Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 28, 2018; 24(16): 1748-1765
Published online Apr 28, 2018. doi: 10.3748/wjg.v24.i16.1748
Nonalcoholic steatohepatitis severity is defined by a failure in compensatory antioxidant capacity in the setting of mitochondrial dysfunction
Michelle L Boland, Stephanie Oldham, Brandon B Boland, Sarah Will, Jean-Martin Lapointe, Silvia Guionaud, Christopher J Rhodes, James L Trevaskis
Michelle L Boland, Stephanie Oldham, Brandon B Boland, Sarah Will, Christopher J Rhodes, James L Trevaskis, Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD 20878, United States
Jean-Martin Lapointe, Pathology, MedImmune Ltd., Cambridge CB21 6GH, United Kingdom
Silvia Guionaud, Pathology, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Cambridge CB22 3AT, United Kingdom
Author contributions: Boland ML and Trevaskis JL conceived of the project; Boland ML, Rhodes CJ and Trevaskis JL designed and interpreted experiments; Boland ML, Oldham S, Boland BB, Will S, Lapointe JM and Guionaud S acquired and analyzed data; Boland ML, Boland BB, Rhodes CJ and Trevaskis JL wrote and edited the manuscript.
Supported by MedImmune.
Institutional animal care and use committee statement: All animal experiments were conducted in accordance with policies of the NIH Guide for the Care and Use of Laboratory Animals and the Institutional Animal Care and Use Committee (IACUC) of MedImmune, LLC. Specific protocols used in this study were approved by the MedImmune IACUC, protocol number MI-16-0034.
Conflict-of-interest statement: All authors are current employees and/or stockholders of MedImmune/AstraZeneca.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: James L Trevaskis, PhD, Principal Scientist, Cardiovascular and Metabolic Diseases, MedImmune, LLC, Gaithersburg, MD 20878, United States.
Telephone: +1-301-3986695
Received: January 17, 2018
Peer-review started: January 17, 2018
First decision: February 11, 2018
Revised: February 22, 2018
Accepted: February 26, 2018
Article in press: February 25, 2018
Published online: April 28, 2018

To comprehensively evaluate mitochondrial (dys) function in preclinical models of nonalcoholic steatohepatitis (NASH).


We utilized two readily available mouse models of nonalcoholic fatty liver disease (NAFLD) with or without progressive fibrosis: Lepob/Lepob (ob/ob) and FATZO mice on high trans-fat, high fructose and high cholesterol (AMLN) diet. Presence of NASH was assessed using immunohistochemical and pathological techniques, and gene expression profiling. Morphological features of mitochondria were assessed via transmission electron microscopy and immunofluorescence, and function was assessed by measuring oxidative capacity in primary hepatocytes, and respiratory control and proton leak in isolated mitochondria. Oxidative stress was measured by assessing activity and/or expression levels of Nrf1, Sod1, Sod2, catalase and 8-OHdG.


When challenged with AMLN diet for 12 wk, ob/ob and FATZO mice developed steatohepatitis in the presence of obesity and hyperinsulinemia. NASH development was associated with hepatic mitochondrial abnormalities, similar to those previously observed in humans, including mitochondrial accumulation and increased proton leak. AMLN diet also resulted in increased numbers of fragmented mitochondria in both strains of mice. Despite similar mitochondrial phenotypes, we found that ob/ob mice developed more advanced hepatic fibrosis. Activity of superoxide dismutase (SOD) was increased in ob/ob AMLN mice, whereas FATZO mice displayed increased catalase activity, irrespective of diet. Furthermore, 8-OHdG, a marker of oxidative DNA damage, was significantly increased in ob/ob AMLN mice compared to FATZO AMLN mice. Therefore, antioxidant capacity reflected as the ratio of catalase:SOD activity was similar between FATZO and C57BL6J control mice, but significantly perturbed in ob/ob mice.


Oxidative stress, and/or the capacity to compensate for increased oxidative stress, in the setting of mitochondrial dysfunction, is a key factor for development of hepatic injury and fibrosis in these mouse models.

Keywords: Nonalcoholic steatohepatitis, Steatosis, Fibrosis, Mitochondrial function, Oxidative stress

Core tip:ob/ob and FATZO mice developed nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NASH) when fed a high trans-fat, high fructose and high cholesterol diet, in the context of obesity and insulin resistance, but showed differences in liver disease severity including collagen deposition and monocyte/macrophage infiltration. Mitochondrial dysfunction and increased numbers of mitochondria were observed in both models, similar to that reported in human NASH. Oxidative damage and antioxidant capacity were associated with disease severity. FATZO mice displayed increased catalase activity and reduced oxidative DNA damage compared to ob/ob mice, which may explain their lower disease burden.