Tumor necrosis factor-alpha-induced proteolytic activation of pro-matrix metalloproteinase-9 by human skin is controlled by down-regulating tissue inhibitor of metalloproteinase-1 and mediated by tissue-associated chymotrypsin-like proteinase

J Biol Chem. 2002 Jul 26;277(30):27319-27. doi: 10.1074/jbc.M202842200. Epub 2002 May 9.

Abstract

The proteolytic activation of pro-matrix metalloproteinase (MMP)-9 by conversion of the 92-kDa precursor into an 82-kDa active form has been observed in chronic wounds, tumor metastasis, and many inflammation-associated diseases, yet the mechanistic pathway to control this process has not been identified. In this report, we show that the massive expression and activation of MMP-9 in skin tissue from patients with chronically unhealed wounds could be reconstituted in vitro with cultured normal human skin by stimulation with transforming growth factor-beta and tumor necrosis factor (TNF)-alpha. We dissected the mechanistic pathway for TNF-alpha induced activation of pro-MMP-9 in human skin. We found that proteolytic activation of pro-MMP-9 was mediated by a tissue-associated chymotrypsin-like proteinase, designated here as pro-MMP-9 activator (pM9A). This unidentified activator specifically converted pro-MMP-9 but not pro-MMP-2, another member of the gelatinase family. The tissue-bound pM9A was steadily expressed and not regulated by TNF-alpha, which indicated that the cytokine-mediated activation of pro-MMP-9 might be regulated at the inhibitor level. Indeed, the skin constantly secreted tissue inhibitor of metalloproteinase-1 at the basal state. TNF-alpha, but not transforming growth factor-beta, down-regulated this inhibitor. The TNF-alpha-mediated activation of pro-MMP-9 was tightly associated with down-regulation of tissue inhibitor of metalloproteinase-1 in a dose-dependent manner. To establish this linkage, we demonstrate that the recombinant tissue inhibitor of metalloproteinase-1 could block the activation of pro-MMP-9 by either the intact skin or skin fractions. Thus, these studies suggest a novel regulation for the proteolytic activation of MMP-9 in human tissue, which is mediated by tissue-bound activator and controlled by down-regulation of a specific inhibitor.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Blotting, Western
  • Cell Division
  • Chymases
  • Cytokines / metabolism
  • Dose-Response Relationship, Drug
  • Down-Regulation
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Activation
  • Fibroblasts / metabolism
  • Humans
  • Keratinocytes / metabolism
  • Matrix Metalloproteinase 9 / metabolism*
  • Models, Biological
  • Recombinant Proteins / metabolism
  • Serine Endopeptidases / chemistry*
  • Serine Endopeptidases / metabolism*
  • Skin / metabolism
  • Tissue Inhibitor of Metalloproteinase-1 / metabolism*
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology*

Substances

  • Cytokines
  • Recombinant Proteins
  • Tissue Inhibitor of Metalloproteinase-1
  • Tumor Necrosis Factor-alpha
  • Serine Endopeptidases
  • pro-MMP-9 activator
  • Chymases
  • Matrix Metalloproteinase 9