Basic Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 21, 2021; 27(43): 7530-7545
Published online Nov 21, 2021. doi: 10.3748/wjg.v27.i43.7530
Genome-wide map of N6-methyladenosine circular RNAs identified in mice model of severe acute pancreatitis
Jun Wu, Xiao-Hui Yuan, Wen Jiang, Yi-Chen Lu, Qi-Lin Huang, Yi Yang, Hua-Ji Qie, Jiang-Tao Liu, Hong-Yu Sun, Li-Jun Tang
Jun Wu, Xiao-Hui Yuan, Wen Jiang, Yi-Chen Lu, Qi-Lin Huang, Yi Yang, Hua-Ji Qie, Jiang-Tao Liu, Hong-Yu Sun, Li-Jun Tang, Department of General Surgery and Pancreatic Injury and Repair Key Laboratory of Sichuan Province, The General Hospital of Western Theater Command, Chengdu 610036, Sichuan Province, China
Jun Wu, Xiao-Hui Yuan, Wen Jiang, Yi-Chen Lu, Hua-Ji Qie, Jiang-Tao Liu, Hong-Yu Sun, Li-Jun Tang, College of Medicine, Southwest Jiaotong University, Chengdu 610036, Sichuan Province, China
Hong-Yu Sun, Laboratory of Basic Medicine, The General Hospital of Western Theater Command, Chengdu 610036, Sichuan Province, China
Author contributions: Wu J and Yuan XH contributed equally to this work; Tang LJ and Sun HY participated in the study conception and design; Wu J and Yuan XH participated in the writing of the main manuscript; Wu J, Yuan XH, Jiang W and Lu YC participated in the performance of the experiments; Huang QL and Yang Y participated in statistical data analysis and interpretation; Qie HJ and Liu JT participated in the preparation of figures; Tang LJ and Sun HY participated in the revision of the manuscript and final approval.
Supported by the National Natural Science Foundation of China, No. 81772001; and the National Clinical Key Subject of China, No. 41732113.
Institutional review board statement: The study was reviewed and approved by the Institutional Ethics Committee at the General Hospital of Western Theater Command (Chengdu, China), No. A20190252005.
Institutional animal care and use committee statement: The experimental procedures were reviewed and approved by the Institutional Animal Care and Use Committee at the General Hospital of Western Theater Command (Chengdu, China), and were conducted in accordance with the established International Guiding Principles for Animal Research.
Conflict-of-interest statement: The authors declare that there is no conflict of interest related to this study.
Data sharing statement: We had submitted the data to the online repository, which can be found at: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE173298.
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: Li-Jun Tang, MD, PhD, Chief Doctor, Professor, Department of General Surgery and Pancreatic Injury and Repair Key Laboratory of Sichuan Province, The General Hospital of Western Theater Command, No. 270 Tianhuan Road, Furong Avenue, Jinniu District, Chengdu 610036, Sichuan Province, China. tanglj2016@163.com
Received: May 19, 2021
Peer-review started: May 19, 2021
First decision: June 22, 2021
Revised: June 23, 2021
Accepted: September 15, 2021
Article in press: September 15, 2021
Published online: November 21, 2021
ARTICLE HIGHLIGHTS
Research background

Severe acute pancreatitis (SAP) is a lethal inflammatory disease with mortality up to 30%. But the genetic pathological mechanism of SAP remains unclear and SAP is still lack of effective therapeutic options. N6-methyladenosine (m6A) modification of circular (circ)RNAs plays a key role in many diseases and physiological processes through regulating the metabolism and function of circRNAs. However, the role of m6A circRNA in SAP has been unexplored yet.

Research motivation

The pathophysiology of SAP at the level of gene regulation is complex and remains unclear. circRNAs are found to participate in many physiological processes and play key roles in pathological processes during SAP. m6A modification can affect the “fate” of m6A modified circRNAs, thereby participating in the regulation of diseases. Therefore, we want to explore whether the m6A modification of circRNAs is related to the pathophysiological mechanism of SAP, and determine their biological significance and potential mechanisms.

Research objectives

The present study aims to determine the transcriptome-wide map of m6A circRNAs and explore their biological significance and its possible mechanisms in SAP.

Research methods

The SAP C57BL/6 mice model was induced by retrograde injection of 4% sodium taurocholate salt. m6A-modified RNA immunoprecipitation sequencing was used to determine the transcriptome-wide map of m6A circRNAs. The biological significance of circRNAs with differentially expressed m6A peaks was identified by GO and KEGG analysis. m6A circRNA-microRNA networks was constructed to explore the underlying mechanism of m6A circRNAs in SAP. The expression of demethylases was measured by western blot and qPCR. H&E staining and measurement of serum lipase and amylase were performed to assess the establishment of SAP mice model.

Research results

In the identified transcriptome-wide map of m6A circRNAs, there were 57 circRNAs with differentially expressed m6A peaks; among which, 32 were upregulated and 25 downregulated. Important pathways in the pathogenetic process during SAP were found by functional analysis of these m6A circRNAs, such as protein digestion and regulation of autophagy. m6A circRNA–miRNA networks showed that several important miRNAs in pathogenesis of SAP were bind to these m6A circRNAs, such as miR-24-3p, miR-26a, miR-92b, miR-216b, miR-324-5p and miR-762. To be note, the total m6A level of circRNAs was reduced in SAP, accompanied by the upregulated demethylase ALKBH5.

Research conclusions

The transcriptome-wide profiling of m6A circRNAs in SAP was identified, and the biological significance and possible potential mechanisms of m6A circRNAs in SAP were predicted, providing new insights into exploring the possible pathophysiological mechanism of SAP and new potential therapeutic targets.

Research perspectives

This present study for the first time identified transcriptome-wide map of m6A circRNAs and determined their biological significance and potential mechanisms. However, the m6A circRNA-mediated precise regulatory mechanisms are need to be explore further in vivo and vitro experiments. What’s more, further studies are needed to reveal the precise mechanism of ALKBH5 in m6A circRNAs during SAP. In the future, we will explore them and investigate these m6A circRNAs in SAP patients.