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ORIGINAL RESEARCH article

Front. Pharmacol.
Sec. Gastrointestinal and Hepatic Pharmacology
Volume 15 - 2024 | doi: 10.3389/fphar.2024.1421577

Vitamin D/Vitamin D receptor protects intestinal barrier against colitis by positively regulating Notch pathway

Provisionally accepted
  • West China Hospital, Sichuan University, Chengdu, China

The final, formatted version of the article will be published soon.

    Objective: Vitamin D/Vitamin D receptor (VD/VDR) signaling and the Notch pathway are involved in intestinal barrier restoration in colitis; however, their relationship and underlying mechanism are largely unknown. Therefore, this study aimed to investigate the role and mechanism of VD/VDR and the Notch pathways in intestinal barrier protection. Methods: Genetic Vdr knockout (VDR KO) and VD deficient (VDd) mice were established, and colitis was induced by feeding 2.5% dextran sodium sulfate (DSS) water. Mechanistic studies, including real-time PCR, immunofluorescence, western blotting and dual-luciferase reporter assays, were performed on cultured Caco-2 cells and intestinal organoids. Results: VD deficiency and VDR genetical KO increased the severity of DSS-induced colitis in mice, which presented a higher disease activity index score, increased intestinal permeability, and more severe intestinal histological damage than controls, accompanied by decreased and disrupted claudin-1 and claudin-3. Moreover, inhibition of Notch pathway by LY411,575 aggravated the severity of DSS-induced colitis and intestinal injury. In Caco-2 cells and intestinal organoids, the expression of Notch-1, N1ICD and Hes1 decreased upon downregulation or KO of VDR but increased upon paricalcitol (PAR, a VDR agonist) treatment. Meanwhile, PAR rescued claudin-1 and claudin-3 impairments that resulted from TNF-α exposure but failed to restore claudin-3 upon Notch inhibition. The dual-luciferase reporter assay further suggested that VD/VDR positively regulated the Notch signaling pathway by modulating Notch-1 transcription. Conclusions: VD/VDR positively modulates Notch activation by promoting Notch-1 transcription to maintain intestinal tight junction integrity and barrier function. This highlights the VD/VDR-Notch pathway as a potential new therapeutic target for protecting the intestinal barrier against ulcerative colitis.

    Keywords: tight junction, intestinal barrier, vitaminD, Vitamin D receptor ( VDR ), ulcerative colitis, Notch pathway

    Received: 22 Apr 2024; Accepted: 08 Jul 2024.

    Copyright: © 2024 Li, Guo, Geng, Song, Yang, Li and Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Chun-Hui Wang, West China Hospital, Sichuan University, Chengdu, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.