Human Embryonic Stem Cells for Neuronal Repair

Human embryonic stem cells may serve as a potentially endeless source of transplantable cells to treat various neurologic disorders. Accumulating data have shown the therapeutic value of various neural precursor cell types in experimental models of neurologic diseases. Tailoring cell therapy for specific disorders requires the generation of cells that are committed to specific neural lineages. To this end, protocols were recently developed for the derivation of dopaminergic neurons, spinal motor neurons and oligodendrocytes from hESC. These protocols recapitulate normal development in culture conditions. However, a novel concept emerging from these studies is that the beneficial effect of transplanted stem cells is not only via cell replacement in damaged host tissue, but also by trophic and protective effects, as well as by an immunomodulatory effect that down-regulates detrimental brain inflammation.