中枢神经系统不同部位来源的神经干细胞在体外生长特性的比较

目的 比较相同发育阶段中枢神经系统不同部位来源的神经干细胞在体外的生长特性。方法 胚胎小鼠(E14)于无菌条件下分别分离并收集皮层、纹状体、间脑、中．后脑和脊髓，各部分制备成单细胞悬液，接种在添加有纤维细胞生长因子(FGF)的无血清培养液内，神经干细胞克隆生成后，经免疫细胞化学方法鉴定细胞特性，并在相同条件下进行传代，相差显微镜下观察克隆生成和细胞的迁移特性。结果 在添加有纤维细胞生长因子的无血清培养液中，少量接种的单个细胞会增殖并形成悬浮于细胞培养液中的细胞克隆。这些克隆具有生成新克隆并分化成神经元和胶质细胞的能力。在相同发育阶段，皮层、纹状体、间脑均可生成悬浮的克隆，其中皮层生成的速度最快，纹状体、间脑较慢，中．后脑、脊髓生成克隆的速度最慢；生成克隆后，皮层克隆的贴壁能力最差，贴壁的克隆少有细胞从其底部迁出，纹状体、间脑克隆较易贴壁，贴壁克隆底部有明显的细胞迁出，中．后脑、脊髓生成的克隆不易悬浮，很快贴壁，在贴壁克隆的底部有大量的细胞迁出。结论 在无血清培养液中，神经干细胞可在体外增殖、传代并分化生成神经元和胶质细胞，不同部位来源的神经干细胞在体外生成克隆的速度和细胞迁移性不同，这可能同体内特定部位细胞的发育特性有关。

THE GROWTH PROPERTY OF NEURAL STEM CELLS ISOLATED FROM DIFFERENT PARTS OF MICE CNS--AN IN VITRO STUDY

Objective To compare the growth property of the stem cells taken from different brain regions at the same developmental stage. Methods Mice embryos at the same development stage were isolated under sterile conditions, cortex, striatum, diencephalon, mid-hind brain and spinal cord were collected and pooled separately, after single-cell suspension obtained, different regions' cell suspensions were seeded in FGF supplemented serum-free culture medium. Followed the neural stem cell clone(neurospheres) fromation, immuno-cytochemistry method was utilized to identify the cell characteristics, all these clones were passaged under same conditions, clone formation and cell migration were observed under phase-contrast microscope. Results In the FGF added serum-free medium, neural cells experienced a large scale death within 48h after being seeded, then few single cells began to proliferate and formed the floating cell clones in the medium. These clones (neurospheres) could form new clones when seeded as single cell suspension. If these clones were seeded on poly-orithine, they could differentiate into neurons and glia cells. Compare the clone formation and cell migration, we found that: cortex, striatum, diencephalon all could form floating clones with different rate, the cortex formed clones at the highest rate, striatum and diencephalon at lower rate; few neurospheres formed from cortex adhered to the culture plate substrate and few cells were found migrating out from the adhered clones, striatum and diencephalon derived neurospheres adhered the plate more easily, and there were apparent cell migration. Mid-hind brain and spinal cord formed clones at the lowest rate, floating clones were scarce, and the clones adhered to the substrate readily, there were large amount of cell migrating out from these adhered clones. Conclusion Neural stem cells could proliferate and be passaged in vitro in serum-free medium, and they could be induced to differentiate under certain conditions into major cells types of CNS, there were differences in clone forming rate and cell migration between neural stem cells derived from different CNC regions, nonetheless they were at the same development stage, this may reflect that, in some degree, these cells can keep some of their region-specified developmental intrinsic property in vitro.