Integrated bioinformatic and molecular analyses reveal the IRF1-TGM2 axis in regulating oxidative stress and apoptosis in in vitro CD-like intestinal epithelial cell models.

Abstract

Crohn's disease (CD) is a chronic recurrent inflammatory bowel disease (IBD). Transglutaminase 2 (TGM2) participates in CD progression, yet its regulatory mechanism remains elusive. Here, transcriptomic, single-cell transcriptomic, metabolomic, and apoptosis-related datasets from GEO, Metabolomics Workbench, and GeneCards were integrated, followed by bioinformatic analyses using R 4.5.1 and MetaboAnalyst 5.0. In vitro experiments included Western blot, cell transfection, TUNEL, ELISA, ROS detection, ChIP, dual-luciferase reporter assay, and RT-qPCR. Bioinformatic analyses identified distinct gene expression profiles, aberrant immune cell infiltration, and disrupted energy and lipid metabolism in CD, yielding 23 candidate targets. TGM2 was enriched in fibroblasts, enterocytes, and myeloid cells, modulating apoptosis, inflammation, and oxidative stress to aggravate CD phenotypes. Mechanistically, interferon regulatory factor 1 (IRF1) directly bound to the TGM2 promoter and enhanced its transcription. The IRF1-TGM2 axis regulated apoptosis, inflammation, and ROS levels, with TGM2 overexpression reversing the inhibitory effects of IRF1 knockdown. IRF1 transcriptionally upregulates TGM2 to promote apoptosis and oxidative stress, providing a plausible mechanistic framework for CD-associated epithelial injury.

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