PLATELET-DERIVED GROWTH-FACTOR IS MITOGENIC FOR O-2AADULT PROGENITOR CELLS

We report that platelet-derived growth factor (PDGF) is a potent mitogen for oligodendrocyte type-2 astrocyte (O-2A) progenitor cells derived from the optic nerves of adult rats. Moreover, O-2A(adult) progenitors cultured in PDGF express the range of properties we have described previously for O-2A(adult) progenitors cultured in the presence of type-1 astrocytes. Similarly, previous studies have demonstrated that PDGF is able to mimic the influence of type-1 astrocytes on O-2A(perinatal) progenitors. Specifically, O-2A(adult) progenitors and O-2A(perinatal) progenitors exposed to PDGF express differences in average cell cycle time (59 +/- 5h for O-2A(adult) progenitors versus 20 +/- 6h for O-2A(perinatal) progenitors), average rate of migration (4.1 +/- 0.6-mu-m h-1 versus 24.6 +/- 5.4 mu-m h-1), morphology (unipolar versus bipolar), and antigenic phenotype (04+vimentin- versus 04-vimentin+). Thus, our present results indicate that a single signalling molecule secreted by type-1 astrocytes produces markedly different cellular behaviours in two related O-2A progenitor populations.