Study on cell lineage of neuronal stem cell in vitro

碱性成纤维细胞生长因子(碱性成纤维细胞生长因子)和表皮生长因子(EGF)可刺激发育早期脑神经干细胞的增殖。对于细胞上的生长因子受体，在培养系统中表达的时机似乎会影响其细胞谱系。在本研究中，重点关注神经干细胞的细胞谱系。胚胎发育12天，细胞从前脑中分离出来。建立了用光散射流式细胞术分离细胞的方法。此方法分离合格的神经干细胞可从影响培养体系中细胞事件的细胞悬液中得到高度纯化。在前脑细胞悬液中，A2B5结合的细胞占总细胞数的12%，而大多数细胞属于巢蛋白阳性细胞，两种抗体中的结合细胞也出现在悬液中。流式细胞仪分离的细胞分别在分化培养液中进行细胞培养。这些细胞群首先产生神经元细胞，然后产生神经胶质细胞。这些细胞随机产生神经前体细胞和神经胶质前体细胞。这一结果表明，神经干细胞在8~10天的培养期间未接受成纤维细胞生长因子的信号，在含有EGF的培养液中，神经干细胞在8~10天出现神经球，而在8天之前则没有。这似乎不同于成纤维细胞生长因子和表皮生长因子刺激细胞。

Basic fibroblast growth factor(bFGF) and epidermal growth factor(EGF) stimulates the proliferation of neural stem cells from early developmental brain. For the receptor of the growth factor on the cells, the timing of expression in culture system is seem to affects its cell lineage. In this study, focus on cell lineage of neural stem cells. The cells are separated from forebrain in embryonic stage at 12 day. The cell isolation method is established to use flow cytometry with light scattering. Isolation qualify in this method would be highly to purify neural stem cells from the cell suspension which effects to cellular events in culture system. In cell suspension of forebrain, A2B5 bound cells were appeared 12% in total cells, whereas almost cells were belonged to nestin-positive cells.The bound cells in both antibody were also appeared in the suspension. Cell culture is performed in differentiation medium in cells isolated by flow cytometry, respectively. These cell populations were generate neuronal cells first and glial cells later. The cells generate neural progenitor and glial progenitor cells randomly. This result would seem that glial progenitor was not accepted FGF signaling in culture period at 8 to 10 days.In medium containing EGF, neural stem cells were appeared neurospheres at 8 to 10 days, whereas not before 8 day. It seem to be a different between FGF and EGF stimulate cells.