ABSTRACT
Aim To explore the role of endoplasmic reticulum stress(ERS) in Astragaloside Ⅳ-induced cardioprotection in H9c2 cardiac cells, and to explore the potential mitochondrial mechanism.Methods Conventional culture was performed of rat heart tissue-derived H9c2 cells.Experiment was randomly divided into the control group, the ERS inducer 2-Deoxy-D-Glucose(2-DG) group, Astragaloside Ⅳ and 2-DG combination group, Astragaloside Ⅳ group.Confocal microscopy was used to observe the changes of TMRE fluorescence intensity so as to confirm the influence of ERS on the mitochondrial potential, and further speculate on the opening of the mitochondrial permeability transition pore(mPTP).Western blot analysis was applied to detect the expressions of ERS proteins GRP 78, GRP 94 and IRE1.Transmission electron microscopy was used to observe the ultrastructure of the cells.Results Different doses of 2-DG could mimic the mPTP opener atractyloside to induce the mPTP opening with the peak at 100 μmol·L-1;Astragaloside Ⅳ significantly reduced 2-DG-induced mPTP opening, the expression of GPR 78, GRP 94 and IRE1 and reduced injury of mitochondria and endoplasmic reticulum.Conclusions Endoplasmic reticulum stress could be induced by 2-DG.Astragaloside ⅳ-induced mitochondrial cardioprotection involves inhibition of the ERS through GRP 78, GRP 94 and IRE1 by prevention of the mPTP opening.