Send to

Choose Destination
See comment in PubMed Commons below
J Bone Miner Res. 2002 Jul;17(7):1200-10.

NF-kappaB p50 and p52 expression is not required for RANK-expressing osteoclast progenitor formation but is essential for RANK- and cytokine-mediated osteoclastogenesis.

Author information

  • 1Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, New York 14642, USA.


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.

[PubMed - indexed for MEDLINE]
Free full text

Publication Types, MeSH Terms, Substances, Grant Support

Publication Types

MeSH Terms


Grant Support

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Write to the Help Desk