Ar431-1.jpg (75.22 kB)
A schematic representation of osteoclast differentiation supported by osteoblasts/stromal cells
figure
posted on 2011-12-30, 22:12 authored by Nobuyuki Udagawa, Shigeru Kotake, Naoyuki Kamatani, Naoyuki Takahashi, Tatsuo SudaCopyright information:
Taken from "The molecular mechanism of osteoclastogenesis in rheumatoid arthritis"
Arthritis Research 2002;4(5):281-289.
Published online 12 Apr 2002
PMCID:PMC128939.
Copyright © 2002 BioMed Central Ltd
RANKL, which is induced by bone resorbing factors such as 1-α,25(OH)D, parathyroid hormone (PTH) and IL-11 on the plasma membrane of osteoblasts/stromal cells, binds its receptor RANK present in osteoclast progenitors and mature osteoclasts. Osteoprotegerin (OPG), a decoy receptor for RANKL, strongly and competitively inhibits the RANKL–RANK interaction. The RANK signaling is transduced via TNF receptor-associated factor 2 (TRAF2) and TNF receptor-associated factor 6 (TRAF6), leading to the activation of NF-κB and Jun kinase (JNK), which in turn stimulates differentiation and activation of osteoclasts. M-CSF, macrophage colony-stimulating factor.