Basic Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Nov 27, 2020; 12(11): 965-975
Published online Nov 27, 2020. doi: 10.4254/wjh.v12.i11.965
Obeticholic acid attenuates human immunodeficiency virus/alcohol metabolism-induced pro-fibrotic activation in liver cells
Moses New-Aaron, Murali Ganesan, Raghubendra Singh Dagur, Kusum K Kharbanda, Larisa Y Poluektova, Natalia A Osna
Moses New-Aaron, Department of Environmental, Agriculture and Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE 68105, United States
Moses New-Aaron, Murali Ganesan, Raghubendra Singh Dagur, Kusum K Kharbanda, Natalia A Osna, Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, United States
Murali Ganesan, Raghubendra Singh Dagur, Kusum K Kharbanda, Natalia A Osna, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68105, United States
Larisa Y Poluektova, Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, United States
Author contributions: New-Aaron M and Dagur RS performed the experiments, acquired, analyzed and interpreted the data; New-Aaron M and Osna NA drafted the manuscript; Ganesan M, Kharbanda KK and Poluektova LY contributed to critical revision, editing of the manuscript; Osna NA contributed to conception, design and funding of the study; all authors approved the final version of the article.
Supported by The National Institutes of Health, No. R01AA027189-01A1.
Institutional review board statement: The study was reviewed and approved by the Subcommittee for Research and Development Review Board at Veterans Affairs Medical Center, Omaha, United States.
Conflict-of-interest statement: Moses New-Aaron, Murali Ganesan, Raghubendra Singh Dagur, Kusum K. Kharbanda, Larisa Y Poluektova , Natalia A. Osna. All authors have nothing to disclose.
Data sharing statement: No additional data are available.
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 that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Natalia A Osna, MD, PhD, Associate Professor, Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, No. 4101 Woolworth Ave, Omaha, NE 68105, United States. nosna@unmc.edu
Received: July 16, 2020
Peer-review started: July 16, 2020
First decision: September 14, 2020
Revised: September 16, 2020
Accepted: October 5, 2020
Article in press: October 5, 2020
Published online: November 27, 2020
Processing time: 130 Days and 14.3 Hours
ARTICLE HIGHLIGHTS
Research background

Due to frequent association of morbidity and mortality of human immunodeficiency virus (HIV)-infection with liver injury, the inclusion of drugs with anti-fibrotic activity to the treatment of people living with HIV (PLWH) is pathogenically important. Alcohol consumption is known to speed up liver fibrosis development. Previously, we have shown that the exposure of hepatocytes to HIV and ethanol metabolites causes high oxidative stress, impairs proteasomal and lysosomal functions leading to accumulation of HIV in these cells, which end-ups with apoptotic cell death and finally, promotes progression to liver fibrosis.

Research motivation

The combined exposure of hepatocytes to HIV and alcohol induces hepatotoxicity and pro-fibrotic activation of hepatic stellate cells (HSC). Since HIV replication in hepatocytes is abortive, it cannot be fully controlled by antiretroviral therapy (ART) and thus, to prevent liver fibrosis progression in alcohol-abused PLWH, ART should be combined with the drugs suppressing apoptosis without enhancing HIV DNA integration in hepatocytes and decreasing pro-fibrotic activation of liver non-parenchymal cells.

Research objectives

The objective of this study was to investigate whether obeticholic acid (OCA) prevents HIV/ethanol metabolism-induced activation of HSC by HIV+ apoptotic hepatocyte engulfment, thereby diminishing liver fibrosis.

Research methods

The study was performed on hepatocyte-like Huh7.5-CYP (RLW) cells infected with HIV ADA and exposed to acetaldehyde-generating system (AGS) in the presence or absence of OCA. As an end-point, we have measured expression of HIV-related markers (HIVgagRNA-by real-time polymerase chain reaction (PCR), p24- by western blot, HIV DNA-by semi-nested PCR, integrated HIV DNA-by ddPCR) and non-HIV-related parameters (lysosomal and proteasomal activities, hepatocytes apoptosis). We also characterized pro-fibrotic activation and inflammasome induction in HSC (LX2 cells) by HIV-containing apoptotic hepatocytes internalization.

Research results

We found that OCA attenuated HIV-AGS-induced accumulation of HIVgagRNA, HIV DNA and p24. It suppressed ROS production, restored chymotrypsin-like proteasome activity as well as cathepsin B lysosome activity and decreased apoptosis in RLW cells. Exposure of HIV-containing apoptotic hepatocytes to OCA prevented activation of inflammasome and pro-fibrotic activation of HSC.

Research conclusions

By suppressing oxidative stress and restoring proteasomal and lysosomal functions impaired by HIV and ethanol metabolism, OCA decreases accumulation of HIV in hepatocytes, leading to down-regulation of apoptosis in these cells. OCA also reverses pro-fibrotic and inflammasome-related activation of HSC triggered by engulfment of HIV-containing apoptotic hepatocytes, potentially contributing to suppression of liver fibrosis development.

Research perspectives

Our in vitro studies are in the frame of pre-clinical characterization of anti-fibrotic effects of OCA in alcohol-exposed PLWH with a high risk of liver fibrosis development. At the next step, these in vitro effects will be confirmed by in vivo experiments on humanized mice infected with HIV and fed ethanol diet.