神经生长因子对缺氧神经干细胞凋亡和分化功能的影响

Effects of NGF on apoptosis and differentiation of hypoxic cultured neural stem cells

目的探讨缺氧环境对培养的胎鼠大脑神经干细胞(neural stem cells,NSCs)凋亡和分化的影响及神经生长因子(nerve growth factor,NGF)的作用。方法将培养至第3代的NSCs分为3组,对照组:正常培养;缺氧组:缺氧培养(5%CO2、90%N2);NGF作用组:缺氧培养同时加入NGF,分别培养3天。Western blot测定NSCsBcl-2、Bax蛋白含量;RT-PCR测定NSCs分化细胞bcl-2、bax和nse、nne、gfap基因表达。结果NSCs分化的第1、2、3天,缺氧组bcl-2较NGF作用组和对照组明显降低,bax明显增加(P<0.01);NGF作用组bcl-2在NSCs分化的第1、3天与对照组比较差异有显著性意义,bax在NSCs分化的第1、2、3天均无差异。缺氧组nse、nne表达在第1、2、3天均低于对照组和NGF作用组,gfap表达高于对照组和NGF作用组(P<0.01);NGF作用组与对照组比较,nse表达在第2、3天差异有显著性意义,nne表达在第1、3天差异有显著性意义,gfap表达在第2天差异有显著性意义(P<0.01)。结论缺氧可引起NSCs凋亡,NGF具有保护NSCs抗凋亡的功能。

Objective To investigate the effects of hypoxia condition on apoptosis and differentia tion of fetal rat cerebral neural stem cells（NSCs） and the protective effects of NGF on NSCs in hypoxia. Methods Third generation of NSCs was randomly divided into three groups： control group of normal cultures without hypoxia, hypoxia group cultivated in hypoxia and NGF group cultivated in hypoxia with addition of NGF. Each group was cultivated for 36 h. Bcl-2 and Bax protein contents were measured by Western blot and bcl-2, bax, nne, nse,gfap gene expression was examined by RT-PCR. Results In hypoxia group,bcl-2 content depressed and bax content in- creased obviously（ P〈0.01） as compared with other two groups after NSCs were differentiated for 1,2,3 days. Bcl-2 and bax expression was not different between NGF group and control group on day 2 and days 1,2,3 of differentiation of NSCs respectively. Expression of nse and nne was lower in hypoxia group than in control and NGF groups,but gfap expression was hipher on days 1,2,3 of differentiation（ P〈0. 01）. Compared with control group,nse expression in NGF group had obvious difference on days 2,3 of differentiation,nne and gfap expression had notable differ-ences on days 1,3 and day 2 of differentiation respectively. Conclusion NSCs apoptosis can be caused by hypoxia and some apoptotic genes and NSCs marker genes show different alterations by hypoxia. NGF has the function of protecting NSCs against apoptosis.