Tissue factor deficiency and PAR-1 deficiency are protective against renal ischemia reperfusion injury.
Ischemia/reperfusion (IR) injury is a leading cause of acute renal failure and an important contributor to allograft damage. Tissue factor (TF) is up-regulated during IR, and TF inhibition reduces renal injury. However, the underlying mechanisms by which TF contributes to injury have not been elucidated. We postulated that TF contributes to IR injury by production of coagulation proteases and subsequent signaling by protease activated receptor (PARs). We compared renal injury after 25 minutes of bilateral renal ischemia and varying periods of reperfusion in C57BL/6 mice, those expressing low levels of TF (low-TF), hirudin-treated C57BL/6, and mice lacking either PAR-1 or PAR-2. C57BL/6 mice developed severe renal failure and died within 48 hours of reperfusion. In contrast, low-TF, hirudin-treated C57BL/6, and PAR-1-/- mice were protected from renal failure and had reduced mortality, tubular injury, neutrophil accumulation, and lower levels of the chemokines KC and MIP-2. Importantly, PAR-1-/- mice had lower chemokine levels despite up-regulation of TF and fibrin deposition. In addition, treating PAR-1-/- mice with hirudin conferred no additional benefit. Somewhat surprisingly, PAR-2 deficiency did not protect from renal failure. These experiments indicate that increased TF activity after renal IR leads to increased CXC chemokine expression and subsequent neutrophil-mediated injury predominantly by thrombin-dependent PAR-1 signaling.
Sevastos
Jacob
J
Prince of Wales Clinical School, University of New South Wales, Sydney, and Prince of Wales Hospital, Barker St, Randwick, NSW 2031, Australia.
Kennedy
Sean E
SE
Davis
Darren R
DR
Sam
Melissa
M
Peake
Philip W
PW
Charlesworth
John A
JA
Mackman
Nigel
N
Erlich
Jonathan H
JH
D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology; D019743:Chemokines, CXC / Q000378:metabolism; D003404:Creatinine / Q000097:blood; D006629:Hirudins / Q000494:pharmacology; D007668:Kidney / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000096:biosynthesis; D044463:Receptor, PAR-1 / Q000172:deficiency* / Q000235:genetics; D044464:Receptor, PAR-2 / Q000172:deficiency / Q000235:genetics; D015427:Reperfusion Injury / Q000473:pathology / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013917:Thrombin / Q000378:metabolism; D013925:Thromboplastin / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism
D000925:Anticoagulants; D019743:Chemokines, CXC; D006629:Hirudins; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D044464:Receptor, PAR-2; D013925:Thromboplastin; D003404:Creatinine; D013917:Thrombin