Secretion of 92 kDa gelatinase (MMP-9) by bovine neutrophils

Vet Immunol Immunopathol. 1999 Feb 22;67(3):247-58. doi: 10.1016/s0165-2427(98)00228-1.


To understand the process of neutrophil migration into mammary glands during mastitis, secretion of MMP-9 by bovine neutrophils was investigated. The methods of zymograms and RT-PCR were used to measure the secretory MMP-9 activity and its gene transcription, respectively. Both MMP-9 protein and mRNA were found to be expressed constitutively and greatly enhanced by PMA. However, the significant increase in the enzyme activity was found after 1 ng/ml PMA treatment for 1 h, while increasing MMP-9 mRNA transcription was only obvious after 1 ng/ml PMA treatment for 3 h. Moreover, secretion of MMP-9 protein was not inhibited by actinomycin D and cycloheximide. These results suggest that quick MMP-9 protein release from bovine neutrophils by the stimulation of PMA was due to the degranulation. As MMP-9 is an important proteinase in breakdown of the extracellular matrix and can be rapidly secreted by neutrophils through degranulation, it should play a critical role in the recruitment of neutrophils into mammary glands in bovine mastitis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle / blood*
  • Collagenases / genetics
  • Collagenases / metabolism*
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Matrix Metalloproteinase 9
  • Neutrophils / drug effects
  • Neutrophils / enzymology
  • Neutrophils / metabolism*
  • Polymerase Chain Reaction / veterinary
  • Tetradecanoylphorbol Acetate / pharmacology
  • Transcription, Genetic


  • Collagenases
  • Matrix Metalloproteinase 9
  • Tetradecanoylphorbol Acetate