Bone to brain change fails

Early reports that adult mouse bone marrow cells (BMCs) were capable of transdifferentiating into cells with neural characteristics in the central nervous system raised hopes of developing effective treatments for neurodegenerative disorders. But, in August 23 Science, Raymond Castro and colleagues at Baylor College of Medicine, Houston, US, show that bone marrow cells from mice do not transdiferentiate into neural cells in vivo (Science 2002, 297:1299).

Castro et al. used C57Bl/6 (B6) mice, which received BMCs or side population cells (SP) derived from a mouse (Rosa26) that offer an unambiguous marker for its donor-derived cells. They observed that one of the mice had neural-like cells in the CNS that could have been derived from ROSA26 BMCs.

These data suggest that 'bone to brain' transdifferentiation may not be a general phenomenon but may instead depend on the experimental system in which the hypothesis is tested.