Basic Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2020; 26(28): 4094-4107
Published online Jul 28, 2020. doi: 10.3748/wjg.v26.i28.4094
Celecoxib attenuates hepatocyte apoptosis by inhibiting endoplasmic reticulum stress in thioacetamide-induced cirrhotic rats
Wei Su, Yang Tai, Shi-Hang Tang, Yan-Ting Ye, Chong Zhao, Jin-Hang Gao, Bi-Guang Tuo, Cheng-Wei Tang
Wei Su, Cheng-Wei Tang, Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Wei Su, Bi-Guang Tuo, Department of Gastroenterology, Affiliated Hospital, Zunyi Medical University, Zunyi 563003, Guizhou Province, China
Yang Tai, Shi-Hang Tang, Yan-Ting Ye, Chong Zhao, Jin-Hang Gao, Cheng-Wei Tang, Laboratory of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Tang CW and Gao JH designed and coordinated the study; Su W, Tai Y, Tang SH, Ye YT, and Zhao C performed the experiments and acquired and analyzed the data; Su W and Tang CW interpreted the data; Tuo BG provide technical assistance; Su W wrote the manuscript; Tang CW reviewed the manuscript, all authors approved the final version of the article.
Supported by the National Natural Science Fund of China, No. U1702281, No. 81670551, and No. 81873584.
Institutional animal care and use committee statement: The animal procedures were approved by the Animal Use and Care Committee of Sichuan University and were conducted according to regulations formulated by Sichuan University (Licence No. 2017005A).
Conflict-of-interest statement: The authors declare that there are no conflicts of interest related to this manuscript.
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:
Corresponding author: Cheng-Wei Tang, MD, PhD, Chief Doctor, Professor, Department of Gastroenterology, West China Hospital, Sichuan University, No. 37 Guoxue Lane, Chengdu 610041, Sichuan Province, China.
Received: January 30, 2020
Peer-review started: January 30, 2020
First decision: April 22, 2020
Revised: May 21, 2020
Accepted: June 25, 2020
Article in press: June 25, 2020
Published online: July 28, 2020
Research background

Liver fibrosis is a significant sign of chronic liver diseases, which could be treated and even reversed in the early stage. Inhibition of hepatocyte apoptosis is an important cause of reversal of liver fibrosis. Endoplasmic reticulum (ER) stress-mediated apoptosis is one of the important mechanisms of liver fibrosis. The cyclooxygenase-2 inhibitor celecoxib can improve the thioacetamide (TAA)-induced liver fibrosis in rats, and thus reverse the development of liver fibrosis. Whether celecoxib can inhibit apoptosis by inhibiting ER stress and further reverse liver fibrosis remains to be further studied.

Research motivation

Celecoxib has been widely used in the clinical treatment of rheumatoid arthritis and osteoarthritis. However, whether celecoxib can suppress apoptosis by inhibiting ER stress and further reverse liver fibrosis remains to be further studied.

Research objectives

This study aimed to explore the important role of celecoxib in modulating hepatocyte apoptosis during the development of liver fibrosis, and to clarify whether its regulatory mechanism is mediated by ER stress.

Research methods

Cirrhosis was induced by intraperitoneal injections of thioacetamide (TAA) for 16 wk (200 mg/kg per 3 d for the first 8 wk and 100 mg /kg per 3 d after 8 wk). Thirty-six male Sprague-Dawley rats were randomly divided into three groups: control, TAA, and TAA + celecoxib groups. In the last 8 wk, TAA-induced cirrhotic rats received celecoxib (20 mg/kg/day) or the vehicle by gastric gavage. After 16 wk, the rats were sacrificed, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin (ALB) were detected. The hepatic fibrosis areas were evaluated by Sirius red staining and the degree of fibrosis was assessed by measuring the level of hydroxyproline. ER stress levels were evaluated by detecting the marker proteins glucose-regulated protein 78 (GRP78), CCAAT/enhancer binding protein homologous protein (CHOP), PKR-like ER protein kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 alpha (IRE1α). Apoptosis levels were evaluated by detecting caspase-12 and caspase-3.

Research results

The serum ALT and AST levels in the liver were significantly reduced by celecoxib; however, the serum ALB had no significant changes. Celecoxib significantly reduced the degree of liver fibrosis and the levels of hydroxyproline (-38% and -25.7%, respectively, P < 0.01). Celecoxib ameliorated ER stress by reducing the level of GRP78 compared to the TAA group (P < 0.05). Consistently, after celecoxib administration, the upregulation of TAA-induced hepatic apoptosis markers (caspase-12 and caspase-3) and CHOP was significantly inhibited. In addition, after celecoxib treatment, the expression of key molecules associated with ER stress (PERK, ATF6, and IRE1) was decreased (P < 0.05).

Research conclusions

Therapeutic administration of celecoxib effectively reduces hepatic apoptosis in TAA-induced cirrhotic rats. The mechanism of action may be attributed to the suppression of CHOP expression, which subsequently inhibits ER stress.

Research perspectives

Our results indicate that celecoxib may play a role in inhibiting ER stress in rat liver fibrosis by inhibiting the expression of CHOP in the ER stress signaling pathway. Our data provide a new target for the treatment of liver fibrosis.