Boston scientists have discovered a protein in muscles that promotes increased growth and power from weight training. The discovery is not only likely to intrigue body builders and sports buffs, but may also point the way to preventing muscle wasting caused by aging, long hospital stays, cancer, muscular dystrophy, and other health conditions.
Scientists at Dana-Farber Cancer Institute have isolated the previously unknown protein — known as PGC-1 alpha-4 — in skeletal muscle tissues in mice and humans. Resistance exercise, such as weight lifting, causes a rise in the protein, which in turn triggers biochemical changes that make muscles larger and more powerful, said the researchers.
The new study, published in the journal Cell, found that mice given extra doses of the protein gained muscle mass and strength, and those with cancer were less affected by muscle loss (a common condition known as cachexia).
"This is basic science at present," said researcher Jorge Ruas. "But if you could find a way to elevate levels of this protein, that would be very exciting. For example, you might be able to reduce muscle wasting in patients in intensive care units whose muscles atrophy because of prolonged bed rest."
The researchers found that the new protein regulates the activity of two known molecular pathways involved in muscle growth. For the new study, the investigators inserted PGC-1 alpha-4 into the leg muscles of mice and found that within several days their muscle fibers were 60 percent bigger than those of untreated mice.
They also engineered mice to have more of the protein in their muscles than normal mice who were not exercising. Tests showed the engineered mice were 20 percent stronger and more resistant to fatigue than the others; they were also leaner and showed "dramatic resistance" to cancer-related muscle wasting, the scientists found.
The study was funded, in part, by the National Institutes of Health.