A number of research groups are looking into ways to manipulate muscle regeneration and maintenance, and an advance here could be useful as a therapy to address age-related loss in muscle mass and strength: "Researchers have long questioned why patients with Duchenne muscular dystrophy (DMD) tend to manage well through childhood and adolescence, yet succumb to their disease in early adulthood, or why elderly people who lose muscle strength following bed rest find it difficult or impossible to regain. Now, researchers [are] beginning to find answers in a specialized population of cells called satellite cells. Their findings [suggest] a potential therapeutic target for conditions where muscle deterioration threatens life or quality of life. ... Suspecting a genetic switch that might turn off satellite cell proliferation in these circumstances, the scientists looked to 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 caused by traumatic injury - satellite cells could not proliferate. Ezh2 expression is known to decline during aging, and the new research in mice suggests that therapies to activate Ezh2 and promote satellite cell proliferation might eventually play a role in treating degenerative muscle diseases. ... in the elderly, tweaking the gene in satellite cells would not increase their lifespan, but could increase their quality of life by helping to prevent falls and enabling them to move and walk better and go about their daily activities."

Link: http://www.nih.gov/news/health/apr2011/niams-15.htm