同型半胱氨酸对人血管平滑肌细胞5,10-亚甲基四氢叶酸还原酶基因启动子甲基化修饰及mRNA表达的影响

Demethylation in the promoter region of MTHFR gene and its mRNA expression in cultured human vascular smooth muscle cells induced by homocysteine

目的探讨同型半胱氨酸(Hcy)对人血管平滑肌细胞(HVSMCs)5,10-亚甲基四氢叶酸还原酶(MTHFR)基因启动子甲基化修饰及其mRNA表达的影响。方法正常人脐动脉血管平滑肌细胞体外培养,在培养基中加入临床高Hcy血症相关浓度及极高浓度的Hcy(0、30、100、200、500和1000μmol/L),并孵育72h,以MS-PCR分析MTHFR启动子区域甲基化状态,采用RT-PCR测定MTHFR mRNA的表达水平。结果不同浓度Hcy处理人血管平滑肌细胞后,其MTHFR基因启动子区域出现去甲基化,甲基化水平明显降低。RT-PCR结果显示MTHFR mRNA表达增加。结论Hcy可促进人血管平滑肌细胞MTHFR启动子区域去甲基化,并使MTHFR mRNA表达增加。

To investigate the effect of homocysteine （ Hcy ） on the methylation modification of 5, 10-methylenetetrahydrofolate reductase（MTHFR） gene promoter and its mRNA expression in cultured human vascular smooth muscle cells（HVSMCs）. Methods HVSMCs from umbulical arteries were isolated and cultured in DMEM/F12 medium, which clinic-relevant and very high homocysteine concentrations （0,30,100,200,500 and 1000μmol/L） were added for 72h treatment. Methylation-specific polymerase chain reaction（MS-PCR） was performed to catalyze the methylation pattern of the MTHFR promoter region, semiquantitative RT-PCR was used to detect the MTHFR mRNA expression after Hcy treatment. Results The homocysteine induced demethylation in the promoter region of MTHFR gene at all concentrations of Hcy, the methylation pattern in MTHFR gene displayed significant hypomethylation and the MTHFR mRNA expression demonstrated obvious upregulation as well. Conclusion The homocysteine could induce demethylation in the promoter region of MTHFR gene in HVSMCs and upregulate the MTHFR mRNA expression.