Release of two key inflammatory stress mediators, NO (a) and PGE2 (b) (normalized by DNA), from OA FLS monolayers treated for 6 days with IL-1α (IL-1), TNF-α (TNF), or cartilage wear particles (CWP), with untreated controls (CTL). N = 10 (a) and 11 (b) donors. *p < 0.05 vs. CTL, **p < 0.05 vs. CTL and CWP. ***p < 0.05 vs. CTL, CWP, and TNF.