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Inhibition of tumor necrosis factor α–induced prostaglandin E2 production by the antiinflammatory cytokines interleukin-4, interleukin-10, and interleukin-13 in osteoarthritic synovial fibroblasts: Distinct targeting in the signaling pathways

✍ Scribed by Nada Alaaeddine; John A. Di Battista; Jean-Pierre Pelletier; Kayghobad Kiansa; Jean-Marie Cloutier; Johanne Martel-Pelletier


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
368 KB
Volume
42
Category
Article
ISSN
0004-3591

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✦ Synopsis


Objective:

To investigate the effects of the antiinflammatory cytokines interleukin-4 (il-4), il-10, and il-13 on tumor necrosis factor alpha (tnfalpha)-induced prostaglandin e2 (pge2) release in the cellular signaling cascade on human osteoarthritis (oa) synovial fibroblasts.

Methods:

Human oa synovial fibroblasts were cultured to explore the impact of il-4, il-10, and il-13 on tnfalpha binding to tnf receptors (tnfr), soluble tnfr (stnfr), cytoplasmic phospholipase a2 (cpla2), and cyclooxygenase-2 (cox-2) production, and on the binding activity of the transcription factors nuclear factor kappab (nf-kappab), ccaat-enhancer binding protein (c/ebp), activator protein 2 (ap-2), and cyclic amp response element-binding protein (creb).

Results:

Il-4, il-10, and il-13 at 5 ng/ml dramatically reduced tnfalpha-induced pge2 release by approximately 90% (p < 0.0001). il-4 up-regulated the level of tnfalpha-induced tnfr by 47% (p < 0.06), while il-10 down-regulated it by 71% (p < 0.02); il-13 had no effect. although statistical significance was not reached, all 3 cytokines up-regulated the basal level of stnfr-55. il-4 and il-10, while not altering the basal level of stnfr-75, significantly increased the tnfalpha-stimulated release of stnfr-75. il-4, il-10, and il-13 reduced the tnfalpha-induced cox-2 level, and il-4 and il-10 reduced the cpla2 level. il-4 had no effect on tnfalpha up-regulation of nf-kappab, and a slight decrease was noted with il-10 and il-13 at the highest concentration used (5 ng/ml). il-4 and il-13 decreased the tnfa-induced c/ebp accumulation in a dose-dependent manner, while il-10 up-regulated its basal level. ap-2 and creb were not induced by tnfalpha.

Conclusion:

The results indicate that these antiinflammatory cytokines reversed the tnfalpha-induced release of pge2 by oa synovial fibroblasts, by acting at various levels of the tnfa-dependent signaling cascade. these data shed new light on the mechanisms by which these cytokines reduce inflammatory processes.