Researchers in California have discovered – almost by accident – that human stem cells can reverse a multiple sclerosis type condition in mice. The findings, which will soon be published in the journal Stem Cell Reports, could potentially lead to new types of treatment for multiple sclerosis (MS).
When scientists first transplanted the stem cells into severely disabled MS mice, they thought the cells would be rejected, much like donor organs are rejected after a transplant. But the experiment had surprising results.
“My postdoctoral fellow Dr. Lu Chen came to me and said, ‘The mice are walking.’ I didn’t believe her,” said co-senior author, Tom Lane, PhD., a professor of pathology at the University of Utah, who began the study at University of California, Irvine.
Within 10 to 14 days, the mice regained their lost motor skills. And six months later, they still show no signs of slowing down.
“This result opens up a whole new area of research for us,” said co-senior author Jeanne Loring, PhD, a professor at The Scripps Research Institute in La Jolla, Calif.
MS is a chronic disease which attacks the body’s central nervous system. The disease occurs when the body’s immune system attacks a fatty substance called myelin, which coats nerves in the brain’s white matter. When the nerves are exposed, transmission of nerve impulses can be slowed or interrupted. Symptoms may be mild or severe, including numbness in the limbs, difficulty walking, paralysis, loss of vision, fatigue and pain.
Researchers say the MS mice treated with human stem cells experienced a dramatic reversal of symptoms within days. Immune attacks were blunted and damaged myelin was repaired.
Their original prediction that the mice would reject the stem cells also came true. There were no signs of the cells after one week.
Researchers are eager to further test the therapy in clinical studies on humans.
“Rather than having to engraft stem cells into a patient, which can be challenging, we might be able to put those chemical signals into a drug that can be used to deliver the therapy much more easily,” said Lane.
“I would love to see something that could promote repair and ease the burden that patients with MS have.”
In 2013, the Food and Drug Administration approved a small study of human stem cells harvested from the bone marrow of MS patients. The stem cells are injected into the cerebrospinal fluid that surrounds the spinal cords of the patients. Previous studies of this therapy in humans found that it reduced brain inflammation and repaired damaged layers of myelin.
There is no known cure for MS and drugs to treat it have limited effectiveness. An estimated 400,000 Americans have the disease and more than 2 million worldwide.