Objective. To examine the effect of human interleukin-17 (IL-17) on nitric oxide (NO) production in human osteoarthritis (OA) cartilage under ex vivo conditions.
Methods. OA cartilage from patients undergoing knee replacement surgery was used in explant assays to assess the effect of IL-17. NO production was measured by estimating the stable NO metabolite, nitrite, in conditioned medium.
Results. IL-17 augmented the spontaneous production of nitric oxide. This augmentation was sensitive to cycloheximide and pyrrolidine dithiocarbamate, but not to dexamethasone or soluble IL-1 receptor.
Conclusion. IL-17 augments nitric oxide production in OA cartilage via nuclear factor KB activation, but independently of IL-1β signaling.