Study On MiR-181a/b Regulate Vascular Smooth Muscle Cells Phenotype Through Serum Response Factor

Objective: To investigate the roles of mi R-181a/b in the smooth muscle cells(SMC) phenotypic switch from contractile phenotype to synthetic phenotype through serum response factor(SRF).Methods: mi R-181a/b mimics or inhibitors were transiently transfected into Human Aortic Smooth Muscle Cells(HAo SMCs), the expression of SMC phenotype marker gene were detected by quantitative realtime PCR(q RT-PCR), the proliferation and migration ability of HAo SMCs were measured by CCK-8 assay and transwell assay respectively. In addition, mi R-181a/b was indicated as directly targeting at 3’ UTR of SRF based on bioinformatic analysis and identified by q RT-PCR, western blot assay and dual-luciferase assay.Results: The results of q RT-PCR showed that mi R-181a/b could downregulated the expression level of SMC contractile marker genes and upregulated the expression level of SMC synthetic marker genes. The results of CCK-8 assay and transwell assay showed that mi R-181a/b could enhanced the proliferation and migration ability of HAo SMCs respectively. The results of Dual-luciferase assay and western blot assay showed that mi R-181a/b could directly target 3’UTR of SRF and inhibited the protein expression level of SRF.Conclusion: mi R-181a/b could regulate the shift of SMCs from contractile phenotype to synthetic phenotype through targeting at 3’ UTR of SRF.