title: Expression of IL-6 receptor and GP130 in mouse bone marrow cells during osteoclast differentiation.
abstract: Interleukin-6 (IL-6) has been postulated as a possible mediator of bone loss after estrogen deficiency, and its signal is transduced via glycoprotein 130 (gp130) after binding IL-6 receptor (IL-6R) in the membrane of target cells. In this study, the expression of IL-6R and gp130 in bone marrow cells during osteoclast differentiation was investigated. Mouse bone marrow cells were isolated and cultured with or without 1alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3]. During the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs), IL-6R and gp130 expression in the mononuclear cells, stromal cells, and TRAP-positive MNCs were quantitated, using a laser cytometer with a fluorescence confocal microscopy. With 1,25(OH)2D3 stimulus, the level of gp130 significantly increased, but that of IL-6R did not in the stromal cells. In contrast, the levels of both gp130 and IL-6R significantly increased in the mononuclear cells by the treatment with 1,25(OH)2D3. The high expression of both gp130 and IL-6R was observed in the TRAP-positive mononuclear cells. Moreover, both IL-6R and gp130 were expressed in the TRAP-positive MNCs and isolated murine osteoclasts. The treatment of TRAP-positive MNCs with IL-6 caused enhancement of the resorbing activity in a dose-dependent manner, and the effect was prevented by a neutralizing antibody against IL-6R. These data suggest that gp130 and IL-6R, as well as IL-6, are involved in the formation and activation of osteoclasts.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: I
authors.initials: I
authors.lastname: Morita
authors.forename: N
authors.initials: N
authors.lastname: Maruo
authors.forename: T
authors.initials: T
authors.lastname: Kubota
authors.forename: S
authors.initials: S
authors.lastname: Murota
authors.forename: T
authors.initials: T
authors.lastname: Aso
mesh_terms: D000135:Acid Phosphatase / Q000494:pharmacology; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D001854:Bone Marrow Cells / Q000187:drug effects / Q000378:metabolism*; D001862:Bone Resorption / Q000139:chemically induced; D002117:Calcitriol / Q000494:pharmacology*; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured / Q000187:drug effects; D050822:Cytokine Receptor gp130; D005260:Female; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000633:toxicity; D007527:Isoenzymes / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D018613:Microscopy, Confocal; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism*; D019947:Receptors, Interleukin-6 / Q000096:biosynthesis*; D013050:Spectrometry, Fluorescence; D017154:Stromal Cells / Q000378:metabolism; D000071681:Tartrate-Resistant Acid Phosphatase; D013977:Tibia
chemical_list: D015703:Antigens, CD; C494200:Il6st protein, mouse; D015850:Interleukin-6; D007527:Isoenzymes; D008562:Membrane Glycoproteins; D019947:Receptors, Interleukin-6; D050822:Cytokine Receptor gp130; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase; D002117:Calcitriol