缺血预处理星形胶质细胞GDNF抑制p38MAPK信号通路减轻神经元凋亡

目的研究缺血预处理星形胶质细胞分泌GDNF抑制p38MAPK信号通路发挥脑保护作用。方法原代培养神经元及星形胶质细胞,给予缺血预处理,将星形胶质细胞培养基制备成条件培养基,沉默GDNF基因的培养基作为另一种条件培养基,将神经元分为对照组、预处理组、预处理+缺血组、缺血组,应用不同条件培养基孵育神经元,流式细胞术检测神经元凋亡,Western Blot法检测神经元p38MAPK及p-p38MAPK的表达。结果预处理+缺血组和缺血组神经元凋亡率明显增高(P<0.05),加入ACM2后凋亡率较ACM1和ACM3两组均减低(P<0.05)。每组神经元的p38MAPK蛋白表达均无明显变化(P>0.05);预处理+缺血组及缺血组p-p38MAPK的蛋白表达均明显高于对照组和预处理组(P<0.05),预处理+缺血组p-p38MAPK的蛋白表达均较缺血组低(P<0.05),加入ACM2组的p-p38MAPK蛋白表达低于ACM1和ACM3两组(P<0.05)。结论缺血预处理后星形胶质细胞分泌GDNF抑制p38MAPK信号通路的激活从而减少神经元凋亡,起到脑保护作用。

Inhibitory effect of GDNF on neuron apoptosis and its influence in p38MAPK signaling pathway

Objective To study the neuroprotective effect of GDNF secreted by astrocytes after ischemic preconditioning on p38MAPK signaling pathway.Methods Primary cultured neurons and astrocytes were pretreated with ischemia.The normal astrocyte medium were collected and named as ACM,the GDNF gene silenced medium was used as another ACM.Neurons were divided into control group,preconditioning group,preconditioning+ischemia group and ischemia group.The neurons were incubated with different ACM and detected by AnnexinV-FITC/PI FCM technique.The expression of p38MAPK and p-p38MAPK were detected by Western blot.Results The apoptotic rate of neurons in preconditioning+ischemia group and ischemia group was significantly higher(P<0.05),and the apoptotic rate of neurons in ACM2 group was lower than that in ACM1 and ACM3 group(P<0.05).There was no significant change in p38MAPK protein expression in each group of neurons(P>0.05);p-p38MAPK protein expression in the pretreatment+ischemia group and ischemia group was significantly higher than that in the irradiation group and pretreatment group(P<0.05),p-p38MAPK protein expression in the preconditioning+ischemia group was lower than that in the ischemia group(P<0.05),and P-P38 MAPK protein expression in the ACM 2 group was lower than that in ACM1 and ACM 3 groups(P<0.05).Conclusion GDNF secreted by astrocytes can inhibit the activation of p38MAPK signaling pathway and decrease neuron apoptosis after ischemic preconditioning,which plays an important role in cerebral ischemia.