A crucial role for reactive oxygen species in RANKL-induced osteoclast differentiation.
Signaling by receptor activator of NF-kappaB (nuclear factor-kappaB) ligand (RANKL) is essential for differentiation of bone marrow monocyte-macrophage lineage (BMM) cells into osteoclasts. Here, we show RANKL stimulation of BMM cells transiently increased the intracellular level of reactive oxygen species (ROS) through a signaling cascade involving TNF (tumor necrosis factor) receptor-associated factor (TRAF) 6, Rac1, and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase (Nox) 1. A deficiency in TRAF6 or expression of a dominant-interfering mutant of TRAF6 blocks RANKL-mediated ROS production. Application of N-acetylcysteine (NAC) or blocking the activity of Nox, a protein leading to the formation of ROS, with diphenylene iodonium (DPI) inhibits the responses of BMM cells to RANKL, including ROS production, activation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein (MAP) kinase, and extracellular signal-regulated kinase (ERK), and osteoclast differentiation. Moreover, both RANKL-mediated ROS production and osteoclast differentiation were completely blocked in precursors depleted of Nox1 activity by RNA interference or by expressing a dominant-negative mutant of Rac1. Together, these results indicate that ROSs act as an intracellular signal mediator for osteoclast differentiation.
Lee
Na Kyung
NK
Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul, 120-750, Korea.
Choi
Young Geum
YG
Baik
Ji Youn
JY
Han
Song Yi
SY
Jeong
Dae-Won
DW
Bae
Yun Soo
YS
Kim
Nacksung
N
Lee
Soo Young
SY
D000818:Animals; D001854:Bone Marrow Cells; D002352:Carrier Proteins / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D019070:Cell Lineage; D020935:MAP Kinase Signaling System; D008264:Macrophages / Q000166:cytology; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000166:cytology; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D000074624:NADPH Oxidase 1; D009479:Neuropeptides / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology*; D053245:RANK Ligand; D017382:Reactive Oxygen Species / Q000378:metabolism*; D053246:Receptor Activator of Nuclear Factor-kappa B; D048029:TNF Receptor-Associated Factor 6 / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020830:rac1 GTP-Binding Protein
D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D009479:Neuropeptides; D053245:RANK Ligand; C484602:Rac1 protein, mouse; D017382:Reactive Oxygen Species; D053246:Receptor Activator of Nuclear Factor-kappa B; D048029:TNF Receptor-Associated Factor 6; C505687:Tnfrsf11a protein, mouse; C505689:Tnfsf11 protein, mouse; D009247:NADH, NADPH Oxidoreductases; D000074624:NADPH Oxidase 1; C000614711:NOX1 protein, mouse; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein