Septic arthritis. Staphylococcal induction of chondrocyte proteolytic activity

Arthritis Rheum. 1990 Apr;33(4):533-41. doi: 10.1002/art.1780330411.


We report herein that cartilage proteolytic activity increased in bovine and rabbit articular cartilage after treatment with a purified staphylococcal culture medium or intraarticular infection with Staphylococcus aureus. Staphylococcal culture medium increased the release of gelatinolytic, collagenolytic, and caseinolytic activity into the medium of isolated chondrocytes or cartilage organ culture. The proteolytic activities were determined in assays using radiolabeled substrate and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Staphylococcal culture medium was proteolytically inactive by both assay techniques. RNA synthesis of isolated chondrocytes was unaffected by staphylococcal culture medium, whereas overall protein synthesis was inhibited by 84%. An analysis of extracts of Staphylococcus aureus-infected rabbit knee cartilage by substrate gels showed increased gelatinolytic and caseinolytic activity compared with extracts of uninfected knee cartilage. Our data suggest that the rapid loss of proteoglycan and persistent degradation of cartilage in staphylococcal septic arthritis is due to the production and activation of chondrocyte proteases.

Publication types

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

MeSH terms

  • Animals
  • Arthritis, Infectious / enzymology*
  • Arthritis, Infectious / metabolism
  • Autoradiography
  • Cartilage, Articular / enzymology*
  • Cartilage, Articular / metabolism
  • Cattle
  • Culture Techniques
  • Electrophoresis
  • Endopeptidases / biosynthesis*
  • Enzyme Induction
  • Gelatinases
  • Metalloendopeptidases*
  • Microbial Collagenase / biosynthesis
  • Pepsin A / biosynthesis
  • Peptide Hydrolases / biosynthesis
  • RNA / biosynthesis
  • Rabbits
  • Staphylococcal Infections / enzymology*
  • Staphylococcal Infections / metabolism
  • Staphylococcus aureus / physiology*


  • RNA
  • Endopeptidases
  • Peptide Hydrolases
  • Pepsin A
  • Gelatinases
  • Metalloendopeptidases
  • caseinase
  • Microbial Collagenase