Simultaneously inhibiting three proteins can increase muscle mass, a finding that could help those with diseases such as muscular dystrophy and cancer that cause muscle deterioration, an Australian study reports.
“As a result of the study we can now more precisely regulate — and increase — muscle mass in the setting of disease,” Dr. Craig Harrison of the Monash institute said in a news release. He was a co-lead author of the study, along with Dr Paul Gregorevic of the Baker Institute.
Myostatin, also known as GDF8, plays a role in muscle mass deterioration by controlling signals that govern the size and number of muscle fibers, research has shown. Other studies have suggested that activin A and activin B play a similar role.
The Australian researchers injected compounds that inhibited activin A and activin B signaling into the muscles of healthy mice. The result was a moderate recovery of about 20 percent of the animals’ muscle mass. That finding confirmed the proteins’ role in muscle mass maintenance, the team said.
Injecting mice with a myostatin inhibitor led to a 45 percent jump in muscle mass, indicating it plays a more prominent role in muscle deterioration.
When the team combined the three inhibitors, they found that their activity was synergistic, generating a muscle mass increase of as much as 150 percent.
The researchers then tested the strategy in mouse models of muscular dystrophy and cancer cachexia, or cancer-related muscle wasting. In one test, simultaneous inhibition of the two activins led to increased muscle mass. In another test, inhibiting myostatin prevented muscle wasting.