缺氧对肝星状细胞基质金属蛋白酶Ⅱ表达及活性调节的影响

Effects of hypoxia on expression and activity of matrix metalloproteinase-2 in hepatic stellate cell

目的研究缺氧对HSC基质金属蛋白酶Ⅱ（matrixmetalloproteinase-2，MMP-2）表达及活性调节的影响。方法大鼠HSC体外原代培养，以免疫细胞化学及ELISA法分别检测细胞内MMP－2及基质金属蛋白酶组织抑制因子Ⅱ（Tissueinhibitorofmetalloproteinade－2、TIMP－2）的表达，和培养上清液中两者的相对量,并以酶图活测培养上清液MMP－2活力。结果缺氧培养12h，免疫细胞化学显示MMP－2表达高于对照组（t＇＝3．4685，P＜0．05），TIMP－2表达则降低（t＇＝2．5673，P＜0．05）；培养上清液中MMP－2酶活性低于对照组（t＇＝4.270,P＜0.01）。缺氧6h上清液MMP－2蛋白相对含量增加值高于12h及24h组（t值分别为4.0945、2.4652;P值分别为＜0.001、0.025）；TIMP－2变化趋势与MMP－2则相反，但各组间差异无显著性。结论缺氧使肝星状细胞MMP－2含量增加。

Objective To study the etTect of hypoxia on the expression and activity of matrix metalloproteinase-2(MMP-2) in the hepatic stellate cell (HSC). Methods The expression of MMP-2 and tissue inhibitor of metalloproteinase-2 (TIMP-2) in cultured rat HSC was detected by immunocytochemistry (ICC). The relative amount of MMP-2 and TIMP-2in the culture supernatant was assayed by ELISA and the activity of MMP-2 in supernatant was examined by zymography.Results The expression of MMP-2 was enhanced in hypoxia group as compared with that in control one (t' = 3.468 5, P <0.05), while the expression 0f TIMP-2 was decreased (t'=2.567 3, P<0.05). The activity of MMP-2 was lower in hypoxiagroup than in control one (t'=4.270, P<0.01 ). Comparing the varied duration of hypoxia, the relative amount of MMP-2 pro-tein was the highest in 6 h group (6 h vs 12 h, t=4.094 5, P<0.001; 6 h vs 24 h, ta2.465 2, P<0.025), with a contrary curve inTIMP-2. Conclusion Hypoxia promotes the expression of MMP-2 and inhibits the expression of TIMP-2 in HSC. It ismore notable at early stage of hypoxia.[