University of California researchers have discovered that human stem cells can reverse a multiple sclerosis-type condition in mice. Soon to be published in the journal Stem Cell Reports, this work could potentially lead to new treatments for multiple sclerosis (MS).
When this team first transplanted the stem cells into severely disabled MS mice, they were quite sure that the immune systems of the mice would attack these transplanted stem cells, which were from humans, would attack and reject them. However, 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., who is presently a professor of pathology at the University of Utah, who began this study at University of California, Irvine.
Within next 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.
A chronic disease, MS results from the body’s own immune system attacks the body’s central nervous system. In particular, the insulating layer that surrounds many nerve fibers – a fatty substance called myelin – is slowly destroyed and this exposes nerves and slows or interrupts the transmission of nerve impulses. The symptoms of MS may be mild or severe, and includes 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.
Chen, Loring and their colleagues were further surprised that not only did the mice not initially reject these implanted stem cells, but they never showed any signs of rejection, even after one week.
Now Lane and others are eager to test this therapy in human clinical trials.
“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. He continued: “I would love to see something that could promote repair and ease the burden that patients with MS have.”
Previous work with stem cells has shown some promise in the treatment of MS. For example, in 2013, the US Food and Drug Administration (FDA) approved a small clinical trial of genetically modified mesenchymal stem cells initially harvested from bone marrow of MS patients. These stem cells were injected into the cerebrospinal fluid that surrounds the spinal cords of MS patients. Previous small studies conducted between 2005 and 2007 of this therapy in humans found that implantation of these modified stem cells reduced brain inflammation and repaired damaged layers of myelin. This small study only treated and tested seven patients.
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.