Regulation of Insulin Secretion and Expression of SUR1 Gene by Chronic Exposure to Free Fatty Acids in Rat Pancreatic β Cells

Insulinresistanceandimpairedinsulinsecretionarethetwomainpathophysicologicalfeaturesoftype2diabetes .Continuinglossofβ cellfunctionistheunderlyingcauseofdeterioratingmetaboliccontrolinpatientswithtype 2diabetes .Fattyacidscouldplayaroleinthereductionofβ…     

祛湿化瘀方对非酒精性脂肪性肝炎大鼠组织蛋白酶B和肿瘤坏死因子α表达的影响

目的：研究祛湿化瘀方防治大鼠非酒精性脂肪肝的作用机制。方法：除正常对照组5只外,Wistar雄性大鼠30只运用四氯化碳（carbon tetrachloride,CCl4）皮下注射联合高脂低蛋白饮食建立非酒精性脂肪肝模型。自造模2周后,随机分为模型组、祛湿化瘀方组和甘乐（复方二氯醋酸二异丙胺）组,每组10只,分别予祛湿化瘀方和甘乐10ml／kg灌胃。用药2周后取材,检测血清丙氨酸氨基转移酶（alanine aminotransferase,ALT）活性和肿瘤坏死因子Q（tumor necrosis factor—α,TNF—α）含量、肝组织甘油三酯（triglyceride,TG）和游离脂肪酸（free fatty acid,FFA）含量;并分析其指标间的相关性。蛋白印迹法检测肝组织组织蛋白酶B（cathepsin B,Ctsb）、磷酸化kB抑制蛋白（phospho-inhibitor kappa B,P—IkB）和TNF—α蛋白表达。免疫组织化学染色检测肝组织中Ctsb表达。结果：祛湿化瘀方可显著降低模型大鼠肝组织TG（P〈0．05）、FFA（P〈0．01）含量和血清ALT活性（P〈0．05）,而对照药物甘乐只显示有降低ALT活性（P〈0．05）作用;模型组肝组织Ctsb、p-IKB、TNF-α蛋白表达均高于正常对照组,同时血清TNF-α水平显著上升;而祛湿化瘀方组的上述蛋白表达则低于模型组。肝组织TG与FFA含量、血清ALT活性呈正相关;血清TNF-α与肝组织FFA含量、血清ALT活性呈正相关。结论：祛湿化瘀方抑制肝脏脂肪沉积和炎症作用可能与其抑制FFA以减轻其下游“FFA—Ctsb—TNF—α”肝脂毒性通路有关。     

祛湿化瘀方对非酒精性脂肪性肝炎大鼠组织蛋白酶B和肿瘤坏死因子α表达的影响

目的：研究祛湿化瘀方防治大鼠非酒精性脂肪肝的作用机制。方法：除正常对照组5只外，Wistar雄性大鼠30只运用四氯化碳（carbon tetrachloride，CCl4）皮下注射联合高脂低蛋白饮食建立非酒精性脂肪肝模型。自造模2周后，随机分为模型组、祛湿化瘀方组和甘乐（复方二氯醋酸二异丙胺）组，每组10只，分别予祛湿化瘀方和甘乐10ml／kg灌胃。用药2周后取材，检测血清丙氨酸氨基转移酶（alanine aminotransferase，ALT）活性和肿瘤坏死因子Q（tumor necrosis factor—α，TNF—α）含量、肝组织甘油三酯（triglyceride，TG）和游离脂肪酸（free fatty acid，FFA）含量；并分析其指标间的相关性。蛋白印迹法检测肝组织组织蛋白酶B（cathepsin B，Ctsb）、磷酸化kB抑制蛋白（phospho-inhibitor kappa B，P—IkB）和TNF—α蛋白表达。免疫组织化学染色检测肝组织中Ctsb表达。结果：祛湿化瘀方可显著降低模型大鼠肝组织TG（P〈0．05）、FFA（P〈0．01）含量和血清ALT活性（P〈0．05），而对照药物甘乐只显示有降低ALT活性（P〈0．05）作用；模型组肝组织Ctsb、p-IKB、TNF-α蛋白表达均高于正常对照组，同时血清TNF-α水平显著上升；而祛湿化瘀方组的上述蛋白表达则低于模型组。肝组织TG与FFA含量、血清ALT活性呈正相关；血清TNF-α与肝组织FFA含量、血清ALT活性呈正相关。结论：祛湿化瘀方抑制肝脏脂肪沉积和炎症作用可能与其抑制FFA以减轻其下游“FFA—Ctsb—TNF—α”肝脂毒性通路有关。     

The Role of IκBα in TNF-α-induced Apoptosis in Hepatic Stellate Cell Line HSC-T6

To investigate the role of NF-κB in TNF-α induced apoptosis in HSC-T6, a mutant IκBα was transfected into HSC-T6 cells by lipofectin transfection technique and its transient effect was examined 48 h after the transfection. The activation of NF-κB was detected by immune fluorescence cytochemistry and Western blotting with anti-p65 antibody. The apoptosis and the rate of inhibition by TNF-α in both transfected and untransfected HSC-T6 cells were measured respectively by FAC-Scan side scatter analysis and MTF methods. Our results showed that TNF-α could activate NF-κB in untransfected cells but not in transfected HSC-T6 cells. The percentage of apoptosis in transfected cells were significantly higher than that in the untransfected ones （P〈0.01） and it was also true of the inhibition rate （P〈0.01）. It is concluded that the resistance of HSC-T6 towards apoptosis induced by TNF-α can be mediated by NF-κB activation. The inhibition of NF-κB activation by mutant IκBα can attenuate the resistance of HSC-T6 cells and increase its sensitivity to TNF-α.     

The Effects of HBx Gene on the Expression of DNA Repair Enzymes hOGG1 and hMYHα mRNA in HepG2 Cells

To observe the alteration in the expression of DNA repair enzymes hOGG1 and hMYHa and the change in 8-OHdG levels in the HBx gene-transfected cells HepG2/HBx and to explore the mechanisms of the HBV-associated hepatocellular carcinoma, the gene-transfected cells HepG2/HBx which stably expressed HBx was established, and the effect of HBx on the cell cycle and proliferation of HepG2 was examined. By using the β-actin as the interior control, real-time polymerase chain reaction （Real-time qPCR） was employed to quantitatively detect the expression of DNA repair enzymes hOGG1 and hMYHα in the HepG2/HBx, the control cells HepG2 and HepG2 transfected with pcDNA3.1 vector （HepG2/pDNA3.1）. The 8-OHdG levels were determined by HPLC/ECD in the established gene-transfected cells HepG2/HBx and the control cells HepG2 and HepG2/pcDNA3.1. Our results showed that the expression of DNA repair enzyme hMYHα in the HepG2/HBx （0.021±0.007） was significantly lower than that of HepG2 （0.099±0.041） （P〈0.05） and HepG2/pDNA3.1 （0.121±0.005） （P〈0.05）. However, the no significant differences existed in the expression of DNA repair enzyme hOGG1 among the three cell strains （P〉0.05）. The 8-OHdG level in the HepG2/HBx was significantly higher than that in HepG2 and HepG2/pcDNA3.1 （P〈0.05）. It is concluded that HBx gene may inhibit the expression of DNA repair enzyme hMYHα mRNA to impair the ability to repair the intracellular DNA oxidative damage, to increase the oxidative DNA-adduct 8-OHdG and to affect the nucleotide excision repair function, thus participate in the occurrence and development of hepatocellular carcinoma.     

Fuzheng Huayu Formula (扶正化瘀方) Prevents Rat Renal Interstitial Fibrosis Induced by HgCl2 via Antioxidative Stress and Down-regulation of Nuclear Factor-Kappa B Activity

Objective: To investigate the mechanism of action of Fuzheng Huayu Formula (扶正化瘀方, FZHY) against renal interstitial fibrosis (RIF) relating to oxidative injury and nuclear factor-kappa B (NF-κB) activity. Methods: Thirty-two Sprague-Dawley rats were randomly divided into 3 groups: normal group, model group and FZHY treatment group. The RIF model was induced by oral administration of HgCl2 at a dose of 8 mg/kg body weight once a day for 9 weeks. Meanwhile, rats in FZHY treatment group orally took FZHY at a dose of 4.0 g/kg rat weight for 9 weeks. The content of hydroxyproline (Hyp) and collagen deposition in kidney were observed. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the content of glutathione (GSH) and malondialdehyde (MDA) of kidney were tested. The expressions of inhibitor-κappa B (IκB), phospho-IκB (p-IκB), tumor necrosis factor-α (TNF-α), matrix metalloproteinase-2 (MMP-2) and α-smooth muscle actin (α-SMA) were analyzed by Western blot. α-SMA expression was also observed by immunofluorescent staining. MMP-2 activity was measured by gelatin zymography. NF-κB activation was determined by electrophoretic mobility shift assay. Results: Renal interstitial fibrosis was induced by HgCl2, demonstrated by remarkably increased Hyp contents and excessive collagen deposition in kidney (P<0.01). FZHY significantly inhibited renal interstitial collagen deposition and reduced Hyp content of the HgCl2-treated rats (P<0.01). GSH content decreased obviously, and MDA content increased significantly in HgCl2-treated rats compared with that of normal rats (P<0.01). FZHY significantly increased GSH content and decreased MDA content in the model rats (P<0.01). The expression α-SMA was increased in model rats compared with that of normal rats, FZHY significantly decreased its expression (P<0.01). The expressions of p-IκB and TNF-α and MMP-2, MMP-2 activity, and NF-κB activation were increased in model group compared with that in normal group (P<0.01), FZHY significantly decreased NF-κB activation, MMP-2 activity and p-IκB and TNF-α expressions (P<0.01). Conclusions: FZHY could protect kidney from oxidative injury intoxicated by HgCl2, and antagonized oxidative stress-stimulated NF-κB activity through inhibition of IκB phosphorylation in the interstitial fibrotic kidney, these effects importantly contributed to FZHY action mechanism against renal interstitial fibrosis.     

Endoplasmic Reticulum Stress Induced by Tunicamycin and Antagonistic Effect of Tiantai No.1(天泰1号) on Mesenchymal Stem Cells

<正>Objective:Changes of the internal and external cellular environments can induce calcium homeostasis disorder and unfolded protein aggregation in the endoplasmic reticulum(ER).This ER function disorder is called endoplasmic reticulum stress(ERS).Severe long-term ERS can trigger the ER apoptosis signaling pathway,resulting in cell apoptosis and organism injury.Recent researches revealed that ERS-induced cell death was involved in the neurocyte retrogradation in the progress of neuron degenerative diseases,such as Alzheimer's disease(AD),Parkinson's disease and so on.Therefore,the protection effect of the traditional Chinese drug——Tiantai No.1(天泰1号) on the ERS injury of AD was investigated at the molecular gene level in this study with a view to explore the gene pharmacodynamic actions and mechanisms of this drug.Methods: Primarily cultured marrow mesenchymal stem cells(MSCs) of rats were treated by tunicamycin(TM) in order to induce ERS.RT-PCR,fluorescence immunocytochemistry and Western blot techniques were used to determine the mRNA and protein expression levels of the protective stress protein-ER molecular chaperones GRP78 and GRP94(which would assist cells to resist cellular stress injury),and to determine the mRNA and protein expression levels of apoptosis promoting molecule Caspase-12 on the membrane of the ER,respectively. Results:Protein expression levels of GRP78 and GRP94 were significantly increased in the TM-induced MSCs, and the mRNA level of Caspase-12 was also remarkably increased in the TM-induced MSCs(P0.05).All these proved that the ERS model was successfully established by TM in MSC.Meanwhile,the mRNA and protein levels of GRP78 and GRP94 were all significantly increased compared with the model group(P0.05 or P0.01) after MSCs were treated with Tiantai No.1 while the mRNA and protein expression levels of Caspase-12 were significantly decreased compared with the model group(P0.05 or P0.01).This effect showed a dose dependent manner.Conclusion:Tiantai No.1 might attenuate the cell apoptosis induced by ERS injury,and thus protect the neurons against AD.