Aryl Hydrocarbon Receptor Activity in Hepatocytes Sensitizes to Hyperacute Acetaminophen-Induced Hepatotoxicity in Mice

TY - JOUR

T1 - Aryl Hydrocarbon Receptor Activity in Hepatocytes Sensitizes to Hyperacute Acetaminophen-Induced Hepatotoxicity in Mice

AU - Schuran, Fenja A

AU - Lommetz, Christoph

AU - Steudter, Andreas

AU - Ghallab, Ahmed

AU - Wieschendorf, Björn

AU - Schwinge, Dorothee

AU - Zuehlke, Sebastian

AU - Reinders, Joerg

AU - Heeren, Joerg

AU - Lohse, Ansgar W

AU - Schramm, Christoph

AU - Herkel, Johannes

AU - Carambia, Antonella

N1 - Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

PY - 2021

Y1 - 2021

N2 - BACKGROUND & AIMS: Acetaminophen (APAP)-induced liver injury is one of the most common causes of acute liver failure, however, a clear definition of sensitizing risk factors is lacking. Here, we investigated the role of the ligand-activated transcription factor aryl hydrocarbon receptor (Ahr) in APAP-induced liver injury. We hypothesized that Ahr, which integrates environmental, dietary, microbial and metabolic signals into complex cellular transcriptional programs, might act as a rheostat for APAP-toxicity.METHODS: Wildtype or conditional Ahr knockout mice lacking Ahr in hepatocytes (AlbΔ/ΔAhr) or myeloid cells (LysMΔ/ΔAhr) were treated with the specific Ahr ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) together with APAP.RESULTS: Ahr activation by ITE, which by itself was non-toxic, exacerbated APAP-induced hepatotoxicity compared to vehicle-treated controls, causing 80% vs. 0% mortality after administration of a normally sublethal APAP overdose. Of note, Ahr activation induced hepatocyte death even at APAP doses within the therapeutic range. Aggravated liver injury was associated with significant neutrophil infiltration; however, lack of Ahr in myeloid cells did not protect LysMΔ/ΔAhr mice from exacerbated APAP hepatotoxicity. In contrast, AlbΔ/ΔAhr mice were largely protected from ITE-induced aggravated liver damage, indicating that Ahr activation in hepatocytes, but not in myeloid cells, was instrumental for disease exacerbation. Mechanistically, Ahr activation fueled hepatic accumulation of toxic APAP metabolites by up-regulating expression of the APAP-metabolizing enzyme Cyp1a2, a direct Ahr downstream target.CONCLUSIONS: Ahr activation in hepatocytes potentiates APAP-induced hepatotoxicity. Thus, individual exposition to environmental Ahr ligands might explain individual sensitivity to hyperacute liver failure.

AB - BACKGROUND & AIMS: Acetaminophen (APAP)-induced liver injury is one of the most common causes of acute liver failure, however, a clear definition of sensitizing risk factors is lacking. Here, we investigated the role of the ligand-activated transcription factor aryl hydrocarbon receptor (Ahr) in APAP-induced liver injury. We hypothesized that Ahr, which integrates environmental, dietary, microbial and metabolic signals into complex cellular transcriptional programs, might act as a rheostat for APAP-toxicity.METHODS: Wildtype or conditional Ahr knockout mice lacking Ahr in hepatocytes (AlbΔ/ΔAhr) or myeloid cells (LysMΔ/ΔAhr) were treated with the specific Ahr ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) together with APAP.RESULTS: Ahr activation by ITE, which by itself was non-toxic, exacerbated APAP-induced hepatotoxicity compared to vehicle-treated controls, causing 80% vs. 0% mortality after administration of a normally sublethal APAP overdose. Of note, Ahr activation induced hepatocyte death even at APAP doses within the therapeutic range. Aggravated liver injury was associated with significant neutrophil infiltration; however, lack of Ahr in myeloid cells did not protect LysMΔ/ΔAhr mice from exacerbated APAP hepatotoxicity. In contrast, AlbΔ/ΔAhr mice were largely protected from ITE-induced aggravated liver damage, indicating that Ahr activation in hepatocytes, but not in myeloid cells, was instrumental for disease exacerbation. Mechanistically, Ahr activation fueled hepatic accumulation of toxic APAP metabolites by up-regulating expression of the APAP-metabolizing enzyme Cyp1a2, a direct Ahr downstream target.CONCLUSIONS: Ahr activation in hepatocytes potentiates APAP-induced hepatotoxicity. Thus, individual exposition to environmental Ahr ligands might explain individual sensitivity to hyperacute liver failure.

U2 - 10.1016/j.jcmgh.2020.09.002

DO - 10.1016/j.jcmgh.2020.09.002

M3 - SCORING: Journal article

C2 - 32932016

VL - 11

SP - 371

EP - 388

JO - CELL MOL GASTROENTER

JF - CELL MOL GASTROENTER

SN - 2352-345X

IS - 2

ER -