Circ-MARC2 silencing protects human cardiomyocytes from hypoxia/reoxygenation (H/R)-induced injury by modulating miR-335-5p/TRPM7 axis

Abstract

Abstract Myocardial ischemia-reperfusion injury (MIRI) is a vital risk factor for cardiovascular diseases. Some circular RNAs (circRNAs) have been identified as modulators of MIRI. But, the effects of circ-mitochondrial amidoxime reducing component 2 (circ-MARC2) in MIRI are unclear. Our results showed that circ-MARC2 was overexpressed in hypoxia/reoxygenation (H/R)-treated AC16 cells. Circ-MARC2 silencing reversed the inhibitory effect of H/R treatment on cell proliferation and promoting effects on lactate dehydrogenase (LDH) activity, creatine kinase (CK-MB) activity and cell apoptosis in AC16 cells. Moreover, circ-MARC2 served as the sponge for miR-335-5p and ameliorated H/R-induced AC16 cell damage by decoying miR-335-5p. Additionally, transient receptor potential cation channel subfamily M member 7 (TRPM7) was identified as the target gene of miR-335-5p. Overexpression of miR-335-5p relieved H/R-induced AC16 cell damage, while TRPM7 elevation abolished the effect. Circ-MARC2 knockdown was able to relieve H/R-induced AC16 cell injury through miR-335-5p/TRPM7 axis.