title: Protease-activated receptor 1 mediates thrombin-dependent, cell-mediated renal inflammation in crescentic glomerulonephritis.
abstract: Protease-activated receptor (PAR)-1 is a cellular receptor for thrombin that is activated after proteolytic cleavage. The contribution of PAR-1 to inflammatory cell-mediated renal injury was assessed in murine crescentic glomerulonephritis (GN). A pivotal role for thrombin in this model was demonstrated by the capacity of hirudin, a selective thrombin antagonist, to attenuate renal injury. Compared with control treatment, hirudin significantly reduced glomerular crescent formation, T cell and macrophage infiltration, fibrin deposition, and elevated serum creatinine, which are prominent features of GN. PAR-1-deficient (PAR-1(-/-)) mice, which have normal coagulation, also showed significant protection from crescentic GN compared with wild-type mice. The reductions in crescent formation, inflammatory cell infiltration, and serum creatinine were similar in PAR-1(-/-) and hirudin-treated mice, but hirudin afforded significantly greater protection from fibrin deposition. Treatment of wild-type mice with a selective PAR-1-activating peptide (TRAP) augmented histological and functional indices of GN, but TRAP treatment did not alter the severity of GN in PAR(-/-) mice. These results indicate that activation of PAR-1 by thrombin or TRAP amplifies crescentic GN. Thus, in addition to its procoagulant role, thrombin has proinflammatory, PAR-1-dependent effects that augment inflammatory renal injury.
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, 3168 Victoria, Australia.
authors.forename: M A
authors.initials: MA
authors.lastname: Cunningham
authors.forename: E
authors.initials: E
authors.lastname: Rondeau
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: S R
authors.initials: SR
authors.lastname: Coughlin
authors.forename: S R
authors.initials: SR
authors.lastname: Holdsworth
authors.forename: P G
authors.initials: PG
authors.lastname: Tipping
mesh_terms: D000818:Animals; D000991:Antithrombins / Q000494:pharmacology; D005921:Glomerulonephritis / Q000209:etiology / Q000235:genetics / Q000503:physiopathology*; D006629:Hirudins / Q000494:pharmacology; D007678:Kidney Glomerulus / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D051379:Mice; D010314:Partial Thromboplastin Time; D010446:Peptide Fragments / Q000494:pharmacology; D010976:Platelet Count; D011480:Protease Inhibitors / Q000494:pharmacology; D044463:Receptor, PAR-1; D018179:Receptors, Thrombin / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D013917:Thrombin / Q000494:pharmacology* / Q000502:physiology
chemical_list: D000991:Antithrombins; D006629:Hirudins; D010446:Peptide Fragments; D011480:Protease Inhibitors; D044463:Receptor, PAR-1; D018179:Receptors, Thrombin; C082835:thrombin receptor peptide (42-47); D013917:Thrombin