非酒精性肝纤维化a-SMA、E-钙粘素和Twist1的变化及意义

Expression and significance of heptocyte a-SMA,E-cadherin and Twist1 in rats with non-alcoholic liver fibrosis

目的初步探讨肝细胞上皮间质转化(epithelial-mesenchyinal transition,EMT)及其调控因子Twist1在非酒精性肝纤维化形成中的作用。方法运用高脂饮食联合小剂量CCl4复制大鼠肝纤维化模型。45只雄性SD大鼠随机分为正常对照组(N),高脂饮食联合小剂量CCl4组(M)。N组皮下注射花生油3 ml.kg-1,每周2次;M组采用高脂饮食联合小剂量CCl4造模,其CCl4用量为400 ml.kg-1花生油混合液,2 ml.kg-1,每周2次皮下注射。造模后8、10周末分批处死,光镜观察大鼠肝脏脂肪变性及肝纤维化程度;免疫组化法检测肝脏EMT标记物E-钙粘素和a-SMA以及肝脏Twist1表达。结果与N组比较,8周末,M组肝脂肪变性明显,部分出现纤维化改变,肝细胞Twist1和a-SMA表达增加,E-钙粘素表达下降;10周末,M组肝脂肪变性程度未见明显增加,但纤维化程度明显加重,肝细胞Twist1和a-SMA表达显著增加,E-钙粘素表达进一步下降,两组比较差异具有统计学意义(P<0.05)。结论非酒精性肝纤维化形成过程中存在肝细胞EMT和Twist1增加,肝细胞EMT及Twist1在非酒精性肝纤维化发病机制中可能起着一定作用。

Objective To evaluate the role of hepatocyte epithelial-mesenchymal transition（EMT） and EMT regulator molecule Twist1 in rats with non-alcoholic liver fibrosis.Methods Liver fibrosis in rats were induced by high fat diet（HFD）and low dose of CCl4.Forty-five male SD rats were randomly divided into the normal control group（N）,HFD＋ low dose of CCL4 group（M）.The group M rats were fed with HFD and subcutaneously injected with low dose of CCl4（2 ml·kg-1,2 times/wk）.The group N rats were fed with normal diet and subcutaneously injected with peanut oil,the concentration and the frequency of which was the same as group M.After eight weeks and ten weeks,the rats should be killed in batches.The degrees of steatosis and fibrosis of the rat livers were observed by light microscope,Twist1,E-cadherin and a-SMA expression in hepatocytes by inmunohistochemical method.Results Compared with the group N,at the 8th week,hepatic steatosis in group M rats was obvious with the development of liver fibrosis,the expressions of hepatocyte Twist1 and a-SMA in group M rat liver were increased,while E-cadherin was decreased.At the 10th week,the degree of liver fibrosis,the expression of hepatocyte Twist1 and a-SMA were obviously increased,with pseudolobules in some rat liver,and the decreased expression of E-cadherin.Conclusion The development of liver fibrosis accompanies hepatocyte EMT and the increased expression of Twist1.Hepatocyte EMT and its regulator factor Twist1 may play a role in the pathogenesis mechanisms of non-alcoholic liver fibrosis.