A Molecule to Help Retain Muscle Mass During Weight Loss?

TOPLINE:

A protein called B cell lymphoma 6 (BCL6) could be key to maintaining healthy muscle mass, and potentially could be used to combat muscle wasting conditions in humans, a study in mice suggests.

METHODOLOGY:

• Researchers used various strategies to identify the mechanism by which BCL6 helps maintain muscle, including mouse studies, muscle histology, cell culture, gene editing, gene expression analysis, data analyses, and various assays.
• They compared mice with and without BCL6 to gauge the differences related to muscle and muscle mass.

TAKEAWAY:

• Mice lacking BCL6 had 40% less muscle mass than their counterparts with normal BCL6, and that muscle was compromised both in structure and function.
• Increasing the expression of BCL6 in the animals’ muscles successfully reversed the losses in muscle mass and strength.
• A related experiment comparing normal mice with those that had fasted overnight found that fasting mice had less BCL6 in their muscles, supporting the role of BCL6 in controlling muscle maintenance.
• The proposed pathway by which BCL6 controls muscle is the following: Fasting promotes the secretion of growth hormone, which reduces BCL6 levels in muscle cells; less BCL6 leads to less suppressor of cytokine signaling 2 (SOCS2) because BCL6 regulates SOCS2 expression; this, in turn, slows insulin-like growth factor 1 production, causing muscles to become smaller and weaker.

IN PRACTICE:

“These findings have the potential to direct therapeutic strategies aimed at preserving muscle mass to afford healthy aging and combat muscle-wasting diseases such as sarcopenia and cachexia,” the authors concluded.

SOURCE:

The study was led by Hui Wang, PhD, of Salk Institute, La Jolla, California, and published online in Proceedings of the National Academy of Sciences. 

LIMITATIONS:

This study was conducted in animals and in the lab. Future research is needed to explore the therapeutic potential of the findings.

DISCLOSURES:

The work was supported by several federal and nonprofit organization grants to individual authors, as shown online. The authors declared no competing interests.