Inhibition of endoplasmic reticulum stress through activation of MAPK/ERK signaling pathway attenuates hypoxia-mediated cardiomyocyte damage

The pathogenesis of post-infarction ischemia-induced myocardial damage is related to hypoxia-mediated cardiomyocyte damage. In the present study, we explored the roles of ERK signaling pathway and endoplasmic reticulum (ER) stress in hypoxia-related cardiomyocyte damage. H9c2 cells were cultured under hypoxia condition in the presence of the ERK activator. Our data demonstrated that ER stress was significantly activated by hypoxia in cardiomyocyte, as evidenced by increased expression of PERK and CHOP through immunofluorescence. Interestingly, application of ERK activator significantly reduced hypoxia-mediated ER stress. Besides, ERK activation also sustained cardiomyocyte viability in the presence of hypoxia, as evidenced by decreased activities of caspase-3 and caspase-9. Altogether, our results demonstrated that ERK activation significantly promoted cardiomyocyte survival through inhibition of ER stress. This finding provides a novel insight into the molecular mechanism underlying hypoxia-mediated cardiomyocyte damage. Besides, our results also offer a potential target for the treatment and prevention of post-infarction ischemia-related myocardial damage.