KUKU

KU ScholarWorks

  • myKU
  • Email
  • Enroll & Pay
  • KU Directory
    • Login
    View Item 
    •   KU ScholarWorks
    • Dissertations and Theses
    • Dissertations
    • View Item
    •   KU ScholarWorks
    • Dissertations and Theses
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    ACETAMINOPHEN HEPATOTOXICITY IN PRIMARY HUMAN HEPATOCYTES AND MICE

    Thumbnail
    View/Open
    Xie_ku_0099D_14624_DATA_1.pdf (2.908Mb)
    Issue Date
    2016-05-31
    Author
    Xie, Yuchao
    Publisher
    University of Kansas
    Format
    206 pages
    Type
    Dissertation
    Degree Level
    Ph.D.
    Discipline
    Pharmacology, Toxicology & Therapeutics
    Rights
    Copyright held by the author.
    Metadata
    Show full item record
    Abstract
    Acetaminophen is the most prevalent cause of acute liver failure (ALF) and drug-induced liver injury (DILI) in western countries. Extensive studies have revealed important intracellular events during the pathogenesis after APAP in vivo and in vitro. However, no detailed mechanistic research has been conducted in freshly isolated primary human hepatocytes (PHH), which are the gold standard to test drug-induced toxicity. To that end, the detailed injury time course, dose-response curves and signaling events were characterized. The overall time course and sequence of events mirror the clinical situation in APAP overdose patients, but occur significantly more slowly than in APAP-treated rodents, emphasizing cautious data extrapolation across experimental models. In addition, c-Jun N-terminal kinase (JNK) inhibitor moderately attenuated cell death after APAP, suggesting a detrimental role of JNK in injury progression. Although APAP-induced hepatotoxicity is reproducible in the murine model, it is not the case for AMAP, a regioisomer of APAP. AMAP was considered for long to be non-hepatotoxic in mice, primary mouse hepatocytes (PMH), hamsters and hepatoma cell lines. The lack of toxicity was largely due to the significantly less mitochondrial protein adduct formation after AMAP compared with APAP. In PHH, significant cell death was observed after AMAP, accompanied by a loss of mitochondrial membrane potential and the absence of JNK activation or P-JNK translocation to mitochondria. Further investigation indicated that AMAP toxicity was readily explained by mitochondria protein adducts formation in primary human but not mouse hepatocytes, highlighting the critical role of mitochondrial protein arylation in determining APAP or AMAP hepatotoxicity. Additional studies were performed to investigate the toxicity of ATP in vitro. ATP released from necrotic hepatocytes is considered a damage-associated molecular pattern (DAMP) molecule which could elicit innate immune responses, and therefore contributes to cell death. A recently published paper also suggested a direct toxicity of ATP. However, experiments in four different hepatocyte types including PHHs demonstrated an absence of toxicity directly by ATP. The fourth study focuses on characterization of APAP metabolites and adducts formation in APAP overdose patients, suggesting the importance of profiling both metabolites and protein adduct formation in the clinical diagnosis of APAP overdose. Given the importance of c-Jun N-terminal kinase (JNK) in APAP-induced liver injury, two pharmacological inhibitors of apoptosis signal-regulating kinase 1 (ASK1), an upstream kinase of JNK, were tested in mice. The ASK1 inhibitor attenuated liver injury both as a pre-treatment and as a 1.5h post-treatment by blocking JNK activation and P-JNK translocation to mitochondria. Importantly, inhibiting ASK1 activity did not affect liver regeneration.
    URI
    http://hdl.handle.net/1808/22502
    Collections
    • Pharmacy Dissertations and Theses [118]
    • Dissertations [4472]

    Items in KU ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.


    We want to hear from you! Please share your stories about how Open Access to this item benefits YOU.


    Contact KU ScholarWorks
    785-864-8983
    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    785-864-8983

    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    Image Credits
     

     

    Browse

    All of KU ScholarWorksCommunities & CollectionsThis Collection

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Contact KU ScholarWorks
    785-864-8983
    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    785-864-8983

    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    Image Credits
     

     

    The University of Kansas
      Contact KU ScholarWorks
    Lawrence, KS | Maps
     
    • Academics
    • Admission
    • Alumni
    • Athletics
    • Campuses
    • Giving
    • Jobs

    The University of Kansas prohibits discrimination on the basis of race, color, ethnicity, religion, sex, national origin, age, ancestry, disability, status as a veteran, sexual orientation, marital status, parental status, gender identity, gender expression and genetic information in the University’s programs and activities. The following person has been designated to handle inquiries regarding the non-discrimination policies: Director of the Office of Institutional Opportunity and Access, IOA@ku.edu, 1246 W. Campus Road, Room 153A, Lawrence, KS, 66045, (785)864-6414, 711 TTY.

     Contact KU
    Lawrence, KS | Maps