title: Extracellular granzyme K mediates endothelial activation through the cleavage of protease-activated receptor-1.
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.
authors.affiliation: Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, BC, Canada.|Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Mehul
authors.initials: M
authors.lastname: Sharma
authors.affiliation: Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, BC, Canada.|Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Merkulova
authors.affiliation: Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, BC, Canada.
authors.forename: Sheetal
authors.initials: S
authors.lastname: Raithatha
authors.affiliation: Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, BC, Canada.|Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Leigh G
authors.initials: LG
authors.lastname: Parkinson
authors.affiliation: Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, BC, Canada.|Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Yue
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Dawn
authors.initials: D
authors.lastname: Cooper
authors.affiliation: Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, BC, Canada.|Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: David J
authors.initials: DJ
authors.lastname: Granville
mesh_terms: D000510:Alpha-Globulins / Q000494:pharmacology; D002070:Butadienes / Q000494:pharmacology; D002448:Cell Adhesion; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D053804:Granzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D059748:Proteolysis / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D044463:Receptor, PAR-1 / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010975:Platelet Aggregation Inhibitors
chemical_list: D000510:Alpha-Globulins; D002070:Butadienes; C111835:CCL2 protein, human; D018932:Chemokine CCL2; C508600:IL6 protein, human; D007093:Imidazoles; D015850:Interleukin-6; D009570:Nitriles; D011725:Pyridines; D044463:Receptor, PAR-1; C113580:U 0126; C011877:inter-alpha-inhibitor; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C088546:GZMK protein, human; D053804:Granzymes; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole; D010975:Platelet Aggregation Inhibitors
keywords: endothelial cells; granzyme K; inflammation; protease-activated receptors; serine proteases