Details

Autor(en) / Beteiligte

• Xie, Yuchao
• McGill, Mitchell R.
• Dorko, Kenneth
• Kumer, Sean C.
• Schmitt, Timothy M.
• Forster, Jameson
• Jaeschke, Hartmut

Titel

Mechanisms of acetaminophen-induced cell death in primary human hepatocytes

Ist Teil von

• Toxicology and applied pharmacology, 2014-09, Vol.279 (3), p.266-274

Ort / Verlag

Amsterdam: Elsevier Inc

Erscheinungsjahr

2014

Quelle

MEDLINE

Beschreibungen/Notizen

• Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5mM, 10mM or 20mM APAP over a period of 48h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24h, which correlated with the clinical onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24h and 48h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6h after APAP and a partial protection when given at 15h. Conclusion: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic. •APAP reproducibly causes cell death in freshly isolated primary human hepatocytes.•APAP induces adduct formation, JNK activation and mitochondrial dysfunction in PHH.•Mitochondrial adducts and JNK translocation are delayed in PHH compared to mice.•JNK inhibitor SP600125 partially protects against APAP-induced cell death in PHH.•N-acetylcysteine provides significant protection even if administered 6h after APAP.