SEATTLE, May 31 Researchers from the University of Pittsburgh School of Medicine report that they have successfully used gene therapy to block the pain response in an animal model of neuropathic pain, a type of chronic pain in people for which there are few effective treatments. These findings are being presented at the 10th annual meeting of the American Society of Gene Therapy, being held May 30 to June 3 at the Washington State Convention & Trade Center, Seattle.
Neuropathic pain is the result of damage to nerve fibers caused by injuries or diseases, such as diabetes and cancer. These damaged nerve fibers continue to send signals to pain centers in the brain even after the surrounding tissue has healed. Unfortunately, neuropathic pain often responds poorly to standard pain treatments and occasionally may get worse instead of better over time. For some people, it leads to serious, long-term disability and dependence on pain medications that have a variety of unwanted side effects, including addiction.
The Pitt research team, led by Joseph Glorioso, III, Ph.D., chair of the department of biochemistry and molecular genetics, University of Pittsburgh School of Medicine, used a genetically engineered herpes simplex virus (HSV) to deliver the gene for part of the human glycine receptor (GlyR), a receptor found primarily on the surface of nerve cells in the spinal cord and the lower brain but not in the nerves in the limbs, to the paws of rats. A group of control rats received only the HSV vector without the inserted gene. After the delivery of the therapeutic gene or empty vector (for the control group), the researchers injected the same paws of each rat with formalin, an irritant known to simulate the symptoms of a peripheral neuropathic pain at the site of injection. Following formalin injection, the rats were then given an injection of glycine to activate the GlyR receptor.
Both control and GlyR-HSV-infected rats showed a typical pa
Contact: Jim Swyers
University of Pittsburgh Schools of the Health Sciences