PMID- 25064435
OWN - NLM
STAT- MEDLINE
DCOM- 20150825
LR  - 20220408
IS  - 1600-0641 (Electronic)
IS  - 0168-8278 (Linking)
VI  - 61
IP  - 6
DP  - 2014 Dec
TI  - Hepatocyte free cholesterol lipotoxicity results from JNK1-mediated mitochondrial 
      injury and is HMGB1 and TLR4-dependent.
PG  - 1376-84
LID - S0168-8278(14)00523-6 [pii]
LID - 10.1016/j.jhep.2014.07.024 [doi]
AB  - BACKGROUND & AIMS: Free cholesterol (FC) accumulates in non-alcoholic 
      steatohepatitis (NASH) but not in simple steatosis. We sought to establish how FC 
      causes hepatocyte injury. METHODS: In NASH-affected livers from diabetic mice, 
      subcellular FC distribution (filipin fluorescence) was established by subcellular 
      marker co-localization. We loaded murine hepatocytes with FC by incubation with 
      low-density lipoprotein (LDL) and studied the effects of FC on JNK1 activation, 
      mitochondrial injury and cell death and on the amplifying roles of the 
      high-mobility-group-box 1 (HMGB1) protein and the Toll-like receptor 4 (TLR4). 
      RESULTS: In NASH, FC localized to hepatocyte plasma membrane, mitochondria and 
      ER. This was reproduced in FC-loaded hepatocytes. At 40 muM LDL, hepatocyte FC 
      increased to cause LDH leakage, apoptosis and necrosis associated with JNK1 
      activation (c-Jun phosphorylation), mitochondrial membrane pore transition, 
      cytochrome c release, oxidative stress (GSSG:GSH ratio) and ATP depletion. 
      Mitochondrial swelling and crystae disarray were evident by electron microscopy. 
      Jnk1(-/-) and Tlr4(-/-) hepatocytes were refractory to FC lipotoxicity; JNK 
      inhibitors (1-2 muM CC-401, CC-930) blocked apoptosis and necrosis. Cyclosporine A 
      and caspase-3 inhibitors protected FC-loaded hepatocytes, confirming 
      mitochondrial cell death pathways; in contrast, 4-phenylbutyric acid, which 
      improves ER folding capacity did not protect FC-loaded hepatocytes. HMGB1 was 
      released into the culture medium of FC-loaded wild type (WT) but not Jnk1(-/-) or 
      Tlr4(-/-) hepatocytes, while anti-HMGB1 anti-serum prevented JNK activation and 
      FC lipotoxicity in WT hepatocytes. CONCLUSIONS: These novel findings show that 
      mitochondrial FC deposition causes hepatocyte apoptosis and necrosis by 
      activating JNK1; inhibition of which could be a novel therapeutic approach in 
      NASH. Further, there is a tight link between JNK1-dependent HMGB1 secretion from 
      lipotoxic hepatocytes and a paracrine cytolytic effect on neighbouring 
      cholesterol-loaded hepatocytes operating via TLR4.
CI  - Copyright (c) 2014. Published by Elsevier B.V.
FAU - Gan, Lay T
AU  - Gan LT
AD  - Liver Research Group, Australian National University (ANU) Medical School at The 
      Canberra Hospital, Garran, ACT, Australia.
FAU - Van Rooyen, Derrick M
AU  - Van Rooyen DM
AD  - Liver Research Group, Australian National University (ANU) Medical School at The 
      Canberra Hospital, Garran, ACT, Australia.
FAU - Koina, Mark E
AU  - Koina ME
AD  - Department of Anatomical Pathology, ACT Pathology, The Canberra Hospital, ACT, 
      Australia.
FAU - McCuskey, Robert S
AU  - McCuskey RS
AD  - Department of Cellular and Molecular Medicine, College of Medicine, University of 
      Arizona, USA.
FAU - Teoh, Narcissus C
AU  - Teoh NC
AD  - Liver Research Group, Australian National University (ANU) Medical School at The 
      Canberra Hospital, Garran, ACT, Australia.
FAU - Farrell, Geoffrey C
AU  - Farrell GC
AD  - Liver Research Group, Australian National University (ANU) Medical School at The 
      Canberra Hospital, Garran, ACT, Australia. Electronic address: 
      geoff.farrell@anu.edu.au.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20140724
PL  - Netherlands
TA  - J Hepatol
JT  - Journal of hepatology
JID - 8503886
RN  - 0 (HMGB1 Protein)
RN  - 0 (HMGB1 protein, mouse)
RN  - 0 (Tlr4 protein, mouse)
RN  - 0 (Toll-Like Receptor 4)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - 9007-43-6 (Cytochromes c)
RN  - 97C5T2UQ7J (Cholesterol)
RN  - EC 2.7.1.24 (Mitogen-Activated Protein Kinase 9)
RN  - EC 2.7.11.24 (Mitogen-Activated Protein Kinase 8)
SB  - IM
MH  - Adenosine Triphosphate/metabolism
MH  - Animals
MH  - Apoptosis/physiology
MH  - Cells, Cultured
MH  - Cholesterol/*metabolism
MH  - Cytochromes c/metabolism
MH  - Disease Models, Animal
MH  - Female
MH  - HMGB1 Protein/*metabolism
MH  - Hepatocytes/*metabolism/pathology
MH  - Mice
MH  - Mice, Inbred C57BL
MH  - Mice, Knockout
MH  - Mice, Mutant Strains
MH  - Mitochondria, Liver/*metabolism
MH  - Mitogen-Activated Protein Kinase 8/deficiency/genetics/*metabolism
MH  - Mitogen-Activated Protein Kinase 9/deficiency/genetics/metabolism
MH  - Non-alcoholic Fatty Liver Disease/metabolism/pathology/physiopathology
MH  - Oxidative Stress/physiology
MH  - Toll-Like Receptor 4/deficiency/genetics/*metabolism
OTO - NOTNLM
OT  - Electron microscopy
OT  - Endoplasmic reticulum stress
OT  - Membrane pore transition
OT  - Mitochondrial oxidative stress
OT  - Plasma membrane
EDAT- 2014/07/30 06:00
MHDA- 2015/08/26 06:00
CRDT- 2014/07/28 06:00
PHST- 2014/05/30 00:00 [received]
PHST- 2014/07/02 00:00 [revised]
PHST- 2014/07/15 00:00 [accepted]
PHST- 2014/07/28 06:00 [entrez]
PHST- 2014/07/30 06:00 [pubmed]
PHST- 2015/08/26 06:00 [medline]
AID - S0168-8278(14)00523-6 [pii]
AID - 10.1016/j.jhep.2014.07.024 [doi]
PST - ppublish
SO  - J Hepatol. 2014 Dec;61(6):1376-84. doi: 10.1016/j.jhep.2014.07.024. Epub 2014 Jul 
      24.