Notch信号通路参与外源性碱性成纤维细胞生长因子对神经干细胞辐射损伤保护作用的实验研究

目的观察外源性碱性成纤维细胞生长因子（bFGF）对有DAPT存在情况下辐射诱导的C17．2神经干细胞凋亡的影响，探讨Nocth信号通路与bFGF之间的关系。方法MTF法检测细胞的活性，培养贴壁后的细胞按照试验设计加入不同浓度的DAPT，培养24h后，直线加速器进行照射，5min后加入40ng／ml的bFGF，培养48h后分别利用流式细胞仪检测细胞的凋亡。结果加入DAPT后，细胞的生长受到抑制，与对照组相比各组均有统计学意义（P〈0．05），加入bFGF组与DAPT组相比各组均有统计学差异（P〈0．05）；流式细胞技术结果显示，各组与正常对照组相比差异均有统计学意义（P〈0．05），辐射组的凋亡率为（11．53±0．81）％，辐射＋bFGF组的凋亡率为（7．18±0．94）％，单纯DAPT（50μmol／L）组的凋亡率为（9．8±0．77）％，辐射＋DAPT（50μmol／L）组的凋亡率为（21．45±0．98）％，辐射＋DAPT（50μmol／L）＋bFGF组的凋亡率为（10．26±1．03）％。辐射＋bFGF组与辐射组相比差异有统计学意义（P〈0．05），单纯DAPT组与辐射＋DAPT组间相同DAPT浓度两两比较差异均有统计学意义（P〈0．05），辐射＋DAPT组与辐射＋DAPT＋bFGF组间相同DAPT浓度两两比较差异均有统计学意义（P〈0．05）。结论外源性bFGF对放射诱导的C17．2神经干细胞凋亡有抑制作用，Notch信号通路阻断剂DAPT促进辐射后神经干细胞的凋亡，bFGF抑制DAPT凋亡的作用。bFGF对放射诱导的神经干细胞的保护作用可能与Notch信号通路有关。

The Notch signal path is involved in the protection of radiation-induced apoptosis of C17.2 neural stem cells by exogenous basic fibroblast growth factor

Objective To observe the effects of exogenous basic fibroblast growth factor （bFGF） on radi- ation-induced apoptosis of C17.2 neural stem cells（NSCs） with γ-seeretase inhibitor（DAPT） condition and ex- plore the relationship between bFGF and Notch signal pathway. Methods The cell viability was detected by using the MTF method.After the cells attached to the flasks, different concentrations of DAPT was added in accordance with the experimental design and cultured cells for 24 h.C17.2 NSCs were subjected to irradiation exposure by line- ar accelerator and treated with bFGF （40 ng/ml） 5 rain after the exposure. After 48 hours, the apoptosis of cells was detected by using Flow Cytometry. Results After adding in DAPT , the cells growth was inhibited and depen- ded on the concentrations of DAPT.Compared with the control group, all groups had statistically significant differ- ences（P〈0.05） .Flow cytometry showed compared with the control group all groups had significant differences （P〈 0.05 ） .The apoptosis rate was （ 11.53 ±0.81 ） % in radiation group, （ 7.18 ± 0.0.94 ） % in radiation ＋ bFGF group, （9.82±0.77） % in DAPT group, （21.45±0.98） % in Radiation＋DAPT group and （ 10.26± 1.03 ） % in Radiation＋ DAPT ＋bFGF group.Between Radiation ＋ bFGF group and Radiation group, it had statistically significant differ- ence（P〈0.05） .The pairwise comparisons of DAPT group and Radiation ＋ DAPT group which had the same DAPT concentration had statistically significant differences（P〈0.05）.The pairwise comparisons of Radiation ＋ DAPT＋bFGF group and Radiation ＋ DAPT group which had the same DAPT concentration had statistically significant difference（P〈0.05）. Conclusion Exogenous bFGF can inhibit apoptosis of C17.2 NSCs. Notch signaling pathway inhibitor DAPT can promote apoptosis of C17.2 NSCs which are subjected to irradiation exposure by linear accelerator and bFGF can weak apoptosis.bF- GF protective effect on radiation-induced neural stem cells may be related to the Notch signaling pathway.