Two already available medications could be used to treat multiple sclerosis (MS). In a new study titled, “Drug Based Modulation of Endogenous Stem Cells,” published in the journal Nature on April 20, 2015, scientists report that two drugs could activate stem cells in the brain, possibly repairing MS-induced damage to white matter.
The white matter in the brain consists of myelin, a fatty substance that helps brain cells transmit impulses along the long axons that connect brain cells (neurons). When myelin is damaged in MS due to an autoimmune response, brain cells no longer transmit impulses correctly. This causes loss of movement, pain, loss of vision and problems with normal sensation. Medications that can repair myelin and white matter and restore proper neuron communication would be of great use for treating MS.
The new report suggests that two such medications may already exist.
“To replace damaged cells, the scientific field has focused on direct transplantation of stem cell-derived tissues for regenerative medicine, and that approach is likely to provide enormous benefit down the road. We asked if we could find a faster and less invasive approach by using drugs to activate native nervous system stem cells and direct them to form new myelin. Our ultimate goal was to enhance the body’s ability to repair itself,” stated Paul J. Tesar, Ph.D., associate professor at Case Western Reserve School of Medicine in Cleveland, and senior author of the study.
Led by Fadi J Najm, Ph.D., of the Department of Genetics and Genome Sciences at Case Western Reserve University School of Medicine in Cleveland, Ohio, the researchers identified 727 drugs known to be safe in humans that could possibly act on oligodendrocytes, the cells that produce myelin in the brain. To find the drugs, the investigators used a database of medications available from the National Institutes of Health (NIH).
They tested the drugs in oligodendrocyte stem cells taken from mice to see if they could mature into fully functioning oligodendrocytes that produce myelin. Two drugs stood out as being the best: miconazole (an antifungal) and clobetasol (a steroid). The researchers then tested the ability of these drugs to produce myelin in mice with an experimental form of MS. After injection, both drugs induced myelin production by oligodendrocytes and even reversed paralysis in mice.
“The ability to activate white matter cells in the brain, as shown in this study, opens up an exciting new avenue of therapy development for myelin disorders such as multiple sclerosis,” said Ursula Utz, Ph.D., who works at the NIH.
However, although the two drugs are approved, they have not been tested in an injectable form in humans, so more safety data is needed in humans before the drugs can be used in MS. The scientists are busy trying to move the research forward.
“Off-label use of the current forms of these drugs is more likely to increase other health concerns than alleviate multiple sclerosis symptoms. We are working tirelessly to ready a safe and effective drug for clinical use,” Dr. Tesar said. Off-label use refers to using an approved drug for a disease that it was not studied for in clinical trials.
Although more work is needed, the current study provides promise for new treatments that hopefully may be available faster due to the already-approved status of these two medications.