Reduced miR-146a Promotes REG3A Expression and Macrophage Migration in Polymyositis and Dermatomyositis
Reduced miR-146a Promotes REG3A Expression and Macrophage Migration in Polymyositis and Dermatomyositis
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DOI：
10.3389/fimmu.2020.00037
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发表时间：
2020-02-21
影响因子：
7.3
通讯作者：
Gao, Mingzhu
中科院分区：
文献类型：
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作者：
Jiang, Tingwang;Huang, Yuanlan;Gao, Mingzhu
背景：来自其他研究的越来越多的证据表明，microRNAs(MiRNAs)在多发性肌炎和皮肌炎(PM/DM)中发挥重要作用。然而，关于它们与再生胰岛衍生蛋白3-α(REG3A)的关系以及它们在巨噬细胞迁移中的联合作用的报道很少。因此，本研究试图建立miR-146a与REG3A之间的联系，并探讨其在巨噬细胞迁移和PM/DM发病机制中的作用。方法：采用密度离心法分离PM/DM患者和健康对照组的外周血单个核细胞(PBMC)。从PBMC中分离纯化的单核细胞，通过分化获得巨噬细胞，然后将其与miRNA或质粒共转染，用Transwell实验检测细胞迁移情况。用实验性自身免疫性肌炎小鼠模型研究PM/DM。结果：PM/DM患者外周血中miR-146a、干扰素-γ、IL-17A和REG3A的mRNA表达水平显著低于正常对照组，而REG3A、干扰素-γ和IL-17A的mRNA水平显著高于正常对照组。PM/DM患者血清中的干扰素-γ和IL-17A水平明显高于正常对照组。免疫组织化学分析显示，REG3A在患者肌肉组织中的表达增加。与临床一致，实验性自身免疫性肌炎小鼠肌肉组织中miR-146a的mRNA表达水平也显著降低，而REG3A、干扰素-γ和IL-17A的mRNA和蛋白水平显著升高。此外，miR-146a抑制单核细胞来源的巨噬细胞迁移，而REG3A促进巨噬细胞迁移。此外，IL-17A诱导REG3A表达，而miR146a抑制健康供者单核细胞来源的巨噬细胞REG3A的表达。结论：miR-146a在PM/DM中的表达降低，导致REG3A表达增加，从而促进炎性巨噬细胞的迁移，这可能是DM/PM的发病机制之一。
Background: Growing evidence from studies elsewhere have illustrated that microRNAs (miRNAs) play important roles in polymyositis and dermatomyositis (PM/DM). However, little has been reported on their relationship with regenerating islet-derived protein 3-alpha (REG3A) as well as their associative roles in macrophage migration. Therefore, this study sought to establish the association between miR-146a and REG3A as well as investigate their functional roles in macrophage migration and PM/DM pathogenesis.Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from PM/DM patients and healthy controls through density centrifugation. Macrophages were obtained from monocytes purified from PBMCs via differentiation before their transfection with miRNA or plasmids to investigate cell migration with transwell assay. An experimental autoimmune myositis murine model was used to investigate PM/DM. Real-time PCR and Western blot analysis were conducted to determine the expression levels of miR-146a, interferon gamma (IFN-gamma), interleukin (IL)-17A, and REG3A.Results: The messenger RNA (mRNA) expression level of miR-146a markedly decreased, while the mRNA level of REG3A, IFN-gamma, and IL-17A expression increased substantially in PBMCs from PM/DM patients compared with the healthy controls. The levels of IFN-gamma and IL-17A in serum from PM/DM patients was much higher than the healthy controls. Immunohistochemistry analysis showed that REG3A expression increased in muscle tissues from patients. Consistent with clinical data, the mRNA expression level of miR-146a also decreased, whereas the mRNA and protein level of REG3A, IFN-gamma, and IL-17A significantly increased in the muscle tissues of experimental autoimmune myositis mice. Moreover, miR-146a inhibited monocyte-derived macrophage migration, and REG3A promoted macrophage migration. In addition, IL-17A induced REG3A expression, while miR146a inhibited expression of REG3A in monocyte-derived macrophages from the PBMCs of the healthy donors. Notably, inhibition of macrophage migration by miR-146a was via the reduction in REG3A expression.Conclusions: Reduced miR-146a expression in PM/DM leads to increased REG3A expression that increases inflammatory macrophage migration, which may be a possible underlying mechanism of DM/PM pathogenesis.