lewis lung cancer;and its mechanism maybe associated to VEGF and endostatin down-regulation.
基金Supported by a Grant From Health Department Foundation of Guangdong Province, No. A2003554
文摘AIM: To explore the changes of nuclear factor-kappa B (NF-κB) DNA-binding activity, the expression of intercellular adhesion molecule-1(ICAM-1) regulated by IMF-κB at various times and to evaluate the effects of pyrrolidine dithiocarbamate (PDTC) on trinitrobenzene sulfonic acid (TNBS)-induced rat colitis. METHODS: TNBS of 0.6 mL was mixed with ethanol of 0.3 mL solution and instilled into the lumen of the rat colon. The rat models were divided into 6 groups, which were killed at 24 h, 3, 7,14, and 21 d after enema. Colonic inflammation and damage were assessed by macroscopical and histological criteria. Activity of NF-κB DNA-binding was analyzed by electrophoresis mobility shift assays (EMSA). Expression of ICAM-1 was detected by in situ hybridization (ISH) and immunohistochemistry (IH). Then various doses of PDTC were injected into rat abdomen 30 min before enema with TNBS/ethanol as pretreatment. The rats were killed 4 h after enema and the colonic inflammation, myeloperoxidase (MPO) activity, malondialdehyde (MDA) level, and DNA-binding activity of NF-κB were assessed. Finally, PDTC was injected intraperitoneally after colitis was induced. Changes of morphology were assayed. RESULTS: During the first week, hyperemia, hemorrhage, edema and ulceration of the colonic mucosa appeared with predominant infiltration of leukocytes. Neutrophils, macrophages, lymphocytes infiltrated in mucosa and submucosa 14 d later. Fibroblasts and granuloma-like structures were also obviously seen. The binding activity of NF-κB began to increase at 24 h time point and reached a peak at 14 d, then decreased but still was higher than control group at 21 d (P<0.01). Levels of ICAM-1 mRNA and protein significantly elevated at 24 h and the peak was at 21 d. Pretreatment with PDTC could attenuate the development of inflammation but not by reducing NF-KB activity. This attenuation of inflammation had a positive relationship with the dose of PDTC. PDTC at the dose of 100 mg/kg had no therapeutic effect after colitis was induced. CONCLUSION: NF-κB activation is an important event that may be involved in acute and chronic inflammation development and may contribute to self-protection against early inflammation damage. NF-κB also regulates ICAM-1 expression during colonic inflammation. Pretreatment of PDTC may attenuate the inflammation development. But PDTC has no therapeutic effect after the colitis is induced.
基金supported by Surface Project of Shandong Provincial Natural Science Foundation(No.ZR2014HM081)
文摘Objective:To study the effect of pyrrolidine dithiocarbamate(PDTC) on the anti-tuberculosis drug-induced liver injury and the molecular mechanism. Methods:Clean male SD rats were selected as experimental animals and randomly divided into normal group,model group,PDTC group and AG490 group. Animal model of anti-tuberculosis drug-induced liver injury was established by intragastric administration isoniazid + rifampicin. PDTC group received intraperitoneal injection of PDTC,and AG490 group received intraperitoneal injection of AG490. Twenty-eight days after intervention,the rats were executed,and the liver injury indexes,inflammation indexes and oxidative stress indexes in serum as well as JAK2/STAT3 expression,liver injury indexes,inflammation indexes and oxidative stress indexes in liver tissue were determined. Results:p-JAK2,p-STAT3,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA expression in liver tissue as well as TBIL,ALT,AST,γ-GT,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA levels in serum of model group were significantly higher than those of normal group while p-JAK2,p-STAT3,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA expression in liver tissu as well as TBIL,ALT,AST,γ-GT,TNF-α,IL-1β,IL-6,ROS,8-OHdG and MDA levels in serum of PDTC group and AG490 group were significantly lower than those of model group. Conclusions:PDTC can inhibit the inflammation and oxidative stress mediated by JAK2/STAT3 signaling pathway to alleviate the anti-tuberculosis drug-induced liver injury.
文摘AIM： To evaluate whether pyrrolidine dithiocarbamate （PDTC）, an enhancer of HO production, attenuates intestinal IR injury. METHODS： Eighteen male rats were randomly allocated into three groups： （a） sham; （b） IR, consisting of 30 min of intestinal ischemia, followed by 2-h period of reperfusion; and （c） PDTC treatment before IR. Intestinal microvascular perfusion （IMP） was monitored continuously by laser Doppler flowmetry. At the end of the reperfusion, serum samples for lactate dehydrogenase （LDH） levels and biopsies of ileum were obtained. HO activity in the ileum was assessed at the end of the reperfusion period. RESULTS： At the end of the reperfusion in the IR group, IMP recovered partially to 42.5% of baseline （P〈0.05 vs sham）, whereas PDTC improved IMP to 67.3% of baseline （P〈0.01 vs IR）. There was a twofold increase in HO activity in PDTC group （2 062.66±106.11） as compared to IR （842.3±85.12） （P〈0.001）. LDH was significantly reduced （P〈0.001） in PDTC group （585.6±102.4） as compared to IR group （1 973.8±306.5）. Histological examination showed that the ileal mucosa was significantly less injured in PDTC group as compared with IR group. CONCLUSION： Our study demonstrates that PDTC improves the IMP and attenuates IR injury of the intestine possibly via HO production. Additional studies are warranted to evaluate the clinical efficacy of PDTC in the prevention of IR injury of the small intestine.
文摘BACKGROUND: The nuclear translocation of transcription factors may be a critical factor in the intracellular pathway involved in ischemia/reperfusion(I/R) injury. The aim of the study was to evaluate the role of nuclear factor-kappa B (NF-κB) in the pathogenesis of liver injury induced by intestinal ischemia/reperfusion (IIR) and to investigate the effect of pyrrolidine dithiocarbamate (PDTC) on this liver injury. METHODS: Male Wistar rats were divided randomly into three experimental groups (8 rats in each): sham operation group (control group); intestinal/reperfusion group(I/R group): animals received 1-hour of intestinal ischemia and 2-hour reperfusion; and PDTC treatment group (PDTC group): animals that received I/R subject to PDTC treatment (100 mg/kg). The histological changes in the liver and intestine were observed, and the serum levels of tumor necrosis factor-α (TNF-α), alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver superoxide dismutase (SOD), and nitrite/nitrate (NO) were measured. The immunohistochemical expression and Western blot analysis of liver NF-κB and intercellular adhesion molecule-1(ICAM-1) were observed. RESULTS: IIR induced liver injury characterized by the histological changes of liver edema, hemorrhage, polymorphonuclear neutrophil (PMN) infiltration, and elevated serum levels of AST and ALT. The serum TNF-α level was significantly higher than that of the control group(P<0.01) and a high level of liver oxidant product was observed (P<0.01). These changes were parallel to the positive expression of NF-κB and ICAM-1. After the administration of PDTC, the histological changes after liver injury were improved; the levels of SOD and NO in the liver were elevated and reduced, respectively (P<0.01). The expressions of ICAM-1 and NF-κB in the liver were weakened (P<0.01). CONCLUSION: NF-κB plays an important role in the pathogenesis of liver injury induced by HR. PDTC, an agent known to inhibit the activation of NF-κB, can reduce and prevent this injury.
基金Supported by CONACYT-Mexico,grant register CB2010-01-155082 to Rivas-Estilla AM
文摘AIM: To elucidate the mechanism(s) by which S-adenosyl-L-methionine(SAM) decreases hepatitis C virus(HCV) expression.METHODS: We examined the effects of SAM on viral expression using an HCV subgenomic replicon cell culture system. Huh7 HCV-replicon cells were treated with 1 mmol/L SAM for different times(24-72 h), then total RNA and proteins were isolated. c DNA was synthesized and real time-PCR was achieved to quantify HCV-RNA, superoxide dismutase 1 and 2(SOD-1, SOD-2) catalase, thioredoxin 1, methionine adenosyltransferase 1A and 2A(MAT1A, MAT2A) expression, and GAPDH and RPS18 as endogenous genes. Expression of cellular and viral protein was evaluated by western-blot analysis using antibodies vs HCV-NS5 A, SOD-1, SOD-2, catalase, thioredoxin-1, MAT1 A, MAT2 A, GAPDH and actin. Total glutathione levels were measured at different times by Ellman's recycling method(0-24 h). Reactive oxidative species(ROS) levels were quantified by the dichlorofluorescein assay(0-48 h); Pyrrolidin dithiocarbamate(PDTC) was tested as an antioxidant control and H2O2 as a positive oxidant agent.RESULTS: SAM exposition decreased HCV-RNA levels 50%-70% compared to non-treated controls(24-72 h). SAM induced a synergic antiviral effect with standard IFN treatment but it was independent of IFN signaling. In addition, 1 mmol/L SAM exposition did not modify viral RNA stability, but it needs cellular translation machinery in order to decrease HCV expression. Total glutathione levels increased upon SAM treatment in HCV-replicon cells. Transcriptional antioxidant enzyme expression(SOD-1, SOD-2 and thioredoxin-1) was increased at different times but interestingly, there was no significant change in ROS levels upon SAM treatment, contrary to what was detected with PDTC treatment, where an average 40% reduction was observed in exposed cells. There was a turnover from MAT1A/MAT2 A, since MAT1 A expression was increased(2.5 fold-times at 48 h) and MAT2 A was diminished(from 24 h) upon SAM treatment at both the transcriptional and translational level. CONCLUSION: A likely mechanism(s) by which SAM diminish HCV expression could involve modulating antioxidant enzymes, restoring biosynthesis of glutathione and switching MAT1/MAT2 turnover in HCV expressing cells.
文摘Objective: To evaluate the antioxidant, immunomodulatory and anti-inflammatory activities of pyrrolidine dithiocarbamate and saxagliptin in rats with thioacetamide-induced ulcerative colitis. Methods: Animals were orally administered with a vehicle, sulfasalazine(500 mg/kg), pyrrolidine dithiocarbamate(100 mg/kg), and saxagliptin(10 mg/kg) for two weeks. Ulcerative colitis was induced by a single intrarectal instillation of thioacetamide on day 8. Colon samples were collected to assess mitogen-activated protein kinase(MAPK), phosphorylated extracellular signal-regulated kinase(ERK), c AMP response element-binding protein(CREB), interleukin-12(IL-12), caspase-3, β-defensin, inducible nitric oxide synthase(i NOS) and glucagon like peptide-1(GLP-1). Moreover, histopathological examination was performed. Results: Rats treated with thioacetamide caused increases in colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin, i NOS, as well as decreases in body weight and GLP-1. In addition, distortion of colonic structure was found by histopathological examination. Pyrrolidine dithiocarbamate and saxagliptin mitigated colitis severity by improving body weight decrease and GLP-1, and reducing colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin and i NOS. Conclusions: Pyrrolidine dithiocarbamate and saxagliptin are efficient against thioacetamide induced colitis through improving inflammatory and oxidative changes.
基金This study was supported by the National Natural Science Foundation of China(No.30571842)
文摘Objective： To test whether IL-1 RI/My088-TIR mimic AS-1 can work as a new compound that targeted at blocking MyD88- dependent signaling pathway, we investigated the physical structure and biological function of AS-1. Methods：The crystallographic structure of AS-1 was examined by 1^H nuclear magnetic resonance. The toxicity of AS-1 was measured with Methyl thiazolyl tetrazolium （MTT） assay. The effect of AS-1 on phosphorylation state of p38 MAPK and IRAK-1 was observed with Western blot. Results：The crystallographic details of AS-1 demonstrated that it was a tri-peptide sequence[（F/Y）-（V/L/I）-（P/G）] of the IL-1R I -TIR domain BBloop. No toxicity of AS-1 was shown to HEK 293A cells. The phosphorylation of p38 MAPK, induced by IL-1β significantly increased from those in the control group. AS-1 significantly reduced the phosphorylation of p38 MAPK induced by IL-1β. IL-1β increased the phosphorylation of IRAK-1 significantly, which was prevented by AS-1. Conclusion：AS-1 is a competitive mimic between IL-1R I-TIR and MyD88-TIR domain, which most likely interferes with MyD88-dependent signaling pathway.
