Basic Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 14, 2017; 23(38): 6995-7008
Published online Oct 14, 2017. doi: 10.3748/wjg.v23.i38.6995
Mitofusin-2 mediated mitochondrial Ca2+ uptake 1/2 induced liver injury in rat remote ischemic perconditioning liver transplantation and alpha mouse liver-12 hypoxia cell line models
Ruo-Peng Liang, Jun-Jun Jia, Jian-Hui Li, Ning He, Yan-Fei Zhou, Li Jiang, Tao Bai, Hai-Yang Xie, Lin Zhou, Yu-Ling Sun
Ruo-Peng Liang, Tao Bai, Yu-Ling Sun, Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
Ruo-Peng Liang, Tao Bai, Yu-Ling Sun, Institute of Hepatobiliary and Pancreatic Diseases, Zhengzhou University, Zhengzhou 450052, Henan Province, China
Jun-Jun Jia, Jian-Hui Li, Ning He, Yan-Fei Zhou, Li Jiang, Hai-Yang Xie, Lin Zhou, Key Lab of Combined Multi-Organ Transplantation, Ministry of Public Health, Hangzhou 310003, Zhejiang Province, China
Jun-Jun Jia, Jian-Hui Li, Ning He, Yan-Fei Zhou, Li Jiang, Hai-Yang Xie, Lin Zhou, Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
Jun-Jun Jia, Jian-Hui Li, Ning He, Yan-Fei Zhou, Li Jiang, Hai-Yang Xie, Lin Zhou, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, Zhejiang Province, China
Author contributions: Sun YL conceived the experiments; Liang RP, Jia JJ, He N, Bai T, Jiang L, Zhou YF conducted the experiments; Xie HY and Zhou L contributed reagents/materials/analysis tools; Liang RP, Bai T analyzed the results; Liang RP wrote the paper. All authors have reviewed the manuscript to be published.
Supported by Science and Technology Innovation Talents Support Plan, Department of Education, Henan Province, China, No. 17HASTIT044; China Postdoctoral Science Foundation, No. 2017M610374.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of Zhengzhou University, Zhengzhou, China (Approval No. 8, 2017).
Conflict-of-interest statement: The authors declare that there is no conflict of interest related to this study.
Data sharing statement: Technical appendix, statistical code, and dataset are available from the corresponding author at ylsun@zzu.edu.cn.
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: Yu-Ling Sun, MD, PhD, Department of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhengzhou University, 1st Jianshe East Road, Zhengzhou 450052, Henan Province, China. ylsun@zzu.edu.cn
Telephone: +86-371-67967126 Fax: +86-371-69767127
Received: July 28, 2017
Peer-review started: August 2, 2017
First decision: August 10, 2017
Revised: August 19, 2017
Accepted: September 6, 2017
Article in press: September 5, 2017
Published online: October 14, 2017
Abstract
AIM

To investigate the protective mechanism of mitofusin-2 (Mfn2) in rat remote ischemic perconditioning (RIC) models and revalidate it in alpha mouse liver-12 (AML-12) hypoxia cell lines.

METHODS

Sprague-Dawley rats were divided into three groups (n = 6 each): sham, orthotopic liver transplantation and RIC. After operation, blood samples were collected to test alanine aminotransferase and aspartate aminotransferase. The liver lobes were harvested for histopathological examination, western blotting (WB) and quantitative real-time (qRT)-PCR. AML-12 cell lines were then subjected to normal culture, anoxic incubator tank culture (hypoxia) and anoxic incubator tank culture with Mfn2 knockdown (hypoxia + Si), and data of qRT-PCR, WB, mitochondrial membrane potential (ΔΨm), apoptosis, endoplasmic reticulum Ca2+ concentrations and mitochondrial Ca2+ concentrations were collected.

RESULTS

Both sham and normal culture groups showed no injury during the experiment. The RIC group showed amelioration of liver function compared with the orthotopic liver transplantation group (P < 0.05). qRT-PCR and WB confirmed that Mfn2-mitochondrial Ca2+ uptake 1/2 (MICUs) axis was changed (P < 0.005). In AML-12 cell lines, compared with the hypoxia group, the hypoxia + Si group attenuated the collapse of ΔΨm and apoptosis (P < 0.005). The endoplasmic reticulum Ca2+ decrease and mitochondrial Ca2+ overloading observed in the hypoxia group were also attenuated in the hypoxia + Si group (P < 0.005). Finally, qRT-PCR and WB confirmed the Mfn2-MICUs axis change in all the groups (P < 0.005).

CONCLUSION

Mfn2 participates in liver injury in rat RIC models and AML-12 hypoxia cell lines by regulating the MICUs pathway.

Keywords: Remote ischemic per-conditioning, Ischemia-reperfusion injury, Ca2+, Mitofusin-2, Mitochondrial Ca2+ uniporter

Core tip: Compared to the orthotopic liver transplantation, the remote ischemic perconditioning (RIC) model can significantly improve liver functions. But, knowledge of its mechanism remains largely unknown. This research is the first to prove the protective mechanism of the mitofusin-2-mitochondrial Ca2+ uptake 1/2 axis by affecting the metabolism of intracellular calcium in the RIC model of liver transplantation and to revalidate it in alpha mouse liver-12 hypoxia cell lines.