Oral approach prevented brain injury in rats, study found
MSNBC NEWS SERVICES
D.
Feb. 24 - Researchers said on Thursday a new approach combining gene therapy and vaccination has prevented epileptic seizures and brain damage in rats and suggested it could eventually be used to protect against strokes in humans.
'I think it represents a new platform of technology, a sort of revolutionary approach to the treating of brain diseases.'
- DR. MATTHEW DURING
Thomas Jefferson University
IN A STUDY to be published Friday in the journal Science, researchers at the medical school of Thomas Jefferson University in Philadelphia report that the vaccine caused rat's immune system to develop antibodies that prevented the action of a protein that causes damage after brain injury.
"It protects them significantly from ... insults such as an epileptic seizure or a stroke for at least five months after a single oral dose," Dr. Matthew During, a professor of neurosurgery who led the study, said in a statement.
The researchers, who reported their findings in the journal Science, said it might be used to help protect people considered at high risk of a stroke or a seizure, such as those who have undergone heart bypass surgery.
And they say the approach might work against a whole range of diseases involving the central nervous system, from Parkinson's to Lou Gehrig's disease motor neuron disease.
"I think it represents a new platform of technology, a sort of revolutionary approach to the treating of brain diseases," During said in a telephone interview.
The vaccine works against a brain protein, called the NMDA receptor, that has been shown to aggravate brain damage after a stroke and to play a role in epileptic seizures.
Other researchers have tried to block the action of the NMDA receptor using drugs, but these drugs often fail to effectively cross the blood-brain barrier, a natural barrier that protects the brain from most destructive substances in the blood.
By using a vaccine, the researchers prompt the body, in effect, to make its own NMDA blocker by creating antibodies that neutralize the protein after brain injury.
STUDY DETAILS
In the study, some rats were immunized with the anti-NMDA antibody while others were not. A month later, the rats were injected with a neurotoxin, kainate, which causes seizures similar to those in epilepsy.
Among the control rats, which were not immunized, there was a seizure rate of 70 percent. Among those with the anti-NMDA antibody, the seizure rate was 20 percent.
In another study, immunized and non-immunized rats were tested after five months for protection from stroke damage. An artificial stroke was induced in the animals using a drug.
Among the immunized rats, said During, "We found dramatic protection in the rats' brains. ... It doesn't stop the stroke from occurring, but the amount of brain damage is diminished by 70 percent."
None of the studied rats showed abnormal behavior from the vaccine, he said.
However, that does not rule out the possibility of adverse effects over time, he said.
The Associated Press and Reuters contributed to this report.
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