MicroRNA-124-3p inhibits collagen synthesis in atherosclerotic plaques by targeting prolyl 4-hydroxylase subunit alpha-1 (P4HA1) in vascular smooth muscle cells

• Published in: Atherosclerosis Vol. 277; pp. 98 - 107
• Main Authors: Chen, Wei'jia, Yu, Fangpu, Di, Mingxue, Li, Mengmeng, Chen, Yifei, Zhang, Yu, Liu, Xiaolin, Huang, Xiaozhen, Zhang, Mei
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.10.2018
• Subjects: Animals; Atherosclerosis - enzymology; Atherosclerosis - genetics; Atherosclerosis - pathology; Atherosclerotic plaques; Cell Line; Collagen - biosynthesis; Collagen synthesis; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Genetic Predisposition to Disease; Humans; Lipoproteins, LDL - metabolism; Male; Mice, Knockout, ApoE; MicroRNAs - genetics; MicroRNAs - metabolism; miR-124-3p; Muscle, Smooth, Vascular - enzymology; Muscle, Smooth, Vascular - pathology; Myocytes, Smooth Muscle - enzymology; Myocytes, Smooth Muscle - pathology; P4HA1; Phenotype; Plaque, Atherosclerotic; Procollagen-Proline Dioxygenase - genetics; Procollagen-Proline Dioxygenase - metabolism; Rupture, Spontaneous; Signal Transduction; Vascular smooth muscle cells; Collagen synthesis; miR-124-3p; P4HA1; Vascular smooth muscle cells; Atherosclerotic plaques
• ISSN: 0021-9150; 1879-1484
• DOI: 10.1016/j.atherosclerosis.2018.08.034

Collagen synthesis in vascular smooth muscle cells (VSMCs) is very important in atherosclerosis, as it affects plaque stability. In this study, we aim to assess whether miR-124-3p is involved in the collagen synthesis process in VSMCs and the role it might play in atherosclerotic development. We modulated the miR-124-3p expression in the aortic root plaques of high-fat-diet fed ApoE−/− mice by lentivirus injection. To determine plaque size and the content of plaque-stability-related cells or molecules, stainings, including hematoxylin and eosin, Oil red O, Sirius Red and immunohistochemical staining, were performed. Fluorescence in situ hybridization (FISH) was used to locate miR-124-3p in atherosclerotic plaques. Western blotting and RT-qPCR were carried out to determine the level of P4HA1 as well as type I and type III collagen protein and mRNA expression. Results showed that collagen and VSMC content of plaques was inversely correlated with miR-124-3p levels. By FISH, we identified that miR-124-3p was primarily expressed by VSMCs. We also found that protein levels of type I and type III collagen in aortas and atherosclerotic plaques were decreased by miR-124-3p. We modulated miR-124-3p level in vitro and found it could inhibit collagen expression in HASMCs. This might be caused by the downregulation of P4HA1. P4HA1 was predicted as miR-124-3p's direct target, which was verified with a dual luciferase reporter assay and RIP test. The results presented here provide evidence that miR-124-3p inhibits VSMC collagen synthesis by directly targeting P4HA1, which might decrease atherosclerotic plaque stability. [Display omitted] •MiR-124-3p reduces the stability of atherosclerotic plaques by decreasing VSMC content and collagen expression.•MiR-124-3p could inhibit type I and type III collagen expression in VSMCs.•MiR-124-3p modulate collagen expression by directly targeting P4HA1.