血管紧张素Ⅱ1a型受体在不同周龄自发性高血压大鼠血管组织中的表达及其甲基化状态的研究  

Differential expression and DNA methylation of angiotensin type 1a receptor in vascular tissues during the development of hypertension

作　　者：裴芳[1,2] 王新全[2] 陈鹏[2] 岳荣川[2] 陈彩宇[2] 曾春雨[2] 

机构地区：[1]中国人民武装警察部队重庆市总队医院心血管内科,重庆400061 [2]第三军医大学大坪医院野战外科研究所心血管内科,重庆市心血管病研究所

出　　处：《中华高血压杂志》2015年第3期231-237,共7页Chinese Journal of Hypertension

基　　金：国家自然科学基金(81200193);国家杰出青年科学基金(30925018)

摘　　要：目的通过对比观察不同周龄自发性高血压大鼠(SHR)和正常血压对照大鼠(WKY)胸主动脉和肠系膜动脉中血管紧张素Ⅱ1a型受体(AT1aR)的mRNA和蛋白质表达及其甲基化水平的差异,探讨DNA甲基化与AT1aR表达及血压状态的内在联系。方法以同龄WKY大鼠为正常对照,分别从转录和翻译水平检测处于高血压前期(4周龄)、高血压发展期(10周龄)和高血压稳定形成期(20周龄)SHR胸主动脉和肠系膜动脉内AT1aR的表达变化,同时应用重亚硫酸盐修饰测序法评估AT1aR基因启动子区的甲基化状况。结果 SHR和WKY大鼠胸主动脉和肠系膜动脉内AT1aR的mRNA和蛋白质表达水平均随周龄增长而递增;自10周龄起,SHR胸主动脉和肠系膜动脉内AT1aR的mRNA和蛋白质表达水平高于同周龄的WKY大鼠,20周龄时差异有统计学意义(mRNA:胸主动脉为1.607±0.084比1.227±0.079,肠系膜动脉为1.713±0.103比1.327±0.066;蛋白:胸主动脉为1.594±0.071比1.237±0.064,肠系膜动脉为2.103±0.115比1.300±0.089;均P<0.01);SHR胸主动脉和肠系膜动脉内AT1aR基因启动子区两个CpG岛随着周龄的增长和血压的升高均发生去甲基化,自10周龄起SHR AT1aR基因启动子区甲基化水平已经开始低于同周龄的WKY大鼠,20周龄时差异有统计学意义(胸主动脉总甲基化率:1.4%比10.9%;肠系膜动脉总甲基化率:0.3%比8.0%;均P<0.01)。结论 SHR动脉血管中AT1aR基因启动子区随着年龄的增加去甲基化,可能在影响AT1aR的表达和原发性高血压的发病机制中起到一定作用。Objective To exp1ore the expression 1eve1s of angiotensin type 1a receptor{AT1aR） mRNA and protein in aorta and mesenteric artery at different hypertension stages, and to investigate whether 1oca1 AT1aR expression is corre1ated to DNA methy1ation status of AT1aR promoter during the deve1opment of hypertension. Methods The expression 1eve1s of AT1aR mRNA and protein, and the methy1ation status of AT1aR promoter in aorta and mesenter- ic artery were measured in ma1e spontaneous1y hypertensive rats （SHR） and age-matched Wistar-Kyoto rats （WKY） at the prehypertensive （4 weeks）, evo1ving （ 10 weeks）, and estab1ished （20 weeks ） stages of hypertension. Resu1ts The expression 1eve1s of AT1aR mRNA and protein did not differ between 4-week-o1d SHR and age-matched WKY, but were significant1y higher in 20-week-o1d SHR than in age-matched WKY （AT1aR mRNA expression： 1. 607±0. 084 vs 1. 227±0. 079 in aorta and 1. 713±0. 103 vs 1. 327±0. 066 in mesenteric artery; ATtaR protein expression： 1. 594±0. 071 vs 1. 237±0. 064 in aorta and 2. 103±0. 115 vs 1. 300±0. 089 in mesenteric artery; a11 P〈0.01 ）. Bisu1fite sequencing revea1ed that AT1aR promoter in both aorta and mesenteric artery of SHR was get- ting hypomethy1ated with aging when compared with that of age-matched WKY （aorta： 1.4 % vs 10.9 % ; mesenteric artery： 0.3% vs 8.00% in 20-week old; both P〈0.01）. Conclusion The DNA methylation status of AT1aR pro motet in SHR displayed age dependent progressive hypometbylation, which might be responsible {or the regulation of the AT1aR expression and further the development of hypertension.

关 键 词：血管紧张素Ⅱ1a型受体 DNA甲基化 高血压 自发性高血压大鼠 

分 类 号：R544.1[医药卫生—心血管疾病]