Objective To discuss the regulation of lysyloxidase expression ,after pre-treatment of vascular endo-thelial cell damage with homocysteine (Hcy) .Methods Subculture HUVEC-12 cells ,and randomly divided them into three groupsch were a low concentration group (Hcy 0 .05 mmol/L) ,a medium concentration group (Hcy 0 .2 mmol/L) and a high concentration group (Hcy 0 .4 mmol/L) .The blank control group was set up in this study .It was extrac-ted RNA cells after intervention for 24 h .After RT-PCR ,do semi-quantitative analysis with the mRNA ratio of MMP-2 ,LOX to β-actin .Results Hcy showed concentration-dependent down-regulated expression of the endothelial cells LOX and up-regulated expression of MMP-2 mRNA .RT-PCR results suggested that the expression of LOX mRNA was significantly reduced after Hcy treatment at different concentrations ,which showed concentration de-pendence (P<0 .01) .The expression of MMP-2 mRNA was greatly increased with the increase of Hcy concentra-tion .After the inhibition of BAPN with LOX ,the expression of MMP-2 mRNA was greatly increased (P<0 .01) . Conclusion Hcy is likely to induce the increase of the expression of endothelial cells MMP-2 by Hcy down-regulation of LOX expression ,indicating that Hcy may cause abnormal M M P-2 expression by inhibiting LOX expression to pro-mote the degradation of ECM and change the elasticity of the vascular wall ,resulting in endothelial dysfunction .%目的 探讨以同型半胱氨酸(Hcy)预处理血管内皮细胞的损伤后赖氨酰氧化酶的表达调节.方法 将HUVEC-12细胞株进行人工传代培养,并随机分为四组,空白对照组、低浓度组(Hcy0.05 mmol/L)、中浓度组(Hcy0.2 mmol/L)及高浓度组(Hcy0.4 mmol/L),干预24 h后提取细胞RNA,RT-PCR后以MMP-2、LOX与β-actin的mRNA比值进行半定量分析.结果 Hcy呈浓度依赖性下调内皮细胞LOX表达及上调MMP-2 mRNA表达.RT-PCR结果提示予不同浓度Hcy处理后LOX mRNA表达明显减少,呈浓度依赖性,差异有统计学意义(P<0.01).MMP-2 mRNA表达随Hcy浓度增加而升高.应用LOX抑制剂BAPN后,MMP-2 mRNA表达明显增加,差异有统计学意义(P<0.01).结论 Hcy引起内皮细胞MMP-2表达增加,可能是通过Hcy下调细胞LOX表达来实现的.提示Hcy可通过抑制细胞LOX表达引起M M P-2表达异常,促使ECM降解、改变血管壁弹性,从而导致内皮功能障碍.
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