Fig. 5.

Synergy between FN III 13–14, IL-1 and TNF in the induction of proteoglycan loss. FN III 13–14 (0.1 μM), IL-1μ (10 ng/ml) or TNF-α (10 ng/ml) were cultured alone, or in combination with porcine articular cartilage over a 6-day culture period in serumfree medium. Conditioned medium was harvested every 2 days and replaced with fresh medium. At the end of the experiment, equal volumes of conditioned medium (50 μl) were deglycosylated using chondroitinase and keratanase. The samples were subjected to Western blotting and GAG release was measured using the anti-ARGSV neoepitope antibody. The signal intensity of the samples (from triplicate wells, n = 3) was measured using Phoretix software and expressed as mean and SEM.