NADPH Exerts Myocardial Protection By Mediating CiRS-7

Objective:In the process of myocardial ischemia,the reduced nicotinamide adenine dinucleotide phosphate(NADPH)has a certain protective effect on the ischemic heart muscle,but there is no research on the level of genes.The purpose of this study was to observe the effect of NADPH on newborn rat cardiomyocytes(NRCM)in an Oxygen glucose deprivation/Reperfusion(OGD/R)model,and to explore the mechanism of its effect by inhibiting CiRS-7 in the protection of myocardial cells.Methods:to establish a primitive rat myocardial cells in vitro,with Hank’s balanced salt solution(HBSS)incubation NRCM,set up an Oxygen glucose deprivation/Reperfusion model by 95%N2 and 5%CO2.Western Blot(WB)method was used to detect the expression levels of MiR-7 target protein Cleaved PARP in NRCM of OGD/R groups at 0,3 and 6 hours after treatment(0.5 μM).Cell Counting kit 8(CCK8)was used to determine the influence of NADPH on the viability of NRCM at 0,3,6,12 and 24 hours after OGD/R.The differences of CiRS-7 and MiR-7’s expression levels and apoptosis degree in NRCM between the NADPH-treated group and the non-treated group after 3 hours of OGD/R were detected by qPCR and flow cytological analysis.It was inferred that NADPH had a protective effect on OGD/R-induced apoptosis of NRCMs.Results:the results of flow cytology and WB detection showed that,after OGD/R,the NRCMs were obviously apoptotic,and Cleaved PARP’s expression was significantly increased.However,after NADPH intervention,Cleaved PARP’s expression was significantly reduced in the dosed group compared to the untreated group,and the largest reduction was observed 3 hours after OGD/R.At this time,the expression of CiRS-7 in the dosed group was also significantly inhibited,and its "sponge effect" was sharply weakened,and the reverse increase of MiR-7’s expression significantly reduced the degree of myocardial cell apoptosisConclusion:NADPH can reduce CiRS-7’s "sponge adsorption effect" on MiR-7,and target the generation of Cleaved PARP,an apoptotic marker,which may be one of the mechanisms that NADPH plays a protective role in the apoptotic primary rat cardiomyocytes after OGD/R.