Lineage restriction of neuroepithelial precursor cells from fetal human spinal cord

In the presence of epidermal growth factor (EGF) and/or fibroblast growth f actor 2 (FGF2), neuroepithelial precursor cells from dissociated fetal huma n spinal cord are mitotically active and form free-floating spheres of undi fferentiated cells, Proliferating cells were obtained in approximately 40% of preparations with each mitogen, were immunoreactive for the intermediate filament nestin, and did not express neuronal- or glial-specific markers, Early passage neuroepithelial precursor cells were pluripotent and differen tiated into neurons expressing MAP2a,b, NF-M, and Tall, and GFAP-positive a strocytes; however, oligodendrocytes were never seen. As the cells were pas saged from PO to P4, the percentage of differentiating neurons significantl y decreased and the prevalence of astrocytes significantly increased. While the majority of cell populations from individual preparations stopped prol iferating between 3 and 6 passages, two expanding cell lines have been succ essfully expanded in EGF and FGF2 for over 25 passages and have been mainta ined in culture for over one year. These cells express nestin and not other cell-specific lineage markers. When differentiated, these neuroepithelial cell lines differentiate only into astrocytes, showing no expression of any neuronal marker. These data suggest that continued passage under these con ditions preferentially selects for spinal cord neural precursors that are r estricted to the astrocytic lineage. Despite the lineage restriction of lat er passage cell populations, these results provide a rationale for future i nvestigation into the lineage potential of these cells in vivo following tr ansplantation into the adult CNS, potentially as a therapeutic approach. fo r traumatic injury and neurodegenerative disease. J. Neurosci. Res. 57:590- 602, 1999, (C) 1999 Wiley-Liss, Inc.