系统性红斑狼疮患者外周血单个核细胞组蛋白H3赖氨酸4三甲基化水平的研究

The study of histone H3 lysine 4 trimethylation in peripheral blood mononuclear cells of systemic lupus erythematosus patients

目的研究系统性红斑狼疮（SLE）患者外周血单个核细胞（PBMCs）组蛋白H3赖氨酸4（H3K4）三甲基化（Me3）水平。方法梯度密度离心法分离10例SLE活动期患者、7例SLE稳定期患者和8名健康者的PBMCs，采用染色质免疫共沉淀联合芯片技术（ChIP—chip）在全基因组范围内对SLE患者及健康者的PBMCs组蛋白H3K4me3进行高通量的筛选。染色质免疫共沉淀一实时定量聚合酶链反应（ChIP—qPCR）验证芯片结果。定量反转录一聚合酶链反应（qRT—PCR）检测H3K4me3显著差异基因的mRNA表达水平。结果10例SLE活动期患者与健康对照相比较，鉴定出413个基因存在H3K4me3显著差异，其中137个基因显示H3K4me3程度增高，276个基因H3K4me3程度降低；7例SLE稳定期患者与健康对照相比较，发现393个基因存在H3K4me3表达差异，其中有112个基因H3K4me3程度增高，281个基因H3K4me3程度降低。ChIP—qPCR验证结果与CpG岛芯片的结果相一致。结论SLE患者与健康者之间的PBMCs存在组蛋白H3K4me3显著改变。ChIP—chiD技术有利于进一步揭示SLE分子机制，发现新的治疗靶点。

Objective To study histone H3 lysine 4 trimethylation （H3K4me3） in peripheral blood mononuclear cells （PBMCs） of systemic lupus erythematosus （SLE） patients. Methods PBMCs were isolated by density gradient centrifugation from 10 active SLE patients,7 inactive SLE patients and 8 healthy volunteers. Chromatin immunoprecipitation linked to microarrays （CHIP-chip） was used to profile the variations in H3K4me3 in CpG island regions in PBMCs of SLE patients and controls. ChIP-qPCR was used to validate the microarray results. To confirm correlations between H3K4me3 and gene expression, expression analysis by qRT-PCR was performed on three randomly selected H3K4me3 candidates. Results 413 （ 137 increased and 276 decreased H3K4me3） and 393 genes （112 increased and 281 decreased H3K4me3） displayed significant differences in H3K4me3 between active and inactive SLE when compared with healthy subjects. The results of ChIP-qPCR were consistent with microarray. Conclusion There are significant differences in H3K4me3 profiling between SLE and healthy subjects. These novel candidate genes may be potential biomarkers for future therapeutic targets. The ChiP-chip technology can help further reveal SLE molecular mechanisms and discover new therapeutic targets.