Figure 3.

Treatment with TNF-α or ceramide induces proteoglycan release from articular cartilage. Cartilage explants were cultured for 24 hours in the presence of (a) TNF-α (0–100 ng/ml) or (b) C₂-ceramide (0–100 μM) and media were analysed for release of sulfated GAGs by dimethylmethylene blue assay. Differences in the release of sGAG associated with culture treatment are expressed as micrograms GAG per milligram wet weight of cartilage. *Significantly different from untreated, control explants at P < 0.05; **P < 0.001. sGAG, sulfated glycosaminoglycan; TNF, tumour necrosis factor.