ABOVE: Osteoblasts
FLICKR, GIREESH REDDY
Experiments in mice and observations in humans have suggested the bone protein osteocalcin acts as a hormone regulating, among other things, metabolism, fertility, exercise capacity and acute stress. That interpretation is now partially in doubt. Two independent papers published yesterday (May 28) in PLOS Genetics, each of which presents a new osteocalcin knockout mouse strain, report that glucose metabolism and fertility were unaffected in the animals. While some researchers praise the studies, others highlight weaknesses.
“I thought they were very good papers. I think the authors should be congratulated for very comprehensive studies of both skeletal and extraskeletal functions of osteocalcin,” says emeritus bone researcher Caren Gundberg of Yale School of Medicine who was not involved in the research.
Skeletal biologist Gerard Karsenty of Columbia University disagrees. “There have been 25 laboratories in the world . . . that have shown osteocalcin is a hormone,” says ...
