August 2, 2012
A Promising Step For Muscular Dystrophy
(Ivanhoe Newswire) - Duchenne muscular dystrophy affects 1 in every 3,600 male infants each year. Due to the way the disease is inherited, girls are not affected. Muscular dystrophy consists of a group of inherited disorders causing muscle weakness and loss of muscle tissue, which progressively becomes worse.
Researchers seem to have discovered a promising new way to reverse the symptoms of the disease in mice. Scientists have reversed symptoms of myotonic muscular dystrophy in mice by eliminating a buildup of toxic RNA in muscle cells.
After experimental antisense compounds were administered to mice twice a week for four weeks, symptoms of the disease were reduced for up to one year — a significant portion of a mouse's lifespan.
The investigators say that while the work is an encouraging step forward against myotonic dystrophy, one of the most common forms of muscular dystrophy, it's too soon to know whether the approach will work in patients. But they are cautiously optimistic, noting that the compound is extremely effective at reversing the disease — whose genetic underpinnings make it particularly vulnerable to an antisense approach — in a mouse model.
"These results give us strong encouragement about the possibility of developing a treatment that could fundamentally alter the disease. It's an important step on a long path," senior author Charles Thornton, M.D., a neurologist at the University of Rochester Medical Center was quoted as saying. "But, it's too early to know if this treatment will work as well in people as it did in the laboratory. Unfortunately, in biomedical research there are previous examples of compounds that worked in mice but not in people."
Now scientists at Isis and the University of Rochester are working to improve their lead compound further, developing antisense compounds with stronger activity against the toxic RNA, but with minimal effects on the rest of the body. An unknown factor at this point is whether the compounds will also improve the muscle-wasting aspect of the disease. That symptom, which causes great difficulty for patients, has been hard for scientists to create in mice, and so it's difficult to predict how it might respond to antisense knockdown technology.
Source: University of Rochester Medical Center, August 2012