二甲基亚硝胺所致大鼠肝硬化形成与逆转过程中Thy1.1与OV6阳性染色细胞比较

Comparison of Thy1.1 with OV6 in hepatic oval cell marking during formation and reversion of rat cirrhosis induced by dimethylnitrosamine

目的:在二甲基亚硝胺(dimechylnitrosanline,DMN)致大鼠肝硬化形成与消减过程中,比较Thy1.1与OV6标记肝脏卵圆细胞(hepaticovalcells,HOC)的不同变化,从而选择最佳的HOC标记物.方法:应用DMN腹腔注射(4wk12次)制备大鼠肝硬化模型,进行胶原组织染色动态观察肝纤维化程度,免疫组化检测Thy1.1和OV6的不同阳性染色细胞表达,光镜下进行Thy1.1标记的HOC计数,westernblot进行该标记细胞的蛋白定量测定.结果:DMN造模4wk大鼠已形成典型的肝硬化;终止造模后2wk、即6wk时肝组织病变较4wk时有所减轻出现不完全纤维间隔.8wk时炎症明显减轻并以不完全纤维间隔为主.OV6在各时间点除了卵圆细胞表达外,也于正常胆管上皮细胞表达.正常大鼠肝组织未见到Thy1.1阳性染色的细胞,3d时可见卵圆细胞微量表达,2wk时呈散在分布,4wk时明显增多,见于纤维间隔周围,终止造模后2wk、即第6wk时阳性染色显著强于4wk,大量出现于汇管区,8wk时较6wk有所减少,表达量基本与4wk时相等.Thy1.1标记的HOCWesternblot结果与细胞计数一致.结论:在DMN大鼠肝硬化形成与消减过程中,Thy1.1标记肝脏卵圆细胞优于OV6,具有特异性和敏感性.

AIM: To screen the best marker for hepatic oval cells (HOC) by comparing the dynamic changes of Thy1.1 and OV6 expression in the hepatic tissue during the formation and reversion of dimethylnitrosamine (DMN)-induced cirrhosis in rats. METHODS: Rat cirrhosis model was induced by DMN treatment (12 times in 4 weeks). The degree of liver fibro-sis was determined by collagen staining. The expression of OV6 and Thy1.1 in various hepatic cells were examined by immunohistochemistry. Thy1.1 positive cells were enumerated under light microscope, and the cell protein was quantified by Western blot. RESULTS: The most typical cirrhosis in the model was observed at the 4th week after DMN injection, which was combined with large area of hemorrhage and putrescence. These changes started to alleviate at the 6th week with a few incomplete fiber septa. The inflammation was lessened distinctly at the 8th week, mainly manifested as incomplete fiber septa. OV6 positive cells were presented in both HOC and normal cholangial epithelia. There were no Thy1.1 positively stained cells in the normal tissues. Very few Thy1.1 positive cells started to appear on the 3rd day, dispersed at the 2nd week, increased significantly at the 4th week around the fiber septa, reached the peak at the 6th week (i.e. 2 week after stopping DMN injection) which was distributed mainly in the periportal district, and decreased at the 8th week. The results of Western blot and the number of HOC were consistent with each other. CONCLUSION: During the formation and reversion of the rat cirrhosis, Thy1.1 is superior to OV6 in marking HOC with better specificity and sensitivity.