Basic Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 21, 2020; 26(15): 1758-1774
Published online Apr 21, 2020. doi: 10.3748/wjg.v26.i15.1758
PTEN-induced kinase 1-induced dynamin-related protein 1 Ser637 phosphorylation reduces mitochondrial fission and protects against intestinal ischemia reperfusion injury
Wasim Qasim, Yang Li, Rui-Min Sun, Dong-Cheng Feng, Zhan-Yu Wang, De-Shun Liu, Ji-Hong Yao, Xiao-Feng Tian
Wasim Qasim, Yang Li, Dong-Cheng Feng, Zhan-Yu Wang, De-Shun Liu, Xiao-Feng Tian, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian 116023, Liaoning Province, China
Yang Li, Department of Gastrointestinal Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
Rui-Min Sun, Ji-Hong Yao, Department of Pharmacology, Dalian Medical University, Dalian 116044, Liaoning Province, China
Author contributions: Qasim W, Li Y and Sun RM contributed equally to the present study; Qasim W, Li Y, Sun RM, Feng DC, Wang ZY, and Liu DS performed the experiments and analyzed the data; Qasim W, Li Y and Sun RM wrote the article; Yao JH and Tian XF designed the experiments, revised the article, and obtained research funding; all authors approved the final version of the article.
Supported by the National Natural Science Foundation of China, No. 81679154, No. 81871547.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board at Dalian Medical University.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Dalian Medical University.
Conflict-of-interest statement: All the authors have nothing to disclose.
Data sharing statement: No additional data are available.
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: Xiao-Feng Tian, MD, PhD, Director, Professor, Surgeon, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, 467 Zhongshan Road, Shahekou District, Dalian 116023, Liaoning Province, China. txfdl@dmu.edu.cn
Received: December 28, 2019
Peer-review started: December 28, 2019
First decision: January 11, 2020
Revised: March 17, 2020
Accepted: March 27, 2020
Article in press: March 27, 2020
Published online: April 21, 2020
Abstract
BACKGROUND

Intestinal ischemia reperfusion (I/R) occurs in various diseases, such as trauma and intestinal transplantation. Excessive reactive oxygen species (ROS) accumulation and subsequent apoptotic cell death in intestinal epithelia are important causes of I/R injury. PTEN-induced putative kinase 1 (PINK1) and phosphorylation of dynamin-related protein 1 (DRP1) are critical regulators of ROS and apoptosis. However, the correlation of PINK1 and DRP1 and their function in intestinal I/R injury have not been investigated. Thus, examining the PINK1/DRP1 pathway may help to identify a protective strategy and improve the patient prognosis.

AIM

To clarify the mechanism of the PINK1/DRP1 pathway in intestinal I/R injury.

METHODS

Male C57BL/6 mice were used to generate an intestinal I/R model via superior mesenteric artery occlusion followed by reperfusion. Chiu’s score was used to evaluate intestinal mucosa damage. The mitochondrial fission inhibitor mdivi-1 was administered by intraperitoneal injection. Caco-2 cells were incubated in vitro in hypoxia/reoxygenation conditions. Small interfering RNAs and overexpression plasmids were transfected to regulate PINK1 expression. The protein expression levels of PINK1, DRP1, p-DRP1 and cleaved caspase 3 were measured by Western blotting. Cell viability was evaluated using a Cell Counting Kit-8 assay and cell apoptosis was analyzed by TUNEL staining. Mitochondrial fission and ROS were tested by MitoTracker and MitoSOX respectively.

RESULTS

Intestinal I/R and Caco-2 cell hypoxia/reoxygenation decreased the expression of PINK1 and p-DRP1 Ser637. Pretreatment with mdivi-1 inhibited mitochondrial fission, ROS generation, and apoptosis and ameliorated cell injury in intestinal I/R. Upon PINK1 knockdown or overexpression in vitro, we found that p-DRP1 Ser637 expression and DRP1 recruitment to the mitochondria were associated with PINK1. Furthermore, we verified the physical combination of PINK1 and p-DRP1 Ser637.

CONCLUSION

PINK1 is correlated with mitochondrial fission and apoptosis by regulating DRP1 phosphorylation in intestinal I/R. These results suggest that the PINK1/DRP1 pathway is involved in intestinal I/R injury, and provide a new approach for prevention and treatment.

Keywords: Intestinal ischemia reperfusion injury, Mitochondrial fission, PTEN-induced putative kinase 1, Dynamin-related protein 1 ser637, Phosphorylation, Apoptosis

Core tip: PTEN-induced kinase 1 (PINK1) is a kind of mitochondrial serine/threonine-protein kinase, which regulates mitochondrial homeostasis through regulating the phosphorylation of target proteins. Depletion of PINK1 has been proved to be associated with mitochondrial fragmentation and apoptosis in ischemic model. However, the underlying mechanism has not been clarified. By establishing an intestinal ischemia reperfusion model in mice and hypoxia/reoxygenation model in Caco-2 cells, we revealed that PINK1 inhibits mitochondrial fission and apoptosis via phosphorylating dynamin-related protein 1 on Ser637. The PINK1/dynamin-related protein 1 pathway may provide a potential target in treatment of intestinal ischemia reperfusion injury.