银杏叶提取物对缺血-再灌流神经元损伤的保护作用及其信号转导机制

目的研究银杏叶提取物(EGB761)对缺糖缺氧/复糖复氧神经元损伤的保护作用,并探讨其主要细胞内信号转导机制。方法利用原代培养的皮层神经元,通过去除培养液中的糖和氧(oxygen and glucose deprivation,OGD)模拟缺血缺氧,恢复糖氧供给模拟再灌流。通过免疫蛋白印迹法测定Akt、磷酸化Akt(p-Akt)蛋白的表达。再灌流时加用银杏叶提取物(EGB761)观察其对神经元保护作用以及对Akt、p-Akt表达的调节作用。结果缺糖缺氧/复糖复氧后神经元p-Akt表达明显下降,EGB761可剂量依赖地保护神经元活性,并可上调因缺糖缺氧/复糖复氧而降低的p- Akt蛋白的表达,但该作用不被Ly294002所阻断。结论EGB761对培养的神经元缺糖缺氧/复糖复氧损伤有保护作用,该作用可能与非PI3K依赖的p-Akt信号转导通路激活有关。

The effect of EGB761 and the role of p-Akt signal on the cultured cortical neurons after oxygen and glucose deprivation/reoxygenation

Objective To investigate the signal pathway involved in cultured reperfusion neurons and the protective effect of EGB761 (extract of folium ginkgo biloba).Method The ischemic-reperfusion model was established by deprivating both glucose and oxygen in medium,and then gave them back.Western blotting was used to detect the expression of both Akt protein kinase B and Phospho-Akt (p-Akt) protein.EGB761 was added with 4 different concentrations at the beginning of reperfusion.Results The expression of p-Akt protein was down regulated after ischemia-reperfusion injury.After they were treated with EGB761,the reduction of both MTT and expression of p-Akt protein was reversed,but Ly294002,a PI3K inhibitor,could not abrogate this effect. Conclusions EGB761 could protect the neurons against reperfusion injury,and the mechanism may be associated with activation of p-Akt protein expression.