Role of Nox4 in Mitigating Inflammation and Fibrosis in Dextran Sulfate Sodium-Induced Colitis

Yura Lee; Sung-Hee Kim; Haengdueng Jeong; Kwang H Kim; Donghun Jeon; Yejin Cho; Daekee Lee; Ki Taek Nam

doi:10.1016/j.jcmgh.2023.05.002

Role of Nox4 in Mitigating Inflammation and Fibrosis in Dextran Sulfate Sodium-Induced Colitis

Cell Mol Gastroenterol Hepatol. 2023;16(3):411-429. doi: 10.1016/j.jcmgh.2023.05.002. Epub 2023 May 18.

Authors

Yura Lee¹, Sung-Hee Kim¹, Haengdueng Jeong¹, Kwang H Kim¹, Donghun Jeon¹, Yejin Cho¹, Daekee Lee², Ki Taek Nam³

Affiliations

¹ Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
² Department of Life Science, Ewha Womans University, Seoul, Korea.
³ Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea. Electronic address: kitaek@yuhs.ac.

Abstract

Background & aims: Fibrosis development in ulcerative colitis is associated directly with the severity of mucosal inflammation, which increases the risk of colorectal cancer. The transforming growth factor-β (TGF-β) signaling pathway is an important source of tissue fibrogenesis, which is stimulated directly by reactive oxygen species produced from nicotinamide adenine dinucleotide phosphate oxidases (NOX). Among members of the NOX family, NOX4 expression is up-regulated in patients with fibrostenotic Crohn's disease (CD) and in dextran sulfate sodium (DSS)-induced murine colitis. The aim of this study was to determine whether NOX4 plays a role in fibrogenesis during inflammation in the colon using a mouse model.

Methods: Acute and recovery models of colonic inflammation were performed by DSS administration to newly generated Nox4^-/- mice. Pathologic analysis of colon tissues was performed, including detection of immune cells, proliferation, and fibrotic and inflammatory markers. RNA sequencing was performed to detect differentially expressed genes between Nox4^-/- and wild-type mice in both the untreated and DSS-treated conditions, followed by functional enrichment analysis to explore the molecular mechanisms contributing to pathologic differences during DSS-induced colitis and after recovery.

Results: Nox4^-/- mice showed increased endogenous TGF-β signaling in the colon, increased reactive oxygen species levels, intensive inflammation, and an increased fibrotic region after DSS treatment compared with wild-type mice. Bulk RNA sequencing confirmed involvement of canonical TGF-β signaling in fibrogenesis of the DSS-induced colitis model. Up-regulation of TGF-β signaling affects collagen activation and T-cell lineage commitment, increasing the susceptibility for inflammation.

Conclusions: Nox4 protects against injury and plays a crucial role in fibrogenesis in DSS-induced colitis through canonical TGF-β signaling regulation, highlighting a new treatment target.

Keywords: Fibrostenotic CD; Oxidative Stress; RNA-Sequencing; T-Cell Lineage Commitment.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Colitis* / pathology
Dextran Sulfate / toxicity
Fibrosis
Inflammation
Mice
NADPH Oxidase 4 / genetics
Reactive Oxygen Species / metabolism
Transforming Growth Factor beta

Substances

Dextran Sulfate
Reactive Oxygen Species
Transforming Growth Factor beta
Nox4 protein, mouse
NADPH Oxidase 4