Filippov Vitali, Kronenberg Golo, Pivneva Tatjyana, Reuter Katja, Steiner Barbara, Wang Li Ping, Yamaguchi Masahiro, Kettenmann Helmut, Kempermann Gerd
Max Delbrück Center for Molecular Medicine (MDS) Berlin-Buch, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
Mol Cell Neurosci. 2003 Jul;23(3):373-82. doi: 10.1016/s1044-7431(03)00060-5.
Based on the expression of glial fibrillary acidic protein (GFAP), a recent hypothesis considered stem or progenitor cells in the adult hippocampus to be a type of astrocyte. In a complementary approach, we used transgenic mice expressing green fluorescent protein (GFP) under the promoter for nestin, an intermediate filament present in progenitor cells, to demonstrate astrocytic features in nestin-GFP-positive cells. Morphologically, two subpopulations of nestin-GFP-positive cells were distinguishable; one had an elaborate tree of processes in the granule cell layer and expression of GFAP (but not of S100beta, another astrocytic marker). Electron microscopy revealed vascular end feet of nestin-positive cells, further supporting astrocytic differentiation. Electrophysiological examination of nestin-GFP-positive cells on acutely isolated hippocampal slices showed passive current characteristics of astrocytes in one subset of cells. Among the nestin-GFP-expressing cells with lacking astrocytic features, two cell types could be identified electrophysiologically: cells with delayed-rectifying potassium currents and a very small number of cells with sodium currents, potentially representing signs of the earliest steps of neuronal differentiation.
基于胶质纤维酸性蛋白（GFAP）的表达，最近有假说认为成年海马体中的干细胞或祖细胞是一种星形胶质细胞。作为一种补充方法，我们使用了在巢蛋白（一种存在于祖细胞中的中间丝）启动子控制下表达绿色荧光蛋白（GFP）的转基因小鼠，来证明巢蛋白-GFP阳性细胞具有星形胶质细胞的特征。从形态学上看，巢蛋白-GFP阳性细胞可分为两个亚群；其中一个在颗粒细胞层有复杂的突起树，并表达GFAP（但不表达另一种星形胶质细胞标志物S100β）。电子显微镜显示巢蛋白阳性细胞的血管终足，进一步支持了星形胶质细胞的分化。对急性分离的海马体切片上的巢蛋白-GFP阳性细胞进行电生理检查，发现其中一个细胞亚群具有星形胶质细胞的被动电流特征。在缺乏星形胶质细胞特征的巢蛋白-GFP表达细胞中，通过电生理方法可鉴定出两种细胞类型：具有延迟整流钾电流的细胞和极少数具有钠电流的细胞，这可能代表了神经元分化最早阶段的迹象。
