ERK 1/2 mediates the cytoprotection of H_2O_2 preconditioning against oxidative injury in PC 12 cells

Aim To explore whether H2O2 precondi-tioning can activate ERK1/2 and the role of ERK1/2in H2O2 preconditioning-induced adaptive cytoprotection.Methods The experimental model of H2O2 preconditioning against PC 12 cells injury induced by H2O2 at high concentration was set up.The viability of cells was measured by MTT assay.The percentage of apoptotic cells was assessed by propidium iodide stain flow cytometry(FCM).The levels of ERK1/2 and procaspase-3 were detected by Western blot assay.Results Preconditioning of H2O2 at 100 μmol·L-1 for 90 min significantly protected PC 12 cells against 300 μmol·L-1 H2O2-induced injury,increasing cell viability and procaspase-3 expression,and reducing percent of apoptotic cells.H2O2 preconditioning obviously induced cytosolic ERK1/2 phosphorylation and promoted its nuclear translocation.UO126(10 μmol·L-1),an inhibitor of ERK1/2,used 30 min before H2O2 preconditioning,markedly blocked the anti-cytotoxibity and anti-apoptosis induce by H2O2 preconditioning.Conclusion H2O2 preconditioning could activate ERK1/2 which mediates the adaptive cytoprotection of H2O2 preconditioning in PC 12 cells.