Second Clinical Medical College, Jinan University, Guangzhou, China.
Am J Nephrol. 2009;30(6):505-13. doi: 10.1159/000243811. Epub 2009 Oct 1.
Studies of the epigenome have attracted some interest in nephrology. However, to date, our knowledge about the alterations in histone modification in minimal change nephrotic syndrome (MCNS) is unknown. This study aimed to investigate the variations in histone H3 lysine 4 trimethylation (H3K4me3) in peripheral blood mononuclear cells of patients with MCNS.
H3K4me3 variations were analyzed in peripheral blood mononuclear cells, from 15 MCNS patients and 15 healthy subjects, using the ChIP-chip approach. ChIP real-time PCR is used to validate the microarray results. In addition, mRNA expression and DNA methylation status can also be further analyzed by quantitative (q) RT-PCR and methyl-DNA immunoprecipitation-q PCR, respectively.
848 increased and 231 decreased H3K4me3 probes displaying significant H3K4me3 differences were found in MCNS patients compared with healthy subjects. The results of ChIP real-time PCR coincided well with the microarray. Expression analysis by qRT-PCR revealed positive correlations between mRNA and H3K4me3 levels. DNA methylation alterations were found on selected positive genes (IL4R, HIVEP3, HPSE2, CDH13 and PRKD2). In addition, we also found that there is an inverse relationship between H3K4me3 and promoter DNA methylation in MCNS patients.
Our studies indicate that there are significant alterations of H3K4me3 in MCNS patients. These significant H3K4me3 candidates may help to explain the immunological disturbance involved in MCNS patients.
表观基因组学的研究在肾脏病学中引起了一定的关注。然而，迄今为止，我们对于微小病变肾病综合征（MCNS）中组蛋白修饰改变的了解仍不清楚。本研究旨在探讨 MCNS 患者外周血单个核细胞中组蛋白 H3 赖氨酸 4 三甲基化（H3K4me3）的变化。
采用 ChIP-chip 方法分析了 15 例 MCNS 患者和 15 例健康对照者外周血单个核细胞中的 H3K4me3 变化。采用 ChIP 实时 PCR 验证芯片结果。此外，还可以通过定量（q）RT-PCR 和甲基化 DNA 免疫沉淀-qPCR 进一步分析 mRNA 表达和 DNA 甲基化状态。
与健康对照组相比，MCNS 患者中发现了 848 个增加和 231 个减少的 H3K4me3 探针，这些探针显示出明显的 H3K4me3 差异。ChIP 实时 PCR 的结果与芯片结果吻合良好。qRT-PCR 表达分析显示 mRNA 和 H3K4me3 水平之间存在正相关。在选定的阳性基因（IL4R、HIVEP3、HPSE2、CDH13 和 PRKD2）上发现了 DNA 甲基化改变。此外，我们还发现 MCNS 患者中 H3K4me3 与启动子 DNA 甲基化之间存在负相关关系。
我们的研究表明，MCNS 患者中存在 H3K4me3 的显著改变。这些显著的 H3K4me3 候选物可能有助于解释 MCNS 患者中涉及的免疫紊乱。
