Myocardial Infarction–associated Transcript Knockdown Inhibits Cell Proliferation, Migration, and Invasion Through miR-490-3p/Intercellular Adhesion Molecule 1 Axis in Oxidized Low-density Lipoprotein-induced Vascular Smooth Muscle Cells

Abstract: Emerging evidence has demonstrated that long noncoding RNAs are related to the pathogenesis of atherosclerosis. We aimed to investigate the roles and molecular mechanisms of myocardial infarction–associated transcript (MIAT) in the proliferation, migration, and invasion of oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs). Quantitative real-time polymerase chain reaction was conducted to determine the levels of MIAT, microRNA490-3p (miR-490-3p), and intercellular adhesion molecule 1 (ICAM1). Cell Counting Kit-8 assay was performed to assess cell proliferation. Transwell assay was used to evaluate cell migration and invasion. Western blot assay was performed to measure the protein levels of proliferating cell nuclear antigen, N-cadherin, matrix metalloprotein-9, and ICAM1. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were conducted to verify the relationship between miR-490-3p and MIAT or ICAM1. MIAT was elevated in atherosclerosis patients' serum and ox-LDL–induced VSMCs. MIAT knockdown suppressed cell proliferation, migration, and invasion in ox-LDL–stimulated VSMCs. MIAT acted as a sponge of miR-490-3p, and miR-490-3p deficiency overturned the inhibition of MIAT knockdown on VSMC proliferation, migration, and invasion. ICAM1 was a direct target of miR-490-3p, and ICAM1 silencing repressed the proliferation, migration, and invasion of ox-LDL–stimulated VSMCs. Moreover, ICAM1 overexpression reversed the impacts of MIAT knockdown on ox-LDL–induced VSMC proliferation, migration, and invasion. MIAT knockdown could depress cell proliferation, migration, and invasion through miR-490-3p/ICAM1 axis in ox-LDL–induced VSMCs.