Working with rats, researchers isolated a compound of the body’s own brain stem cells that can tell nerve tissue to regenerate. The finding offers hope to those diagnosed with multiple sclerosis, a disease for which there is no cure.
MS Nerve Damage
About 350,000 people in the U.S. and 2.5 million worldwide suffer from the chronic inflammation of the central nervous system known as multiple sclerosis. Patients suffer vision and cognition problems; muscle numbness, tingling or spasticity; and difficulties with strength, balance and coordination.
Disability in multiple sclerosis results when myelin, the fatty tissue that insulates nerves, is damaged. Smooth transmission of neural messages from the brain is interrupted or blocked. As the damaged nerve cells begin to degenerate, more disability occurs.
The culprit is the body’s own immune system which, for reasons still unknown, attacks the tissue as if it were a foreign invader. Many of the recent developments in treating MS symptoms are based on regulating the immune system. Now, new research is concentrating on stem cells as a therapy to repair damaged myelin.
Researchers Find a Key to Remyelination
In December 2010, a group of scientists from Cambridge and Edinburgh universities announced that they had found a molecule that appears to trigger the brain to repair myelin.
The research team profiled thousands of genes in focusing on a substance known as RXR-gamma (RXR stands for retinoid acid receptor). They found that when the receptor was present, immature nerve cells were encouraged to mature and go on to repair myelin. When the receptor was inhibited, the cells remained immature.
“Therapies that repair damage are the missing link in treating multiple sclerosis,” Professor Robin Franklin, director of the Cambridge Center for Myelin Repair, said in a press release from the university. “In this study we have identified a means by which the brain's own stem cells can be encouraged to undertake this repair, opening up the possibility of a new regenerative medicine for this devastating disease."
Toxins Induce Demyelination
In MS studies, laboratory rats are traditionally infected with experimental autoimmune encephalomyelitis, a disease similar to multiple sclerosis in humans. But in the Cambridge study, researchers wanted to ensure that reduced inflammation wasn’t a factor in remyelination. They used toxins to induce demyelination lesions in the rats, then checked tissue samples as the nerves began to regenerate.
Using gene chip technology, they were able eventually to isolate RXR-gamma as the trigger for the remyelinating activity. That discovery allowed them to experiment with turning RXR-gamma on and off. When RXR-gamma was blocked, so was regeneration. When it was active, there was more myelin repair.
The study was funded by the MS Society in the UK and the National Multiple Sclerosis Society in the U.S, and published in Nature Neuroscience.
When Will an MS Treatment Be Available?
MS remyelination in rodents is one thing; MS remyelination in humans another. In between are long years of further study with animals and many phases of drug trials in humans.
Franklin estimates it will be 15 years before the results of the research translate into a multiple sclerosis treatment.
References and Further Reading
Multiple Sclerosis: Hope Through Research at the National Institute for Neurological Disorders and Stroke; good background on MS and the issues surrounding it
Cambridge University's announcement of the research findings
Nature Neuroscience article on the research, published online December 5, 2010
Science Daily article on University of Bristol research
National MS Society report on the research
Multiple Sclerosis International Foundation report on the research; a more technical discussion
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
Fran Gardner - Fran Gardner is a writer and editor who lives in Portland, Oregon. She retired in 2008 from The Oregonian, a big newspaper in town. She ...
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