1. miR-770-5p inhibits the activation of pulmonary fibroblasts and silica-induced pulmonary fibrosis through targeting TGFBR1.
- Author
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Yuan J, Li P, Pan H, Xu Q, Xu T, Li Y, Wei D, Mo Y, Zhang Q, Chen J, and Ni C
- Subjects
- Adult, Aged, Animals, Down-Regulation, Fibroblasts metabolism, Fibrosis, Humans, Lung metabolism, Lung pathology, Male, Mice, Mice, Inbred C57BL, Middle Aged, Pulmonary Fibrosis chemically induced, Signal Transduction, Silicosis pathology, Transforming Growth Factor beta1 metabolism, Fibroblasts drug effects, Lung drug effects, MicroRNAs metabolism, Pulmonary Fibrosis metabolism, Receptor, Transforming Growth Factor-beta Type I metabolism, Silicon Dioxide adverse effects, Silicosis metabolism
- Abstract
Silicosis is a devastating interstitial lung disease arising from long-term exposure to inhalable silica. Regrettably, no therapy currently can effectively reverse the silica-induced fibrotic lesion. Emerging evidence has indicated that the dysregulation of microRNAs is involved in silica-induced pulmonary fibrosis. The aim of this study is to explore the expression pattern and underlying mechanisms of miR-770-5p in silica-induced pulmonary fibrosis. Consistent with our previous miRNA microarray analysis, the results of qRT-PCR showed that miR-770-5p expression was downregulated in silica-induced pulmonary fibrosis in humans and animal models. Administration of miR-770-5p agomir significantly reduced the fibrotic lesions in the lungs of mice exposed to silica dust. MiR-770-5p also exhibited a dramatic reduction in TGF-β1-activated human pulmonary fibroblasts (MRC-5). Transfection of miR-770-5p mimics significantly decreased the viability, migration ability, and S/G0 phase distribution, as well as the expression of fibronectin, collagen I, and α-SMA in TGF-β1-treated MRC-5 cells. Transforming growth factor-β receptor 1 (TGFBR1) was confirmed as a direct target of regulation by miR-770-5p. The expression of TGFBR1 was significantly increased in pulmonary fibrosis. Knockdown of TGFBR1 blocked the transduction of the TGF-β1 signaling pathway and attenuated the activation of MRC-5 cells, while overexpression of TGFBR1 effectively restored the activation of MRC-5 cells inhibited by miR-770-5p. Together, our results demonstrated that miR-770-5p exerted an anti-fibrotic effect in silica-induced pulmonary fibrosis by targeting TGFBR1. Targeting miR-770-5p might provide a new therapeutic strategy to prevent the abnormal activation of pulmonary fibroblasts in silicosis., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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