title: Lysosomal Cholesterol Accumulation Sensitizes To Acetaminophen Hepatotoxicity by Impairing Mitophagy.
abstract: The role of lysosomes in acetaminophen (APAP) hepatotoxicity is poorly understood. Here, we investigated the impact of genetic and drug-induced lysosomal cholesterol (LC) accumulation in APAP hepatotoxicity. Acid sphingomyelinase (ASMase)(-/-) mice exhibit LC accumulation and higher mortality after APAP overdose compared to ASMase(+/+) littermates. ASMase(-/-) hepatocytes display lower threshold for APAP-induced cell death and defective fusion of mitochondria-containing autophagosomes with lysosomes, which decreased mitochondrial quality control. LC accumulation in ASMase(+/+) hepatocytes caused by U18666A reproduces the susceptibility of ASMase(-/-) hepatocytes to APAP and the impairment in the formation of mitochondria-containing autolysosomes. LC extraction by 25-hydroxycholesterol increased APAP-mediated mitophagy and protected ASMase(-/-) mice and hepatocytes against APAP hepatotoxicity, effects that were reversed by chloroquine to disrupt autophagy. The regulation of LC by U18666A or 25-hydroxycholesterol did not affect total cellular sphingomyelin content or its lysosomal distribution. Of relevance, amitriptyline-induced ASMase inhibition in human hepatocytes caused LC accumulation, impaired mitophagy and increased susceptibility to APAP. Similar results were observed upon glucocerebrosidase inhibition by conduritol β-epoxide, a cellular model of Gaucher disease. These findings indicate that LC accumulation determines susceptibility to APAP hepatotoxicity by modulating mitophagy, and imply that genetic or drug-mediated ASMase disruption sensitizes to APAP-induced liver injury.
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Baulies
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.
authors.forename: Vicent
authors.initials: V
authors.lastname: Ribas
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Núñez
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Torres
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Alarcón-Vila
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Martínez
authors.affiliation: Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University of Southern California Research Center for Liver Diseases, University of Southern California, Los Angeles, CA 90089-9121, USA.
authors.forename: Jo
authors.initials: J
authors.lastname: Suda
authors.affiliation: Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University of Southern California Research Center for Liver Diseases, University of Southern California, Los Angeles, CA 90089-9121, USA.
authors.forename: Maria D
authors.initials: MD
authors.lastname: Ybanez
authors.affiliation: Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University of Southern California Research Center for Liver Diseases, University of Southern California, Los Angeles, CA 90089-9121, USA.
authors.forename: Neil
authors.initials: N
authors.lastname: Kaplowitz
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.|University of Southern California Research Center for Alcohol Liver and Pancreatic Diseases and Cirrhosis, Keck School of Medicine, USC, Los Angeles, CA, USA.
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Ruiz
authors.affiliation: Department of Cell Death and Proliferation, Instituto Investigaciones Biomedicas de Barcelona, CSIC, Barcelona, and Liver Unit-Hospital Clinic-IDIBAPS.|Centro de Investigación Biomédica en Red (CIBERehd), Barcelona, Spain.|University of Southern California Research Center for Alcohol Liver and Pancreatic Diseases and Cirrhosis, Keck School of Medicine, USC, Los Angeles, CA, USA.
authors.forename: Jose C
authors.initials: JC
authors.lastname: Fernández-Checa
mesh_terms: D000082:Acetaminophen / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D056486:Chemical and Drug Induced Liver Injury / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002784:Cholesterol / Q000378:metabolism*; D004351:Drug Resistance / Q000235:genetics; D005978:Glutathione / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D063306:Mitophagy / Q000187:drug effects*; D010588:Phagosomes; D013108:Sphingomyelin Phosphodiesterase / Q000172:deficiency
chemical_list: D000082:Acetaminophen; D002784:Cholesterol; D048031:JNK Mitogen-Activated Protein Kinases; C577975:ASMase, mouse; D013108:Sphingomyelin Phosphodiesterase; D005978:Glutathione