Characterization of a mouse tet-on glia precursor cell line in vitro and in vivo using the electrophysiological measurement

We report here a partial characterization of a "tet-on" glia O2A precursor cell line established from the reverse tetracycline-transactivator (rtTA)-SV40 T antigen (Tag) double transgenic mice. In culture, withdrawal of doxycycline prevents proliferation and the cell line undergoes apoptosis. Importantly, differentiation into type-2-astrocytes and oligodendrocytes can be induced when the cell line is cultured, in the absence of doxycycline, and with epithelial stem cell lines secreting hIL3 or hIL6. In contrast, no maturation into progeny was observed when a hCNTF-secreting cell line was used as the co-culture partner under the same condition. In order to address the question of whether the morphological distinct cells-spindle and stellar shaped cells are of a similar or different cell types, we have performed cell size analysis of these cells by FACS and electro-physiology measurement by the patch clamping technique. They are of a similar cell size, but poses distinct electrophysiological properties-spindle cells are less mature than the stellar cells. These tet-on glia O2A precursor cells were implanted to sites of transected sciatic nerve of adult mice and kept in the precursor stage by feeding mice with doxycycline containing drinking water. The toe movement of injured foot was measured every 3 weeks and the electrophysiological property of motor neuron was determined three months after the operation. Preliminary data have shown that these tet-on glia precursor cells are not toxic to the implanted hosts and can enhance the recovery of damaged motor nerves.