miR-132-3p mediates Functions of Vascular Smooth Muscle Cells through targeting PTEN expression and ERK1/2 pathway

Abstract Background This study was aimed to investigate the functional role of the microRNA (miR)-132-3p in rat vascular smooth muscle cells (VSMCs) and the potential mechanisms in abdominal aortic aneurysm (AAA). Methods VSMCs were transfected with miR-132-3p mimics and inhibitors, and the effects of miR-132-3p on VSMCs proliferation, migration were assessed by CCK-8 assay and Boyden chamber cell invasion assay, respectively. miRNA targets were determined using bioinformatics and luciferase reporter assays. The protein expression of phenotype markers and related signaling pathways were detected by Western blot. Results Overexpression of miR-132-3p in VSMCs attenuated VSMCs proliferation and migration. Conversely, the opposite effect was obtained with the inhibition of miR-132-3p. We further demonstrated that miR-132 could significantly promote the expression of VSMCs marker genes ACTA2 and MYH1. Reporter assays and western blot validated that PTEN as a direct target of miR-132-3p in VSMCs. Besides, miR-132-3p overexpression could also promote the expression of ras and c-myc, and activate the phosphorylation levels of ERK1/2. Conclusions These results indicate that miR-132-3p is a critical regulator in maintaining normal functions of VSMCs through PTEN-ERK1/2 axis. Restoring expression of miR-132-3p may serve as a potential therapeutic approach for treatment of AAAs.