Chondrocyte matrix metalloproteinase-8. Human articular chondrocytes express neutrophil collagenase

J Biol Chem. 1996 May 3;271(18):11023-6. doi: 10.1074/jbc.271.18.11023.


This study confirms that normal human articular chondrocytes express neutrophil collagenase or matrix metalloproteinase-8 (MMP-8), a gene product previously thought to be expressed exclusively by neutrophil leukocytes. Both MMP-8 protein and mRNA were present in articular cartilages collected from normal human donors. Cartilage extracts were assayed by immunoblotting and by analysis of enzymatic activity on gelatin-substrate gels. Latent MMP-8 extracted from cartilage has a molecular mass of 55 kDa; active MMP-8 was identified at 46 and 42 kDa. In the absence of a reducing agent, MMP-8 migrated in a high molecular mass complex above 200 kDa. Northern blotting results demonstrated the expression of MMP-8 in chondrocytes, which could be up-regulated by stimulation with interleukin-1 beta. In addition, reverse transcription-polymerase chain reaction using nested primers and in situ hybridization revealed the presence of MMP-8 mRNA in chondrocytes. The presence of both MMP-8 protein and message in cartilage supports the concept that neutrophil collagenase could be the enzyme described as "aggrecanase".

Publication types

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

MeSH terms

  • Blotting, Northern
  • Cartilage, Articular / cytology
  • Cartilage, Articular / enzymology*
  • Cells, Cultured
  • Collagenases / genetics
  • Collagenases / metabolism*
  • Endopeptidases / genetics
  • Endopeptidases / metabolism
  • Humans
  • In Situ Hybridization
  • Matrix Metalloproteinase 8
  • Neutrophils / enzymology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism


  • RNA, Messenger
  • Endopeptidases
  • Collagenases
  • Matrix Metalloproteinase 8
  • aggrecanase