IgA肾病组蛋白H3K4三甲基化和DNA甲基化基因修饰的相关性

Correlation of gene modification between histone H3 lysine 4 trimethylation and DNA methylation in IgA nephropathy patients

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。

AIM： To investigate the correlation of gene modification between histone H3 lysine 4（H3K4） trimethylation 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（P0.05）.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.