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.
G Cirino, C Cicala, M Bucci, L Sorrentino, G Ambrosini, G DeDominicis, D C Altieri
Usage data is cumulative from May 2023 through May 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 109 | 65 |
20 | 36 | |
Citation downloads | 4 | 0 |
Totals | 133 | 101 |
Total Views | 234 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.