Nakafuku M, Nakamura S
Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.
J Neurosci Res. 1995 Jun 1;41(2):153-68. doi: 10.1002/jnr.490410203.
In the mammalian central nervous system (CNS), multipotential neural stem cells in the neuroepithelium generate the three major types of neural cells, namely, neurons, astrocytes, and oligodendrocytes. To explore the molecular mechanisms underlying proliferation and differentiation of these neural stem cells, we established a cell line named MNS-57 from the embryonic day 12 rat neuroepithelium by introducing the mycer fusion gene, in which c-myc can be conditionally activated by adding oestrogen to the culture medium. MNS-57 cells expressed nestin, vimentin, and the RC1 antigen, which are potential markers for neural stem cells. We show that under particular culture conditions, MNS-57 cells can conditionally generate neurons, astrocytes, and oligodendrocytes in vitro, indicating that they are likely to originate from multipotential neural stem cells. Incubating MNS-57 cells with either oestrogen, which activates mycer, or growth factors such as basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) stimulated their growth, and the combination of oestrogen and bFGF (or EGF) had a synergistically stronger mitogenic effect than the single factors. Furthermore, both c-myc activation and bFGF appeared to be necessary for the differentiation of MNS-57 cells, and only when stimulated by both signals simultaneously, the cells committed to generating multiple neural cell types. Thus, the property of the cell line is unique in that its differentiation into neurons and glia can be conditionally manipulated in vitro in an exogenous signal-dependent manner. We propose that the cell line described here will provide an useful in vitro model to understand genetic and environmental mechanisms that control the generation of neural cell diversity in the CNS.
在哺乳动物的中枢神经系统（CNS）中，神经上皮中的多能神经干细胞可生成三种主要类型的神经细胞，即神经元、星形胶质细胞和少突胶质细胞。为了探究这些神经干细胞增殖和分化的分子机制，我们通过导入mycer融合基因，从胚胎第12天的大鼠神经上皮中建立了一个名为MNS-57的细胞系，在该基因中，c-myc可通过向培养基中添加雌激素来实现条件性激活。MNS-57细胞表达巢蛋白、波形蛋白和RC1抗原，这些都是神经干细胞的潜在标志物。我们发现，在特定的培养条件下，MNS-57细胞能够在体外条件性地生成神经元、星形胶质细胞和少突胶质细胞，这表明它们可能起源于多能神经干细胞。用激活mycer的雌激素或诸如碱性成纤维细胞生长因子（bFGF）和表皮生长因子（EGF）等生长因子培养MNS-57细胞，可刺激其生长，并且雌激素与bFGF（或EGF）的组合比单一因子具有更强的协同促有丝分裂作用。此外，c-myc激活和bFGF似乎都是MNS-57细胞分化所必需的，只有当同时受到这两种信号刺激时，细胞才会分化生成多种神经细胞类型。因此，该细胞系的特性独特之处在于其向神经元和神经胶质细胞的分化可在体外以依赖外源性信号的方式进行条件性调控。我们认为，本文所述的细胞系将为理解控制中枢神经系统中神经细胞多样性生成的遗传和环境机制提供一个有用的体外模型。
