ABOVE: A mouse osteocyte visualized with electron microscopy
LYNDA F. BONEWALD
Exercise helps beef up bones, but exactly how hasn’t been clear. A study published today (December 13) in Cell points to irisin, dubbed the “exercise hormone,” as a messenger between muscle and bone tissue that triggers the process of replacing old or damaged bone cells with new ones. Researchers also found the receptors for irisin, a group of proteins called αV integrins, in fat and bone cells.
“This is a pretty big discovery because in the past years, nobody has identified the receptor for this particular hormone,” says Jake Chen, a bone biologist at Tufts University who studies irisin but was not involved with this work.
Irisin is a hormone secreted from muscles during exercise. In animal studies, researchers have found it plays a part in strengthening bones and burning calories.
Previous studies on irisin were mired in controversy, and ...
