Foxp1在胚胎神经干细胞分化过程中的表达及其过表达对神经干细胞分化的影响

Expression of Foxp1 in differentiation of embryonic neural stem cells and effect of its overexpression on differentiation of neural stem cells

目的利用胚胎小鼠神经干细胞体外培养和分化模型过表达转录因子Foxp1,探讨Foxp1在胚胎神经干细胞分化过程中的表达及其过表达后对神经干细胞向神经元和星形胶质细胞分化的影响。方法从E12. 5d的胎鼠皮层分离培养神经干细胞并诱导分化3 d和7 d,经RT-PCR、Western blot检测Foxp1在神经干细胞分化过程中的表达;脂质体转染法在神经干细胞中过表Foxp1,免疫荧光及RT-PCR鉴定Map2阳性的神经元和GFAP阳性的星形胶质细胞分化; RT-PCR检测Jak/Stat信号通路相关分子Jak1和Stat1、Stat3、gp130的表达。结果 Foxp1在神经干细胞诱导分化3 d和7 d其mRNA和蛋白表达水平都显著升高(P <0. 05),且在分化3 d时表达水平最高;与对照组相比,在神经干细胞中过表达Foxp1提高了Map2阳性的神经元的分化比例及相应的Map2表达(P <0. 01),并降低了GFAP阳性的星形胶质细胞比例及GFAP的表达(P <0. 05);过表达Foxp1抑制了Jak1和Stat1、Stat3、gp130的表达(P <0. 01)。结论 Foxp1在神经干细胞向神经元分化过程表达水平升高,其过表达可促进神经干细胞向神经元方向的分化,并通过调节Jak/Stat信号通路抑制星形胶质细胞的产生。

Objective To explore the expression profile of Foxp1 in the differentiation of embryonic neural stem cells into neurons and astrocytes and the effect of its overexpression in the process in the model of in vitro culture and differentiation of neural stem cells. Methods Neural stem cells from the cortices of E12. 5 embryos of C57/6 J mice were isolated and cultured in vitro,and then induced to differentiate into neurons and astrocytes for 3 and 7 d. RT-PCR and Western blotting were employed to analyze the expression of Foxp1 during the differentiation. Lipofection was used to overexpress Foxp1 in neural stem cells,and then immunofluorescence assay and RT-PCR were employed to identify Map2 positive neurons and GFAP positive astrocytes. The mRNA levels of the related molecules of Jak/Stat signaling,including Jak1,Stat1,Stat3 and gp130 were tested by RT-PCR. Results The expression of Foxp1 at mRNA and protein levels was increased significantly in 3 d and 7 d after inducing the differentiation of neural stem cells(P < 0. 05),and its expression reached the highest level in 3 d(P < 0. 05). Compared to the control,overexpression of Foxp1 advanced the percentage of Map2 positive neurons(P < 0. 01),enhanced the expression level of MAP2(P < 0. 01),and decreased the proportion of GFAP positive astrocytes and the expression level of GFAP(P < 0. 05).Furthermore,Foxp1 overexpression also suppressed the expression of Jak1,Stat1,Stat3 and gp130(P < 0. 01).Conclusion Foxp1 is highly expressed in the neuronal differentiation of neural stem cells, and its overexpression can promote the neuronal differentiation and inhibit the astrocyte differentiation by modulating the Jak/Stat signaling pathway.