Korean J Intern Med.  2010 Sep;25(3):317-326. 10.3904/kjim.2010.25.3.317.

Induction of Macrophage Migration Inhibitory Factor in ConA-Stimulated Rheumatoid Arthritis Synovial Fibroblasts through the P38 MAP Kinase-Dependent Signaling Pathway

• Kim HR
• Park MK
• Cho ML
• Kim KW
• Oh HJ
• Park JS
• Heo YM
• Lee SH
• Kim HY
• Park SH

• KMID: 1776614
• DOI: http://doi.org/10.3904/kjim.2010.25.3.317

Abstract

BACKGROUND/AIMS
This study was undertaken to identify the intracellular signaling pathway involved in induction of macrophage migration inhibitory factor (MIF) in human rheumatoid arthritis (RA) synovial fibroblasts.
METHODS
Human RA synovial fibroblasts were treated with concanavalin A (ConA), various cytokines, and inhibitors of signal transduction molecules. The production of MIF by synovial fibroblasts was measured in culture supernatants by ELISA. The expression of MIF mRNA was determined using reverse transcriptase polymerase chain reaction (RT-PCR) and real-time PCR. Phosphorylation of p38 mitogen-activated protein (MAP) kinase in synovial fibroblasts was confirmed using Western blotting. The expression of MIF and p38 MAP kinase in RA synovium was determined using dual immunohistochemistry.
RESULTS
The production of MIF by RA synovial fibroblasts increased in a dose-dependent manner after ConA stimulation. MIF was also induced by interferon-gamma, CD40 ligand, interleukin-15, interleukin-1beta, tumor necrosis factor-alpha, and transforming growth factor-beta. The production of MIF by RA synovial fibroblasts was significantly reduced after inhibition of p38 MAP kinase. The expression of MIF and p38 MAP kinase was upregulated in the RA synovium compared with the osteoarthritis synovium.
CONCLUSIONS
These results suggest that MIF production was induced through a p38 MAP-kinase-dependent pathway in RA synovial fibroblasts.

Keyword

Macrophage, migration-inhibitory factors; Arthritis rheumatoid; Synovial fibroblast; p38 mitogen-activated protein kinases

MeSH Terms

Arthritis, Rheumatoid/genetics/*metabolism
Base Sequence
Cells, Cultured
Concanavalin A/pharmacology
Cytokines/pharmacology
DNA Primers/genetics
Fibroblasts/drug effects/metabolism
Humans
Macrophage Migration-Inhibitory Factors/*biosynthesis/genetics
RNA, Messenger/genetics/metabolism
Signal Transduction/drug effects
Synovial Membrane/drug effects/metabolism
p38 Mitogen-Activated Protein Kinases/metabolism