Oxyen glucose deprivation ischemic preconditioning prevents neuron apoptosis through GDNF secreted by astrocytes

• 1、Department of Neurolrogy, the China-Japan Union Hospital of Jilin University
• 2、Author address Department of Neurolrogy, the China-Japan Union Hospital of Jilin University

Abstract：Objective: To explore the influence of GDNF secreted by preconditioning astrocytes on the apoptosis of primary cortical neurons and to identify the effect of GDNF on different stage of apoptosis. Methods: ACM1 was collected from normal astrocyte medium. Astrocytes were exposed to preconditioning and ischemia, after 24h reperfusion, astrocyte medium was collected, and named as ACM2. The astrocytes, transfected GDNF RNAi pGenesil-1, were exposed to OGD preconditioning and ischemia, and the astrocyte medium was collected at 24h reperfusion named as ACM3. Neurons were divided into 4 groups: the normal control group, the preconditioning group, the preconditioning and ischemia group and the ischemia group. After the last ischemia, using ACM1, ACM 2 and ACM 3 to culture the neurons, so an interaction system of astrocyte/neuron was established. 24h later, the apoptosis of neurons were detected by staining method of AO/EB and AnnexinV-FITC/PI FCM technique. Results: The AO/EB double staining method showed clearly that there were more necrotic neurons in ischemia group, and the rate of apoptosis in preconditioning and ischemia group was lower than that in the ischemia group(p<0.05). The rate of apoptosis in ACM2 group was lower than in ACM1 and ACM3 groups. The early apoptotic neurons were less in the ACM2 group than in the ACM1 and ACM3 groups by FCM (p<0.05). Conclusions: OGD preconditioning could induce astrocytes to secrete GDNF that could decrease the rate of ischemic neuronal apoptosis. The results of FCM showed that GDNF could play an endogenous protection role through decreasing the rate of neuronal early apoptosis.

Keywords： preconditioning astrocyte GDNF apoptosis