title: Relevance of an in vitro osteoclastogenesis system to study receptor activator of NF-kB ligand and osteoprotegerin biological activities.
abstract: Receptor activator of NF-kB Ligand (RANKL) is an essential requirement for osteoclastogenesis and its activity is neutralized by binding to the soluble decoy receptor osteoprotegerin (OPG). The purpose of this work was to study the effects of RANKL and OPG during osteoclastogenesis using the murine monocytic cell line RAW 264.7 that can differentiate into osteoclasts in vitro. RAW 264.7 cells plated at 10(4) cells/cm(2) and cultured for 4 days in the presence of RANKL represent the optimal culture conditions for osteoclast differentiation, with an up-regulation of all parameters related to bone resorption: tartrate resistant acid phosphatase (TRAP), calcitonin receptor (CTR), RANK, cathepsin K, matrix metalloproteinase (MMP)-9 mRNA expressions. RANKL and OPG biological effects vary according to the differentiation state of the cells: in undifferentiated RAW 264.7 cells, TRAP expression was decreased by OPG and RANKL, RANK expression was inhibited by OPG, while MMP-9 and cathepsin K mRNA expressions were not modulated. In differentiated RAW 264.7 cells, RANKL and OPG both exert an overall inhibitory effect on the expression of all the parameters studied. In these experimental conditions, OPG-induced MMP-9 inhibition was abrogated in the presence of a blocking anti-RANKL antibody, suggesting that part of OPG effects are RANKL-dependent.
authors.affiliation: Laboratoire de Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, EE 99-01, Faculté de Médecine, 1 rue Gaston Veil, 44035 Nantes cedex 1, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Wittrant
authors.forename: S
authors.initials: S
authors.lastname: Theoleyre
authors.forename: S
authors.initials: S
authors.lastname: Couillaud
authors.forename: C
authors.initials: C
authors.lastname: Dunstan
authors.forename: D
authors.initials: D
authors.lastname: Heymann
authors.forename: F
authors.initials: F
authors.lastname: Rédini
mesh_terms: D000135:Acid Phosphatase / Q000235:genetics; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015415:Biomarkers; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology*; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D056657:Cathepsin K; D002403:Cathepsins / Q000235:genetics; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000235:genetics; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051379:Mice; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects / Q000378:metabolism*; D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D053246:Receptor Activator of Nuclear Factor-kappa B; D018003:Receptors, Calcitonin / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor; D015203:Reproducibility of Results; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism*; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D000906:Antibodies; D015415:Biomarkers; D002352:Carrier Proteins; D006023:Glycoproteins; D007527:Isoenzymes; D008562:Membrane Glycoproteins; D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger; D053246:Receptor Activator of Nuclear Factor-kappa B; D018003:Receptors, Calcitonin; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C505687:Tnfrsf11a protein, mouse; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase; D002403:Cathepsins; D056657:Cathepsin K; C534132:Ctsk protein, mouse; D020780:Matrix Metalloproteinase 9