胆汁淤积性肝病大鼠肝脏及其胆管上皮细胞转化生长因子β的表达

Expression of transforming growth factor β in the liver and its biliary epithelial cells of rats with cholestatic liver disease

目的探究胆汁淤积性肝病大鼠肝脏及其胆管上皮细胞转化生长因子β(TGF-β)的表达。方法将60只6~8周龄健康雌性SPF级SD大鼠分为对照组(d0组)、胆总管结扎术后7 d组(d7组)、胆总管结扎术后14 d组(d14组)及胆总管结扎术后21 d组(d21组),各15只,其中d0组大鼠开腹后轻触胆总管后即关腹。运用Knodell组织学活动指数(HAI)评分来评价各组大鼠肝脏组织学改变,以PCR方法测量各组大鼠肝脏组织和胆管上皮细胞中TGF-βm RNA的表达情况,使用比色法测算细胞培育后4 d内胆管上皮细胞的数量,观察TGF-β1对胆管上皮细胞的增殖作用。结果肝脏Knodell HAI评分随着术后时间的延长而提高(P<0.05);肝脏组织和胆管上皮细胞中TGF-β1、TGF-β2及TGF-β3的m RNA表达水平随着胆汁淤积时间的延长而显著上调(P<0.05);体外研究显示,TGF-β1可抑制胆管上皮细胞增殖。结论在胆总管结扎导致的胆汁淤积性肝病中,肝脏的受损以及TGF-β的m RNA表达水平也会随着胆汁淤积的时间延长而增加,机体TGF-β1水平与胆汁淤积性肝病的发生发展有着密切关系,随着增生的胆管上皮细胞中TGF-β1表达增高,胆汁淤积性肝脏纤维化发生率也会相应增加。

Objective To explore the expression of transforming growth factor β(TGF-β) in the liver and its biliary epithelial cells of rats with cholestatic liver disease. Methods Sixty healthy female SPF SD rats aged 6-8 weeks were divided into control group(d0group), 7 days after common bile duct ligation group(d7group), 14 days after common bile duct ligation group(d14group) and 21 days after common bile duct ligation group(d21group), with 15 rats in each group, among which, the common bile duct of d0 group was touched softly after laparotomy and then abdomen was closed immediately. Knodell histological activity index(HAI) grading was used to evaluate the hepatic histologic changes of rats, the expression of TGF-β m RNA in liver tissue and biliary epithelial cells was detected by PCR, the amount of biliary epithelial cells within 4 d after cell culture was calculated by colorimetric method, the proliferative effect of TGF-β1for biliary epithelial cells was observed. Results The Knodell HAI scores were improved with the extension of postoperative time(P < 0.05); the levels of m RNA expression of TGF-β1, TGF-β2and TGF-β3were increased with the extension of cholestasis time(P < 0.05); the study in vitro showed that TGF-β1could inhibit the proliferation of biliary epithelial cells. Conclusion In the cholestatic liver disease caused by common bile duct ligation,the liver damage and expression of TGF-β m RNA are increased with the extension of cholestasis time, the level of TGF-β1is closely related to the genesis and development of cholestatic liver disease, with the increase of the expression of TGF-β1in hyperplastic biliary epithelial cells, the incidence of cholestatic hepatic fibrosis will be increased relevantly.