Generation and potential biomedical applications of embryonic stem cell-derived glial precursors.

Recent progress in embryonic and adult stem cell research has opened new perspectives for generating large numbers of different neural cell types in vitro and using them for nervous system repair. Several lines of arguments suggest that myelin diseases represent particularly attractive targets for cell-based therapies. First, in contrast to neuronal cell replacement, a single and uniform cell type, the oligodendrocyte progenitor, suffices for therapeutic remyelination in all areas of the CNS, with no need for complex circuit integration. Second, there is an increasing understanding of the mechanisms regulating the recruitment of stem and progenitor cells into CNS lesions. Third, stem cells represent excellent vehicles for cell-mediated gene transfer, enabling novel approaches, which combine classic cell replacement with the delivery of therapeutic factors. Among the various donor sources, embryonic stem (ES) cells stand out as a population featuring pluripotency, unlimited self-renewal and amenability to gene targeting. Here we discuss the advantages, challenges and perspectives of bringing this unique cell type closer to a clinical application for treating myelin diseases and other neurological disorders.