氟西汀调控胎鼠神经干细胞增殖中Notch1通路基因表达的改变

Fluoxetine increases cell proliferation and mRNA expression of notch1 signaling in cultured neural stem cells

目的:探讨Notch1信号系统与氟西汀促进神经干细胞(NSCs)增殖的关系。方法:不同浓度的氟西汀干预NSCs,获取最适作用浓度。分别予Notch1信号通路抑制剂DAPT和氟西汀干预NSCs后,采用MTT检测NSCs的增殖,real time-PCR法检测Notch1信号各因子的基因表达。结果:(1)不同浓度的氟西汀干预细胞48 h后,10、15和20μmol.L-1组NSCs的活性高于0μmol.L-1组,差异有统计学意义(P<0.01);(2)与对照组相比,氟西汀组的细胞活性增高,DAPT组的活性降低,差异均有统计学意义(P<0.001)。与氟西汀干预组相比,氟西汀加DAPT组细胞活性降低,差异有统计学意义(P<0.001);(3)与对照组相比,DAPT组Hes1mRNA和Hes5 mRNA表达显著降低(P<0.001),氟西汀组Notch1 mRNA、Hes1 mRNA和Hes5mRNA表达显著增高(P<0.001或P<0.01);与氟西汀干预组相比,氟西汀加DAPT组的Notch1 mRNA、Hes1 mRNA和Hes5 mRNA表达均显著降低(P<0.001)。结论:氟西汀可能通过调控Notch1信号的传导促进NSCs的增殖。

Objective： To investigate whether the effect of fluoxetine on cell proliferation involves Notchl signaling in cultured neural stem cells（NSCs）. Methods： MTT assay was used to evaluate cell viability. The expression of Notchl signaling components（including Notchl mRNA, Hesl mRNA and Hes5 mRNA） was detected by real time PCR. Results： （ 1 ） When the cells were treated with the 10, 15 and 20 μmol·L^-1 fluoxetine for 48 h, the cell viabilities in cell- conditioned media were increased more significantly than that of the 0 μmol·L^-1 group （ P 〈 0. 01 ）. （2） MTT assay showed the presence of fluoxetine strongly enhanced the cell proliferation（P 〈 0. 001 ） compared with the control group, while DAPT decreased the cell proliferation （ P 〈 0. 001 ）. When fluoxetine was used in combination with DAPT, the cell proliferation was declined（ P 〈0.001 ） compared with fluoxetine group. （3） Inactivation of Notch signaling with DAPT led to a rapid reduction in the expression of Hesl mRNA and Hes5 mRNA （P 〈 0.001 ）. After the treatment of fluoxetine for 48 h, the expression of Notchl mRNA, Hesl mRNA and Hes5 mRNA increased significantly （ P 〈 0. 001 or P 〈 0. 01 ）. um with DAPT, real time PCR analysis revealed that the When NSCs were exposed to fluoxetine-conditioned mediexpression of Notchl mRNA, Hesl mRNA and Hes5 mRNA was decreased relative to fluoxetine-conditioned medium without DAPT（P 〈0. 001 in all case）. Conclusion： Notchl signaling might play a major role in the proliferation of NSCs promoted by fluoxetine.