Effects of miR-652-3p targeting homeotype nuclear gene 1 in the regulation of angiotensin II-induced cardiomyocyte apoptosis

Objective To investigate the effect of miR-652-3p targeting autonomous heterologous nuclear gene 1 (PRRX1) in the regulation of angiotensinⅡ (AngII) -induced cardiomyocyte apoptosis. Methods Rat cardiac cell H9c2 cultured under normal conditions were used as the control group, while AngⅡgroup were established in medium containing 1 μmol/L AngⅡ. These cells were transfected with miR-652-3p+Vctor and miR-652-3p mimics respectively. In addition AngⅡ-H9c2 cells transfected with miR-652-3p mimics were transfected with pc-PRRX1 and overexpressed-PRRX1. The expression of miR-652-3p in H9c2 was determined by quantitative real-time PCR (qRT-qPCR) . Detection of cell apoptosis was evaluated by using flow cytometry. In addition the protein expression levels of Bax and Bcl-2 were assessed by Western blot analysis. Gene regulatory relations between miR-652-3p and PRRX1 were confirmed by Dual-Luciferase reporter gene system. The t-test was applied for comparison between two groups and single factor variance analysis (one-way ANOVA) was used for comparison among several groups. The SNK-q test method was used to compare between groups. Results Compared with control group, the level of miR-652-3p (1.00±0.08 vs 0.21±0.05) and Bcl-2 protein (0.83±0.08 vs 0.40±0.04) in H9c2 cells were lower in AngⅡgroup, while PRRX1 protein level (0.06±0.01 vs 0.41±0.04) , apoptosis rate (5.02﹪±1.41﹪vs 25.33﹪±3.75﹪) , Bax protein level (0.46±0.05 vs 0.96±0.10) were higher (all P< 0.05) . Compared with AngⅡ+NC group, the expression level of miR-652-3p (0.24±0.06 vs 0.98±0.07) and Bcl-2 protein level in the AngⅡ+miR-652-3p group (0.38±0.04 vs 0.72±0.07) were higher while the PRRX1 protein level (0.39±0.04 vs 0.13±0.01) , and apoptosis rate (27.02﹪±4.11﹪ vs 12.19﹪±1.63﹪) , Bax protein level (0.95±0.09 vs 0.53±0.05) were lower (all P< 0.05) . Compared with the AngⅡ+miR-652-3p+Vctor group, the apoptosis rate of H9c2 cells (12.88﹪±1.84﹪vs 25.45﹪±3.58﹪) as well as expression of PRRX1 protein (0.13±0.01 vs 0.35±0.04) and Bax protein (0.54±0.05 vs 0.82±0.08) in the AngⅡ+ miR-652-3p+PRRX1 group were higher (all P< 0.05) , whereas Bcl-2 protein level (0.72±0.07 vs 0.46±0.05) was lower (all P< 0.05) . Conclusion AngⅡcould down-regulatethe expression of miR-652-3p in cardiomyocytes. Additionally, Up-regulation of miR-652-3p could reduce the apoptosis of H9c2 cells induced by AngⅡ by targeting the inhibition of PRRX1 expression. Key words: miR-652-3p; Autonomous heterologous nuclear gene 1; AngiotensinⅡ; Cardiomyocyte apoptosis