Interleukin 13 blocks the release of collagen from bovine nasal cartilage treated with proinflammatory cytokines

Objective-To investigate whether interleukin 13 (IL13) could act in a chond roprotective manner and protect cartilage stimulated to resorb with a combi nation of IL1 alpha and oncostatin M (OSM), in a similar way to the anti-in flammatory cytokine, IL4. Methods-IL13 was added to explant cultures of bovine nasal cartilage stimul ated to resorb with IL1 alpha and OSM, and the release of collagen and prot eoglycan determined. Collagenolytic and tissue inhibitors of metalloprotein ase (TIMP) activities were determined by bioassay. Northern blot analyses w ere performed to determine the effects of IL13 on the induction of matrix m etalloproteinase-l (MMP-1), MMP-3, MMP-13, and TIMP-1 gene expression. Results-IL13 can prevent the release of collagen from bovine nasal cartilag e in a dose dependent manner. This was accompanied by a concomitant decreas e in measurable collagenolytic activity in the culture supernates and an in crease in TIMP activity. Northern blot analysis showed that IL13 down regul ated MMP-3 and MMP-13 levels but up regulated MMP-1 and TIMP-1 gene express ion in bovine nasal chondrocytes at 24 hours. Conclusion-This study showed for the first time that IL13 can block collage n release from resorbing cartilage in a similar manner to IL4. This is acco mpanied by a reduction in detectable collagenolytic activity, a decrease in MMP-3 and MMP-13 mRNA levels, and an up regulation of TIMP-1 expression.