miR-125a-5p Inhibits Oxidized Low-Density Lipoprotein-Induced Proliferation and Migration of Vascular Smooth Muscle Cells Through PI3K/AKT Signaling

Abstract

Certain microRNAs (miRNA/miRs) serve important roles in the progression of atherosclerosis (AS); however, the exact regulatory mechanisms of miRNAs in AS remain to be fully elucidated. The present study aimed to investigate the effects of miR-125a-5p in AS and the underlying mechanisms. Oxidized low-density lipoprotein (ox-LDL) was employed to stimulate human aortic vascular smooth muscle cells (HAVSMCs) to establish a cell model of AS. Reverse transcription-quantitative PCR was used to determine the expression levels of miR-125a-5p. Cell proliferation was evaluated using a Cell Counting Kit-8 (CCK-8) and migration was detected using a Transwell assay. In addition, the levels of the VSMC-specific marker gene α-smooth muscle actin, the cell cycleregulatory proteins cyclin-dependent kinase (CDK)2, cyclin D1, cyclin E and p27, as well as the migration-associated proteins matrix metalloproteinase-2 (MMP2) and MMP9, and phosphorylated phosphoinositide 3-kinase (p-PI3K) and p-AKT were determined by western blot analysis. The results revealed that transfection of miR-125a-5p mimics inhibited the ox-LDL-induced proliferation of HSVSMCs, accompanied by decreased expression of CDK-2, cyclin D1 and cyclin E, and increased expression of p27. Furthermore, miR-125a-5p mimics attenuated the ox-LDL-induced migration of HAVSMCs in parallel with downregulation of the expression of MMP2 and MMP9. Furthermore, the effect of ox-LDL to increase p-PI3K and p-AKT levels was significantly blunted by miR-125a-5p mimics. In conclusion, the present results suggested that miR-125a-5p mimics inhibited ox-LDL-induced proliferation and migration of HAVSMCs through inhibition of PI3K/AKT signaling, providing a potential novel therapeutic strategy for AS.