title: The skeleton as an endocrine organ.
abstract: Surprising new discoveries in the field of skeletal biology show that bone cells produce endocrine hormones that regulate phosphate and glucose homeostasis. In this Review, we examine the features of these new endocrine pathways and discuss their physiological importance in the context of our current understanding of energy metabolism and mineral homeostasis. Consideration of evolutionary and comparative biology provides clues that a key driving force for the emergence of these hormonal pathways was the development of a large, energy-expensive musculoskeletal system. Specialized bone cells also evolved and produced endocrine hormones to integrate the skeleton in global mineral and nutrient homeostasis. The recognition of bone as a true endocrine organ represents a fertile area for further research and should improve the diagnosis and treatment of metabolic diseases such as osteoporosis and diabetes mellitus.
authors.affiliation: Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, 601 North Caroline Street, Baltimore, MD 21287, USA. ddigiro2@jhmi.edu
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: DiGirolamo
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Clemens
authors.forename: Stavroula
authors.initials: S
authors.lastname: Kousteni
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004703:Endocrine System; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006706:Homeostasis; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D015675:Osteocalcin / Q000378:metabolism*; D010011:Osteocytes / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D012863:Skeleton
chemical_list: D006728:Hormones; D010710:Phosphates; D015675:Osteocalcin; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D005947:Glucose