title: Fibrin(ogen) drives repair after acetaminophen-induced liver injury via leukocyte αMβ2integrin-dependent upregulation of Mmp12.
abstract: Acetaminophen (APAP)-induced liver injury is coupled with activation of the blood coagulation cascade and fibrin(ogen) accumulation within APAP-injured livers of experimental mice. We sought to define the role of fibrin(ogen) deposition in APAP-induced liver injury and repair.
  
  
  
  Wild-type, fibrinogen-deficient mice, mutant mice with fibrin(ogen) incapable of binding leukocyte αMβ2integrin (Fibγ390-396Amice) and matrix metalloproteinase 12 (Mmp12)-deficient mice were fasted, injected with 300mg/kg APAP i.p. and evaluated at a range of time-points. Plasma and liver tissue were analyzed. Rescue of Fibγ390-396Amice was carried out with exogenous Mmp12. To examine the effect of the allosteric leukocyte integrin αMβ2activator leukadherin-1 (LA-1), APAP-treated mice were injected with LA-1.
  
  
  
  In wild-type mice, APAP overdose increased intrahepatic levels of high molecular weight cross-linked fibrin(ogen). Anticoagulation reduced early APAP hepatotoxicity (6h), but increased hepatic injury at 24h, implying a protective role for coagulation at the onset of repair. Complete fibrin(ogen) deficiency delayed liver repair after APAP overdose, evidenced by a reduction of proliferating hepatocytes (24h) and unresolved hepatocellular necrosis (48 and 72h). Fibγ390-396Amice had decreased hepatocyte proliferation and increased multiple indices of liver injury, suggesting a mechanism related to fibrin(ogen)-leukocyte interaction. Induction of Mmp12, was dramatically reduced in APAP-treated Fibγ390-396Amice. Mice lacking Mmp12 displayed exacerbated APAP-induced liver injury, resembling Fibγ390-396Amice. In contrast, administration of LA-1 enhanced hepatic Mmp12 mRNA and reduced necrosis in APAP-treated mice. Further, administration of recombinant Mmp12 protein to APAP-treated Fibγ390-396Amice restored hepatocyte proliferation.
  
  
  
  These studies highlight a novel pathway of liver repair after APAP overdose, mediated by fibrin(ogen)-αMβ2integrin engagement, and demonstrate a protective role of Mmp12 expression after APAP overdose.
  
  
  
  Acetaminophen overdose leads to activation of coagulation cascade and deposition of high molecular weight cross-linked fibrin(ogen) species in the liver. Fibrin(ogen) is required for stimulating liver repair after acetaminophen overdose. The mechanism whereby fibrin(ogen) drives liver repair after acetaminophen overdose requires engagement of leukocyte αMβ2integrin and subsequent induction of matrix metalloproteinase 12.
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Kopec
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA.
authors.forename: Nikita
authors.initials: N
authors.lastname: Joshi
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA.
authors.forename: Holly
authors.initials: H
authors.lastname: Cline-Fedewa
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA.
authors.forename: Anna V
authors.initials: AV
authors.lastname: Wojcicki
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Ray
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA; Current affiliation: Pfizer Inc., Lake Forest, IL, USA.
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Sullivan
authors.affiliation: Michigan State University-Department of Energy Plant Research Laboratory, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Froehlich
authors.affiliation: Michigan State University-Department of Energy Plant Research Laboratory, USA.
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Johnson
authors.affiliation: Cancer and Blood Diseases Institute, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital, Cincinnati, OH, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Flick
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA; Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA. Electronic address: luyendyk@msu.edu.
authors.forename: James P
authors.initials: JP
authors.lastname: Luyendyk
mesh_terms: D000082:Acetaminophen / Q000633:toxicity; D000347:Afibrinogenemia / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000991:Antithrombins / Q000494:pharmacology; D056486:Chemical and Drug Induced Liver Injury / Q000378:metabolism* / Q000473:pathology; D000069604:Dabigatran / Q000494:pharmacology; D005260:Female; D005337:Fibrin / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D005340:Fibrinogen / Q000235:genetics / Q000378:metabolism*; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008115:Liver Regeneration / Q000187:drug effects / Q000502:physiology; D016177:Macrophage-1 Antigen / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D053508:Matrix Metalloproteinase 12 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008817:Mice, Mutant Strains
chemical_list: D000991:Antithrombins; D016177:Macrophage-1 Antigen; D000082:Acetaminophen; D005337:Fibrin; D005340:Fibrinogen; D053508:Matrix Metalloproteinase 12; C000602031:matrix metallopeptidase 12, mouse; D000069604:Dabigatran
keywords: Acetaminophen; Blood coagulation; Fibrin; Fibrinogen; Hemostasis; Inflammation; Liver repair; Macrophages; Metalloproteinase; α(M)β(2)