依普利酮通过阻断Kv1.3通道调控Treg细胞外泌体miRNA信号抑制心肌纤维化的分子机制

调节性T细胞(Tregs)为重要抗炎细胞，在抑制免疫反应、维持机体免疫自适应平衡等方面具有重要生理意义，其主要分泌抗炎细胞因子IL-10和促纤维化因子TGF-β。免疫细胞因子可促进心肌纤维化(MF)，但有报道Tregs通过分泌IL-10能逆转MF。我们前期发现Tregs明显促进共培养的心肌成纤维细胞(CFs)增殖，胞内外TGF-β的增加明显高于IL-10的增加；而Tregs Kv1.3通道可被醛固酮受体拮抗剂eplerenone直接阻断或RNAi沉默则抑制Tregs活化，减少TGF-β分泌，抑制CFs增殖。外泌体携带miRNAs在细胞通讯中发挥重要作用，我们已证实Tregs来源的外泌体可促CFs增殖达84%。本研究拟过表达/沉默/抑制剂干预Kv1.3通道，高通量测序外泌体miRNA表达谱，明确差异miRNAs在Tregs促MF的中介作用，为抗MF提供免疫学新途径，为新药靶点研究奠定基础。

Regulatory T cell (Tregs) is an important anti-inflammatory cell, which plays an important role in inhibiting immune response and maintaining immune adaptive balance. It mainly secretes anti-inflammatory cytokine IL-10 and pro-fibrotic factor TGF-β. Immune cytokines can promote myocardial fibrosis (MF), but it has been reported that Tregs can reverse MF by secreting IL-10. Previously we found that Tregs significantly promoted the proliferation of co-cultured cardiac fibroblasts (CFs), and the increase of TGF-β was significantly higher than that of IL-10 whatever in extracellular or intracellular environments, meanwhile the Tregs Kv1.3 channels could be inhibited by eplerenone, an aldosterone antagonist directly or silenced through RNAi, to suppress the activation of Tregs, and decreased the secretion of TGF-β, so that to restrain the proliferation of CFs. Exosome carrying miRNAs exerts a crucial role in cell communication. We have confirmed that Tregs-derived exosome can facilitate CFs proliferation up to 84%. In this study, we plan to overexpress/silence/inhibit Kv1.3 channels, to conduct high-throughput sequencing of expression profile on the exosome miRNA, to clarify the mediating role of differential miRNAs in promoting MF by Tregs. It will provide a new immunologic approach for anti-MF, and lay a foundation for new drug target exploitation.