Australian scientists have suggested that a protein called Grb10 plays a crucial role in increasing muscle mass during development.
Structure of the GRB10 protein (Emw / CC BY-SA 3.0)
The discovery appears in the Journal of the Federation of American Societies for Experimental Biology (FASEB Journal). Outside of aesthetics, this study has important implications for a wide range of conditions that are worsened by, or cause muscle wasting, such as injury, muscular dystrophy, Type 2 diabetes, and problems produced by muscle inflammation.
“By identifying a novel mechanism regulating muscle development, our work has revealed potential new strategies to increase muscle mass,” said lead author Dr Lowenna Holt of the Diabetes and Obesity Research Program at the Garvan Institute of Medical Research in Sydney, Australia. “Ultimately, this might improve treatment of muscle wasting conditions, as well as metabolic disorders such as Type 2 diabetes.”
To make this discovery, Dr Holt’s team compared two groups of mice. Once group had disruption of the Grb10 gene, and were very muscular. The other group, where the Grb10 gene was functional, had normal muscles. The researchers examined the properties of the muscles in both adult and newborn mice and discovered that the alterations caused by loss of Grb10 function had mainly occurred during prenatal development.
These results provide insight into how Grb10, nicknamed ‘Hulk’ protein, works, suggesting that it may be possible to alter muscle growth and facilitate healing, as the processes involved in muscle regeneration and repair are similar to those for the initial formation of muscle.
“Don’t turn in your gym membership just yet,” said Dr Gerald Weissmann, Editor-in-Chief of the FASEB Journal. “If you want big muscles, the classic prescription still applies: lift heavy things, eat and sleep right, and have your hormones checked. But this study shows that when we understand the basic science of how muscle fibers grow and multiply, we will be able to lift the burden – literally – of muscle disease for many of our patients.”
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Bibliographic information: Lowenna J. Holt et al. 2012. Grb10 regulates the development of fiber number in skeletal muscle. FASEB J 26: 3658-3669; doi: 10.1096/fj.11-199349