Skeletal Muscle as an Endocrine OrganMonday, May 13, 2013
This week, I am attending the 20th European Congress on Obesity in Liverpool.
The opening plenary lecture this morning was presented by Bente Pedersen from the University of Copenhagen, who reviewed her work demonstrating that the profound positive effects of exercise on metabolism, inflammation, mood and cognitive function are mediated by 100s of proteins secreted from skeletal muscle cells in response to muscle contraction.
These molecules are now referred to as “myokines” and have been shown to exert either autocrine, paracrine or endocrine effects on other organs like adipose tissue, liver, pancreas, bones and brain..
This exciting area of research is nicely summarized in a recent paper by Bente Pedersen and Mark Febbraio published in Nature Endocrine Reviews.
For example, exercise-induced increases in myocellular production of BDNF and IL-6 can increase AMPK-mediated fat oxidation, whereby IL-6 appears to have systemic effects on the liver, adipose tissue and the immune system and even mediates crosstalk between intestinal L cells and pancreatic islets.
Other myokines (e.g. the osteogenic factors IGF-1 and FGF-2; FSTL-1) can improve the endothelial function of the vascular system.
More recently, the myokine irisin, has been shown to promote “browning” of adipose tissue.
Other lines of research suggest that myokines can influence the growth of cancer cells as well as modulate immune function, bone development and pancreatic B-cells.
Current research using proteomic techniques will likely provide further insights into the hundreds of molecules secreted from skeletal muscle in response to physical activity and explain how these myokines mediate the wide-ranging beneficial effects of exercise and the detrimental effects of sedentariness on many chronic diseases.
You can follow live tweets from the conference at #ECO2013