MiR-128-3p inhibits vascular smooth muscle cell proliferation and migration by repressing FOXO4/MMP9 signaling pathway.

BACKGROUND: MicroRNAs (miRNAs) have been identified as important participants in the development of atherosclerosis (AS). The present study explored the role of miR-128-3p in the dysfunction of vascular smooth muscle cells (VSMCs) and the underlying mechanism. METHODS: Human VSMCs and ApoE knockout (ApoE-/-) C57BL/6J mice were used to establish AS cell and animal models, respectively. Expression levels of miR-128-3p, forkhead box O4 (FOXO4) and matrix metallopeptidase 9 (MMP9) were detected using qRT-PCR and Western blot, respectively. CCK-8, BrdU, and Transwell assays as well as flow cytometry analysis were performed to detect the proliferation, migration and apoptosis of VSMCs. Levels of inflammatory cytokines and lipids in human VSMCs, mice serum and mice VSMCs were also determined. The binding site between miR-128-3p and 3'UTR of FOXO4 was confirmed using luciferase reporter gene assay. RESULTS: MiR-128-3p was found to be decreased in AS patient serum, ox-LDL-treated VSMCs, AS mice serum and VSMCs of AS mice. Transfection of miR-128-3p mimics suppressed the proliferation and migration of VSMCs, accompanied by the promoted apoptosis and the decreased levels of inflammatory cytokines. Further experiments confirmed the interaction between miR-128-3p and FOXO4. Augmentation of FOXO4 or MMP9 reversed the effects of miR-128-3p. Besides, miR-128-3p inhibited triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) but increased high-density lipoprotein cholesterol (HDL-C) in the serum of AS mice. CONCLUSION: MiR-128-3p repressed the proliferation and migration of VSMCs through inhibiting the expressions of FOXO4 and MMP9.