Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 14, 2016; 22(18): 4501-4514
Published online May 14, 2016. doi: 10.3748/wjg.v22.i18.4501
miR-30b inhibits autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate
Shi-Peng Li, Jin-Dan He, Zhen Wang, Yao Yu, Shu-Yu Fu, Hai-Ming Zhang, Jian-Jun Zhang, Zhong-Yang Shen
Shi-Peng Li, Jin-Dan He, Zhen Wang, Yao Yu, Hai-Ming Zhang, Jian-Jun Zhang, Zhong-Yang Shen, First Central Clinical College of Tianjin Medical University, Tianjin 300192, China
Hai-Ming Zhang, Jian-Jun Zhang, Zhong-Yang Shen, Oriental Organ Transplant Center of Tianjin First Central Hospital, Tianjin 300192, China
Shu-Yu Fu, Laboratory of Immunology and Inflammation, Tianjin Medical University, Tianjin 300070, China
Shi-Peng Li, Jin-Dan He, Zhen Wang, Yao Yu, Hai-Ming Zhang, Jian-Jun Zhang, Zhong-Yang Shen, Key Laboratory of Organ Transplantation of Tianjin, Tianjin 300192, China
Author contributions: Li SP, Wang Z, and Yu Y performed the majority of experiments and analyzed the data; He JD, Wang Z, and Yu Y performed the molecular investigations; He JD, Wang Z, and Yu Y participated equally in treatment of animals; Zhang HM, Zhang JJ, and Shen ZY designed and coordinated the research; Li SP, Fu SY, and Zhang JJ wrote the paper; Li SP, He JD, Wang Z, Yu Y, and Fu SY contributed equally to this work.
Supported by National High Technology Research and Development Program (863) of China, No. 2012AA021001; National Natural Science Foundation of China, No. 81270554; Special Fund for Health Research in the Public Interest of China, No. 201302009; National Key Specialty Construction of Clinical Projects, No. 201354409.
Institutional review board statement: The study were performed according to Tianjin Medical University Institutional review board guidelines and work was approved by the Institutional review board. All experiments were performed according to institutional guidelines.
Institutional animal care and use committee statement: All animals were housed and handled according to Tianjin Medical University Institutional Animal Care and Use Committee guidelines, and all animal work was approved by the appropriate committee.
Conflict-of-interest statement: There is no conflict of interest in this study.
Data sharing statement: No additional data are available.
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/
Correspondence to: Jian-Jun Zhang, MD, PhD, First Central Clinical College of Tianjin Medical University, Oriental Organ Transplant Center of Tianjin First Central Hospital, Key Laboratory of Organ Transplantation of Tianjin, No. 24 Fukang Road, Nankai District, Tianjin 300192, China. zhangjianjun9999@yeah.net
Telephone: +86-22-23626600 Fax: +86-22-23626600
Received: January 9, 2016
Peer-review started: January 10, 2016
First decision: January 28, 2016
Revised: January 30, 2016
Accepted: March 1, 2016
Article in press: March 2, 2016
Published online: May 14, 2016
Processing time: 115 Days and 10.8 Hours
Abstract

AIM: To explore the role and potential mechanism of miR-30b regulation of autophagy in hepatic ischemia-reperfusion injury (IRI).

METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studies, AML12 cells were immersed in mineral oil for 1 h and then cultured in complete Dulbecco’s Modified Eagle’s Medium (DMEM)/F12 to simulate IRI. Mice and cells were transfected with miR-30b agomir/mimics or antagomir/inhibitor to examine the effect of miR-30b on autophagy to promote hepatic IRI. The expression of miR-30b was measured by real-time polymerase chain reaction. Apoptotic cells were detected by terminal uridine nick-end labeling (TUNEL) staining, and cell viability was detected by methylthiazole tetrazolium assay. The expression of light chain 3, autophagy-related gene (Atg)12, Atg5, P62, and caspase-3 were detected by western blotting analysis.

RESULTS: miR-30b levels were significantly downregulated after hepatic IRI, and the numbers of autophagosomes were increased in response to IRI both in vivo and in vitro. These findings demonstrate that low levels of miR-30b could promote hepatic IRI. Furthermore, we found that miR-30b interacted with Atg12-Atg5 conjugate by binding to Atg12. Overexpression of miR-30b diminished Atg12 and Atg12-Atg5 conjugate levels, which promoted autophagy in response to IR. In contrast, downregulation of miR-30b was associated with increased Atg12-Atg5 conjugate levels and increased autophagy.

CONCLUSION: miR-30b inhibited autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate.

Keywords: miR-30b; Autophagy; Atg12-Atg5 conjugate; Hepatic ischemia-reperfusion injury

Core tip: miR-30b levels were significantly downregulated after hepatic ischemia-reperfusion injury (IRI) in mice. The number of autophagosomes was increased in response to IRI both in vivo and in vitro. Decreased levels of miR-30b could promote hepatic IRI, as revealed by reductions in cells viability in vitro. Overexpression of miR-30b diminished autophagy-related gene (Atg)12 and Atg12-Atg5 conjugate levels which promoted autophagy in response to hepatic IRI. Therefore, miR-30b inhibits autophagy to alleviate hepatic IRI via decreasing the Atg12-Atg5 conjugate.