U. COLORADO (US) — A drug developed to treat chronic pain shows promise in reversing the effects of multiple sclerosis in rats.
Researchers report that a single injection of a compound called ATL31—an anti-inflammatory drug being developed to treat chronic pain—stopped the progression of MS-related paralysis in rats for weeks at a time.
MS is an inflammatory disease where the body’s immune system attacks a protective sheath called myelin that encompasses nerves in the spinal cord and brain. As the disease progresses, the myelin develops lesions, or scars, that cause permanent neurological problems.
“What happens now with MS drugs is they slow or stop the progression of MS, but they don’t treat it,” says Linda Watkins, professor of psychology at the University of Colorado at Boulder. “They don’t take people back to normal because the lesions caused by MS don’t heal.”
Watkins and colleagues hope to use spinal cord and brain-imaging technology to extend their studies to determine if lesions are being healed in rats that received an ATL313 injection.
“If we have a drug that is able to heal these lesions, this treatment could be a major breakthrough in how we treat the symptoms of MS in the future,” she says.
The new findings were quite a surprise. Researchers had originally wanted to look at the drug’s potential in treating pain associated with MS, because about 70 to 80 percent of MS patients suffer from chronic pain that is not treatable.
“What we had originally thought about this class of compounds is that they would calm down glial cells in the spinal cord because their pro-inflammatory activation is what causes pain,” she says.
Under normal circumstances glial cells are thought to be like housekeepers in the nervous system, essentially cleaning up debris and providing support for neurons.
Recent work has shown that glial cells in the central nervous system also act as key players in pain enhancement by exciting neurons that transmit pain signals.
“What’s become evident is that glial cells have a Dr. Jekyll and Mr. Hyde personality,” Watkins says.
“Under normal circumstances they do all these really good things for the neurons, but when they shift into the Mr. Hyde formation they release a whole host of chemicals that cause problems like neuropathic pain and other chronic pain conditions.”
ATL313 appears to reset the glial cells from an angry activated state to a calm anti-inflammatory state that may heal MS lesions.
The study was funded by PGxHealth and grants from the state of Colorado’s CO-Pilot program, the National Institutes on Drug Abuse, and the National Institute on Neurological Disease and Stroke.
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