NEW RESEARCH OPENS DOOR TO STEM CELL THERAPY
FOR ALS AND SMA

Muscular Dystrophy Association Following Other Leads

TUCSON, Ariz., Nov. 8, 2000 -- Soon after scientists identified neural stem cells -- primitive cells that can generate new nerve cells (neurons) -- they recognized the cells held potential for treating neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA).

Now, MDA-funded scientists have made the breakthrough discovery that neural stem cells can repair neuronal damage in rodents that have a condition similar to ALS and SMA.

ALS and SMA are both paralyzing diseases, caused by the destruction of muscle-controlling neurons (motor neurons) in the spinal cord. ALS typically attacks middle-aged adults without warning, and follows a rapid, ultimately fatal course. SMA is an inheritable disease that can strike during infancy or adulthood, and while it causes gradual weakening in adults, it's among the most common inherited causes of death in infants.

"The [new] research may lead to improved treatments for patients with paralyzing motor neuron diseases," said Jeffrey Rothstein, leader of the research team and co-director of the MDA/ALS Center at Johns Hopkins University in Baltimore.

Rothstein, along with MDA grantee Douglas Kerr of Johns Hopkins and Evan Snyder of Harvard University in Boston, discussed their research during a Nov. 5 press conference at the Society for Neuroscience meeting in New Orleans.

The following addresses the main points of the research.

Q: How was the study done?

A: The researchers infected rodents with a virus -- called Sinbis virus -- which destroyed their motor neurons and caused paralysis. They then treated some of the rodents with neural stem cells by injecting the cells into the fluid-filled space within the spinal cord. Another control group of rodents received a "sham" injection that didn't contain stem cells.

Q: What happened to the rodents that received stem cell treatment?

A: The stem cell-treated rodents recovered some movement in their hind limbs. (The control group didn't show any recovery.) When Rothstein and colleagues examined the rodents' spinal cords, they found the stem cells had dispersed to areas with damaged neurons. Although some of the transplanted cells appeared to have become new neurons, it's not yet clear if they replaced dead neurons or nurtured dying ones.

Q: Does this mean stem cell therapy could be a "cure" for ALS and SMA?

A: Not quite, but it might offer some effective treatment where there is presently none. The researchers warn that the improvement in the rodents was small. At present, scientists are hopeful that stem cell therapy could at least lessen the most life-threatening effects of motor neuron diseases, such as weakening of the muscles that control the lungs. Rothstein predicts that, under the best circumstances, stem cell therapy for motor neuron diseases could move to clinical trials within one or two years.

Q: What are the next steps in research?

A: Rothstein's group plans to refine stem cell treatment by first figuring out exactly how the cells promote spinal cord repair in rodents. In the meantime, MDA is supporting several other research groups that are trying to understand how stem cells produce mature, functional cells. MDA is also supporting the investigation of other possible treatments for motor neuron disease, including nerve growth factors and dietary supplements.