Mice with an experimental version of Parkinson’s disease improved after a natural protein was injected into their brains, suggesting a possible lead for human therapy.
An estimated 500,000 to 1 million Americans have Parkinson’s disease, which robs people of control over their movements.
The disease results from the death of brain cells that produce a substance called dopamine and use it to communicate.
For the mouse experiments, researchers injected a toxin that killed the same kind of cells. That made the animals less mobile.
After these mice were treated with the natural protein, called GDNF, their movements increased, their brain partly regained its dopamine supply, and their surviving brain cells sprouted new fibers to connect to neighboring cells, researchers said.
The result is the most promising yet for such a protein in Parkinson research, neurobiologist Dr. Lars Olson of the Karolinska Institute in Stockholm, Sweden, said Wednesday. He and colleagues at several institutions report the results in today’s issue of the journal Nature.
In a second study involving Parkinson’s disease, GDNF was found to largely prevent the degeneration of injured brain cells in rats. The researchers were from Genentech Inc. in South San Francisco and the University of Southern California in Los Angeles.
Dr. Serge Przedborski of the Columbia University College of Physicians and Surgeons in New York said the two studies were important in showing that powerful proteins such as GDNF may be useful in treating degenerative diseases such as Parkinson’s.
But “much more work remains to be done before claiming that we have a breakthrough in the treatment of Parkinson’s disease,” he said.
In two other animal studies, GDNF was shown to protect nerve cells that tell muscles how to move. That suggests the protein might one day be useful in treating Lou Gehrig’s disease, or amyotrophic lateral sclerosis, which progressively paralyzes people by destroying musclecontrolling nerve cells.