Protective Effects Of P38MAPK Inhibitor SB203580on NMDA-induced Injury In Primary Cerebral Cortical Neurons

ObjectiveTo observe the protective effects of SB203580on NMDA-induced cerebralcortical neurons apoptosis in vitro, then to explore whether p38MAPK signaltransduction pathway, Bcl-2and Bax are involved in anti-apoptosis actionproduced by SB203580and its mechanism.MethodsThe primary cortical neurons was adopted and then they were randomlydivided into five groups, Control group, Injury group and SB203580groups(10μmol/L,100μmol/L,1000μmol/L). The release rate of LactateDehydrogenase (LDH), MTT staining and acridine orange/ethidium bromidefluorescence staining were used to investigate the effects of the drugs. Cellapoptosis morphology was observed by acridine orange/ethidium bromidefluorescence staining. Expression states of p38MAPK, Bcl-2and Bax wereobserved by Immunohistochemical methods and Western Blot, thereby toinvestigate its possible protective mechanism.Results①Neurons were labeled by NSE antibody using immunocytochemistryABC method, The ratio of positive neurons was90.35%.②Cerebral corticalneurons were damaged by different concentrations of NMDA in adose-dependent manner, The result showed that50μmol/L NMDA damage toneurons apoptosis.③The cell survival was assaid by MTT. Compared with thecontrol group, the OD value of the injury group was decreased (P<0.01),Compared with the injury, the OD value of protection groups were increased(P<0.01or P<0.05).④The extent of cell injury was determined by therelease rate of LDH. Compared with the control group, the release rate of LDHof the injury group was increased (P<0.01). Compared with the injury group, therelease rate of LDH of the protection groups were decreased (P<0.01), therewere dose-dependent neuroprotective effects in protection groups (P<0.05).⑤The number of apoptotic cells and cell apoptosis morphology were observedby acridine orange/ethidium bromide fluorescence staining. The number ofapoptotic cells was decreasing in the protection groups with dose-dependentrelationship.⑥Results of Immunohistochemical and Western Blotting showedthat SB203580can decrease the expression states of p38MAPK and Bax, andincrease the expression of Bcl-2, there are significant differences both the injurygroup and every protection group (P<0.01). In protection groups, the expressionstates of p38MAPK and Bax were decreasing (P<0.05), there aredose-dependent neuroprotective effects.Conclusions①SB203580has protective role on the NMDA-induced cortical neuronapoptosis in vitro. Compared with the injury group, cell survival of the evryprotection group is enhanced and LDH release rate is significantly decreased.②SB203580can decrease the expression states of p38MAPK and Bax, andincrease the expression of Bcl-2, then may reduce the cells apoptosis.③SB203580has dose-dependent neuroprotective effects relationship in theexperimental range.