J Korean Med Sci.  2010 Jul;25(7):985-991. 10.3346/jkms.2010.25.7.985.

Integrative Physiology: Defined Novel Metabolic Roles of Osteocalcin

Affiliations
  • 1Laboratory of Exercise Physiology and Medicine, Department of Physical Education, Yonsei University, Seoul, Korea. ssh@yonsei.ac.kr
  • 2Department of Pediatrics, Korea University of College of Medicine, Seoul, Korea.

Abstract

The prevailing model of osteology is that bones constantly undergo a remodeling process, and that the differentiation and functions of osteoblasts are partially regulated by leptin through different central hypothalamic pathways. The finding that bone remodeling is regulated by leptin suggested possible endocrinal effects of bones on energy metabolism. Recently, a reciprocal relationship between bones and energy metabolism was determined whereby leptin influences osteoblast functions and, in turn, the osteoblast-derived protein osteocalcin influences energy metabolism. The metabolic effects of bones are caused by the release of osteocalcin into the circulation in an uncarboxylated form due to incomplete gamma-carboxylation. In this regard, the Esp gene encoding osteotesticular protein tyrosine phosphatase is particularly interesting because it may regulate gamma-carboxylation of osteocalcin. Novel metabolic roles of osteocalcin have been identified, including increased insulin secretion and sensitivity, increased energy expenditure, fat mass reduction, and mitochondrial proliferation and functional enhancement. To date, only a positive correlation between osteocalcin and energy metabolism in humans has been detected, leaving causal effects unresolved. Further research topics include: identification of the osteocalcin receptor; the nature of osteocalcin regulation in other pathways regulating metabolism; crosstalk between nutrition, osteocalcin, and energy metabolism; and potential applications in the treatment of metabolic diseases.

Keyword

Osteocalcin; Energy Metabolism; Bone Remodeling; Leptin; Protein Tyrosine Phosphatases

MeSH Terms

Bone Remodeling/physiology
Bone and Bones/*metabolism
*Energy Metabolism
Humans
Leptin/metabolism
Osteocalcin/genetics/*metabolism
Full Text Links
  • JKMS
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2022 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr