低氧诱导星形胶质细胞血管内皮生长因子表达

Hypoxia induced expression of vascular endothelial growth factor in cultured astrocytes

目的探讨低氧环境对体外培养的胎鼠大脑星形胶质细胞血管内皮生长因子(VEGF)表达的影响。方法采用孕16d的SD胎鼠大脑组织培养星形胶质细胞,实验分为正常组(正常培养,5%CO_2,95%空气,37℃,绝对湿度)和低氧组(低氧培养,5%CO_2,2%O_2,93%N_2,37℃、绝对湿度)。MTT实验观察细胞经2、4、6、8、10h低氧培养后细胞增殖情况,免疫荧光染色观察细胞经4、8、12、24、32h低氧培养后VEGF表达的变化。结果低氧组胶质细胞增殖除6h与正常组无差异外,2、4、8、10h较正常组均明显增高,差异有统计学意义(P<0.05);低氧组8、12h VEGF表达明显高于正常组,24、32h VFGF表达明显低于正常组(P<0.05)。结论低氧培养短期可促进星形胶质细胞增殖,VEGF表达升高,长期低氧可至星形胶质细胞损伤,VEGF表达下降。

Objective To investigate the effect of hypoxia on expression of vascular endothelial growth factor（VEGF） in astrocytes isolated from fetal rat brain. Methods Astrocytes were isolated from cerebral cortex of pregnant 16 d fetal SD rats,and divided into two groups：control group （5%CO2,95%air,37℃ ,absolute humidity） and hypoxia group（5%CO2,2%O2,93%N2,37℃ ,absolute humidity）. After the cells were cultured for 2,4,6,8 and 10 h, the proliferation of astrocytes was detected by MTT assay. The change of VEGF expression was examined by immunoflo- rescance staining after the cells were cultured for 4,8,12,24 and 32 h in hypoxia. Results Compared with the control group, the cell viability of hypoxia group was markedly increased at 2,4,8, 10 h except 6 h （P 〈 0.05）. VEGF expression of astrocytes in hypoxia group was higher after the cells exposed to hypoxia for 8,12 h and lower at 24,32 h than that in control group （P 〈 0.05）. Conclusion Proliferation and VEGF expression of astrocytes were promoted after a short-time hypoxia culturing,but the cells would be injured and VEGF expression decreased after long-time exposure to hypoxia.