CircRNA ACAP2 induces myocardial apoptosis after myocardial infarction by sponging miR-29

BACKGROUND: The aim of this study was to investigate the effect of circular RNA circ ACAP2 on apoptotic phenotype of rat cardiomyocytes and its molecular mechanism. METHODS: Left anterior descending ligation was used to establish a rat myocardial infarction (MI) model, and real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of circ ACAP2 in apoptotic rat cardiomyocytes. The stability of circ ACAP2 was tested by actinomycin D and RNase R. H9C2 cells were infected by recombinant circ ACAP2 adenovirus (rAd-circ ACAP2), and the expression of apoptotic related genes Bax and BCL-2 in H9C2 was detected. Double luciferase reporter gene experiment, RNA antisense purification experiment and RNA PullDown experiments verified the binding effect of circ ACAP2 and miR-29. RESULTS: RT-qPCR results showed that the expression of circ ACAP2 was increased in cardiomyocytes of MI rats. Actinomycin D and RNase R experiment confirmed that circ ACAP2 had better stability and resistance to RNase R degradation than its host gene ACAP2 mRNA. Overexpression of circ ACAP2 promotes apoptosis. The double luciferase reporter gene assay, RNA antisense purification assay and RNA Pulldown assay consistently confirmed the specific binding effect between circ ACAP2 and miR-29, and circ ACAP2 promoted the apoptotic phenotype in rats. CONCLUSIONS: The expression of circ ACAP2 increased in cardiomyocytes after MI and promoted apoptosis by binding to miR-29.