Human neural precursors are considered to have widespread therapeutic possibilities on account of their ability to provide large numbers of cells whilst retaining multipotentiality. Application to human demyelinating diseases requires improved understanding of the signalling requirements underlying the generation of human oligodendrocytes from immature cell populations. In this study, we compare and contrast the capacity of neural precursors derived from the developing human and rodent spinal cord to generate oligodendrocytes. We show that the developing human spinal cord (6-12 weeks of gestation) displays a comparable ventrodorsal gradient of oligodendrocyte differentiation potential to the embryonic rodent spinal cord. In contrast, fibroblast growth factor 2 (FGF-2) expanded human neural precursors derived from both isolated ventral or dorsal cultures show a reduced capacity to generate oligodendrocytes, whereas comparable rodent cultures demonstrate a marked increase in oligodendrocyte formation following FGF-2 treatment. In addition, we provide evidence that candidate growth factors suggested from rodent studies, including FGF-2 and platelet-derived growth factor (PDGF) do not stimulate proliferation of human oligodendrocyte lineage cells. Finally, we show that the in vivo environment of the acutely demyelinating adult rat spinal cord is insufficient to stimulate the differentiation of immature human spinal cord cells to oligodendrocytes. These results provide further evidence for inter-species difference in the capacity of neural precursors to generate oligodendrocytes.
Copyright 2004 Wiley-Liss, Inc.