Ultraviolet-B induction of interstitial collagenase and stromelyin-1 occurs in human dermal fibroblasts via an autocrine interleukin-6-dependent loop

Ultraviolet-B irradiation of human dermal fibroblasts has earlier been show n to induce matrix-degrading metalloproteinases, thus driving connective ti ssue degradation in photoaging and photocarcinogenesis. Herein,,vc report t hat Ultraviolet-B irradiation led to a dramatic increase in specific mRNA a nd protein levels of interstitial collagenase, stromelysin and interleukin- 6. By contrast, the major tissue inhibitor of matrix-degrading metalloprote inases, TIMP-1, was unaffected, Monospecific neutralizing antibodies direct ed against human interleukin-6 significantly reduced the interstitial colla genase and stromelysin-1 protein levels, Taken together, our data provide t he first evidence that Ultraviolet-B induction of interstitial collagenase and stromelysin-l occurs, ia the synthesis and release of interleukin-6. He nce, this newly identified autocrine mechanism may contribute to dermal pho todamage. (C) 1999 Federation of European Biochemical Societies.