title: NF-kappaB p50 and p52 expression is not required for RANK-expressing osteoclast progenitor formation but is essential for RANK- and cytokine-mediated osteoclastogenesis.
abstract: Expression of RANKL by stromal cells and of RANK and both NF-kappaB p50 and p52 by osteoclast precursors is essential for osteoclast formation. To examine further the role of RANKL, RANK, and NF-KB signaling in this process, we used NF-kappaB p50-/- ;p52-/- double knockout (dKO) and wild-type (WT) mice. Osteoclasts formed in cocultures of WT osteoblasts with splenocytes from WT mice but not from dKO mice, a finding unchanged by addition of RANKL and macrophage colony-stimulating factor (M-CSF). NF-kappaB dKO splenocytes formed more colony-forming unit granulocyte macrophage (CFU-GM) colonies than WT cells, but no osteoclasts were formed from dKO CFU-GM colonies. RANKL increased the number of CFU-GM colonies twofold in WT cultures but not in dKO cultures. Fluorescence-activated cell sorting (FACS) analysis of splenocytes from NF-kappaB dKO mice revealed a two-to threefold increase in the percentage of CD11b (Mac-1) and RANK double-positive cells compared with WT controls. Treatment of NF-kappaB dKO splenocytes with interleukin (IL)-1, TNF-alpha, M-CSF, GM-CSF, and IL-6 plus soluble IL-6 receptor did not rescue the osteoclast defect. No increase in apoptosis was observed in cells of the osteoclast lineage in NF-kappaB dKO or p50-/-;p52+/- (3/4KO) mice. Thus, NF-kappaB p50 and p52 expression is not required for formation of RANK-expressing osteoclast progenitors but is essential for RANK-expressing osteoclast precursors to differentiate into TRAP+ osteoclasts in response to RANKL and other osteoclastogenic cytokines.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, New York 14642, USA.
authors.forename: Lianping
authors.initials: L
authors.lastname: Xing
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Bushnell
authors.forename: Louise
authors.initials: L
authors.lastname: Carlson
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Tai
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Tondravi
authors.forename: Ulrich
authors.initials: U
authors.lastname: Siebenlist
authors.forename: Fay
authors.initials: F
authors.lastname: Young
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Boyce
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis; D001854:Bone Marrow Cells / Q000166:cytology; D002352:Carrier Proteins / Q000494:pharmacology; D002454:Cell Differentiation; D002478:Cells, Cultured; D006023:Glycoproteins / Q000096:biosynthesis*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000494:pharmacology; D051379:Mice; D018345:Mice, Knockout; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D053244:Osteoprotegerin; D011392:Proline / Q000031:analogs & derivatives* / Q000494:pharmacology; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis*; D019947:Receptors, Interleukin-6; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis*; D015398:Signal Transduction; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects; D013859:Thiocarbamates / Q000494:pharmacology; D014108:Tosylphenylalanyl Chloromethyl Ketone / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D002352:Carrier Proteins; D006023:Glycoproteins; D007375:Interleukin-1; D015850:Interleukin-6; D007976:Leupeptins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D019947:Receptors, Interleukin-6; D018124:Receptors, Tumor Necrosis Factor; D013859:Thiocarbamates; C505687:Tnfrsf11a protein, mouse; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse; D014409:Tumor Necrosis Factor-alpha; C066229:prolinedithiocarbamate; D014108:Tosylphenylalanyl Chloromethyl Ketone; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D011392:Proline; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde