miR-33a-5p Inhibits the Proliferation and Migration of Vascular Smooth Muscle Cells in Atherosclerosis by Targeting S1PR1

Abstract

Background: Atherosclerosis is determined as a chronic, complicated disease, and arterial walls were mainly composed of vascular smooth muscle cells (VSMCs). microRNAs (miRNAs) have been consistently demonstrated to be involved in VSMCs, and miR-33a-5p was reported concerning many biological functions of cells. However, the role of miR-33a-5p during atherosclerosis still unclear. Methods: In present study, human VSMCs were treated with platelet-derived growth factorbb (PDGF-bb) after transfection. The miR-33a-5p and S1PR1 expression levels were determined by qRT-PCR and/or Western blot assays. VSMCs proliferation, invasion and migration were measured by CCK-8, transwell and wound healing assays, respectively. Luciferase reporter assay was employed to validate the direct targeting of S1PR1 by miR-33a-5p. Results: The results showed that PDGF-bb treated after 24 h could promote cell proliferation and regulate the expression of miR-33a-5p and S1PR1 in VSMCs. Overexpression of miR-33a-5p inhibited proliferation, invasion and migration in PDGF-bb treated VSMCs. Furthermore, we proved that miR-33a-5p could directly target S1PR1, and miR-33a-5p mimic suppressed the expression of S1PR1 in PDGF-bb treated VSMCs. Conclusions: The results suggested that miR-33a-5p could inhibit the proliferation, invasion and migration of VSMCs via suppressed the expression of S1PR1. miR-33a-5p/S1PR1 axis may represent a potential therapeutic strategy to improve atherosclerosis.