赖氨酰氧化酶在半胱氨酸诱导静脉内皮细胞损伤后的表达调节

Differential regulation of Lysyl Oxidase by Homocysteine in vein endothelial cells

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(Hcy0.2mmol/L)及高浓度组(Hcy0.4mmol/L),干预24h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-2mRNA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-2mRNA表达随Hcy浓度增加而升高。应用LOX抑制剂BAPN后,MMP-2mRNA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MMP-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。

Objective To discuss the regulation of lysyloxidase expression,after pre-treatment of vascular endothelial 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 extracted RNA cells after intervention for 24 h.After RT-PCR,do semi-quantitative analysis with the mRNA ratio of MMP-2,LOX toβ-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 dependence（P〈0.01）.The expression of MMP-2 mRNA was greatly increased with the increase of Hcy concentration.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 MMP-2 expression by inhibiting LOX expression to promote the degradation of ECM and change the elasticity of the vascular wall,resulting in endothelial dysfunction.