Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
EECS, University of California, Berkeley, Berkeley, CA, USA.
Brain. 2019 Mar 1;142(3):647-661. doi: 10.1093/brain/awy344.
Cell-permeable formulations of metabolites, such as fumaric acid esters, have been used as highly effective immunomodulators in patients with multiple sclerosis and yet their mechanism of action remains elusive. Since fumaric acid esters are metabolites, and cell metabolism is highly intertwined with the epigenetic regulation of gene expression, we investigated whether this metabolic-epigenetic interplay could be leveraged for therapeutic purposes. To this end we recruited 47 treatment-naïve and 35 fumaric acid ester-treated patients with multiple sclerosis, as well as 16 glatiramer acetate-treated patients as a non-metabolite treatment control. Here we identify a significant immunomodulatory effect of fumaric acid esters on the expression of the brain-homing chemokine receptor CCR6 in CD4 and CD8 T cells of patients with multiple sclerosis, which include T helper-17 and T cytotoxic-17 cells. We report differences in DNA methylation of CD4 T cells isolated from untreated and treated patients with multiple sclerosis, using the Illumina EPIC 850K BeadChip. We first demonstrate that Krebs cycle intermediates, such as fumaric acid esters, have a significantly higher impact on epigenome-wide DNA methylation changes in CD4 T cells compared to amino-acid polymers such as glatiramer acetate. We then define a fumaric acid ester treatment-specific hypermethylation effect on microRNA MIR-21, which is critical for the differentiation of T helper-17 cells. This hypermethylation effect was attributed to the subpopulation of T helper-17 cells using a decomposition analysis and was further validated in an independent prospective cohort of seven patients before and after treatment with fumaric acid esters. In vitro treatment of CD4 and CD8 T cells with fumaric acid esters supported a direct and dose-dependent effect on DNA methylation at the MIR-21 promoter. Finally, the upregulation of miR-21 transcripts and CCR6 expression was inhibited if CD4 or CD8 T cells stimulated under T helper-17 or T cytotoxic-17 polarizing conditions were treated with fumaric acid esters in vitro. These data collectively define a direct link between fumaric acid ester treatment and hypermethylation of the MIR-21 locus in both CD4 and CD8 T cells and suggest that the immunomodulatory effect of fumaric acid esters in multiple sclerosis is at least in part due to the epigenetic regulation of the brain-homing CCR6+ CD4 and CD8 T cells.
细胞可渗透的代谢物制剂，如富马酸酯，已被用作多发性硬化症患者的高效免疫调节剂，但它们的作用机制仍不清楚。由于富马酸酯是代谢物，而细胞代谢与基因表达的表观遗传调控高度交织，我们研究了这种代谢-表观遗传相互作用是否可以用于治疗目的。为此，我们招募了 47 名未经治疗和 35 名接受富马酸酯治疗的多发性硬化症患者，以及 16 名接受格拉替雷治疗的患者作为非代谢物治疗对照。在这里，我们确定了富马酸酯对多发性硬化症患者 CD4 和 CD8 T 细胞中脑归巢趋化因子受体 CCR6 表达的显著免疫调节作用，其中包括辅助性 T 细胞 17 和 T 细胞毒性 17 细胞。我们使用 Illumina EPIC 850K BeadChip 报告了未经治疗和接受治疗的多发性硬化症患者分离的 CD4 T 细胞中 DNA 甲基化的差异。我们首先证明，与氨基酸聚合物（如格拉替雷）相比，三羧酸循环中间体（如富马酸酯）对 CD4 T 细胞的全基因组 DNA 甲基化变化有更显著的影响。然后，我们定义了富马酸酯治疗对 microRNA MIR-21 的特异性高甲基化效应，这对于辅助性 T 细胞 17 细胞的分化至关重要。使用分解分析确定了这种高甲基化效应归因于辅助性 T 细胞 17 细胞亚群，并在接受富马酸酯治疗前后的七名患者的独立前瞻性队列中进一步验证。体外用富马酸酯处理 CD4 和 CD8 T 细胞，支持 MIR-21 启动子上 DNA 甲基化的直接和剂量依赖性效应。最后，如果在体外用富马酸酯处理 T 辅助 17 或 T 细胞毒性 17 极化条件下刺激的 CD4 或 CD8 T 细胞，则 miR-21 转录物和 CCR6 表达的上调被抑制。这些数据共同定义了富马酸酯治疗与 CD4 和 CD8 T 细胞中 MIR-21 基因座的高甲基化之间的直接联系，并表明富马酸酯在多发性硬化症中的免疫调节作用至少部分归因于脑归巢 CCR6+CD4 和 CD8 T 细胞的表观遗传调控。
