title: Mitochondrial protein adducts formation and mitochondrial dysfunction during N-acetyl-m-aminophenol (AMAP)-induced hepatotoxicity in primary human hepatocytes.
abstract: 3'-Hydroxyacetanilide orN-acetyl-meta-aminophenol (AMAP) is generally regarded as a non-hepatotoxic analog of acetaminophen (APAP). Previous studies demonstrated the absence of toxicity after AMAP in mice, hamsters, primary mouse hepatocytes and several cell lines. In contrast, experiments with liver slices suggested that it may be toxic to human hepatocytes; however, the mechanism of toxicity is unclear. To explore this,we treated primary human hepatocytes (PHH) with AMAP or APAP for up to 48 h and measured several parameters to assess metabolism and injury. Although less toxic than APAP, AMAP dose-dependently triggered cell death in PHH as indicated by alanine aminotransferase (ALT) release and propidium iodide (PI) staining. Similar to APAP, AMAP also significantly depleted glutathione (GSH) in PHH and caused mitochondrial damage as indicated by glutamate dehydrogenase (GDH) release and the JC-1 assay. However, unlike APAP, AMAP treatment did not cause relevant c-jun-N-terminal kinase (JNK) activation in the cytosol or phospho-JNK translocation to mitochondria. To compare, AMAP toxicity was assessed in primary mouse hepatocytes (PMH). No cytotoxicity was observed as indicated by the lack of lactate dehydrogenase release and no PI staining. Furthermore, there was no GSH depletion or mitochondrial dysfunction after AMAP treatment in PMH. Immunoblotting for arylated proteins suggested that AMAP treatment caused extensive mitochondrial protein adduct formation in PHH but not in PMH. In conclusion, AMAP is hepatotoxic in PHH and the mechanism involves the formation of mitochondrial protein adducts and mitochondrial dysfunction.
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Yuchao
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Mitchell R
authors.initials: MR
authors.lastname: McGill
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Kuo
authors.initials: K
authors.lastname: Du
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Dorko
authors.affiliation: Department of Surgery, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Sean C
authors.initials: SC
authors.lastname: Kumer
authors.affiliation: Department of Surgery, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Schmitt
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Wen-Xing
authors.initials: WX
authors.lastname: Ding
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA. Electronic address: hjaeschke@kumc.edu.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Jaeschke
mesh_terms: D000083:Acetanilides / Q000633:toxicity*; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D024101:Mitochondrial Proteins / Q000378:metabolism*; D010766:Phosphorylation; D061251:Primary Cell Culture; D011485:Protein Binding; D015398:Signal Transduction / Q000187:drug effects; D013045:Species Specificity; D013997:Time Factors
chemical_list: D000083:Acetanilides; D024101:Mitochondrial Proteins; C026137:3-hydroxyacetanilide; D007770:L-Lactate Dehydrogenase; D005969:Glutamate Dehydrogenase; D048031:JNK Mitogen-Activated Protein Kinases; D005978:Glutathione
keywords: 3′-Hydroxyacetanilide (AMAP); Acetaminophen; Hepatotoxicity; Mitochondrial dysfunction; Protein adducts