Osteoprotegerin ligand modulates murine osteoclast survival in vitro and in vivo.

Published

Journal Article

Osteoprotegerin ligand (OPGL) targets osteoclast precursors and osteoclasts to enhance differentiation and activation, however, little is known about OPGL effects on osteoclast survival. In vitro, the combination of OPGL + colony-stimulating factor-1 (CSF-1) is required for optimal osteoclast survival. Ultrastructurally, apoptotic changes were observed in detached cells and culture lysates exhibited elevated caspase 3 activity, particularly in cultures lacking CSF-1. DEVD-FMK (caspase 3 inhibitor) partially protected cells when combined with OPGL, but not when used alone or in combination with CSF-1. CSF-1 maintained NF-kappaB activation and increased the expression of bcl-2 and bcl-X(L) mRNA, but had no effect on JNK activation. In contrast, OPGL enhanced both NF-kappaB and JNK kinase activation and increased the expression of c-src, but not bcl-2 and bcl-X(L) mRNA. These data suggest that aspects of both OPGL's and CSF-1's signaling/survival pathways are required for optimal osteoclast survival. In mice, a single dose of OPG, the OPGL decoy receptor, led to a >90% loss of osteoclasts because of apoptosis within 48 hours of exposure without impacting osteoclast precursor cells. Therefore, OPGL is essential, but not sufficient, for osteoclast survival and endogenous CSF-1 levels are insufficient to maintain osteoclast viability in the absence of OPGL.

Full Text

Cited Authors

  • Lacey, DL; Tan, HL; Lu, J; Kaufman, S; Van, G; Qiu, W; Rattan, A; Scully, S; Fletcher, F; Juan, T; Kelley, M; Burgess, TL; Boyle, WJ; Polverino, AJ

Published Date

  • August 2000

Published In

Volume / Issue

  • 157 / 2

Start / End Page

  • 435 - 448

PubMed ID

  • 10934148

Pubmed Central ID

  • 10934148

Electronic International Standard Serial Number (EISSN)

  • 1525-2191

International Standard Serial Number (ISSN)

  • 0002-9440

Digital Object Identifier (DOI)

  • 10.1016/s0002-9440(10)64556-7

Language

  • eng