Stem Cells Treat Multiple Sclerosis

Researchers at the Cleveland Clinic, University Hospitals Seidman Cancer Center and Case Western Reserve University believe that they have made a significant break through in the use of stem cells to treat multiple sclerosis—an autoimmune disease in which the immune system attacks the myelin sheaths that surround and protect nerve cells.

They began their investigative journey by injecting human mesenchymal stem cells (MSC) into mice which had been given a mouse version of the disease. Following the injections, the mice improved but the researchers did not know why. One reason could be that the stem cells themselves, by coming in physical contact with the myelin damage, were having a healing effect. Or it could be something the stem cells were secreting into the liquid culture, or media that they were grown in, that was the key.

The researchers discovered that it was the stem cell secretions that were bringing about the improvements when they injected the liquid the stem cells were grown in, but not the stem cells themselves, into the mice they were studying. When the mice improved, they figured it had to be the media.

Last May, the research group headed up by neurosciences professor Robert Miller, discovered that the item in the stem-cell soup that had a healing effect was a large molecule called a hepatocyte growth factor, or HGF that is secreted by stem cells. The team published their results in Nature Neuroscience.

When they isolated the small, medium and large molecules from the media and tried each size on the mice they found that only the large-molecule treatment had the healing effect. "The molecule that jumped out at us was HGF, " he said in the September 4 news release, because it is the right size and is made by MSCs.

Miller and his team injected HGF into the sick mice. They got better. When they blocked the receptor for HGF in the mice, they stayed sick. Miller said that this result was compelling evidence that they had found what they were looking for. "We went on to show that HGF, like the MSCs, is regulating the immune response, and it is independently promoting myelin repair in the brain."

The local Phase 1 trial has enrolled 16 of 24 total patients, 8 of whom have completed the trial protocol, said Jeffrey Cohen, M.D., Cleveland Clinic neurologist and lead investigator of the trial. So far, the treatment seems to be working, Cohen said.