Basic Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 14, 2021; 27(18): 2141-2159
Published online May 14, 2021. doi: 10.3748/wjg.v27.i18.2141
Alleviation of acute pancreatitis-associated lung injury by inhibiting the p38 mitogen-activated protein kinase pathway in pulmonary microvascular endothelial cells
Xiao-Xin Zhang, Hao-Yang Wang, Xue-Fei Yang, Zi-Qi Lin, Na Shi, Chan-Juan Chen, Lin-Bo Yao, Xin-Min Yang, Jia Guo, Qing Xia, Ping Xue
Xiao-Xin Zhang, Hao-Yang Wang, Xue-Fei Yang, Zi-Qi Lin, Na Shi, Chan-Juan Chen, Lin-Bo Yao, Xin-Min Yang, Jia Guo, Qing Xia, Ping Xue, Department of Integrated Traditional Chinese and Western Medicine, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Zhang XX, Guo J and Xue P obtained funding and designed the experiments; Zhang XX, Wang HY, Yang XF and Lin ZQ performed the experiments and literature search; Shi N, Chen CJ, Yao LB and Yang XM evaluated histological images and carried out a biochemical analysis; Zhang XX, Xia Q and Xue P wrote and revised the manuscript; All authors have read and approved the final manuscript.
Supported by National Natural Science Foundation of China, No. 81873107, No. 82004154 and No. 81573766; and Science and Technology Planning Program of Sichuan, No. 2019YFS0259.
Institutional animal care and use committee statement: The study was performed according to the Guidelines of Animal Care and Use Committee of West China Hospital of Sichuan University (protocol number, 2017082A).
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The manuscript has been 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: Ping Xue, MD, PhD, Professor, Department of Integrated Traditional Chinese and Western Medicine, West China Hospital of Sichuan University, No. 37 Guoxue Lane, Chengdu 610041, Sichuan Province, China. xueping@wchscu.cn
Received: December 25, 2020
Peer-review started: December 26, 2020
First decision: January 29, 2021
Revised: February 6, 2021
Accepted: March 29, 2021
Article in press: March 29, 2021
Published online: May 14, 2021
Abstract
BACKGROUND

Previous reports have suggested that the p38 mitogen-activated protein kinase signaling pathway is involved in the development of severe acute pancreatitis (SAP)-related acute lung injury (ALI). Inhibition of p38 by SB203580 blocked the inflammatory responses in SAP-ALI. However, the precise mechanism associated with p38 is unclear, particularly in pulmonary microvascular endothelial cell (PMVEC) injury.

AIM

To determine its role in the tumor necrosis factor-alpha (TNF-α)-induced inflammation and apoptosis of PMVECs in vitro. We then conducted in vivo experiments to confirm the effect of SB203580-mediated p38 inhibition on SAP-ALI.

METHODS

In vitro, PMVEC were transfected with mitogen-activated protein kinase kinase 6 (Glu), which constitutively activates p38, and then stimulated with TNF-α. Flow cytometry and western blotting were performed to detect the cell apoptosis and inflammatory cytokine levels, respectively. In vivo, SAP-ALI was induced by 5% sodium taurocholate and three different doses of SB203580 (2.5, 5.0 or 10.0 mg/kg) were intraperitoneally injected prior to SAP induction. SAP-ALI was assessed by performing pulmonary histopathology assays, measuring myeloperoxidase activity, conducting arterial blood gas analyses and measuring TNF-α, interleukin (IL)-1β and IL-6 levels. Lung microvascular permeability was measured by determining bronchoalveolar lavage fluid protein concentration, Evans blue extravasation and ultrastructural changes in PMVECs. The apoptotic death of pulmonary cells was confirmed by performing a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis and examining the Bcl2, Bax, Bim and cle-caspase3 levels. The proteins levels of P-p38, NFκB, IκB, P-signal transducer and activator of transcription-3, nuclear factor erythroid 2-related factor 2, HO-1 and Myd88 were detected in the lungs to further evaluate the potential mechanism underlying the protective effect of SB203580.

RESULTS

In vitro, mitogen-activated protein kinase (Glu) transfection resulted in higher apoptotic rates and cytokine (IL-1β and IL-6) levels in TNF-α-treated PMVECs. In vivo, SB2035080 attenuated lung histopathological injury, decreased inflammatory activity (TNF-α, IL-1β, IL-6 and myeloperoxidase) and preserved pulmonary function. Furthermore, SB203580 significantly reversed changes in the bronchoalveolar lavage fluid protein concentration, Evans blue accumulation, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cell numbers, apoptosis-related proteins (cle-caspase3, Bim and Bax) and endothelial microstructure. Moreover, SB203580 significantly reduced the pulmonary P-p38, NFκB, P-signal transducer and activator of transcription-3 and Myd88 levels but increased the IκB and HO-1 levels.

CONCLUSION

p38 inhibition may protect against SAP-ALI by alleviating inflammation and the apoptotic death of PMVECs.

Keywords: Acute pancreatitis, Acute lung injury, Pulmonary microvascular endothelial cells, P38, SB203580, Apoptosis

Core Tip: We explored the role of the p38 mitogen-activated protein kinase pathway in the tumor necrosis factor-alpha-induced inflammation and apoptosis of pulmonary microvascular endothelial cells in vitro and verified the effect of SB203580-mediated p38 inhibition on severe acute pancreatitis-related acute lung injury in rats. p38 mitogen-activated protein kinase overactivation promoted tumor necrosis factor-alpha-induced inflammatory cytokine expression and pulmonary microvascular endothelial cell apoptosis in vitro. SB203580 improved severe acute pancreatitis-related acute lung injury by downregulating P-p38, NFκB, P-SATA3 and Myd88 and upregulating IκB and HO-1, which alleviated inflammation and apoptotic cell death in rats.