Monday, June 9, 2008

Stem Cell Success


Scientists at the University of Rochester Medical Center and elsewhere reported a dramatic success in what is believed to be the first documented rescue of a congenital brain disorder by transplantation of human neural stem cells.

The research, published in the journal Cell Stem Cell, may lead the way to new strategies for treating certain hereditary and perinatal neurological disorders. Nerve cell projections are sheathed by a fatty substance called myelin that is produced by oligodendrocytes, a type non-nerve cell in the brain and spinal cord. Myelin enhances the speed and coordination of the electrical signals by which nerve cells communicate with one another.

In their study, researchers used a “shiverer mouse” animal model, which lacks normal myelin and typically dies within months of birth. To date, no transplantation of human neural stem cells or of their derivatives has ever altered the condition or fate of recipient animals. The researchers devised a more robust method for the acquisition and purification of human fetal glial progenitor cells. They also developed a new cell delivery strategy, based on multiple injection sites, to encourage widespread and dense donor cell engraftment throughout the central nervous system of recipient mice. The researchers transplanted human glial stem cells into neonatal shiverer mice that also had a genetically deficient immune system to minimize the rejection of the transplanted cells. The researchers found that the new transplant procedure resulted in infiltration of human glial progenitor cells throughout the brain and spinal cord.

The engrafted mice exhibited robust, efficient and functional myelination. Most notably, many of the mice displayed progressive, neurological improvement and a fraction of the mice were actually rescued by the procedure. Untreated control mice uniformly died within five months.