Relative differential expression of MMPs, ADAMTS, and metalloproteinase inhibitors in resorbing cartilage. Bovine nasal cartilage chips were cultured in medium ± IL-1+OSM for 14 days exactly as described in the legend to Figure 1. RNA was extracted from the cartilage, and metalloproteinase and inhibitor gene expression were determined by real-time polymerase chain reaction as described in Materials and methods. The mean 2-ΔCT of each gene (where ΔCT is calculated as [CT gene - CT 18S]) was used as a measure of relative gene expression to allow simultaneous comparisons. The heat map was generated using GeneSpring GX 7.3 (Agilent Technologies, Palo Alto, CA, USA) with the expression range set at 0.025 (high), 5 × 10-6 (normal), and 1 × 10-10 (low) arbitrary units. ADAMTS, a disintegrin and metalloproteinase domain with thrombospondin motifs; CT, cycle threshold; IL-1, interleukin-1; MMP, matrix metalloproteinase; OSM, oncostatin M.