BMP-2和EGF对神经干细胞向神经元分化及Notch信号分子表达的影响

采用BMP-2(bonemorphogeneticprotein2)和EGF(epidemicgrowthfactor)诱导体外培养的神经干细胞分化,通过免疫荧光染色以及细胞计数方法,观察其分化为神经元的情况;用RTPCR和Westernblot检测Notch信号分子Notch1、PS1、RBPJk和HES1的表达水平。结果表明:BMP2组分化为神经元的比例明显高于对照(control,Ctrl)组和EGF组;EGF组分化为神经元的比例与Ctrl组相比无显著差别;与Ctrl组相比,BMP-2组和EGF组中Notch通路4种信号分子的mRNA表达量均无显著差异;PS1蛋白表达量也无明显差异。结果提示,BMP-2对神经干细胞分化为神经元的诱导作用强于EGF和自主分化,其分化为神经元的比例增加与Notch信号分子的表达水平无关。

EFFECTS OF BMP-2 AND EGF ON NEURONAL DIFFERENTIATION OF NEURAL STEM CELLS AND EXPRESSION OF NOTCH SIGNAL MOLECULES

Neural stem cells were induced to differentiate by BMP-2 (bone morphogenetic protein 2) and EGF (epidemic growth factor) in vitro respectively. Neuronal differentiation of neural stem cells was identified by immunofluorescence staining and cell counting. RT-PCR and Western-blot were employed to assay the expression of Notch pathway signal molecules: Notch1, PS1, RBP-Jk and HES1. The results revealed that the percentage of neurons in BMP-2 group was much higher as compared with EGF and Ctrl (control) groups; The percentage of neurons showed no difference between EGF and Ctrl groups. Neither the mRNA expression of Notch1, PS1, RBP-Jk and HES1 nor the expression of PS1 protein showed any difference among three groups. The present results indicate that BMP-2 shows more influence on neuronal differentiation of neural stem cells than EGF and Ctrl and there is no relationship between the increase of neurons induced with BMP-2 and Notch signaling.