title: [Diabetes and bone metabolism].
abstract: In the past decade several novel findings point to the critical role of the skeleton in several homeostatic processes, including energy balance. The connection begins in the bone marrow with lineage allocation of mesenchymal stem cells to adipocytes or osteoblasts. Osteoblasts and adipocytes produce factors affecting insulin homeostasis. The hormonally active adipose tissue can regulate bone metabolism. In this review authors discuss targets taking critical part in the bone-fat network: leptin, osteocalcin, PPAR γ2 and the Wnt/beta catenin pathway. Leptin regulates energy metabolism through controlling appetite. Mutation of the leptin gene resulting leptin resistance leads to high leptin levels, enormous appetite and pathologic obesity. Leptin also can influence the bone mass. The main effects of the thiazolidinedions - PPARγ agonists - are mediated through receptors located in adipocytes. However, beside their positive effects, they also suppress osteoblastogenesis and increase the risk for pathologic fractures. Osteocalcin, a known marker of bone formation, produced by osteoblasts decreases fat mass, promotes adiponectin production and insulin sensitivity, increases the number of pancreatic β-cells and increases insulin secretion. Thus, the skeletal system can regulate glucose metabolism and this substantially changed our view on this issue. Novel molecules can now be tested as targets in order to enhance bone formation and possibly prevent fractures.
authors.affiliation: Országos Reumatológiai és Fizioterápiás Intézet Budapest Frankel Leó út 38-40. 1023. evaruzicska@gmail.com
authors.forename: Eva
authors.initials: E
authors.lastname: Ruzicska
authors.forename: Gyula
authors.initials: G
authors.lastname: Poór
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D006801:Humans; D020738:Leptin / Q000378:metabolism*; D015227:Lipid Peroxidation; D015675:Osteocalcin / Q000378:metabolism*; D010012:Osteogenesis; D018384:Oxidative Stress; D047495:PPAR gamma / Q000378:metabolism*; D015398:Signal Transduction; D051155:Wnt1 Protein / Q000378:metabolism*
chemical_list: D020738:Leptin; D047495:PPAR gamma; D051155:Wnt1 Protein; D015675:Osteocalcin