中文摘要：

目的观察和分析大脑皮质细胞低氧条件液对神经干细胞增殖的影响，并探讨磷脂酰肌醇3-激酶（P13-K）和C—Jun氨基末端激酶（JNK）两条信号通路在此过程中的作用。方法原代培养出生后24h内SD大鼠大脑皮质细胞5d后，全量换液并在4％O21％O2和常氧环境下继续培养细胞6h以制备低氧条件液和常氧条件液。分别用3种条件液及结合使用P13-K、JNK信号通路抑制剂LY294002和SP600125悬浮培养神经干细胞，并用免疫荧光染色鉴定神经干细胞，使用增殖效率（神经球数量）和增殖速度（神经球直径）分析神经于细胞的增殖情况。结果（1）4％低氧条件液组和常氧条件液组神经干细胞的增殖效率高于1％低氧条件液组（P〈0．01），但前两者之间差异无统计学意义；（2）与常氧条件液相比，两个低氧条件液均提高了神经干细胞的增殖速度（P〈0．01），且4％低氧条件液组神经干细胞的增殖速度较1％低氧条件液组快（P〈0．01）；（3）在4％低氧条件液中使用LY294002和SP600125同时抑制了神经干细胞的增殖效率和增殖速度，且LY294002抑制作用在24h之后尤为明显。结论4％大脑皮质细胞低氧条件液能提高神经干细胞的增殖速度，P13-K信号通路在此过程中发挥主要作用。

英文摘要：

Objective To investigate the effects of hypoxic conditioned medium （HCM） of cerebral cortex cells on the proliferation of neural stem cells （NSCs） and to discuss the role of phosphoinositide 3-kinase （PI3 K） and c Jun N terminal kinase （JNK） signal pathways in the process. Methods The cerebral cortex cells of newborn SD rats （within 24 h after birth） were primarily cultured for 5 days, the cells were then cultured under 4% 02, 1% 02 or normal oxygen for 6 h, and the cultured media were collected as the HCM and normoxic conditioned medium （NCM）. The specific inhibitors of P13-K and JNK （LY294002 and SP600125） were added into the conditioned medium to culture NSCs. And then immunofluorescence staining was performed to identify NSCs in the neurospheres. The proliferation efficiency（number of neurospheres） and speed （diameter of neurospheres） were used to analyze the effects of hypoxic conditioned media on the proliferation of NSCs. Results The proliferation efficiencies of 4 % HCM and NCM groups were significantly higher than that of 1% HCM group（P〈0.01）, and there was no significant difference between former two groups. The proliferation speed of two HCM groups was significantly faster than that of the NCM group（P〈0.01）, with the speed of 4% HCM group being the fastest one. The two inhibitors inhibited both the proliferation efficiency and speed of NSCs in the 4% HCM group（P〈0.01）, and the inhibitory effect of LY294002 was more prominent after 24 h. Conclusion 4% HCM of cerebral cortex cells can promote the proliferation speed of NSCs, and P13-K pathway may play an important role in it.