Differentiation of oligodendrocytes from mouse induced pluripotent stem cells without serum.

Cell therapy using induced pluripotent stem (iPS) cells might become a new approach for treating neonatal hypoxic-ischemic injury such as periventricular leukomalacia. To obtain appropriate donor cells for transplantation, we differentiated oligodendrocyte (OL) lineage cells from mouse iPS cells. Induction of OL lineage cell differentiation from iPS cells was carried out with a seven-step culture method. Mouse iPS cells (stage 1) were induced to form embryoid bodies for 4 days under a serum-free condition that was suitable for ectoderm induction (stage 2), following by selection of nestin-positive neural stem cells (NSCs) for 10-12 days (stage 3). NSCs were cultured in expansion medium containing fibroblast growth factor (FGF)-2 for 4 days (stage 4), induced to differentiate into glial progenitor cells by epidermal growth factor and fibroblast growth factor (FGF-2) treatment for 4-5 days (stage 5), and then into OL progenitor cells by culture in neurobasal A medium containing FGF-2 and platelet-derived growth factor for 6-8 days (stage 6). Terminal differentiation into O4-positive OLs was carried out by culture in neurobasal A containing T3 and ciliary neurotrophic factor for 7 days (stage 7). Inwardly rectifying K+ currents, which are characteristic of OLs, were detected in iPS cell-derived cells at stage 7 in whole cell clamp mode. Our data suggest that OLs can be effectively differentiated from mouse iPS cells without serum in a stepwise manner, which may be appropriate for use as donor cells in transplantation.