过氧化氢对血管平滑肌细胞增殖和明胶酶A及其抑制因子基因表达的影响

Effects of hydrogen peroxide on cell proliferation and expression of gelatinase A and its inhibitor in vascular smooth muscle cells

目的 :探讨过氧化氢 (H2 O2 )对体外培养大鼠血管平滑肌细胞 (VSMC)增殖和明胶酶A(MMP - 2 )、及其抑制因子 (TIMP - 2 )基因表达的影响。方法 :先用四甲基偶氮唑 (MTT)法筛选出H2 O2 对VSMC的毒性作用浓度和增殖作用浓度 ,在此基础上用逆转录聚合酶链反应 (RT -PCR)法测定H2 O2 对MMP - 2、TIMP - 2mRNA表达的影响。结果 :H2 O2 浓度大于 30 0 μmol/L后显示出对VSMC的致死毒性作用 ;H2 O2 浓度在 0 0 1 - 50 μmol/L内可以刺激VSMC的增殖 ,且呈时间依赖性 ;1 μmol/LH2 O2 、1 0 μmol/LH2 O2 对MMP - 2基因转录有明显的促进作用 ;不同浓度的H2 O2对TIMP - 2基因转录无明显促进作用。结论 :适当浓度的H2 O2 可以促进VSMC的增殖和MMP - 2mRNA表达 ,但对TIMP - 2mRNA表达无明显作用 ,提示H2 O2 参与了血管重塑的不同病理环节。

AIM: To study the effects of hydrogen peroxied (H 2O 2) on cell proliferation and transcription of gelatinase A (MMP-2) and its inhibitor (TIMP-2) in vascular smooth muscle cells (VSMC). METHODS: Cell proliferation and toxicity by H 2O 2 were tested through MTT. The expression of MMP-2 mRNA and TIMP-2 mRNA in VSMC were evaluated by RT-PCR. RESULTS: The present study showed that H 2O 2 (more than 300 μmol/L)was lethal to VSMC. 0 01-50 μmol/L H 2O 2 promoted proliferation of VSMC in a time-dependant manner. A value (optical density) was reached to peak at 24 h after continuing stimulation of 10 μmol/L H 2O 2. MMP-2/β-actin mRNA ratio significantly increased after stimulation with 1 μmol/L?10 μmol/L H 2O 2. TIMP-2/β-actin mRNA ratio was not significantly fluctuated at 12 h?24 h?36 h?48 h after continuing stimulation with 1 μmol/L, 10 μmol/L, and 50 μmol/L H 2O 2.CONCLUSION: H 2O 2 at suitable concentrations stimulated proliferation of VSMC and induced transcription of MMP-2 gene in VSMC. There was no effect of H 2O 2 on transcription of TIMP-2 gene in VSMC. These results imply that H 2O 2 takes part in the pathological course of vascular remodeling through VSMC.