PLATELET-DERIVED GROWTH-FACTOR INDUCES CHEMOTAXIS OF NEUROEPITHELIAL STEM-CELLS

The ability of differentiating cells to migrate within the developing central nervous system (CNS) depends on extrinsic guidance signals, so me of which are growth factors. In this study we have investigated the chemotactic response of cultured stem cells from the embryonic rat co rtex to platelet-derived growth factor (PDGF). Nestin-positive stem ce lls from the developing CNS can be maintained and expanded in vitro un der serum-free conditions in the presence of basic fibroblast growth f actor (bFGF). Northern blot analysis of PDGF receptor expression revea led both alpha- and P-receptors on bFGF-treated neural stem cells. Bot h PDGF-AA and PDGF-BB readily induced directed migration of cultured n euroepithelial cells as measured in a microchemotaxis assay. Blocking of the migratory response was achieved by incubation with PDGF isoform -specific antibodies. More than 90% of the migrating cells were nestin -positive and incorporation of BrdU was also seen suggesting the cells to be immature and not yet committed to a specific cell lineage. Thes e findings suggest a role for PDGF in cell migration in the developing cortex. J. Neurosci. Res. 53:521-530, 1998, (C) 1998 Wiley-Liss, Inc.