Transplanted Cells May Arrest Genetic Diseases.

• Position: Brief Article

Using stem cells grown in the laboratory, a team of scientists from the University of Bonn (Germany) Medical Center, the National Institute of Neurological Disorders and Stroke, and the University of Wisconsin-Madison have successfully transplanted those cells into the nervous systems of ailing rats and arrested the course of a debilitating congenital disease. Although years from clinical application, the work is important because it shows that cells grown from scratch can be used to repair defective nerves.

The work was accomplished using embryonic stem cells that arise within days of conception in a fertilized egg and very quickly develop into all the different kinds of cells--blood, bone, muscle, neurons--that make up the body. Such cells hold an enormous therapeutic potential through the promise of unlimited supplies of laboratory-grown replacement tissue to treat many congenital and acquired illnesses, including heart disease, neurological disorders such as Parkinson's disease or multiple sclerosis, and diabetes.

In the study, stem cells were coaxed down a developmental pathway to become oligodendrocytes and astrocytes, key cells of the central nervous system. Transplanted into the spinal cords of fetal and newborn rats that lack myelin, a tissue that covers some nerve fibers, the cells were observed to promote the growth of the myelin sheaths essential to the ability of nerves to conduct electrical impulses and function normally. Myelin is a...