Korean J Bone Metab > Volume 12(1); 2005 > Article
Korean Journal of Bone Metabolism 2005;12(1):9-16.
Eosinophil Chemotactic Factor-L (ECF-L) Enhances Osteoclast Formation by Increasing ICAM-1 Expression
ICAM-1 발현 증가에 의한 Eosinophil Chemotactic Factor-L의 파골세포 생성
정호연,김성훈,임창훈,한기옥,박원근,윤현구,한인권,G. David Roodman1
성균관대학교 의과대학 삼성제일병원 내과, University of Pittsburgh1
Abstract
Background
We recently identified ECF-L as a novel stimulator of osteoclast (OCL) formation that acts at differentiation stages of OCL formation. ECF-L is a chemoattractant for OCL precursors and is a cofactor for RANK ligand (RANKL), but its mechanism of action on osteoclastogenesis is unknown. To further examine the role of ECF-L in osteoclastogenesis, we investigated the effects of ECF-L on OCL formation and on the intracellular signaling pathways utilized by RANKL, including the activation of the nuclear factor kappa B (NF-κB), the stimulation of the protein kinase, c-Jun N-terminal kinase (JNK) and its capacity to enhance OCL formation by ICAM-1/LFA-1 mediated action.
Methods
Mouse ECF-L Fc or control Fc protein was purified from stably transfected 293 cells and used for all bioassays. RAW 264.7 cells were treated with RANKL and/or ECF-L Fc protein to determine their effect on NF-κB and AP-1 activity. JNK activity was measured with mouse marrow cells after stimulation with ECF-L Fc. Mouse marrow cell cultures for OCL formation were treated with ECF-L Fc under variety of conditions. ICAM-1 and LFA-1 expression levels were measured by RT-PCR and Western blot analysis. The effects of blocking ICAM-1 were assessed in marrow cultures stimulated with ECF-L Fc and 10-10 M 1,25(OH)2D3 and treated with ICAM-1 antibody. The ICAM-1 effect on osteoclast formation by ECF-L was also assessed by using marrow cultures from ICAM-1 KO mice.
Results
NF-κB binding was modestly increased in ECF-L Fc treated RAW 264.7 cells by 30 minutes and was further enhanced in the presence of 20 ng/ml of RANKL. ECF-L Fc also increased JNK activity by 20% as measured by immunoprecipitation and Western blotting and increased RANKLinduced JNK activity by 65%. However, ECF-L Fc increased lymphocyte function-associated antigen-1 (LFA-1), and intercellular adhesion molecule (ICAM)-1 mRNA levels approximately 1.8-fold increases detected by RT-PCR in mouse marrow cultures, and anti-ICAM-1 antib
Key Words: ECF-L, Osteoclastogenesis, NF-κB, ICAM-1, Chemotaxis
TOOLS
METRICS Graph View
  • 930 View
  • 3 Download
Related articles

Eosinophil Chemotactic Factor-L (ECF-L) Blocks The Suppressive Effects of IL-12 On Osteoclast Formation 2007 November;14(2)



ABOUT
ARTICLE CATEGORY

Browse all articles >

BROWSE ARTICLES
EDITORIAL POLICY
FOR CONTRIBUTORS
Editorial Office
#1001, Hyundai Kirim Officetel, 42 Seocho-daero 78-gil, Seocho-gu, Seoul 06626, Korea
Tel: +82-2-3473-2231    Fax: +82-70-4156-2230    E-mail: editors.jbm@gmail.com                

Copyright © 2024 by The Korean Society for Bone and Mineral Research.

Developed in M2PI

Close layer
prev next