Factor Xa as an interface between coagulation and inflammation. Molecular mimicry of factor Xa association with effector cell protease receptor-1 induces acute inflammation in vivo

J Clin Invest. 1997 May 15;99(10):2446-51. doi: 10.1172/JCI119428.


Coagulation proteases were tested in a rat model of acute inflammation. Subplantar injection of Factor Xa (10-30 microg) produced a time- and dose-dependent edema in the rat paw, and potentiated carrageenin-induced edema. In contrast, the homologous protease Factor IXa was ineffective. This inflammatory response was recapitulated by the Factor Xa sequence L83FTRKL88(G), which mediates ligand binding to effector cell protease receptor-1 (EPR-1), while a control scrambled peptide did not induce edema in vivo. Conversely, injection of the EPR-1-derived peptide S123PGKPGNQNSKNEPP137 (corresponding to the receptor binding site for Factor Xa) inhibited carrageenin-induced rat paw edema, while the adjacent EPR-1 sequence P136PKKRERERSSHCYP150 was without effect. EPR-1-Factor Xa-induced inflammation was characterized by fast onset and prominent perivascular accumulation of activated and degranulated mast cells, was inhibited by the histamine/serotonin antagonists cyproheptadine and methysergide, but was unaffected by the thrombin-specific inhibitor, Hirulog. These findings suggest that through its interaction with EPR-1, Factor Xa may function as a mediator of acute inflammation in vivo. This pathway may amplify both coagulation and inflammatory cascades, thus contributing to the pathogenesis of tissue injury in vivo.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Analysis of Variance
  • Animals
  • Antithrombins / pharmacology
  • Blood Coagulation*
  • Carrageenan
  • Cyproheptadine / pharmacology
  • Edema / chemically induced
  • Edema / physiopathology
  • Factor Xa / chemistry
  • Factor Xa / physiology*
  • Factor Xa / toxicity
  • Hirudins / analogs & derivatives
  • Hirudins / pharmacology
  • Histamine H1 Antagonists / pharmacology
  • Inflammation / chemically induced
  • Inflammation / pathology
  • Inflammation / physiopathology*
  • Male
  • Mast Cells / drug effects
  • Mast Cells / pathology
  • Mast Cells / physiology
  • Methysergide / pharmacology
  • Molecular Sequence Data
  • Peptide Fragments / pharmacology
  • Peptide Fragments / toxicity
  • Rats
  • Rats, Wistar
  • Recombinant Proteins / pharmacology
  • Serotonin Antagonists / pharmacology
  • Time Factors


  • Antithrombins
  • Hirudins
  • Histamine H1 Antagonists
  • Peptide Fragments
  • Recombinant Proteins
  • Serotonin Antagonists
  • Cyproheptadine
  • Carrageenan
  • Factor Xa
  • bivalirudin
  • Methysergide