Drugs stimulate body’s stem cells to replace the brain cells lost in multiple sclerosis

Two FDA approved drugs were found to stimulate stem cells in the brain and spinal cord to regenerate to the protective coating around neurons that is damaged in diseases such as multiple sclerosis. Illustrator: Megan Kern

Approach may offer new way to reverse disability in multiple sclerosis patients

A pair of topical medicines already alleviating skin conditions may prove to have another, even more compelling use: instructing stem cells in the brain to reverse damage caused by multiple sclerosis.

Led by researchers at Case Western Reserve University, a multi-institutional team used a new discovery approach to identify drugs that could activate mouse and human brain stem cells in the laboratory. The two most potent drugs—one that currently treats athlete’s foot, and the other, eczema—were capable of stimulating the regeneration of damaged brain cells and reversing paralysis when administered systemically to animal models of multiple sclerosis. The results were published online (dx.doi.org/10.1038/nature14335) Monday, April 20, in the scientific journalNature.

“We know that there are stem cells throughout the adult nervous system that are capable of repairing the damage caused by multiple sclerosis, but until now, we had no way to direct them to act,” said Paul Tesar, the Dr. Donald and Ruth Weber Goodman Professor of Innovative Therapeutics, and associate professor in the Department of Genetics & Genome Sciences at the Case Western Reserve School of Medicine. “Our approach was to find drugs that could catalyze the body’s own stem cells to replace the cells lost in multiple sclerosis.”

The findings mark the most promising developments to date in efforts to help the millions of people around the world who suffer from multiple sclerosis. The disease is the most common chronic neurological disorder among young adults, and results from aberrant immune cells destroying the protective coating, called myelin, around nerve cells in the brain and spinal cord.

Without myelin, neural signals cannot be transmitted properly along nerves; over time, a patient’s ability to walk, hold a cup or even see is inexorably eroded. Current multiple sclerosis therapies aim to slow further myelin destruction by the immune system, but the Case Western Reserve team used a new approach to create new myelin within the nervous system. Their work offers great promise of developing therapies that reverse disabilities caused by multiple sclerosis or similar neurological disorders.

“To replace damaged cells, much of the stem cell 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,” said Tesar, also a New York Stem Cell Foundation Robertson Investigator and member of the National Center for Regenerative Medicine. “But here we asked if we could find a faster and less invasive approach by using drugs to activate native stem cells already in the adult nervous system and direct them to form new myelin. Our ultimate goal was to enhance the body’s ability to repair itself.”

Tesar emphasized that much work remains before multiple sclerosis patients might benefit from the promising approach. Scientists still must find ways to transform the topical medications for internal use and determine their long-term efficacy and potential side effects. That said, using existing, federally approved drugs enhances the likelihood that the compounds can be made safe for human use.

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