What if, in this dawning era of regenerative medicine, we could help the body heal itself? Not by replacing diseased or damaged cells, as is so often the paradigm in this field, but by stimulating the stem cells already present in a given tissue to differentiate and then repair the damage. No, this isn’t science fiction, like using one of Dr. McCoy’s futuristic devices from Star Trek to heal the injured Captain Kirk. This approach is now being assessed as a potential treatment for multiple sclerosis.
Multiple sclerosis (MS) affects about 2.3 million people worldwide and is thought to be caused by an immune system-mediated attack on the body. There are multiple forms of MS and those afflicted with it can experience a range of symptoms but the underlying problem is damage to the insulation around the nerves, known as myelin, and the cells that produce it, known as oligodendrocytes.
The loss of this insulation creates communication defects throughout the nervous system. Treatment of MS typically involves trying to relieve the symptoms that manifest from the communication defect or control the immune system to lessen disease activity. Although these treatments can be effective, they do not prevent chronic disease progression. A recently published research study in the scientific journal Nature introduces a treatment paradigm, stimulating the production of myelin, which may change the way MS is treated.
The idea behind the treatment was to find a way to stimulate stem cells to repair the damaged insulation. Neural stem cells can self-renew and give rise to multiple cell types including oligodendrocytes. To find drugs that could specifically stimulate the maturation of central nervous system stem cells into myelin-producing oligodendrocytes, Dr. Paul Tesar and his scientific team “mined” drugs. Not unlike how miners sift the ground for precious metals, the Tesar laboratory was sifting through, or “screening,” drugs, most of which had previously been used in U.S. Food and Drug Administration (FDA)-approved clinical trials, though not specifically for MS
Dr. Tesar’s team identified two promising drugs out of nearly 700 in the screen - Miconazole, an ingredient in over-the-counter treatments for fungal infections such as athlete’s foot and clobetasol, a topical corticosteroid used for various skin conditions. Not only were Miconazole and clobetasol able to stimulate the differentiation of stem cells into mature oligodendrocytes, most importantly, these drugs stimulated the formation of new insulation (myelin) and reversed disease severity in animal models of MS. While not all adult tissues in our body contain stem cells, this approach may change the way MS is managed.
It is too early to say whether these drugs can be successfully transitioned from topical creams to effective MS medicines, but the discovery of potential new drugs to treat MS is very encouraging. The drug discovery method used by Dr. Tesar also offers hope that more novel MS drugs will soon follow.
Dr. Paul Tesar is the recipient of the 2015 ISSCR Outstanding Young Investigator Award and will be presenting at the ISSCR 2015 Annual Meeting in Stockholm, Sweden.