【摘要】 为探讨氧化型低密度脂蛋白致动脉粥样硬化的作用是否与基质金属蛋白酶表达活性改变有关 ,应用Northernblot、Dotblot、Westernblot和明胶酶图分析方法观察氧化型低密度脂蛋白对体外培养的大鼠血管平滑肌细胞表达基质金属蛋白酶 - 2和 9的影响。结果显示 ,10mg/L氧化型低密度脂蛋白作用于血管平滑肌细胞 2 4h ,可明显增强基质金属蛋白酶 - 2和 9mRNA表达、蛋白分泌和酶的活性 ,高浓度的氧化型低密度脂蛋白对基质金属蛋白酶 - 2和 9表达的影响不同 ,氧化型低密度脂蛋白浓度为 5 0mg/L时 ,基质金属蛋白酶 - 9表达活性仍然高于对照细胞 ,但与 10mg/L氧化型低密度脂蛋白的作用强度无显著差别 ;相同条件下 ,基质金属蛋白酶 - 2的基因表达和蛋白分泌明显降低。以上结果提示 ,氧化型低密度脂蛋白可诱导血管平滑肌细胞基质金属蛋白酶 - 2和 9的表达 ,并可促进细胞外基质降解。更多还原

【Abstract】 Aim To examine the effects of oxidized low density lipoprotein (ox-LDL) on expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 in cultured rat vascular smooth muscle cells (VSMCs), and explore the relation between the migration and proliferation of VSMCs and the expression activity of these two genes. Methods Northern blot, Dot blot, Western blot and SDS-PAGE containing gelatin were used to detect MMP-2 and MMP-9 mRNA expression, protein synthesis and enzyme activities. Results The mRNA expressions, protein levels and enzyme activities of MMP-2 and MMP-9 significantly increased after VSMCs were stimulated by 10 mg/L ox-LDL for 24 h. When the concentration of ox-LDL were enhanced to 50 mg/L, different effects were exerted on MMP-2 and MMP-9. The levels of MMP-9 were still higher than control group and as the same as the group of 10 mg/L ox-LDL. However, the expression of MMP-2 decreased markedly at the same condition. Conclusion Ox-LDL could increase the expression activities of MMP-2 and MMP-9 and the degradation of ECM.更多还原