Calreticulin is involved in the protection of hypoxic preconditioning against cardiomyoblast H9c2 cell oxidative injury / 中国病理生理杂志

ABSTRACT

AIM:To investigate whether hypoxic preconditioning(HPC)protects cardiomyoblast H9c2 cells against oxidative injury,and to discuss whether calreticulin(CRT)contribute to this protection through p38 MAPK signaling pathway.METHODS:Cardiomyoblast H9c2 cells were randomly divided into eight groups as followshydrogen peroxide stress(H2O2);brief hypoxic exposure of 20 min to simulate hypoxic preconditioning(HPC);20 min of hypoxic exposure followed by 24 h of normoxic reoxygenation before hydrogen peroxide stress(HPC+H2O2),SB203580(the specific inhibitors of p38 MAPK)+HPC+H2O2,antisense oligonucleotides transfection of calreticulin(AS),AS+H2O2,AS+HPC+H2O2 and control.Morphological studies,estimation of lactate dehydrogenase(LDH)leakage and flow cytometry were employed to assess the cell apoptosis and necrosis.RT-PCR and Western blotting analysis was used to detect calreticulin expression and phosphorylation of p38 MAPK.RESULTS:The results obtained are as follows(1)HPC relieved cell injury caused by H2O2.Compared with those in H2O2 group,apoptosis rate and LDH leakage in culture medium in HPC + H2O2 group decreased 13.4% and 44.0%,respectively(P