目的:探讨Notchl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Notchl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,realtime—PCR法检测Notchl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48h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Hes1 mRNA和Hes5 mRNA表达显著降低(P〈0.001),氟西汀组Notch1 mRNA、Hes1 mRNA和Hes5 mRNA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.