Retinoic acid combines with interleukin-1 to promote the degradation of collagen from bovine nasal cartilage: Matrix metalloproteinases-1 and -13 are involved in cartilage collagen breakdown
✍ Scribed by W.D. Shingleton; A.J. Ellis; A.D. Rowan; T.E. Cawston
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 237 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
✦ Synopsis
Retinoic acid (RetA) and interleukin-1␣ (IL-1) together can induce a reproducible release of proteoglycan fragments from bovine nasal cartilage in culture. However, release of collagen fragments with either agent alone is often variable. In this study over 70% of the total collagen was released from bovine nasal cartilage in culture by day 14 when RetA and IL-1 were combined. This release was accompanied by the appearance of collagenolytic activity in the culture medium that cleaved collagen specifically at the 1 ⁄4/ 3 ⁄4 position. Tissue inhibitor of metalloproteinases (TIMP) activity was present at day 7 but low or absent in media from resorbing tissue at day 14. The breakdown of cartilage collagen could be prevented by the addition of BB-94, a specific metalloproteinase inhibitor. These results suggest that RetA promotes the early release of TIMP from the tissue and that IL-1 stimulates pro-collagenase secretion which, when activated, exceeds the local concentration of TIMP. Thus in the later stages of culture collagen destruction occurs. Both MMP-1 and MMP-13 were detected and appear to be involved in IL-1 ϩ RetA induced bovine cartilage destruction. However, for the first time, we also present evidence to suggest that MMP-13 is the predominant collagenase in this system.