Basic Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 28, 2019; 25(44): 6527-6540
Published online Nov 28, 2019. doi: 10.3748/wjg.v25.i44.6527
Gasdermin D-mediated hepatocyte pyroptosis expands inflammatory responses that aggravate acute liver failure by upregulating monocyte chemotactic protein 1/CC chemokine receptor-2 to recruit macrophages
Hong Li, Xue-Ke Zhao, Yi-Ju Cheng, Quan Zhang, Jun Wu, Shuang Lu, Wei Zhang, Yang Liu, Ming-Yu Zhou, Ya Wang, Jing Yang, Ming-Liang Cheng
Hong Li, Xue-Ke Zhao, Yi-Ju Cheng, Quan Zhang, Jun Wu, Shuang Lu, Yang Liu, Ming-Yu Zhou, Ya Wang, Jing Yang, Ming-Liang Cheng, Department of Infectious Diseases, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, Guizhou Province, China
Wei Zhang, Comprehensive Liver Cancer Center of the Fifth Medical Center of PLA General Hospital, Beijing 100039, China
Author contributions: Cheng ML and Wu J designed the research; Li H, Zhao XK and Wang Y performed the experiments shown in Figures 1-5; Cheng YJ, Zhang Q, Lu S and Zhang W analyzed the data; Li H wrote the paper; Yang J, Liu Y and Zhou MY provided technical assistance and contributed to the preparation of the figures; Li H, Zhao XK and Cheng YJ contributed equally to this work. All authors reviewed the results and approved the final version of the manuscript.
Supported by the National Natural Science Foundation of China, No. 81570543 and No. 81560104.
Institutional review board statement: This study was approved by the Ethics Committee of the Affiliated Hospital of Guizhou Medical University.
Institutional animal care and use committee statement: This study was approved by the Institutional Animal Care and Use Committee of Guizhou Medical University.
Conflict-of-interest statement: The authors declare that there is no conflict of interest related to this study.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines and prepared the manuscript accordingly.
Open-Access: This 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 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: Ming-Liang Cheng, BSc, Chief Physician, Professor, Department of Infectious Diseases, Affiliated Hospital of Guizhou Medical University, No. 28, Guiyi Road, Guiyang 550004, Guizhou Province, China. mlcheng@yeah.net
Telephone: +86-851-86773914 Fax: +86-851-86741623
Received: September 18, 2019
Peer-review started: September 18, 2019
First decision: October 14, 2019
Revised: October 31, 2019
Accepted: November 13, 2019
Article in press: November 13, 2019
Published online: November 28, 2019
Abstract
BACKGROUND

Massive hepatocyte death is the core event in acute liver failure (ALF). Gasdermin D (GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death. However, the role of hepatocyte pyroptosis and its mechanisms of expanding inflammatory responses in ALF are unclear.

AIM

To investigate the role and mechanisms of GSDMD-mediated hepatocyte pyroptosis through in vitro and in vivo experiments.

METHODS

The expression of pyroptosis pathway-associated proteins in liver tissues from ALF patients and a hepatocyte injury model was examined by Western blot. GSDMD short hairpin RNA (shRNA) was used to investigate the effects of downregulation of GSDMD on monocyte chemotactic protein 1 (MCP1) and its receptor CC chemokine receptor-2 (CCR2) in vitro. For in vivo experiments, we used GSDMD knockout mice to investigate the role and mechanism of GSDMD in a D-galactose/lipopolysaccharide (D-Galn/LPS)-induced ALF mouse model.

RESULTS

The levels of pyroptosis pathway-associated proteins in liver tissue from ALF patients and a hepatocyte injury model increased significantly. The level of GSDMD-N protein increased most obviously (P < 0.001). In vitro, downregulation of GSDMD by shRNA decreased the cell inhibition rate and the levels of MCP1/CCR2 proteins (P < 0.01). In vivo, GSDMD knockout dramatically eliminated inflammatory damage in the liver and improved the survival of D-Galn/LPS-induced ALF mice (P < 0.001). Unlike the mechanism of immune cell pyroptosis that involves releasing interleukin (IL)-1β and IL-18, GSDMD-mediated hepatocyte pyroptosis recruited macrophages via MCP1/CCR2 to aggravate hepatocyte death. However, this pathological process was inhibited after knocking down GSDMD.

CONCLUSION

GSDMD-mediated hepatocyte pyroptosis plays an important role in the pathogenesis of ALF, recruiting macrophages to release inflammatory mediators by upregulating MCP1/CCR2 and leading to expansion of the inflammatory responses. GSDMD knockout can reduce hepatocyte death and inflammatory responses, thus alleviating ALF.

Keywords: Gasdermin D, Hepatocyte, Pyroptosis, Acute liver failure, Monocyte chemotactic protein 1/CC chemokine receptor-2

Core tip: The expression of gasdermin D N terminal domain was significantly increased in the liver during human acute liver failure (ALF), in a D-galactose/lipopolysaccharide (D-Galn/LPS)-induced ALF mouse model and in D-Galn/LPS-treated AML12 hepatocytes. GSDMD-mediated hepatocyte pyroptosis expanded the inflammatory response by upregulating monocyte chemotactic protein 1 and its receptor CC chemokine receptor-2 to recruit macrophages. GSDMD knockout could significantly alleviate ALF in the mouse model. Finding effective intervention targets or drugs inhibiting GSDMD may provide a possible treatment approach to improve the outcomes of ALF.