Cortical Neurons Injury Induced By NMDA Via P38MAPK Signaling Pathway And Protective Mechanism Of MK801and SB203580

ObjectiveTo observe the effects of N-methyl-D-aspartic acid (NMDA)-induced injuryon primary cultured cerebral cortical neurons, using NMDAR inhibitor andp38MAPK inhibitor to intervene, to explore the role and mechanism of p38mitogen-activated protein kinases (p38MAPK) signaling pathway on neuronsinjury in the two aspects of the signal transduction pathway and apoptosisfactors.MethodsNMDAR specific agonist NMDA was chosen to build cells injury model invitro. Newborn SD rat cortical neurons were cultured for7days, then randomlyassigned to five groups: control group, NMDA injury group（NMDA50μmol/L）,MK801interventional group（NMDA50μmol/L+MK80110μmol/L）, SB203580interventional group （NMDA50μmol/L+SB20358010μmol/L）, Combinedinterventional group （NMDA50μmol/L+MK801and SB20358010μmol/L,respectively）. Immunofluorescence staining for NSE identify the purity ofneurons, MTT assays and LDH release were employed to assess viability ofprimary neurons and cell membrane damage, respectively. Acridineorange/ethidium bromide (AO/EB) double fluorescent staining to observemorphology and cell apoptosis. Expression of p-p38MAPK, BCL-2and BAX were observed respectively by IHC and Western Blot.ResultsCompared to control group, Cells viability were decreased markedly,leakage of LDH and the number of apoptosis were increased significantly, theexpression of p-p38MAPK and BAX were increased, the expression of BCL-2were decreased in NMDA group (P<0.05, P<0.01); Compared to NMDA injurygroup, MK801and SB203580improved the cell viability, reduced LDH releaserate and apoptosis, decreased the expressions of p-p38MAPK and BAX,increased the expression of BCL-2(P<0.05,P<0.01), and Combinedinterventional group have most obvious effect.ConclusionNMDA can induce cortical neuronal injury, MK801and SB203580haveprotective effects on NMDA-induced injury neurons, MK801may protect theneurons from NMDA injury through p38MAPK pathway, the commonmechanism is partly inhibiting p38MAPK signaling pathway mediated apoptosisrelated proteins.