Observational Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Nov 27, 2021; 13(11): 1448-1462
Published online Nov 27, 2021. doi: 10.4240/wjgs.v13.i11.1448
Novel roles of lipopolysaccharide and TLR4/NF-κB signaling pathway in inflammatory response to liver injury in Budd-Chiari syndrome
Jie Li, Xiao-Ming Chen, Chun-Ze Zhou, Wei-Wei Fang, Wei-Fu Lv, De-Lei Cheng
Jie Li, Chun-Ze Zhou, Wei-Fu Lv, De-Lei Cheng, Department of Interventional Radiology, The First Affiliated Hospital of University of Science and Technology of China, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, Anhui Province, China
Xiao-Ming Chen, Department of Gastroenterology, The Second Hospital of Anhui Medical University, Hefei 230000, Anhui Province, China
Wei-Wei Fang, Department of Radiology, The Third People’s Hospital of Hefei, Hefei 230022, Anhui Province, China
Author contributions: Cheng DL and Lv WF designed the study; Li J, Cheng DL, Zhou CZ, Chen ZM and Fang WW performed the experiments, collected and analyzed the data; Lv WF, Zhou CZ, Chen XM and Fang WW contributed to sample collection and experimental data input into computer; Li J and Cheng DL drafted and wrote the manuscript; Li J and Cheng DL gave advice on the experimental design, interpreted the results and critically revised the manuscript; Lv WF, Zhou CZ and Chen XM provided pathological assistance; all authors read and approved the final version of the manuscript.
Supported by Natural Science Foundation Project of Anhui Province, No. 1708085QH218.
Institutional review board statement: All procedures were performed in accordance with the ethical standards of the committee of human experimentation (institutional and national) and with the guidelines of the Helsinki Declaration of 1975 that have been revised in 2008 (5).
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare no conflicts of interest.
Data sharing statement: Data are available on reasonable request from the corresponding author.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
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: De-Lei Cheng, Department of Interventional Radiology, The First Affiliated Hospital of University of Science and Technology of China, Division of Life Sciences and Medicine, University of Science and Technology of China, No. 218 Jixi Road, Hefei 230001, Anhui Province, China. 39055004@qq.com
Received: January 13, 2021
Peer-review started: January 13, 2021
First decision: July 14, 2021
Revised: August 19, 2021
Accepted: October 31, 2021
Article in press: October 31, 2021
Published online: November 27, 2021
Processing time: 317 Days and 14.4 Hours
ARTICLE HIGHLIGHTS
Research background

Budd-Chiari syndrome (BCS) is an uncommon but potentially life-threatening clinical syndrome of portal and/or inferior vena cava hypertension caused by obstruction of the hepatic and/or inferior vena cava. Liver injury in BCS is considered to be a specific form of liver injury with a mechanism different from that caused by common factors (e.g., viruses, poisoning, alcohol or biliary stasis). Until now, the exact mechanism underlying BCS-induced liver injury is not yet known. It has been shown that lipopolysaccharide (LPS) inactivation is diminished in all causes of liver injury, leading to intrahepatic LPS accumulation, as is the case in acute hepatic injury. LPS accumulation can bind to TLR4 in intrahepatic tissue cells to activate the TLR4/NF-κB pathway and thereby regulate NF-κB-dependent acute and chronic inflammatory liver injury. To date, it remains to be elucidated whether LPS and the TLR4/NF-κB signaling pathway could play a role in the inflammatory response to liver injury in BCS.

Research motivation

We anticipated that investigating the mechanism with involvement of NF-κB may advance our understanding of the pathogenesis of liver injury in BCS, and help to develop new therapeutic strategies for treatment of patients with BCS.

Research objectives

We performed this study, aiming to investigate the potential role of NF-κB-mediated inflammation in BCS-induced liver injury in humans and rats.

Research methods

In this study, 180 rats were randomly assigned into nine groups: four BCS model groups (1, 3, 6 and 12 wk), four sham-operated groups (1, 3, 6 and 12 wk), and one control group. LPS levels in each group were detected by the Tachypleus amebocyte lysate test. The mRNA and protein levels of TLR4, NF-κB, tumor necrosis factor (TNF)-α, interleukin (IL)-2 and interferon (IFN)-γ were quantified. In addition, 60 patients with BCS and 30 healthy controls were enrolled, and their blood samples were analyzed.

Research results

Hepatic and plasma LPS levels were significantly increased in rats. The mRNA and protein expression levels of TLR4, NF-κB and inflammatory cytokines (TNF-α, IL-2 and IFN-γ) in liver tissues were significantly higher in the BCS model groups compared with those in the other two groups. In addition, the model groups (1, 3, 6 and 12 wk after BCS induction) showed significant differences in the levels of LPS, TLR4, NF-κB, TNF-α, IL-2 and IFN-γ. Notably, there was a significant correlation between the LPS concentrations and mRNA and protein levels of TLR4, NF-κB and inflammatory cytokines. Importantly, it was revealed that the levels of LPS, TLR4, NF-κB and inflammatory cytokines were significantly greater in chronic BCS patients than healthy controls and acute BCS patients.

Research conclusions

This study has demonstrated that LPS level is markedly elevated in BCS, in turn activating the TLR4/NF-κB signaling pathway, leading to induction of inflammatory cytokines (TNF-α, IL-2 and IFN-γ) in response to BCS-induced liver injury.

Research perspectives

The findings of the present study implicated that the TLR4/NF-κB signaling pathway could serve as a potential target in the developing of new therapeutic strategies for BCS-induced liver injury, which may ultimately improve the care for patients with BCS.