Parkinson's Disease and Stem Cells
Research is currently being performed with stem cells in animals with brain damage resembling Parkinson's disease. Recent studies have found that embryonic stem cells can spontaneously acquire many of the features of dopamine-producing neurons. Continued research is necessary to help scientists learn how to control these cells in ways that improve their effectiveness and reduce the risk of tumors and other side effects.
Stem Cell Research and Parkinson's Disease: An OverviewParkinson's disease is a common condition that affects more than 2 percent of the population over 65 years of age. The disease is caused by a progressive loss of dopamine -- producing nerve cells. This leads to the classic Parkinson's disease symptoms, including tremors, rigidity, and abnormally decreased mobility.
Parkinson's disease may be the first disease where stem cell transplantation proves successful, for a couple of reasons. The first is that scientists know the specific type of nerve cell needed to relieve the symptoms of the disease. Second, several laboratories have been successful in transplanting stem cells into animals with Parkinson's disease.
Current Findings on Parkinson's Disease and Stem CellsThere is a lot of excitement surrounding the use of stem cells to treat Parkinson's disease. Part of this excitement comes from a study that was published in January 2002 in the Proceedings of the National Academy of Sciences.
This study showed that mouse embryonic stem cells transplanted into rats with brain damage resembling Parkinson's disease spontaneously acquired many of the features of dopamine-producing brain cells. These animals also showed a gradual reduction in their Parkinson's disease symptoms, and brain scans revealed evidence that the transplanted cells integrated with the surrounding area and began to produce dopamine.
The findings raise the possibility that embryonic stem cell transplants may one day be useful in Parkinson's disease treatment, as well as treatments for other brain disorders.
Many of the symptoms of Parkinson's result from the loss of neurons that produce dopamine, a nerve-signaling chemical. Previous studies have shown that embryonic stem cells can take on the characteristics of dopamine-producing neurons in culture. However, this is the first study to show that undifferentiated (unspecialized) embryonic stem cells transplanted into the brains of animals with Parkinson's-like diseases can develop into dopamine-producing cells -- with no special pretreatment to control their fate.