Findings of a preliminary study in this week's issue of THE LANCET suggest that transplanted adult bone-marrow cells could regenerate nerve cells in the brains of human stem-cell recipients. These early findings, if confirmed in future research, have implications for the treatment of neurodegenerative disorders such as Parkinson's disease.
Ethical concerns over the use of embryonic stem cells has focused attention on the potential of adult bone-marrow cells to stimulate new cell growth in transplant recipients. Previous research has shown that the transplantation of adult human bone-marrow cells can generate new nerve cells in the brains of mice; a recent Lancet study (Lancet 2003; 361: 1084/88) showed how adult male bone-marrow cells regenerated growth in the cheek cells of female stem-cell recipients.
Edward Scott from the University of Florida Shands Cancer Center, USA, and colleagues examined the brain tissue of three women who had received bone-marrow transplantation from male donors to help treat leukaemia. The investigators found that donor cells containing a Y chromosome (ie, from a male origin) were present in all three women's brains up to 6 years after bone-marrow transplantation. All recipients had transgender brain tissue, and in the longest survivor three different types of brain tissue including neurons were found.
Dr Scott comments: "This study suggests that bone marrow could be used as a therapeutic source of readily harvestable cells for the regeneration of nerve cells, with potential application to various neurodegenerative diseases and traumatic central nervous system damage".