Extracellular granzyme K mediates endothelial activation through the cleavage of protease-activated receptor-1

FEBS J. 2016 May;283(9):1734-47. doi: 10.1111/febs.13699. Epub 2016 Mar 22.

Abstract

Granzymes are a family of serine proteases that were once thought to function exclusively as mediators of cytotoxic lymphocyte-induced target cell death. However, non-apoptotic roles for granzymes, including granzyme K (GzK), have been proposed. As recent studies have observed elevated levels of GzK in the plasma of patients diagnosed with clinical sepsis, we hypothesized that extracellular GzK induces a proinflammatory response in endothelial cells. In the present study, extracellular GzK proteolytically activated protease-activated receptor-1 leading to increased interleukin 6 and monocyte chemotactic protein 1 production in endothelial cells. Enhanced expression of intercellular adhesion molecule 1 along with an increased capacity for adherence of THP-1 cells was also observed. Characterization of downstream pathways implicated the mitogen-activated protein kinase p38 pathway for intercellular adhesion molecule 1 expression, and both the p38 and the extracellular signal-regulated protein kinases 1 and 2 pathways in cytokine production. GzK also increased tumour necrosis factor α-induced inflammatory adhesion molecule expression. Furthermore, the physiological inhibitor of GzK, inter-α-inhibitor protein, significantly inhibited GzK activity in vitro. In summary, extracellular GzK promotes a proinflammatory response in endothelial cells.

Keywords: endothelial cells; granzyme K; inflammation; protease-activated receptors; serine proteases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alpha-Globulins / pharmacology
  • Butadienes / pharmacology
  • Cell Adhesion
  • Cell Line
  • Chemokine CCL2 / genetics
  • Chemokine CCL2 / metabolism
  • Gene Expression Regulation
  • Granzymes / antagonists & inhibitors
  • Granzymes / genetics
  • Granzymes / metabolism
  • Granzymes / pharmacology*
  • Human Umbilical Vein Endothelial Cells / cytology
  • Human Umbilical Vein Endothelial Cells / drug effects*
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Humans
  • Imidazoles / pharmacology
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase 3 / genetics
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Monocytes / cytology
  • Monocytes / drug effects*
  • Monocytes / metabolism
  • Nitriles / pharmacology
  • Proteolysis / drug effects
  • Pyridines / pharmacology
  • Receptor, PAR-1 / antagonists & inhibitors
  • Receptor, PAR-1 / genetics*
  • Receptor, PAR-1 / metabolism
  • Signal Transduction
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / genetics
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Alpha-Globulins
  • Butadienes
  • CCL2 protein, human
  • Chemokine CCL2
  • IL6 protein, human
  • Imidazoles
  • Interleukin-6
  • Nitriles
  • Pyridines
  • Receptor, PAR-1
  • U 0126
  • inter-alpha-inhibitor
  • MAPK1 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • p38 Mitogen-Activated Protein Kinases
  • GZMK protein, human
  • Granzymes
  • 4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole

Grant support