UCSD Researchers Use Gene Therapy To Promote Recovery From Spinal Cord Injuries

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UCSD RESEARCHERS USE GENE THERAPY TO PROMOTE RECOVERY FROM SPINAL CORD INJURIES

Researchers from the UCSD School of Medicine report the first successful use of gene therapy to achieve partial recovery from spinal cord injuries.

In studies involving laboratory rats, gene therapy was used to stimulate the regrowth of damaged axons by changing the function of an injured animal's cells allowing them to produce a growth factor directly at the site of injury.

"This novel use of gene therapy provides the opportunity for injured axons to regenerate through the spinal cord and restore function," said Mark H. Tuszynski, M.D., Ph.D., associate professor of neurosciences at the UCSD School of Medicine and a neurologist at the Veterans Affairs Medical Center in San Diego.

The findings appear in the July 15 issue of The Journal of Neuroscience.

Axons are the "wires" that cells use to communicate with one another as they relay messages from the brain. Injured adult mammal spinal cords show little spontaneous recovery after injury often leading to paralysis.

In previous studies, Tuszynski and his colleagues have shown that injured spinal cord cells can be stimulated to regrow when exposed to certain nerve growth proteins. In the study reported today, rats with spinal cord injuries had a sample of normal skin cells removed that were cultured in the laboratory and genetically modified to produce the growth factor neurotrophin-3 (NT-3). When grafted back into the animal, the modified cells secreted NT-3 at the site of spinal cord injury, which in turn stimulated axon regrowth and resulted in some recovery of walking ability.

In addition, the genetically modified cells were also found to deliver NT-3 continuously for several months, further enhancing the regeneration of injured axons and the partial restoration of function.

"The goal in spinal injury research is to promote the regrowth of cut or damaged axons," said Tuszynski. "These results indicate that cellular delivery of NT-3 through gene therapy can restore function by promoting the sustained growth of axons after spinal cord injury."

Individuals contributing to the study included Ray Grill, Ph.D.; Keith Mural; Fred Gage, Ph.D., and Armin Blesch, Ph.D. This work was supported by the Hollfelder Foundation, International Spinal Research Trust, and Veterans Affairs Research.

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