Replacing cells in multiple sclerosis.

Cell transplantation is emerging as a major potential therapeutic approach in the treatment of otherwise untreatable neurodegenerative diseases. In multiple sclerosis (MS), a major direction of current research is to devise strategies that will remyelinate axons and protect them against subsequent ongoing degeneration. Ongoing loss of axons will lead to chronic disability. Oligodendrocytes and their progenitors are lost during multiple relapses in the course of MS and either needs to be replaced from an exogenous source or the remaining progenitors stimulated to differentiate and remyelinate. The successful isolation and purification of human oligodendrocytes from neural or embryonic stem cells offer hope that a source of sufficient cells for translational application might be achievable in the future. Focal repair of strategic lesions followed by more disseminated delivery of exogenous cells will be the short and long-term goals.