阿托伐他汀钙对血脂异常大鼠主动脉组织bcl-2基因甲基化的影响

Effects of atorvastatin on methylation of bcl-2 in aortic tissue of hyperlipidemia wistar rats

目的:研究阿托伐他汀钙对血脂异常大鼠主动脉组织中bcl-2基因甲基化及bcl-2基因mRNA表达的影响。方法:将Wistar大鼠66只随机分为对照组、血脂异常组和阿托伐他汀钙干预组(简称他汀干预组),每组22只。对照组大鼠给予普通饲料喂养,其他两组给予高脂饲料喂养,以复制血脂异常大鼠模型,从实验第12周开始灌胃,灌胃4周后心脏取血检测血清TC、TG、LDL-C和HDL-C。提取主动脉核蛋白检测基因组DNA总甲基转移酶(DNMT)活力;采用nMSP法检测各组大鼠主动脉组织bcl-2基因启动子区甲基化情况;采用实时荧光定量PCR法检测bcl-2基因mRNA的表达情况。结果:12周高脂饮食可以诱导血脂异常大鼠模型;与血脂异常组比较,他汀干预组血清TC、TG与LDL-C降低,HDL-C升高(均P<0.05);HE染色结果显示,他汀干预组较血脂异常组大鼠动脉粥样硬化病变减轻;与对照组比较,血脂异常组DNMT活力及bcl-2基因启动子区甲基化水平升高,bcl-2基因mRNA表达降低(均P<0.01);与血脂异常组比较,他汀干预组DNMT活力及bcl-2基因启动子区甲基化水平降低,bcl-2基因mRNA表达升高(均P<0.01)。结论:阿托伐他汀钙能够降低bcl-2基因启动子区甲基化水平,增高其mRNA表达,参与延缓动脉粥样硬化的形成及发展。

Objective：To investigate the effects of atorvastatin on methylation status of bcl-2 gene promoter and mRNA expression of bcl-2 in aortic tissue of hyperlipidemia wistar rats. Method：Sixty-six wistar rats were equally randomized into 3 groups： control group,hyperlipidemia group and atorvastatin group.The rats in control group were fed with normal chaw,and the other groups were fed with chaw formula for 12 weeks.Gavage experiment was started at 12th week.Heart blood was drawn for detecting serum TC,TG,LDL-C and HDL-C after 4 weeks of gavege.Aortic nucleoprotein was extracted for detecting DNA methyltransferase（DNMT） activity,the methylation specific poly merase chain reaction（MSP） method was used to detect bcl-2 gene methylation in aortic tissue.The expression of bcl-2 mRNA in aortic tissue was detected by real-time quantitative polymerase chain reaction. Result：A high fat diet for 12 weeks was sufficient to induce hyperlipidemia.Compared with hyperlipidemia group,serum TC,TG,and LDL-C in atorvastatin group were lower,while HDL-C was higher（both P〈0.05）.Compared with control group,the DNMT activity and methylation status of bcl-2 gene promoter significantly were increased and the expression of bcl-2 mRNA was decreased in hyperlipidemia group（both P〈0.01）.Compared with hyperlipidemia group,the DNMT activity and methylation status of bcl-2 gene promoter were significantly decreased and the expression of bcl-2 mRNA was increased in atorvastatin group（both P〈0.01）. Conclusion：Atorvastatin can decrease the methylation status of bcl-2 gene promoter and increase the expression of bcl-2 mRNA,which prevents and delays atherosclerosis.