title: Omentin-1 attenuates arterial calcification and bone loss in osteoprotegerin-deficient mice by inhibition of RANKL expression.
abstract: OBJECTIVE
  Omentin-1 (also known as intelectin-1) is a recently identified visceral adipose tissue-derived cytokine that is inversely related to obesity. Our previous study showed that omentin-1 inhibits osteoblastic differentiation of calcifying vascular smooth muscle cells (CVSMCs) in vitro. This study was undertaken to investigate the effects of omentin-1 on arterial calcification and bone metabolism in vivo.
  
  
  RESULTS
  In vitro, omentin-1 stimulated production of osteoprotegerin (OPG) and inhibited production of receptor activator for nuclear factor κB ligand (RANKL) in both CVSMCs and osteoblasts. In vivo, adenovirus-mediated over-expression of omentin-1 attenuated arterial calcification and bone loss in OPG(-/-) mice. All these in vitro and in vivo actions were abrogated by blockade of the PI3K-Akt signalling pathway. Furthermore, omentin-1 reduced serum levels of RANKL, tartarate-resistant acid phosphatase-5b and osteocalcin, all of which are increased dramatically in OPG(-/-) mice.
  
  
  CONCLUSIONS
  These data suggest that omentin-1 ameliorates arterial calcification and bone loss in vivo through the regulation of the RANK signalling pathway.
authors.affiliation: Institute of Endocrinology and Metabolism, Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, People's Republic of China. huixie_csu@yahoo.com.cn
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.forename: Ping-Li
authors.initials: PL
authors.lastname: Xie
authors.forename: Xian-Ping
authors.initials: XP
authors.lastname: Wu
authors.forename: San-Mei
authors.initials: SM
authors.lastname: Chen
authors.forename: Hou-De
authors.initials: HD
authors.lastname: Zhou
authors.forename: Ling-Qing
authors.initials: LQ
authors.lastname: Yuan
authors.forename: Zhi-Feng
authors.initials: ZF
authors.lastname: Sheng
authors.forename: Si-Yuan
authors.initials: SY
authors.lastname: Tang
authors.forename: Xiang-Hang
authors.initials: XH
authors.lastname: Luo
authors.forename: Er-Yuan
authors.initials: EY
authors.lastname: Liao
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D052242:Adiponectin / Q000378:metabolism; D000818:Animals; D015519:Bone Density; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D015536:Down-Regulation; D005260:Female; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D015316:Genetic Therapy; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D037102:Lectins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D010006:Osteoblasts / Q000378:metabolism*; D015675:Osteocalcin / Q000378:metabolism; D010024:Osteoporosis / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D053244:Osteoprotegerin / Q000172:deficiency* / Q000235:genetics; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D061205:Vascular Calcification / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D016207:Cytokines; D058851:GPI-Linked Proteins; C432397:ITLN1 protein, human; D007527:Isoenzymes; D037102:Lectins; D053244:Osteoprotegerin; D053245:RANK Ligand; D011994:Recombinant Proteins; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse; D015675:Osteocalcin; D058539:Phosphatidylinositol 3-Kinase; D051057:Proto-Oncogene Proteins c-akt; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase