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World J Clin Cases. Dec 6, 2019; 7(23): 3915-3933
Published online Dec 6, 2019. doi: 10.12998/wjcc.v7.i23.3915
Overview of organic anion transporters and organic anion transporter polypeptides and their roles in the liver
Ting-Ting Li, Jia-Xing An, Jing-Yu Xu, Bi-Guang Tuo
Ting-Ting Li, Jia-Xing An, Jing-Yu Xu, Bi-Guang Tuo, Department of Gastroenterology, Affiliated Hospital, Zunyi Medical University, Zunyi 563100, Guizhou Province, China
Author contributions: All authors equally contributed to this paper with conception and design of the study, literature review and analysis, manuscript drafting, critical revision, and editing, and approval of the final version.
Conflict-of-interest statement: No potential conflicts of interest exist.
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: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Bi-Guang Tuo, MD, PhD, Professor, Department of Gastroenterology, Affiliated Hospital, Zunyi Medical University, 149 Dalian Road, Zunyi 563003, Guizhou Province, China. tuobiguang@aliyun.com
Telephone: +86-851-28609205 Fax: +86-851-28609205
Received: October 8, 2019
Peer-review started: October 8, 2019
First decision: November 10, 2019
Revised: November 20, 2019
Accepted: November 27, 2019
Article in press: November 27, 2019
Published online: December 6, 2019
Processing time: 59 Days and 7.1 Hours
Abstract

Organic anion transporters (OATs) and organic anion transporter polypeptides (OATPs) are classified within two SLC superfamilies, namely, the SLC22A superfamily and the SLCO superfamily (formerly the SLC21A family), respectively. They are expressed in many tissues, such as the liver and kidney, and mediate the absorption and excretion of many endogenous and exogenous substances, including various drugs. Most are composed of 12 transmembrane polypeptide chains with the C-terminus and the N-terminus located in the cell cytoplasm. OATs and OATPs are abundantly expressed in the liver, where they mainly promote the uptake of various endogenous substrates such as bile acids and various exogenous drugs such as antifibrotic and anticancer drugs. However, differences in the locations of glycosylation sites, phosphorylation sites, and amino acids in the OAT and OATP structures lead to different substrates being transported to the liver, which ultimately results in their different roles in the liver. To date, few articles have addressed these aspects of OAT and OATP structures, and we study further the similarities and differences in their structures, tissue distribution, substrates, and roles in liver diseases.

Keywords: Organic anion; Substrate transport; Liver fibrosis; Liver cirrhosis; Liver cancer; Targeted therapy

Core tip: As important anion transporters, organic anion transporters (OATs) and organic anion transporter polypeptides (OATPs) have similar structures and transport substrates. So far, the role of some members of OATs and OATPs in the liver has been reported, but studies on both families are still rare. In this paper, we study their structure, distribution, substrate of action, and regulatory mechanisms in various diseases of the liver. With the further study of the relationship between OATs/OATPs and various liver diseases, targeted therapy with OATs/OATPs is expected to improve the adverse reactions of drugs in the liver and improve the survival rate of patients with liver diseases.