U.S. researchers have found that a supplemental protein may help restore impaired mobility of people who suffer from a stroke.
Naturally occurring in humans, the protein has proved to work well in restoring motor function in rats after a stroke, according to two new studies by researchers at the University of California, Irvine (UCI).
The researchers hope that the protein will also help humans.
Administered directly to the brain, the protein restores 99 percent of lost movement; if it’s given through the nose, 70 percent of lost movement is regained. Untreated rats improve by only 30 percent.
“No drugs exist that will help a stroke after a few days. If you have a stroke, you don’t have many treatment options,” said James Fallon, psychiatry & human behavior professor and senior co-author of the studies. “Now we have evidence there may be therapies that can repair damage to a significant degree long after the stroke. It ‘s a completely unexpected and remarkable finding, and it’s worth trying in humans.”
The studies chronicle the success of a small protein called transforming growth factor (TGF) alpha, which plays critical tissue-forming and developmental roles in humans from just after conception through birth and into old age.
“TGF alpha has been studied for two decades in other organ systems but never before has been shown to reverse the symptoms of a stroke,” said UCI postdoctoral researcher Magda Guerra-Crespo who led the study. No lasting side effects were observed.
In the first study, published in the Jan. issue of Neuroscience, scientists sought to learn whether TGF alpha administered directly to the brain could help rats with stroke-induced loss of limb function, typically on one side as is seen in humans.
Scientists examined the rats’ brains and found that TGF alpha was stimulating neuron growth. First, it prompted adult stem cells in the brain to divide, creating more cells. Those cells then turned into brain cells and moved to the injured part of the brain, replacing neurons lost to the stroke. These new neurons, the scientists believe, helped restore motor function.
In the second study, appearing online Jan. 11 in the Journal of Stroke & Cerebrovascular Diseases, scientists placed TGF alpha in the rats’ noses, simulating a nasal spray. They used a slightly different chemical version of the protein to render it more stable on its journey to the brain. After a month, the injured rats had regained 70 percent of their function, indicating that the intranasal method also works well.
“We saw the same phenomena,” Fallon said. “It wasn’t as profound, but we still ended up with very significant behavioral improvements and the same regenerative anatomical process.”