Embryonic-derived glial-restricted precursor cells (GRP cells) can differentiate into astrocytes and oligodendrocytes in vivo

We have isolated and characterized a unique glial-restricted precursor cell (GRP) from the embryonic spinal cord. Clonal analysis demonstrated that th ese cells are able to generate oligodendrocytes and two distinct type of as trocytes (type I and type 2) when exposed to appropriate signals in vitro. We now show that many aspects of these cells are retained in vivo. GRP cell s are restricted to the glial lineage in vivo as they seem to be unable to generate neuronal phenotypes in an in vivo neurogenic environment. GRP cell s survive and migrate in the neonatal and adult brain. Transplanted GRP cel ls differentiate into myelin-forming oligodendrocytes in a myelin-deficient background and also generate immature oligodendrocytes in the normal neona tal brain. In addition, GRP cells also consistently generated glial fibrill ary protein-expressing cells in the neonatal and adult brain, a property no t consistently expressed by other glial precursor cells like the O-2A/OPC c ells. We suggest that the lineage restriction of GRP cells and their abilit y to generate both oligodendrocytes and astrocytes in vivo together with th eir embryonic character that allows for extensive in vitro expansion of the population makes the cell useful for clinical application. (C) 2001 Academ ic Press.