大鼠肝纤维化过程星形细胞MMP-2的表达及白细胞介素10的影响

Expression of MMP-2 in Hepatic Stellate Cells during Rat Hepatic Fibrosis and its Inhibition by Interleukin-10

目的 探讨基质金属蛋白酶 2 (MMP 2 )表达在实验性大鼠肝纤维化发病中的意义及外源性白细胞介素 10 (IL 10 )抗肝纤维化作用的机制。 方法 6 0只SD雄性大鼠随机分为生理盐水对照组 (N组 ) 8只、四氯化碳(CCl4)组 2 8只和IL 10干预组 2 4只 ,建立正常对照、CCl4诱导肝纤维化模型及IL 10干预模型。造模第 7周和第11周 ,采用链霉蛋白酶E、Ⅳ型胶原酶经门静脉体外灌流消化 ,11%Nycodenz密度梯度离心分离肝星形细胞(HSC)。半定量RT PCR法检测各组HSC的MMP 2mRNA表达水平 ;免疫细胞化学法检测培养 72h时HSC的MMP 2蛋白表达情况。 结果 各组均检出MMP 2的mRNA表达 ;造模第 7周 ,CCl4组与IL 10组的MMP 2mRNA表达均高于N组 (P <0 0 1) ,IL 10组低于CCl4组 (P <0 0 1) ;造模第 11周 ,CCl4组与IL 10组的表达水平较第 7周均有下降 (P <0 0 1) ,IL 10组低于CCl4组 (P <0 0 1)。SP免疫细胞化学法检测各组MMP 2的蛋白表达情况与mRNA一致。 结论 MMP 2在实验性大鼠肝纤维化早期表达升高 ,后期下降是肝纤维化发生发展的重要机制之一 ;外源性IL 10可能通过抑制早期MMP 2的表达发挥抗肝纤维化作用。

Objective To investigate matrix metalloproteinases-2(MMP-2) expression in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10(IL-10). Methods 60 rats were randomly divided into a normal control group(N group, 8 rats), CCl-4 group(28 rats) and CCl-4+IL-10 group(24 rats). At 7th and 11th week, rats in each group were routinely perfused with pronase E and type Ⅳ collagnase through portal vein catheter and the suspension was centrifuged by 11%nycodenz density gradient to isolate hepatic stellate cells(HSC). RT-PCR was used to analyze RNA of HSC. Densitometric data was standardized with β-actin. Immunocytochemistry was performed to detect MMP-2 expression in cultured HSC. Results Compared to N group at the 7th week, MMP-2 mRNA increased in both CCl-4 group and CCl-4+IL-10 group(P<0.01); but IL-10 group was lower than the CCl-4 group. At the 11th week, MMP-2 mRNA in IL-10 group was still lower than CCl-4 group. Same results were found by immunocytochemistry. Conclusion MMP-2 expression increased in the early stage of hepatic fibrosis but decreased by IL-10 intervention. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 expression.