by If you’re among the 13% of American adults who have taken a GLP-1 drug for weight loss, you may know that while fat may appear to be melting away, muscle is also disappearing. And if you’re not a lifter or have other conditions that prevent you from starting a new workout program, there’s not much you can do about it.
But scientists at the Salk Institute have now identified a molecule that could potentially be boosted to help in that department. They found that a protein called BCL6 is responsible for maintaining muscle structure – and by increasing its presence, it could stop tissue breakdown without affecting weight loss.
“Muscle is the most abundant tissue in the human body, so maintaining it is critical to our health and quality of life,” said Ronald Evans, professor and director of the Gene Expression Laboratory at Salk. “Our study shows how our body coordinates the maintenance of all that muscle with our diet and energy levels. “With this new insight, we can develop therapeutic interventions for patients who are losing muscle as a side effect of weight loss, age or disease.”
The discovery, of course, extends beyond those taking GLP-1 drugs. And although the discovery of BCL6 came as part of a study in mice, researchers are confident that it can be translated to human physiology.
Salk Institute
The researchers examined the mechanisms involved during periods of fasting, when the stomach and brain communicate to promote the secretion of a growth hormone that is targeted to muscle cells. They discovered that this chain reaction lowered BCL6 levels. When BCL6 is depleted, it essentially leads to weakening and shrinkage of muscle tissue structures.
When the researchers increased BCL6 levels, the muscle tissue became resistant to this process – so the weight loss came from fat instead. In the mouse study, the team found that the rodents without this BCL6 boost had 40% less muscle mass than the control group. The muscles they retained were also structurally weak and weaker. When the BCL6-suppressed mice were then boosted with the protein, the muscle loss and strength were reversed.
And in fasting mice, BCL6 was significantly degraded in a short period of time, such as overnight.
“We are excited to uncover the important role of BCL6 in maintaining muscle mass,” said lead author Hunter Wang, a postdoctoral researcher in Evans’ lab. “These were very surprising and special findings that open the door to many new discoveries and potential therapeutic innovations.”
The researchers believe this discovery paves the way for the development of a BCL6 booster that could be administered alongside the GLP-1 drug to protect against muscle loss. In the meantime, the team plans to study the effects of longer periods of fasting and its effects on muscle tissue. This same type of BCL6 therapy has the potential to help a broader population, such as older adults and people with muscle-impairing diseases, including cancer.
The research was published in the journal Proceedings of the National Academy of Sciences.
Source: Salk Institute
