Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 28, 2018; 24(36): 4104-4118
Published online Sep 28, 2018. doi: 10.3748/wjg.v24.i36.4104
Role of microRNAs in alcohol-induced liver disorders and non-alcoholic fatty liver disease
Jorge-Luis Torres, Ignacio Novo-Veleiro, Laura Manzanedo, Lucía Alvela-Suárez, Ronald Macías, Francisco-Javier Laso, Miguel Marcos
Jorge-Luis Torres, Laura Manzanedo, Ronald Macías, Francisco-Javier Laso, Miguel Marcos, Department of Internal Medicine, University Hospital of Salamanca, Institute of Biomedical Research of Salamanca-IBSAL, Salamanca 37007, Spain
Jorge-Luis Torres, Ignacio Novo-Veleiro, Francisco-Javier Laso, Miguel Marcos, Spanish Working Group on Alcohol and Alcoholism, Spanish Society of Internal Medicine, Madrid 28016, Spain
Ignacio Novo-Veleiro, Department of Internal Medicine, University Hospital of Santiago de Compostela, A Coruña 15706, Spain
Lucía Alvela-Suárez, Department of Internal Medicine, HM Rosaleda Hospital, Santiago de Compostela, A Coruña 15701, Spain
Francisco-Javier Laso, Miguel Marcos, Department of Medicine, Faculty of Medicine, University of Salamanca, Salamanca 37007, Spain
Author contributions: Torres JL and Novo-Veleiro I contributed equally as first authors of this manuscript; Torres JL, Novo-Veleiro I, Manzanedo L, Alvela-Suárez L, Macías R and Marcos M carried out the literature research and drafted the manuscript; Torres JL, Novo-Veleiro I, Laso FJ and Marcos M contributed to manuscript conception and design; all authors approved the final version of the manuscript.
Supported by the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III and the European Union FEDER funds, Una manera de hacer Europa, (No. PI16/01548 to Miguel Marcos and No. RD16/0017/0023 to Francisco-Javier Laso) and Junta de Castilla y León GRS 1362/A/16 and INT/M/17/17 to Miguel Marcos and GRS 1587/A/17 to Jorge-Luis Torres).
Conflict-of-interest statement: No potential conflicts of interest.
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: Miguel Marcos, MD, PhD, Associate Professor, Staff Physician, Department of Internal Medicine, University Hospital of Salamanca, Paseo de San Vicente 182, Salamanca 37007, Spain.
Telephone: +34-923-291100-55437 Fax: +34-923-294739
Received: April 14, 2018
Peer-review started: April 14, 2018
First decision: May 21, 2018
Revised: June 25, 2018
Accepted: June 27, 2018
Article in press: June 27, 2018
Published online: September 28, 2018

MicroRNAs (miRNAs) are small non-coding RNAs that regulate multiple physiological and pathological functions through the modulation of gene expression at the post-transcriptional level. Accumulating evidence has established a role for miRNAs in the development and pathogenesis of liver disease. Specifically, a large number of studies have assessed the role of miRNAs in alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD), two diseases that share common underlying mechanisms and pathological characteristics. The purpose of the current review is to summarize and update the body of literature investigating the role of miRNAs in liver disease. In addition, the potential use of miRNAs as biomarkers and/or therapeutic targets is discussed. Among all miRNAs analyzed, miR-34a, miR-122 and miR-155 are most involved in the pathogenesis of NAFLD. Of note, these three miRNAs have also been implicated in ALD, reinforcing a common disease mechanism between these two entities and the pleiotropic effects of specific miRNAs. Currently, no single miRNA or panel of miRNAs has been identified for the detection of, or staging of ALD or NAFLD. While promising results have been shown in murine models, no therapeutic based-miRNA agents have been developed for use in humans with liver disease.

Keywords: Alcohol use disorder, Alcoholic liver disease, Non-alcoholic fatty liver disease, Steatosis, Obesity, miRNA, Biomarkers

Core tip: MicroRNAs (miRNAs) are small RNAs that regulate gene expression at a post-transcriptional level. Altered miRNA expression has been found in a variety of liver diseases, including non-alcoholic fatty liver disease and alcoholic liver disease. A group of miRNAs (miR-155, miR-122 and miR-34a) contributes to the pathogenesis of these two diseases and these miRNAs have potential use as biomarkers or therapeutic targets. Several technical limitations and a lack of clinical studies, however, preclude their clinical use.