According to an article from Medical Xpress, an experimental chemical compound being developed by Oregon Health & Science University (OHSU) has proven effective in reversing simulated symptoms of multiple sclerosis (MS) in a group of mice.
Multiple sclerosis, which is characterized by the progressive break-down of myelin (a protective coating that forms the outermost layer of a neuron), has no known cure. Various treatments exist to minimize a patient’s symptomatic burden, but no FDA-approved therapy can reverse the demyelinating process.
About Multiple Sclerosis
Scientists have yet to identify a root cause of multiple sclerosis. As with most diseases without a clear genetic or environmental origin, it is believed that a variety of factors could contribute to development of MS.
The disease is autoimmune, meaning the body’s own defense systems mistakenly target healthy tissues as foreign antigens. In this case, the healthy tissues that are mistakenly targeted are the myelin coatings that surround nerve fibers and give them insulating structure. Immune cells that normally target and destroy bacteria or viruses instead start to eat away at nerve fibers.
As the destruction of myelin worsens, the ability of nerves to transmit electric impulses diminishes. Eventually, nerve fibers themselves may start to deteriorate.
Symptoms and severity vary between individual cases, though difficulties controlling voluntary motion are common and usually progress over time.
Can What’s Been Demyelinated be Remyelinated?
Researchers certainly hope so. So far, re-myelinating treatments have eluded discovery. The only existing treatments for multiple sclerosis patients are symptom-managing, treating the observable effects of the disease but not combating the root causes.
Researchers at Oregon Health & Science University think they might be onto something, though. A recent study conducted by the university found that in mice, simulated human symptoms of MS could be reversed through the administration of sobetirome, a chemical compound thought to generate re-myelination by stimulating and enhancing the thyroid’s natural ability to repair myelin.
Hormones released by the thyroid are known to stimulate new myelin production, but scientists have avoided using these hormones in treatment due to “unacceptable side effects” in the form of hypothyroidism.
In mice, sobetirome was found to remyelinate nerve fibers without the serious side effects that would accompany thyroid hormone therapy. A newly-synthesized form of the decades-old drug (originally developed as a cholesterol-lowering treatment) showed a tenfold increase in ability to penetrate the highly selective blood-brain barrier, which would allow the drug to penetrate deep into the central nervous system where the effects of MS can be the most serious.
In short, the mice got better – showing close to full recovery. Researchers are hopeful sobetirome could be just as effective in humans, though the gamut of clinical testing has yet to begin. To prepare the drug for human trials, Oregon Health & Science University licensed the new form of sobetirome to Llama Therapeutics Inc., who will be responsible for further testing and development of the drug.
Scientists on the project say they’re confident the compound will be effective in humans, too. However, that could be the optimism talking – success in animal trials has historically not been a foolproof predictor of effectiveness in humans.
“Right now, what it means is hope,” said Dr. Dennis Bourdette, co-author of the OHSU research. After more research, “It could have a significant impact on patients debilitated by MS.”
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