Division of Rheumatology and Clinical Immunology, Charité - Universitätsmedizin Berlin, Institute of Health, Freie Universität and Humboldt-Universität, Berlin, Germany.
Deutsches Rheuma-Forschungszentrum Berlin (DRFZ), a Leibniz-Institute, Berlin, Germany.
Rheumatology (Oxford). 2021 Apr 6;60(4):1984-1995. doi: 10.1093/rheumatology/keaa649.
Epigenetic modifications are dynamic and influence cellular disease activity. The aim of this study was to investigate global DNA methylation in peripheral blood mononuclear cells (PBMCs) of RA patients to clarify whether global DNA methylation pattern testing might be useful in monitoring disease activity as well as the response to therapeutics.
Flow cytometric measurement of 5-methyl-cytosine (5'-mC) was established using the cell line U937. In the subsequent prospective study, 62 blood samples were investigated, including 17 healthy donors and 45 RA patients at baseline and after 3 months of treatment with methotrexate, the IL-6 receptor inhibitor sarilumab, and Janus kinase inhibitors. Methylation status was assessed with an anti-5'-mC antibody and analysed in PBMCs and CD4+, CD8+, CD14+ and CD19+ subsets. Signal intensities of 5'-mC were correlated with 28-joint DASs with ESR and CRP (DAS28-ESR and DAS28-CRP).
Compared with healthy individuals, PBMCs of RA patients showed a significant global DNA hypomethylation. Signal intensities of 5'-mC correlated with transcription levels of DNMT1, DNMT3B and MTR genes involved in methylation processes. Using flow cytometry, significant good correlations and linear regression values were achieved in RA patients between global methylation levels and DAS28-ESR values for PBMCs (r = -0.55, P = 0.002), lymphocytes (r = -0.57, P = 0.001), CD4+ (r = -0.57, P = 0.001), CD8+ (r = -0.54, P = 0.001), CD14+ (r = -0.49, P = 0.008) and CD19+ (r = -0.52, P = 0.004) cells.
The degree of global DNA methylation was found to be associated with disease activity. Based on this novel approach, the degree of global methylation is a promising biomarker for therapy monitoring and the prediction of therapy outcome in inflammatory diseases.
表观遗传修饰是动态的，会影响细胞疾病的活性。本研究旨在研究类风湿关节炎（RA）患者外周血单个核细胞（PBMCs）中的全基因组 DNA 甲基化，以明确全基因组 DNA 甲基化模式检测是否可用于监测疾病活动及治疗反应。
采用 U937 细胞系建立 5-甲基胞嘧啶（5'-mC）的流式细胞术测量方法。在随后的前瞻性研究中，检测了 62 个血样，包括 17 名健康供体和 45 名 RA 患者，这些患者在基线时以及接受甲氨蝶呤、白细胞介素-6 受体抑制剂沙利鲁单抗和 Janus 激酶抑制剂治疗 3 个月后进行检测。采用抗 5'-mC 抗体评估甲基化状态，并在 PBMCs 以及 CD4+、CD8+、CD14+和 CD19+亚群中进行分析。5'-mC 的信号强度与 28 关节疾病活动度评分（DAS28）与红细胞沉降率（ESR）和 C 反应蛋白（DAS28-ESR 和 DAS28-CRP）相关联。
与健康个体相比，RA 患者的 PBMCs 表现出显著的全基因组 DNA 低甲基化。5'-mC 的信号强度与参与甲基化过程的 DNMT1、DNMT3B 和 MTR 基因的转录水平相关。在 RA 患者中，采用流式细胞术检测，全基因组甲基化水平与 PBMCs（r=-0.55，P=0.002）、淋巴细胞（r=-0.57，P=0.001）、CD4+（r=-0.57，P=0.001）、CD8+（r=-0.54，P=0.001）、CD14+（r=-0.49，P=0.008）和 CD19+（r=-0.52，P=0.004）细胞的 DAS28-ESR 值之间存在显著的良好相关性和线性回归值。
全基因组 DNA 甲基化程度与疾病活动度相关。基于这种新方法，全基因组甲基化程度有望成为炎症性疾病中治疗监测和治疗结果预测的有前途的生物标志物。
