Following up on yesterday's post below, another important study was just published in the journal Science Translational Medicine that brings closer the use of stem cells to treat central nervous system damage. In the first of its kind experiment, researchers at UCSF, in collaboration with StemCells, Inc., treated 4 children affected with neural degenerative genetic disease with human neuronal stem cells.
Oligodendrocytes, a type of nerve cells whose primary function is to support and coat axons (the signal carrying nerve cells) with myelin--a fatty protein layer that protect the axons and facilitate movement of the electrical signals along the axon cell membranes. Myelin can be thought of as the insulation layer around the neural wiring.
With Pelizaeus-Merzbacher disease, the oligodendrocytes cannot properly make myelin because of a genetic mutation. The effect is similar as with other diseases that compromise the myelin layer, such as multiple sclerosis. The neural axons cannot transmit signals correctly so sufferers with this condition have significant motor coordination problems and impaired intellectual function, and there is no effective treatment currently.
In this clinical trial (ClinicalTrials.gov NCT00337636), the researchers surgically injected into the brains of four boys 1 to 5 years old, central nervous system stem cells isolated from a donated fetal brain. About 300 million stem cells were injected into each patient in four different locations. The implanted stem cells integrated into the brain tissue and aligned with the neural cells, and measurements indicated increased levels of myelination in the injected regions. Also, 3 of the 4 patients showed some small improvements.
The study was not designed as a comprehensive treatment for the disease. As a Phase I clinical trial, the main purpose was to evaluate the safety of the technique. The results indicate it is possible to safely implant and integrate foreign stem cells into children afflicted with this disease.