脑梗死患者中血浆同型半胱氨酸水平对血栓调节蛋白甲基化及表达的影响

目的:探讨脑梗死患者中血浆同型半胱氨酸(Hcy)水平对血栓调节蛋白(TM)甲基化及表达的影响.方法:选择脑梗死患者80例(脑梗死组),及同期住院的非脑梗死患者60例(对照组).采集患者静脉血,提取总DNA,并对总DNA进行亚硫酸氢盐修饰.利用巢式甲基化特异性PCR(nMSP)对TM基因启动子区甲基化进行分析.测定血浆中Hcy表达水平,比较不同组别Hcy水平差异,并分析其对TM启动子区甲基化的影响.提取各组TM总RNA,比较不同甲基化总RNA的差异.测定血浆中TM表达水平,比较不同组别TM水平差异.结果:2组在高血压患者人数、血糖(GLU)、总胆固醇(TC)方面差异有统计学意义(P＜0.05).脑梗死组检出TM基因启动子区甲基化60例(75.00％),对照组检出29例(48.33％),脑梗死组比对照组有更高的TM基因启动子区甲基化检出率(=10.528,P＜0.01).2组血浆中Hcy、TM水平及TM基因mRNA的表达量有统计学差异(P＜0.01).脑梗死组TM启动子区UMe、HMe、FMe组mRNA的表达量分别比对照组减少84％、73％、34％.TM启动子区甲基化程度随着血浆中Hcy水平的升高而显著升高(r=0.68,P＜0.01),随着TM基因mRNA表达量的升高而显著降低(r=-0.72,P＜0.01).结论:脑梗死患者血浆中高Hcy水平会可能会造成TM基因启动子区甲基化程度升高,进而造成TM基因mRNA的表达量降低.此外,血浆中TM水平过高,可能是由于脑梗死患者内皮损伤引起.

Effect of Plasma Homocysteine Level on the Methylation and Expression of Thrombomodulin in Patients with Cerebral Infarction

Objective:To study the effects of plasma homocysteine level on the methylation and expression of plasma homocysteine in patients with cerebral infarction.Methods:Eighty patients with cerebral infarction (infarction group) and 60 patients without cerebral infarction (control group) were enrolled.The venous blood samples were collected and total DNA was extracted,and then the total DNA was modified by sodium hydrogen sulfate.The methylation of TM gene promoter region was analyzed by nMSE The expression level of Hcy in plasma was measured.The Hcy level in different groups was compared,and the effect of TM on the methylation of the promoter region was analyzed.TM total RNA was extracted,and the levels of total RNA were compared between different groups.The expression levels of TM were determined in plasma,and compared in different groups.Results:The Glucose levels,cholesterols levels were significantly different in the two groups of patients with hypertension (P＜0.05).The TM gene promoter region methylation was detected in 60 cases of cerebral infarction group with a detection rate of 75％.29 cases in the control group were detected TM gene promoter region methylation,the detection rate was 48.33％.The TM gene methylation rate was higher in the cerebral infarction group than that in the control group(x2=9.41,P＜0.01).There were significant differences in the expressions of Hcy,TM and mRNA in the plasma between the two groups (P＜0.01).The expression levels of UMe,HMe and mRNA in the TM promoter region of the cerebral infarction group were decreased 84％,73％ and 34％,compared with the control group,respectively.The degree of methylation of TM promoter was significantly elevated with the increase of plasma Hcy level (r=0.68,P＜0.01)whereas it decreased with the increase of mRNA expression ofTM gene (r=-0.72,P＜0.01).Conclusion:The high level of Hcy in the plasma of patients with cerebral infarction may increase TM gene promoter region methylation,and decrease the expression of mRNA of TM gene.In addition,the high plasma level of TM may be caused by endothelial injury.