Jan. 29, 2002 -- Japanese researchers may have found a way to bypass the controversial use of human embryonic stem cells while still reaping the benefits of the emerging technology. A new study shows that monkey stem cells can be coaxed into becoming mature brain cells that can be used for research and treatment of a variety of brain diseases such as Parkinson's.
Using a relatively quick and simple technique called stromal cell-derived inducing activity or SDIA, researchers were able to make primate stem cells develop into a variety of specialized brain cells. These cells share many similarities with their human counterparts -- making them useful for medical research and potentially even transplantation into humans.
For example, 35% of the brain cells created through the SDIA method produced dopamine, a chemical in the body that plays an important role in maintaining motor skills and emotional functioning. People with Parkinson's disease don't produce enough of this chemical.
Other studies have shown that transplantation of human fetal brain tissue can improve functioning in Parkinson's patients, but the use of human tissue from aborted fetuses remains controversial. Researchers hope using animal stem cells along with the SDIA technique may one day provide an alternative to human embryonic stem cell use.
"The SDIA method is a promising approach that brings stem cell therapy for Parkinson's disease toward the practical level," the authors write. Their report appears in this week's issue of the Proceedings of the National Academy of Sciences.
The researchers also found that the SDIA technique has an unexpected benefit. It caused some of the primate stem cells to become cells found in the outermost layer of the retina, which aid light-sensitive photoreceptor cells in the eye. The availability of these specialized cells from animal sources could help researchers study and treat degenerative diseases of the eye.
Although clinical trials in humans are a long way off, the study authors plan to test their methods in animals.