Amplification of the synovial inflammatory response through activation of mitogen-activated protein kinases and nuclear factor kappaB using ligation of CD40 on CD14+ synovial cells from patients with rheumatoid arthritis.
OBJECTIVE
To determine the signal transduction pathways in CD14+ synovial cells from patients with rheumatoid arthritis (RA) after CD40 ligation, and to examine their role in amplifying synovial inflammation in affected joints.


METHODS
Expression of messenger RNA was analyzed using quantitative reverse transcription-polymerase chain reaction. Cytokines and chemokines were measured using enzyme-linked immunosorbent assay. Activation of kinases was detected using Western blotting. Nuclear translocation of NF-kappaB was examined using immunohistochemistry. CD14+ synovial cells were enriched using magnetic cell sorting. Fibroblast-like synoviocytes (FLS) were obtained by passaging primary synovial cell culture.


RESULTS
Stimulation of CD14+ synovial cells from RA patients by recombinant soluble CD154 (rsCD154) significantly induced expression of tumor necrosis factor alpha (TNFalpha), interleukin-1alpha (IL-1alpha), and IL-1beta. CD14+ RA synovial cells stimulated with rsCD154 plus interferon-gamma (IFNgamma) induced significantly higher production of IL-6, IL-8, and monocyte chemoattractant protein 1 by FLS compared with unstimulated CD14+ synovial cells, through TNFalpha-, IL-1alpha-, and IL-1beta-mediated pathways. Stimulation with rsCD154 plus IFNgamma induced the activation of ERK-1/2, p38 MAPK, and NF-kappaB. Specific inhibitors of MAPK/ERK-1/2 kinases and p38 MAPK significantly reduced the production of TNFalpha and IL-1beta by rsCD154 plus IFNgamma-stimulated CD14+ synovial cells, and also inhibited production of these cytokines by freshly isolated synovial cells from RA patients.


CONCLUSIONS
These data indicate that the CD40-CD154 interaction activates the ERK, p38, and NF-kappaB pathways in CD14+ synovial cells from RA patients to produce TNFalpha, IL-1alpha, and IL-1beta, which in turn amplifies inflammatory responses by stimulating FLS. Inhibition of the CD40-CD154 interaction or its signal transduction pathways would be a strong and efficient strategy for the management of synovial inflammation in RA.
Harigai
Masayoshi
M
Institute of Rheumatology, Tokyo Women's Medical University, Tokyo, Japan. mharigai.mpha@tmd.ac.jp
Hara
Masako
M
Kawamoto
Manabu
M
Kawaguchi
Yasushi
Y
Sugiura
Tomoko
T
Tanaka
Michi
M
Nakagawa
Miki
M
Ichida
Hisae
H
Takagi
Kae
K
Higami-Ohsako
Satomi
S
Shimada
Katsuhiko
K
Kamatani
Naoyuki
N
D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D001692:Biological Transport / Q000187:drug effects; D023201:CD40 Ligand / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D018950:Lipopolysaccharide Receptors / Q000378:metabolism*; D008875:Middle Aged; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010003:Osteoarthritis / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction; D012995:Solubility; D013583:Synovial Membrane / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D013585:Synovitis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology
D016207:Cytokines; D004791:Enzyme Inhibitors; D018950:Lipopolysaccharide Receptors; D016328:NF-kappa B; D012333:RNA, Messenger; D011994:Recombinant Proteins; D023201:CD40 Ligand; D007371:Interferon-gamma; D020928:Mitogen-Activated Protein Kinases