RANKL induces formation of avian osteoclasts from macrophages but not from macrophage polykaryons.
We have shown that chick macrophages express RANK at their surface and human RANKL (hRANKL) triggers the formation of osteoclasts able to degrade dentine. As described for mammalian osteoclasts, hRANKL also stimulates the resorbing activity of chick bone-derived osteoclasts. In other hands, in culture, chick macrophages spontaneously form polykaryons sharing most of the osteoclast markers but unable to resorb bone. Since both bone-resorbing osteoclasts and macrophage polykaryons found in inflammatory tissues are multinucleated cells deriving from the fusion of macrophages, we examined whether macrophage polykaryons could be induced toward bone-resorbing osteoclasts. Long-term exposure of macrophage polykaryons to hRANKL failed to activate any resorbing activity, indicating that although deriving from the same precursors macrophage polykaryons and osteoclasts are independent cell types and polykaryons are not immature osteoclasts.
Boissy
P
P
Laboratoire de Biologie Moléculaire et Cellulaire de l'Ecole Normale Supérieure de Lyon, UMR5665 CNRS/ENS, INRA 913, 46, allée d'Italie, 69364 Lyon Cédex 07, France.
Destaing
O
O
Jurdic
P
P
D000818:Animals; D015415:Biomarkers; D002352:Carrier Proteins / Q000494:pharmacology*; D002645:Chickens; D003804:Dentin / Q000378:metabolism; D015726:Giant Cells / Q000187:drug effects* / Q000502:physiology; D006023:Glycoproteins / Q000096:biosynthesis / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D010010:Osteoclasts / Q000378:metabolism*; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor
D015415:Biomarkers; D002352:Carrier Proteins; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C505686:TNFRSF11A protein, human; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human