LincRNA RMRP Regulates Phenylephrine-induced Cardiomyocyte Hypertrophy by Means of Targeting miR-1.

Abstract

Cardiac hypertrophy is a feature of hypertrophic cardiomyopathy (HCM), which could lead to heart failure and other cardiovascular diseases. Cardiomyocyte hypertrophy (CH) is the primary characteristic of cardiac hypertrophy. Long noncoding RNA (lncRNA, lincRNA) plays an important role in CH. In this study, the expression of linc-RMRP and its correlation with cardiac hypertrophy were analyzed in cardiac tissues of patients with HCM. Real-time qPCR and western blotting measured the expressions of lincf-RMRP, miR-1, and hypertrophic marker genes. RNA pulldown and luciferase reporter gene assays were performed to validate the combination between linc-RMRP and miR-1. We confirmed that Linc-RMRP was upregulated in both cardiac hypertrophy tissues and phenylephrine (PE)-induced CH cells, and the cells presented hypertrophic features, enlarged cell surface area and volume, elevated total protein contents, and increased expressions of ANP, BNP, β-MHC, and activated p70S6K and 4EBP1. Bioinformatic analysis found that linc-RMRP directly bonds to miR-1. RNA pulldown, mutation, and luciferase reporter gene assays verified this combination. Silencing linc-RMRP significantly attenuated hypertrophic responses induced by PE while the expression of miR-1 was released. However, the transfection of miR-1 inhibitor reversed the effects of linc-RMRP knockdown exerted on PE-treated cardiomyocytes. In summary, our study identified the modulatory role linc-RMRP played in regulating PE-induced CH by means of binding miR-1, and this might provide a new target for cardiac hypertrophy therapy.