摘要目的 将星形胶质细胞与β-淀粉样蛋白(Aβ1-40)诱导凋亡的PCI2细胞共育,观察星形胶质细胞条件培养液(ACM)对胚胎大鼠皮层神经干细胞(NSCs)体外定向分化为神经元的比例影响及机制,探讨神经营养素家族蛋白[包括脑源性神经营养因子(BDNF)、神经生长因子(NGF)、神经营养素-3(NT-3)]是否参与此过程. 方法 PC12细胞分别经10 μg/mLAβ1-40诱导不同时间(0、4、6、12、24h)后分为两部分,第一部分应用流式细胞技术检测不同时间点PC12细胞凋亡率;第二部分分别与星形胶质细胞共育2 d,将收集的ACM分为两部分.一部分应用ELISA法检测ACM中BDNF、NGF、NT-3蛋白含量,另一部分以1;3比例同DMEM/F12堵养基混合,对NSCs进行体外诱导分化,应用激光共聚焦显微镜、NSE免疫荧光技术鉴定和计数神经元分化比例. 结果 在Aβ1-40作用6 h时间点,PC12细胞凋亡率达高峰,与其共育的ACM中BDNF蛋白总量明显增高,诱导的NSCs神经元分化比例明显升高,与其他组比较,差异均有统计学意义(P<0.05). 结论 星形胶质细胞与Aβ1-40诱导凋亡的PCI2细胞共育后.ACM提高了NSCs向神经元的分化比例,ACM中BDNF可能参与了这一过程.

abstractsObjective To observe the effect of the conditioned medium obtained from the coculture of astrocytes and β-amyloid (Aβ1-40)-induced apoptotic PC12 cells on the neuronal differentiation efficiency of neural stem cells (NSCs), and investigate the possible involvement of the neurotrophins proteins including brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF)and neurotrophin-3 (NT-3) in the induced differentiation of the NSCs. Methods PCI2 cells wereinduced by Aβ1-40 for different time lengths (0, 4, 6, 12, and 24 h), and after detection of the apoptotic rates using flow cytometry, the cells were cocultured with astrocytes for 2 days. The astrocyte-conditioned medium (ACM), after analysis of the neurotrophins proteins using erLzyme-linked immunosorbent assay (ELISA), was mixed with DMEM/F12 medium at the proportion of 1:3 to induce the differentiation of the NSCs. The cell differentiation was identified by laser confocal microscopy, NSE immunofluorescent labeling, and neuronal counting. Results Flow cytometry showed that induction by Aβ1-40 for 6 h resulted in the highest apoptosis rate of PC12 cells (P<0.05). BDNF content in the ACM derived from the coculture of astrocytes and the PC12 cells induced for 6 h was significantly increased, and the NSCs induced in this ACM showed the highest neuronal differentiation rates, showing significant difference from those induced by other ACMs (P<0.05). Conclusion The ACM derived from the coculture of Aβ1-40-induced PC12 cells and astrocytes can increase the neuronal differentiation rates of NSCs in vitro, and BDNF in the ACM may play a role in this process.