IgA肾病组蛋白H3K4三甲基化和DNA甲基化基因修饰的相关性

摘要

目的:探讨IgA肾病(IgAN)外周血单个核细胞(PBMCs)组蛋白H3赖氨酸4 (H3K4)三甲基化与DNA甲基化之间的关系.方法:采用染色质免疫共沉淀联合芯片技术(ChIP-chip)对40例IgAN患者和40例健康者的PBMCs H3K4三甲基化进行高通量筛选,染色质免疫共沉淀-实时定量聚合酶链反应 (ChIP-qPCR) 验证芯片结果,定量反转录聚合酶链反应(qRT-PCR)检测阳性基因的mRNA表达水平,采用甲基化DNA免疫共沉淀定量聚合酶链反应(MeDIP-qPCR)检测DNA甲基化水平.结果:IgAN病人PBMCs 基因组H3K4三甲基化水平升高,基因组DNA甲基化水平降低.4个阳性基因H3K4三甲基化水平和DNA甲基化水平与正常对照组相比,显著差异(P<0.05).结论:IgAN患者PBMCs基因组H3K4三甲基化和DNA甲基化水平存在显著改变,DNA甲基化和组蛋白H3K4三甲基化基因修饰存在相互作用.%ADM: To investigate the correlation of gene modification between histone H3 lysine 4 ( H3K4 ) tri-methylation and DNA methylation in IgA nephropathy patients. METHODS: H3K4 trimethylation variations were analyzed in peripheral blood mononuclear cells ( PBMCs ) from 40 IgAN patients and 40 healthy controls by the method of chromatin immunoprecipitation linked to microarrays ( ChIP - chip ). ChIP real - time PCR was used to validate the microarray results. Quantitative real - time PCR ( qRT - PCR ) was employed to analyze mRNA expression. DNA methylation in 4 selected positive genes was analyzed by the method of methylated DNA immunoprecipitation - quantitative PCR ( MeDIP - qPCR ). RESULTS: IgAN patients displayed higher H3K4 trimethylation level and lower DNA methylation level than those of the healthy controls. There were significant differences in DNA methylation and H3K4 trimethylation of 4 selected genes between IgAN patients and the healthy controls ( P <0. 05 ). CONCLUSION: Our studies indicate that significant alterations of H3K4 trimethylation and DNA methylation exist in IgAN patients. There is a correlation of gene modification between DNA mathylation and histone H3 lysine 4 trimethylation in IgAN patients.