Abstract: Objective To explore the role of conventional protein kinase C (cPKC) γ in hypoxic preconditioning (HPC) protecting mouse N2A neuroblastoma cells against oxygen-glucose deprivation (OGD)-induced ischemic injuries in vitro and its possible molecular mechanism. Methods By establishing hypoxic preconditioning (HPC) and oxygen-glucose deprivation (OGD) N2a cell models, and using thiazolyl blue tetrazolium bromide (MTT), lactate dehydrogenase (LDH) assay, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining and Western blot for LC3 II/I to detect the levels of N2a cell injury, necrosis, apoptosis and autophagy, respectively. Results OGD 2 and 4 h could significantly affect the viability and mortality of N2a cells, respectively (P<0.05, n=6 per group); HPC (20 min) could protect the N2a cells against OGD 3 h-induced ischemic injuries, but the cPKCγ inhibitor Go6983b (6 nmol/L) abolished this neuroprotection of HPC (P<0.05, n=16); OGD 3 h significantly increased the apoptosis numbers(P<0.05, n=6), but both HPC and HPC+Go6983 did not affect OGD 3 h-induced cell apoptosis of N2a cells; OGD 3 h could enhance the autophagy level of N2a cells, but both Go6983 and HPC+Go6983, not HPC alone, could inhibit OGD 3 h-induced cell autophagy (P<0.05, n=6); HPC could significantly inhibit OGD 3 h-induced cell necrosis, but cPKCγ inhibitor Go6983 (HPC+ Go6983) abolished this HPC-induced neuroprotection (P<0.05, n=16). Conclusion These results demonstrated that cPKCγ plays an important role in HPC protecting N2a cells against OGD-induced ischemic injuries, and this neuroprotective effect of HPC is mainly due to the reduction in necrosis of OGD treated N2a cells.

Key words: Hypoxic preconditioning (HPC), Oxygen-glucose deprivation (OGD), Cell apoptosis, Cell autophagy, Cell necrosis