Peptide Promotes New Growth In Injured Spinal Cords

The finding could lead to the reversal of functional deficits resulting from brain and spinal cord injuries and caused by trauma and stroke, or brought about by degenerative diseases, such as multiple sclerosis.

The lead author of the study, Stephen Strittmatter, M.D., associate professor of neurology and neurobiology at Yale School of Medicine, said the study confirms which molecules block axon regeneration in the spinal cord and shows that a peptide can promote new growth. Axons are the telephone lines of the nervous system and carry a nerve impulse to a target cell.

"One of the prominent inhibitors is Nogo and we developed a way to block Nogo action with a peptide that binds to the Nogo receptor and prevents it from doing its normal job," Strittmatter said. "There is no drug used today to promote axon recovery in humans, so it is hard to predict how well this drug will work in humans."

He said the laboratory rats were administered the peptide for four weeks through a catheter inserted into the spinal canal. A number of nerve fibers did grow back and the rats were able to walk better than without the treatment.

Before moving to human trials, Strittmatter said researchers first must determine whether the synethetic peptide can promote nerve fiber growth in animals weeks and months after injury and whether the compound is effective and safe for use in humans.

"There is some reason to think that the peptide might promote growth in older injuries because some damaged nerve fibers in the brain and spinal cord just sit there," he said. "If we had some way to block these inhibitors the nerve fibers might grow back again."

The paper is the third that Strittmatter has published in Nature about this research. The first paper described the Nogo protein. The second paper detailed the receptor through which Nogo acts. This newest data demonstrates how to block the interaction and how to reverse its function pharmacologically.

The synthetic peptide Strittmatter and his colleagues developed is 40 amino acids long and acts as an inhibitor at the Nogo receptor site.

Co-researchers included Tadzia GrandPre, a graduate student, and Shuxin Li, a postdoctoral fellow.