Ubiquitin D is Upregulated by Synergy of Notch Signalling and TNF-α in the Inflamed Intestinal Epithelia of IBD Patients

• Published in: Journal of Crohn's and colitis 2019-03, Vol.13 (4), p.495-509
• Main Authors: Kawamoto, Ami, Nagata, Sayaka, Anzai, Sho, Takahashi, Junichi, Kawai, Mao, Hama, Minami, Nogawa, Daichi, Yamamoto, Kouhei, Kuno, Reiko, Suzuki, Kohei, Shimizu, Hiromichi, Hiraguri, Yui, Yui, Shiro, Oshima, Shigeru, Tsuchiya, Kiichiro, Nakamura, Tetsuya, Ohtsuka, Kazuo, Kitagawa, Masanobu, Okamoto, Ryuichi, Watanabe, Mamoru
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Cell Line; Doxycycline - pharmacology; Drug Synergism; Epithelial Cells - metabolism; Gastrointestinal Agents - pharmacology; Gastrointestinal Agents - therapeutic use; Gene Expression; Gene Expression Regulation; Humans; Inflammatory Bowel Diseases - drug therapy; Inflammatory Bowel Diseases - genetics; Inflammatory Bowel Diseases - metabolism; Inflammatory Bowel Diseases - pathology; Infliximab - pharmacology; Infliximab - therapeutic use; Intestinal Mucosa - metabolism; NF-kappa B - metabolism; Organoids - metabolism; Receptors, Notch - genetics; Receptors, Notch - metabolism; Signal Transduction; Transcription, Genetic; Transcriptome; Tumor Necrosis Factor-alpha - metabolism; Tumor Necrosis Factor-alpha - pharmacology; Ubiquitins - genetics; Ubiquitins - metabolism; Up-Regulation
• ISSN: 1873-9946; 1876-4479
• DOI: 10.1093/ecco-jcc/jjy180

Abstract Background and Aims The intestinal epithelium of inflammatory bowel disease [IBD] patients is exposed to various pro-inflammatory cytokines, most notably tumour necrosis factor alpha [TNF-α]. We have previously shown that the Notch signalling pathway is also upregulated in such an epithelium, contributing to intestinal epithelial cell [IEC] proliferation and regeneration. We aimed to reproduce such environment in vitro and explore the gene regulation involved. Methods Human IEC cell lines or patient-derived organoids were used to analyse Notch- and TNF-α-dependent gene expression. Immunohistochemistry was performed to analyse expression of ubiquitin D [UBD] in various patient-derived intestinal tissues. Results In human IEC cell lines, we found that Notch signalling and TNF-α-induced NFκB signalling are reciprocally regulated to promote expression of a specific gene subset. Global gene expression analysis identified UBD to be one of the most highly upregulated genes, due to synergy of Notch and TNF-α. The synergistic expression of UBD was regulated at the transcriptional level, whereas the UBD protein had an extremely short half-life due to post-translational, proteasomal degradation. In uninflamed intestinal tissues from IBD patients, UBD expression was limited to IECs residing at the crypt bottom. In contrast, UBD-expressing IECs were seen throughout the crypt in inflamed tissues, indicating substantial induction by the local inflammatory environment. Analysis using patient-derived organoids consistently confirmed conserved Notch- and TNF-α-dependent expression of UBD. Notably, post-infliximab [IFX] downregulation of UBD reflected favourable outcome in IBD patients. Conclusion We propose that UBD is a novel inflammatory-phase protein expressed in IECs, with a highly rapid responsiveness to anti-TNF-α treatment.