缺氧、高氧对肝星形细胞基质金属蛋白酶Ⅱ表达及活性的影响

目的　研究缺氧、高氧对肝星形细胞基质金属蛋白酶Ⅱ (MMP 2 )表达及其活性影响。方法　分离大鼠肝星形细胞 ,在缺氧或高氧条件下培养 ,以免疫细胞化学标记链霉素卵白素生物素(LSAB)法及酶联免疫吸附 (ELISA)法分别检测细胞内MMP 2、基质金属蛋白酶组织抑制因子Ⅱ(TIMP 2 )、膜型基质金属蛋白酶Ⅰ (MT1 MMP)的表达 ,和培养上清中MMP 2、TIMP 2的相对含量 ,并以酶谱法测培养上清MMP 2活力。结果　 (1)缺氧培养 12h ,MMP 2表达增高 (缺氧组阳性指数 :5 7±2 0 ;对照组 :3 2± 1 0 ,;P <0 0 1) ,TIMP 2表达则降低 (缺氧组阳性指数 :2 5± 0 7;对照组 :3 6±1 0 ;P <0 0 5 ) ;培养上清中MMP 2酶活性明显降低 (缺氧组总吸光度值 :7 334± 1 92 2 ;对照组 :17 2 77± 7 4 2 4 ;P <0 0 1)。缺氧不同时段 (6、12、2 4h)比较 ,变化以 6h段最明显。 (2 )高氧培养 12h ,上清中MMP 2、TIMP 2蛋白相对含量均高于对照组 ,TIMP 2更明显 (高氧组A450 :0 0 5 0± 0 0 14 ;对照组 :0 0 2 2± 0 0 10 ;P <0 0 1) ,酶活性亦高于对照组 (高氧组总吸光度值 :5 2 5 2± 0 771;对照组 :4 30 4± 1 0 83;P <0 0 5 ) ,高氧组MT1 MMP表达增强。结论　肝星形细胞对氧敏感。缺氧使肝星形细胞MMP 2表达增加 ,该影响在

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

OBJECTIVE: To study the effects of hypoxia and hyperoxia on the expression and activity regulation of matrix metalloproteinase-2 (MMP-2) of the hepatic stellate cell (HSC). METHODS: The expression of MMP-2, tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) and membrane type matrix metalloproteinase-1 (MT1-MMP) in cultured rat HSC under hypoxic or hyperoxic conditions were detected with immunocytochemistry (LSAB method), the contents of MMP-2, TIMP-2 in culture supernatant with ELISA and the activity of MMP-2 in supernatant with zymography. RESULTS: (1) In the situation of hypoxia for 12 h, the expression of MMP-2 increased (hypoxia group positive indexes: 5.7 +/- 2.0; control: 3.2 +/- 1.0; P < 0.01), while TIMP-2 decreased (hypoxia group positive indexes: 2.5 +/- 0.7; control: 3.6 +/- 1.0; P < 0.05) in HSC, and the activity of MMP-2 in supernatant declined obviously (hypoxia group: 7.334 +/- 1.922; control: 17.277 +/- 7.424; P < 0.01). At the different time courses of hypoxia, the change of expression and activity of MMP-2 was most notable at 6 h. (2) In the situation of hyperoxia for 12 h, the protein contents of MMP-2, TIMP-2 in supernatant were both higher than those of the control, especially the TIMP-2 (hyperoxia group A(450): 0.050 +/- 0.014; control: 0.022 +/- 0.010; P < 0.01), and so was the activity of MMP-2 (hyperoxia group total A: 5.252 +/- 0.771; control: 4.304 +/- 1.083; P < 0.05). The expression of MT1-MMP was also increased. CONCLUSIONS: The HSC is sensitive to the oxygen. Hypoxia accelerates the expression of MMP-2 and the effect is more marked at the early stage. Hyperoxia increases the activity of MMP-2.