Bacteria Enzyme May Help Regrow Spinal Cords

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A treatment that promotes the regrowth of injured spinal cord nerves has proven successful in rats, U.S. researchers report.

A team at Johns Hopkins University in Baltimore and the University of Michigan in Ann Arbor used an enzyme called sialidase -- isolated from bacteria -- to treat a group of rats with nerve injuries. Within four weeks, the treated rats had grown twice as many new nerve fibers as untreated rats with the same kind of injury.

"We have established that the enzyme sialidase, which destroys one of the molecules that inhibits nerve regeneration, is sufficient to robustly improve nerve fiber outgrowth from the spinal cord," study director Ronald Schnaar, a professor of pharmacology and neuroscience at Hopkins' Institute of Basic Biomedical Sciences, said in a prepared statement.

As reported in the July 18 issue of the journal Proceedings of the National Academy of Sciences, the injury in the rats was similar to an injury that can occur in humans during childbirth or in a violent accident -- such as a motorcycle crash -- when the arm is pulled violently away from the body. This kind of injury causes nerves to be yanked out of the spinal cord, which results in a loss of feeling and muscle tone in the arm.

Surgery can be used to re-attach the yanked nerves to the spinal cord, but the results are often unsatisfactory. Unlike other nerves in the body, brain and spinal cord nerves fail to grow new nerve fibers because they're surrounded by signals from other cells in the injured area that tell the nerves to stop growing.

The next step in this research is to test whether this nerve regrowth helps restore muscle function. The scientists are also studying whether treatment with sialidase helps nerve regeneration in other types of spinal cord injuries.