Mouse Stem Cells Treat Paralysis in Rats

Researchers at Johns Hopkins University in Baltimore and SUNY Upstate Medical University in Syracuse, N.Y., have developed a multistep regimen that they say improves the functional effect of transplanted stem cells in paralyzed rats.

The study suggests that similar techniques may be useful for treating spinal cord injury, amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA).

The research team, led by MDA grantee Douglas Kerr at Hopkins and including Jeffrey Rothstein, who has MDA research funding and directs the MDA/ALS Center at the same institution, say their strategy restored functional nerve-to muscle connections and movement in the back legs of rats that had been paralyzed by a virus.

In a four-step process, the investigators transplanted mouse embryonic stem cells and injected the nerve growth factor GDNF into the sciatic nerve near the spinal cord. At the same time, they infused two compounds that counteract the effects of myelin, a normal substance that ensheaths nerve fibers but which has been found to interfere with the growth of new fibers.

“We conclude that restoration of functional motor units [a nerve cell with fibers connecting to muscle fibers] by embryonic stem cells is possible and represents a potential therapeutic strategy for patients with paralysis,” the authors write in the June 26 online version of Annals of Neurology.