Gene Identification Leads to Muscle Repair

Researchers at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), part of the National Institutes of Health, began to discover reasons behind muscle degeneration and ways to prolong its' effects. While reading an article about their research, the question was asked why patients with Duchenne muscular dystrophy (DMD) have very little problems through childhood and adolescence, yet succumb to the disease in adulthood. It was also asked why elderly people who lose muscle strength following bed rest find it difficult or impossible to regain. They started exploring possibilities by researching into satellite cells. While satellite cells actively increase muscle mass during infancy, they decrease in number and become inactive unless activated by injury or degeneration. Scientists than looked into a gene called Ezh2, known to keep the activity of other genes in check. When they genetically inactivated Ezh2 in satellite cells of laboratory mice, the mice failed to repair muscle damage meaning satellite cells could not proliferate. Ezh2 expression is known to decline during aging. If scientists could find therapies to continue Ezh2 expression and continue the production of satellite cells, they could increase the lifespan and quality of life in DMD patients and the elderly.

"We will not be able to cure the muscular dystrophies with this approach because the mutation in the gene that causes the diseases would remain. But certainly, if we can extend the period in which the satellite cells proliferate and compensate for the underlying defect, we might increase the lifespan of people with muscular dystrophy. We could certainly increase their quality of life," said Dr. Sartorelli ( Senior investigator in the NIAMS Laboratory of Muscle Stem Cells and Gene Regulation and lead author of the study).