人胚额叶皮层和海马干细胞的自主分化研究

目的 研究人胚胎额叶皮层和海马组织神经干细胞的自主分化特性。观察额叶皮层神经干细胞和海马神经干细胞特性的异同。方法 从人胚胎额叶皮层和海马组织分别分离提出神经干细胞，经无血清体外培养、扩增，形成神经球。神经球贴壁进行不加诱导剂的自主分化。采用细胞生长曲线检测神经干细胞的增殖能力。使用5-溴脱氧尿嘧啶核苷（BrdU）标记分裂增生的细胞，观察细胞的分裂增殖情况。免疫细胞化学法鉴定神经干细胞的自主分化能力，比较额叶皮层和海马神经干细胞的分化特点。结果 从人胚胎额叶皮层和海马分离的神经干细胞具有增殖能力，额叶皮层神经干细胞的细胞倍增时间为3．9d，海马神经干细胞的细胞倍增时间为3．2d。细胞贴壁分化后出现Nestin、GFAP、Tuj-1表达阳性的细胞。皮层和海马神经干细胞分化产生的Tuj-1阳性细胞分别是40．7％和19．3％；皮层和海马神经干细胞分化产生的GFAP阳性细胞分别是59．3％和80．7％。结论 分离培养的额叶皮层和海马神经干细胞具有自我更新和增殖能力，可以向神经元、胶质细胞分化。额叶皮层神经干细胞与海马神经干细胞的倍增时问、自主分化特点和分化为神经细胞和胶质细胞的比率各有不同。

The characteristics of neural stem cells derived from human fetal cortex and hippocampus in default differentiation

Objective To study the biological characteristics of neural stem cells derived from human fetal cortex and hippocampus in vitro culture and the differences between them. Methods Neural stem cells were isolated from human fetal cortex and hippocampus. By culturing in serum-free medium, Neurospheres formed after proliferation. Upon the removal of mitogens,neurospheres was adhered to the dish wall. The proliferation of the neural stem cells were measured via growth curve. The cells were labeled with BrdU for observation of cell division and proliferation. The neural stem cells and the default differentiated cells were distinguished via immunochemical method and to observe the differences between cortex and hippocampus neural stem cells. Results It was found that the neural stem cells from human fetal cortex and hippocampus had the ability of proliferation. Their doubling time were 3.9 and 3.2 days. Nestin, GFAP, and Tuj-1 expressing cells were identified after adhesion differentiation. Tuj-1 positive cells were 40.7% and 19.3% in the differentiated neural stem cells of cortex and hippocampus. GFAP positive cells were 59.3% and 80.7% in the differentiated neural stem cells of cortex and hippocampus. Conclusion The neural stem cells isolated and cultured from human fetal cortex and hippocampus have the ability of self-renewal and proliferation. They are able to differentiate into neurons and astrocytes. The doubling time, characteristics of neural stem cells in default differentiation and the rate of Tuj-1 and GFAP positive cells are different between cortex and hippocampus.