氧化苦参碱对肝纤维化大鼠Smad基因表达的影响

Effect of oxymarine on Smad gene expression in CCI_4-induced hepatic fibrosis in rats

目的:研究氧化苦参碱(oxymarine,苦参素)对四氯化碳诱导的肝纤维化大鼠肝组织Smad基因表达的影响.方法:SD大鼠90只分为正常对照组(C组)、模型组(M组)和苦参素干预组(T组).CCl4sc诱导大鼠肝纤维化,干预组大鼠在造模的同时给予苦参素注射液ip,正常对照组给予液体石蜡sc和生理盐水ip,8wk实验结束时处死动物.HE和Masson染色观察大鼠肝组织病理学变化和胶原沉积,原位杂交和免疫组化检测Smad4,Smad7基因表达情况.结果:氧化苦参碱干预组大鼠肝半定量组织学积分(1.9±0.3vs3.6±0.8,P<0.05)和胶原面积(94±37vs691±189μm2,P<0.05)明显减少;Smad7蛋白表达阳性率增加[(5.09±0.68)%vs(2.86±0.865%,P<0.05];Smad4蛋白表达阳性率减少[(2.33±1.64)%vs(9.56±1.34)%,P<0.05];Smad4mRNA表达阳性率显著减少(0.31±0.12vs0.62±0.23,P<0.05);Smad7mRNA的表达则明显增加(0.26±0.11vs0.16±0.03,P<0.05).结论:氧化苦参碱能抑制Smad4基因表达,促进Smad7基因表达.

AIM: To study the effect of oxymatrine in the prevention of experimental hepatic fibrosis in rats induced by chronic administration of CCI4, to evaluate its effect on gene expression of Smad 4, Smad 7, and to explore its potential anti-fibrotic mechanism. METHODS: Healthy male SD rats were randomly divided into three groups:the normal group (n = 10), the oxymarine treatment group (n = 40) and the fibrosis group (n = 40). Hepatic fibrosis was induced by subcutaneous injection of CCI4 (300 mL/L,3 mL/Ag,twice per wk for 8 wks). The rats in the treatment group received celiac injection of oxymatrine at 10 mg/kg twice a week. The deposition of collagen was examined with Masson staining. Gene expression of Smad 4 and Smad 7 was detected by in situ hybridization (ISH) and immunohistochemistry (IH), respectively. The data were analyzed with specific software. RESULTS: Reduction of collagen deposition and rearrangement of the parenchyma were noted in oxymatrine-treated rats. The semi-quantitative histological scores (1.9±0.3 vs 3.6±0.8, P<0.05) and average area of collagenous fibre [(94±37)μm2 vs (691±189)μm2,P<0.01 ] in treatment group were decreased. The expression of Smad 7 was increased, whereas the expression of Smad 4 was decreased considerably in treated animals. The positive rate of Smad 4 mRNA (0.31±0.12 vs 0.62±0.23,P<0.05) and Smad 4 protein [(2.33±1.64)% vs (9.56±1.34)%, P<0.05] were lower in treatment group. In contrast, the positive rate of Smad 7 mRNA (0.26±0.11 vs 0.16±0.03, P<0.05) and Smad 7 protein [(4.27±0.43)% vs (2.86±0.86)%, P<0.05] were increased considerably in treated animals. CONCLUSION: Oxymatrine can promote the gene expression of Smad 7 and inhibit the expression of Smad 4.