Effect of dexmedetomidine on Src-mediated NR2A tyrosine phosphorylation in hippocampal neurons subjected to hypoxia-reoxygenation in mice

Abstract

Objective To evaluate the effect of dexmedetomidine on Src-mediated NR2A tyrosine phosphorylation in hippocampal neurons subjected to hypoxia-reoxygenation(H/R)in mice. Methods C57 mice at 18 days of gestation were sacrificed by pulling neck, fetal mice were obtained by caesarean section, and hippocampal neurons were isolated.Neurons were cultured in culture medium for 7 days and then divided into 3 groups(n=30 each)using a random number table method: control group(group C), H/R group and dexmedetomidine group(D group). Hippocampal neurons were exposed to 95% N2-5% CO2 in an incubator at 37 ℃ for 4 h followed by reoxygenation with 95% O2-5% CO2 for 24 h to establish the model of H/R.Dexmedetomidine was given at a final concentration of 1 μmol/L, and neurons were incubated for 4 h before establishing the model.The viability of hippocampal neurons was measured by MTT assay, TUNEL staining was used to observe apoptosis in hippocampal neurons, and the expression of c-Src, phosphorylated Src Y416(p-Src Y416), NR2A, phosphorylated NR2A Y1325(p-NR2A Y1325)and cleaved caspase-3 was determined by Western blot.Apoptosis index was calculated. Results Compared with group C, the viability of hippocampal neurons was significantly decreased, apoptosis index was increased, and the expression of p-Src Y416, p-NR2A Y1325 and cleaved caspase-3 was up-regulated in group H/R(P 0.05). Conclusion Dexmedetomidine can inhibit apoptosis in hippocampal neurons subjected to H/R, and the mechanism may be associated with decreasing Src-mediated NR2A tyrosine phosphorylation in mice. Key words: Dexmedetomidine; Anoxia; Hippocampus; Neurons; src-Family kinases; Receptors, N-methyl-D-aspartate; Tyrosine