WASHINGTON (Reuters) Apr 21 - Shutting off a single gene can help stop the cascade of damage that can paralyze people with spinal cord injuries, U.S. researchers reported on Wednesday.

They propose using a common, generic diabetes drug (glyburide) in combination with a gene-silencing technique to stop spine injuries from getting any worse, and believe the approach may also work in people with stroke and traumatic brain injuries.

Their experiment, published online April 21st in Science Translational Medicine, shows it is possible to stop the bleeding that can cause the damage from an injured spinal cord to spread and worsen.

"What we're doing is preventing bleeding from occurring," said Dr. Marc Simard of the University of Maryland, which has licensed the technology to a company Simard works with called Remedy Pharmaceuticals.

When the spinal cord or brain is injured, the capillaries can burst, bringing in an overwhelming wave of inflammatory factors. Dr. Simard's team demonstrated that a gene called Abcc8 starts this process. It controls a molecule called the sulfonylurea receptor 1 or SUR1.

"It gets activated after an injury like ischemia...or trauma," Dr. Simard said.

Dr. Simard's team blocked this gene in mice and rats using gene-blocking therapy called antisense and showed that after a spinal cord injury, the damage and effects were much less without Abcc8.

They also tested the spinal cords of seven patients who died within five days of a spinal cord injury and showed the same gene was active.

"I think we are pretty darn close to a clinical trial," Dr. Simard said in a telephone interview.

The antisense drugs are easy to make, he said. And glyburide blocks the destructive SUR1 protein made by the gene.
Remedy Pharmaceuticals is working to make an infused version of both drugs that could work together to block the gene and block the protein that the gene makes.

Glyburide is already in Phase I safety trials for treating traumatic brain injury and stroke, Dr. Simard said.
"My hope is eventually you could get it into the ambulance," he added. He hopes there will be no side-effects from giving the drug, even to lightly injured people, so that ambulance workers could give an immediate infusion to anyone with apparent brain or spinal cord damage to stop the deadly cascade of damage.

Science Translational Medicine 2010 by Maggie Fox