DNA甲基化转移酶在MRL／lpr狼疮鼠CD4^＋T淋巴细胞中的表达水平研究及功能分析  

Transcript levels and functional analysis of DNA methyltransferases in CD4^＋ T cells of MRL/lpr mice

作　　者：袁敏[1] 慕丽娟[1] 崔慧娟 罗晓兵 黄新芳[1] 郑一君[1] 唐元家 沈南[1] 

机构地区：[1]上海交通大学医学院附属仁济医院风湿病科 上海市风湿病学研究所,200001 [2]中国科学院上海生命科学研究院 上海交通大学医学院健康科学研究所分子风湿病学研究组

出　　处：《中华风湿病学杂志》2009年第8期521-524,共4页Chinese Journal of Rheumatology

基　　金：国家科技部863计划（2007AA02Z123）;国家自然科学基金（30500460）;上海市重点学科建设项目（T0203）;上海市科委优秀学科带头人计划（07XD14021）;上海市科委基础研究重点项目（08JC1414700）;医院临床科研资源共享平台项目（SHDC12007205）

摘　　要：目的研究DNA甲基化转移酶DNMT1、DNMT3A、DNMT3B在发病MRL/lpr狼疮鼠脾脏CD4^＋T淋巴细胞的表达情况，并对其与免疫相关的甲基化敏感基因ITGAL、CD70的表达水平进行相关性分析。方法CD4单抗标记的免疫磁珠分选小鼠脾脏CD4^＋T淋巴细胞，实时定量聚合酶链反应（real—time PCR）测定DNMT1、DNMT3A、DNMT3B和免疫相关的甲基化敏感基因ITGAL、CD70的相对表达量。结果①DNA甲基化转移酶DNMT1、DNMT3A、DNMT3B在发病MRL／lpr狼疮鼠CD4^＋T淋巴细胞中与健康对照BALB／c小鼠相比，表达水平均有降低趋势，其中DNMT3B差异有统计学意义（P〈0．05）；CD70在发病MRL/lpr狼疮鼠表达水平升高（P〈0．01），ITGAL表达水平呈升高趋势，差异无统计学意义（P〉0．05）。②相关性分析显示：DNMT3B与CD70分子表达水平呈显著负相关（r=-0．769，P〈0．01）。结论DNMT3B在发病MRL／lpr狼疮鼠CD4^＋T淋巴细胞中表达水平降低，可能通过影响免疫相关的甲基化敏感基因CD70的表达，造成CD4^＋T淋巴细胞功能异常，参与系统性红斑狼疮的发病。Objective To investigate the expression levels of DNA methyhransferases 1, 3A and 3B in CD4^＋ T. cells of MRL/lpr mice, and explore their relationship with the expression levels of methylation-sensitive genes （ITGAL, CD70）. Methods CD4^＋ T cells were isolated from spleens of 16-week-old MRL/lpr and BALB/c control mice by anti-CD4 antibody labeled magnetic beads. Transcription levels of DNA methyltransferases 1, 3A and 3B and methylation-sensitive genes（ITGAL, CD70） were measured by real-time qPCR. Results ① The mRNA expression of DNMT3B in CD4^＋ T cells was lower in 16-week-old MRL/Ipr mice when compared with BALB/c control mice and the difference was significant （P〈0.05）, while the expression of DNMT1 and DNMT3A showed a tendency of decrease （P〉0.05）. The mRNA expression of CD70 was significantly higher （P〈0.01）, but the expression of ITGAL had no significant difference between the two groups （P〉0.05）; ② DNMT3B was significantly negatively correlated with the expression of CD70 （r=-0.769, P 〈0.01 ）. Conclusion Decreased expression of DNMT3B may attribute to the elevated expression of methylation-sensitive gene CD70, thus lead to the dysfunction of CD4^＋ T cell and play an important role in the pathogenesis of SLE.

关 键 词：红斑狼疮 系统性 DNA甲基化 小鼠 近交MRL LPR CD4阳性T淋巴细胞 

分 类 号：R686[医药卫生—骨科学]