动脉粥样硬化病人雌激素受体基因的甲基化与高同型半胱氨酸血症关系的研究

目的探讨动脉粥样硬化(AS)患者雌激素受体(ER-α)基因启动子区CpG岛的甲基化改变,及其与血总同型半胱氨酸(tHcy)水平的关系。方法82例研究对象分为AS组(54例),对照组(28例),所有入选对象均行颈部血管彩超检查。巢式甲基化特异性PCR(nMSP)法检测研究对象ER-α启动子区CpG岛的甲基化状态,荧光生化法检测血tHcy水平,spearman等级相关分析甲基化程度与tHcy的相关关系。结果54例AS患者中有38例ER-α基因启动子区CpG岛甲基化,甲基化率为70.4%;28例健康对照者中有8例ER-α基因启动子区CpG岛甲基化,甲基化率为28.6%;两组甲基化率差异有显著性(P<0.05)。同时,AS组tHcy水平显著高于对照组(P<0.05),经spearman等级相关分析,ER-α基因启动子区甲基化程度与tHcy相关系数为r=0.809(P<0.05)。且随tHcy升高,AS病损程度亦递次加重。结论AS患者ER-α基因启动子区CpG岛高度甲基化,且甲基化程度与血tHcy浓度呈正相关,提示高Hcy血症很可能通过干扰ER-α基因的甲基化而促进AS的发生、发展。

Hypermethylation of estrogen receptor-α gene and high homocysteine in atheromatosis patients

OBJECTIVE: To investigate the methylation status in promoter region of ER-alpha gene and the relationship beteen the degree of methylation in ER-alpha gene and the level of total plasma homocysteine(tHcy) in atherosclerosis patients. METHODS: 82 cases including 54 atherosclerosis patients and 28 healthy control subjects were selected under carotid colorized ultrasound examination. The methylation status of CpG islands in ER-alpha gene promoter region were analyzed by nested-methylation-specific PCR (nMSP). tHcy was examined by fluorescent-biochemical method. Using spearman rank correlation to analyse the relatinship between the degree of methylation in ER-alpha gene and the level of tHcy. RESULTS: Hypermethylation of ER-alpha gene promoter region was found in 38 cases of atherosclerosis patients, the methylation frequency was 70.4%. While the only 28.6% methylation frequency was detected in healthy controls, just 8 of 28 samples were found hypermethylation, much lower than the one in atherosclerosis group (P < 0.05). Meanwhile, the level of tHcy in atherosclerosis group was significantly higher than that in control group (P < 0.05). The spearman rank correlation analysis explored an obviously correlation between the degree of methylation in ER-alpha gene and the level of tHcy (r = 0.809, P < 0.05), and the severity of atherosclerotic lesion was also heightened along with the increment of plasma level of tHcy. CONCLUSION: Hyermethylation of CpG islands in ER-alpha gene promoter region was found in high frequency in atherosclerosis patients, which is positive correlated with the increased level of plasma tHcy and the severity of atherosclerotic lesion. This clinical data further extended our in vitro experimental result that HHcy can lead to the hypermethylation of ER-alpha gene, and hence to promote the occurrence and development of AS.