Abstract

Background

Macrophage migration and infiltration contribute to the pathogenesis of polymyositis (PM). This study aims to investigate the effect and underlying mechanism of miR-409-3p on macrophage migration in PM.

Methods

The GSE143845 database was used to predict the altered expression of microRNAs (miRNAs) in PM. The quantitative real-time PCR (qRT-PCR), western blot and Transwell assay were performed to detect migration of macrophages and expressions of related molecules. A luciferase activity assay was conducted to confirm the binding of miR-409-3p and CXCR4 3'-UTR. Next, a mouse model of experimental autoimmune myositis (EAM) was established. Haematoxylin and eosin (HE) staining, immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA) were used to measure associated factors.

Results

MiR-409-3p was downregulated in PM of GSE143845 database and patients. Differently, the serum creatine kinase (s-CK), TNF-α, and IL-6 in patients with PM were increased. Furthermore, miR-409-3p mimic transfection reduced the migration of macrophages and CXCR4 levels, while miR-409-3p inhibitor exerted the opposite effects. CXCR4 was a target of miR-409-3p, and the effect of CXCR4 on promoting macrophage migration was reversed by miR-409-3p mimic. In vivo, miR-409-3p agomir injection reduced inflammatory cells, macrophages, and TNFα and IL-6 levels in muscles and serum of EAM mouse models.

Conclusions

In conclusion, miR-409-3p reduces the migration of macrophages through negatively regulating CXCR4 expression in PM.

中文翻译：

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MicroRNA-409-3p 通过靶向 CXCR4 调节多发性肌炎中的巨噬细胞迁移

摘要

背景

巨噬细胞迁移和浸润有助于多发性肌炎 (PM) 的发病机制。本研究旨在探讨 miR-409-3p 对 PM 中巨噬细胞迁移的影响及其潜在机制。

方法

GSE143845 数据库用于预测 PM 中 microRNA (miRNA) 的表达改变。进行定量实时PCR（qRT-PCR），蛋白质印迹和Transwell测定以检测巨噬细胞的迁移和相关分子的表达。进行荧光素酶活性测定以确认 miR-409-3p 和 CXCR4 3'-UTR 的结合。接下来，建立了实验性自身免疫性肌炎（EAM）小鼠模型。苏木精和伊红 (HE) 染色、免疫组织化学 (IHC) 和酶联免疫吸附试验 (ELISA) 用于测量相关因素。

结果

MiR-409-3p 在 GSE143845 数据库和患者的 PM 中下调。不同的是，PM 患者的血清肌酸激酶 (s-CK)、TNF-α 和 IL-6 升高。此外，miR-409-3p 模拟转染降低了巨噬细胞的迁移和 CXCR4 水平，而 miR-409-3p 抑制剂发挥了相反的作用。CXCR4 是 miR-409-3p 的靶标，而 miR-409-3p 模拟物逆转了 CXCR4 促进巨噬细胞迁移的作用。在体内，注射 miR-409-3p agomir 可降低 EAM 小鼠模型肌肉和血清中的炎症细胞、巨噬细胞以及 TNFα 和 IL-6 水平。

结论

总之，miR-409-3p 通过负调节 PM 中 CXCR4 的表达来减少巨噬细胞的迁移。