Strong. In mice, increased the production of utrophin maintains healthy muscle tissue ( right ), which prevents damage ( left ) seen in muscular dystrophy Duchenne.
For decades, researchers have struggled to find ways to help patients with Duchenne muscular dystrophy, a devastating genetic disease that kills most victims in their 20s . Now they have had some success in mice. The scientists found that by stimulating the production of an enzyme on the membranes of the muscle fibers, they can prevent Duchenne animals that would normally have the disease
caused by a missing or defective gene on the X chromosome Duchenne affects 1 5,000 children, almost all boys (women with a faulty copy of the gene are carriers). The gene codes for dystrophin, a protein that helps the muscle fibers attach to surrounding connective tissue. Lack of dystrophin causes progressive muscle weakness. While some research groups are working on gene therapy treatments, others have focused on approaches that would slow down the relentless disease.
neuroscientist Paul Martin and his team at the University of California, San Diego, believes that a solution might be to coax the body to produce more utrophin, a protein similar to dystrophin. There is a catch: dystrophin and utrophin are not usually found in the same parts of muscle tissue. The trick is the production of utrophin where dystrophin would normally. To do this, the team developed a strain of mice with multiple copies of a gene that produces high doses of a certain enzyme. This enzyme, called CT GalNAc transferase generates sugars thought to stimulate the production of utrophin and anchor the protein in place. The group then multiplied mice with men who had the disease and women who were carriers.
Strikingly, none of the children had any muscle degeneration. The analysis of muscle tissues showed the enzyme and utrophin dotted over the entire surface of each muscle fiber. Scientists still can not explain how to make more of the enzyme allows the propagation utrophin around. But the work demonstrates that even in mice that would normally Duchenne, improving the amount of utrophin can help build strong muscle tissue healthy, the team reports in the April 15 issue of Proceedings of the national Academy of sciences .
"This is really exciting," said neuroscientist Stephen Kaufman of the University of Illinois, Urbana-Champaign, who think an enzyme-based treatment may be easier to develop that therapy gene. The body is less likely to reject an enzyme, it is already in production, he said, compared with a foreign gene.
Related Sites
The Web page of Paul Martin
Muscular Dystrophy Association
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