ESTABLISHMENT AND CHARACTERIZATION OF A MULTIPOTENTIAL NEURAL CELL-LINE THAT CAN CONDITIONALLY GENERATE NEURONS, ASTROCYTES, AND OLIGODENDROCYTES IN-VITRO

In the mammalian central nervous system (CNS), multipotential neural s tem cells in the neuroepithelium generate the three major types of neu ral cells, namely, neurons, astrocytes, and oligodendrocytes. To explo re the molecular mechanisms underlying proliferation and differentiati on of these neural stem cells, we established a cell line named MNS-57 from the embryonic day 12 rat neuroepithelium by introducing the myce r fusion gene, in which c-myc can be conditionally activated by adding oestrogen to the culture medium. MNS-57 cells expressed nestin, vimen tin, 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 i n vitro, indicating that they are likely to originate from multipotent ial neural stem cells. Incubating MNS-57 cells with either oestrogen, which activates mycer, or growth factors such as basic fibroblast grow th factor (bFGF) and epidermal growth factor (EGF) stimulated their gr owth, and the combination of oestrogen and bFGF (or EGF) had a synergi stically stronger mitogenic effect than the single factors. Furthermor e, both c-myc activation and bFGF appeared to be necessary for the dif ferentiation of MNS-57 cells, and only when stimulated by both signals simultaneously, the cells committed to generating multiple neural cel l types. Thus, the property of the cell line is unique in that its dif ferentiation into neurons and glia can be conditionally manipulated in vitro in an exogenous signal-dependent manner. We propose that the ce ll line described here will provide an useful in vitro model to unders tand genetic and environmental mechanisms that control the generation of neural cell diversity in the CNS. (C) 1995 Wiley-Liss, Inc.