title: Analysis of changes in hepatic gene expression in a murine model of tolerance to acetaminophen hepatotoxicity (autoprotection).
abstract: Pretreatment of mice with a low hepatotoxic dose of acetaminophen (APAP) results in resistance to a subsequent, higher dose of APAP. This mouse model, termed APAP autoprotection was used here to identify differentially expressed genes and cellular pathways that could contribute to this development of resistance to hepatotoxicity. Male C57BL/6J mice were pretreated with APAP (400mg/kg) and then challenged 48h later with 600mg APAP/kg. Livers were obtained 4 or 24h later and total hepatic RNA was isolated and hybridized to Affymetrix Mouse Genome MU430_2 GeneChip. Statistically significant genes were determined and gene expression changes were also interrogated using the Causal Reasoning Engine (CRE). Extensive literature review narrowed our focus to methionine adenosyl transferase-1 alpha (MAT1A), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), flavin-containing monooxygenase 3 (Fmo3) and galectin-3 (Lgals3). Down-regulation of MAT1A could lead to decreases in S-adenosylmethionine (SAMe), which is known to protect against APAP toxicity. Nrf2 activation is expected to play a role in protective adaptation. Up-regulation of Lgals3, one of the genes supporting the Nrf2 hypothesis, can lead to suppression of apoptosis and reduced mitochondrial dysfunction. Fmo3 induction suggests the involvement of an enzyme not known to metabolize APAP in the development of tolerance to APAP toxicity. Subsequent quantitative RT-PCR and immunochemical analysis confirmed the differential expression of some of these genes in the APAP autoprotection model. In conclusion, our genomics strategy identified cellular pathways that might further explain the molecular basis for APAP autoprotection.
authors.affiliation: Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092, USA; Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road, Ridgefield, CT 06877-0368, USA. Electronic address: meeghan.oconnor@boehringer-ingelheim.com.
authors.forename: Meeghan A
authors.initials: MA
authors.lastname: O'Connor
authors.affiliation: Pfizer Inc., Groton, CT 06340, USA. Electronic address: petra.h.koza-taylor@pfizer.com.
authors.forename: Petra
authors.initials: P
authors.lastname: Koza-Taylor
authors.affiliation: Pfizer Inc., Groton, CT 06340, USA. Electronic address: sarah.campion@pfizer.com.
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Campion
authors.affiliation: Rutgers University, Department of Pharmacology and Toxicology, Environmental and Occupational Health Sciences Institute, Piscataway, NJ 08854, USA. Electronic address: aleksunes@eohsi.rutgers.edu.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Aleksunes
authors.affiliation: Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092, USA. Electronic address: xinsheng.gu@uconn.edu.
authors.forename: Xinsheng
authors.initials: X
authors.lastname: Gu
authors.affiliation: Pfizer Inc., Groton, CT 06340, USA. Electronic address: ahmed.enayetallah@pfizer.com.
authors.forename: Ahmed E
authors.initials: AE
authors.lastname: Enayetallah
authors.affiliation: Pfizer Inc., Groton, CT 06340, USA. Electronic address: michael.lawton@pfizer.com.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Lawton
authors.affiliation: Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092, USA. Electronic address: jose.manautou@uconn.edu.
authors.forename: José E
authors.initials: JE
authors.lastname: Manautou
mesh_terms: D000082:Acetaminophen / Q000633:toxicity*; D000818:Animals; D056486:Chemical and Drug Induced Liver Injury / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal
chemical_list: D000082:Acetaminophen
keywords: ALT; APAP; Acetaminophen; Autoprotection; CCl(4); CFB; Fmo3; Gene array; H(2)0(2); Hepatotoxicity; Lgals3; Liver; MAT1A; MMLV-RT; Mrp; NFE2L2 or Nrf2; PPAR; Vnn1; WT; acetaminophen; alanine aminotransferase; carbon tetrachloride; clofibrate; flavin-containing monooxygenase 3; galectin-3; hydrogen peroxide; i.p.; intraperitoneal; methionine adenosyl transferase-1 alpha; moloney murine leukemia virus reverse transcriptase; multidrug resistance-associated protein; nuclear factor (erythroid-derived 2)-like 2; peroxisome proliferator activated receptor; qRT-PCR; quantitative Real-Time Polymerase Chain Reaction; vanin 1; wild type