EGb761对谷氨酸诱导海马神经元兴奋毒性损伤中p75NTR表达的影响

Effect of EGb761 on expression of p75NTR in cultured hippocampal neurons after glutamate-induced excitotoxicity

目的：观察谷氨酸诱导海马神经元兴奋毒性损伤中神经营养因子受体p75（p75neurotrophin receptor,p75NTR）表达水平的变化,探讨银杏叶提取物（EGb761）抗兴奋毒性神经保护作用与p75NTR的相关性.方法：建立谷氨酸诱导的新生大鼠海马神经元兴奋毒性损伤模型,观察25200mg/L剂量下EGb761的神经保护作用;RT-PCR,Western Blot及细胞免疫荧光染色方法检测p75NTR的表达变化.结果：100mg/LEGb761预处理给药的神经保护效果最明显;谷氨酸刺激后,p75NTR在mRNA和蛋白质水平的表达较对照组明显增高（P〈0.01）;EGb761本身对p75NTR表达无影响,而EGb761预处理组p75NTR在mRNA和蛋白质水平的表达较谷氨酸组均显著降低（P〈0.05）.结论：p75NTR在谷氨酸诱导兴奋毒性神经损伤中起着重要作用,EGb761抗兴奋毒性神经保护作用可能与抑制p75NTR的表达有关.

AIM：To observe the changes in the expression level of p75NTR（p75 neurotrophin receptor）in cultured hippocampal neurons after glutamate-induced excitotoxicity and to explore the correlation between the antiexcitotoxic effect of Ginkgo biloba extract（EGb761）and p75NTR.METHODS：Excitotoxicity was induced by glutamate in rat cultured hippocampal neurons and the neuroprotective effect of 25-200 mg/L EGb761 was observed.RT-PCR,Western blot and immunofluorescence staining were used to detect the changes in the expression level of p75NTR.RESULTS：100 mg/L was determined as the optimal dose of EGb761 against glutamate-induced excitotoxicity.p75NTR at mRNA and protein levels increased markedly compared with those in control group（P〈0.01）.EGb761 itself had no obvious effect on p75NTR expression,but EGb761 pretreatment decreased p75NTR at mRNA and protein levels dramatically compared with that in glutamate group（P〈0.05）.CONCLUSION：p75NTR plays an important role in neuronal damage after glutamate-induced excitotoxicity and the antiexcitotoxic effect of EGb761 might relate to reduction of the expression level of p75NTR.