Capsaicin Protects Cardiomyocytes Subjected To Anoxia/Reoxygenation Injury Mediated By 14-3-3?

Objective:Capsaicin(Cap)having a stimulating flavor is extracted from the pepper plant alkaloids.A beneficial role of capsaicin has been reported in cardiovascular in recent studies.Mitochondria plays an extremely important role in the pathways of apoptosis induced by myocardial ischemia/reperfusion(I/R)injury.14-3-3? is known as a protective factor in myocardial cells I/R injury,involved in stabilizing mitochondrial membrane potential,preventing mPTP open and reducing mitochondrial apoptosis.However,the mechanism has been rarely demonstrated that capsaicin protects cardiomyocytes from anoxia/reoxygenation(A/R)damage.In this study,we have established the H9c2 cell A/R injury model to determine whether capsaicin protects against myocardial hypoxia/reoxygenation injury,and to further explore the underlying mechanisms involved.Method:In this study,the H9c2 cardiomyocytes were randomly divided into 6 groups:(1)Control group;(2)hypoxia/reoxygenation group(Cap);(3)10?M capsaicin pretreatment group(Cap + A/R);(4)10?M capsaicin + AD-14-3-3?RNAi pretreatment group(Cap+AD-14-3-3?RNAi+A/R);(5)10?M capsaicin + ADscrRNAi pretreatment group(Cap + ADscrRNAi + A/R);(6)10?M capsaicin + 2?M ABT-737 pretreatment group(Cap + ABT-737 + A/R).The cell viability was measured by MTS colorimetric assay.According to the kit,the release of lactate dehydrogenase(LDH),the degree of mitochondrial permeability transition pore(mPTP)and the activity of cysteine protease(caspase-3)were analyzed with UV spectrophotometer.The standard of intracellular reactive oxygen species(ROS)and apoptosis were detected by flow cytometry.Western blotting analysis assayed the expression of 14-3-3?,antiapoptotic Bcl-2 protein and proapoptotic Bax protein.Results:1.The pretreatment of Cap decreased the release of LDH and increased the cell viability in H9c2 cells undergoing A/R injury(p<0.01).The 10?M capsaicin pretreatment group had a significant effect compared with A/R group.2.Compared with A/R group,preprocessing 10?M capsaicin was significantly attenuated ROS production along with inhibited mPTP opening and caspase-3 activation,downregulated expression of Bax and upregulated expression of 14-3-3? and Bcl-2,and ultimately reduced apoptosis in H9c2 cells undergoing A/R injury(p<0.01).3.Before capsaicin pretreatment,the addition of adenovirus 14-3-3?RNAi markedly eliminated the protective effect of Cap pretreatment in H9c2 cells undergoing A/R injury.In addition,addition of ABT-737(Bcl-2 inhibitor)significantly eliminated Cap protection compared with Cap + A/R group(p<0.01).Conclusion:The pretreatment of Cap protected against myocardial anoxia-reoxygenation injury,inhibited mitochondrial apoptosis pathway.The cardioprotective effects of Cap were involved in 14-3-3? signal pathway,and at least partly 14-3-3? dependent.