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©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
Involvement of toll-like receptor 5 in mouse model of colonic hypersensitivity induced by neonatal maternal separation
Geoffroy Mallaret, Amandine Lashermes, Mathieu Meleine, Ludivine Boudieu, Julie Barbier, Youssef Aissouni, Agathe Gelot, Benoit Chassaing, Andrew T Gewirtz, Denis Ardid, Frederic Antonio Carvalho
Geoffroy Mallaret, Mathieu Meleine, Ludivine Boudieu, Julie Barbier, Youssef Aissouni, Agathe Gelot, Denis Ardid, Department of Pharmacology, UMR 1107 NeuroDol, University of Clermont Auvergne, Clermont-Ferrand 63000, France
Amandine Lashermes, Department of Microbiology, Université Paris-Saclay, National Research Institute for Agriculture, Food and the Environment, AgroParisTech, Micalis Institute, Jouy-en-Josas 78350, France
Benoit Chassaing, Team “Mucosal Microbiota in Chronic Inflammatory Diseases”, INSERM U1016, CNRS UMR 8104, Université Paris Cité, Paris 75014, France
Andrew T Gewirtz, Center for Inflammation, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA30033, United States
Frederic Antonio Carvalho, Department of Pharmacology, INSERM 1107 NeuroDOL/University of Clermont Auvergne, Clermont-Ferrand 63000, France
Author contributions: Mallaret G and Lashermes A contributed equally to this article; Study concept and design done by Mallaret G, Lashermes A, Ardid D and Carvalho FA; Acquisition of data done by Mallaret G, Lashermes A, Barbier J, Aissouni Y, Chassaing B; Analysis and interpretation of data done by Mallaret G, Lashermes A, Chassaing B, Gewirtz AT, Ardid D and Carvalho FA; Drafting of the manuscript done by Mallaret G, Lashermes A Meleine M, Boudieu L and Carvalho FA; Obtained funding done by Ardid D and Carvalho FA; Study supervision done by Gewirtz AT, Ardid D and Carvalho FA.
Supported by the Region Auvergne-Rhône-Alpes and FEDER, No. Thématiques émergentes and Pack Ambition Recherche; the French Government IDEX-ISITE Initiative, No. 16-IDEX-0001-CAP 20-25; the Ministère de la Recherche et de la Technologie, INSERM and University of Clermont Auvergne, No. UMR1071.
Institutional animal care and use committee statement: All experiments were performed according to the ethical guidelines set out by the International Association for the Study of Pain, complied with the European Union regulation and were approved by ethics committees: the local committees C2EA-02 of Clermont-Ferrand (approvals CE110-12 and CE111-12).
Conflict-of-interest statement: All authors have nothing to disclose.
Data sharing statement: All sequencing raw data have been deposited in European Nucleotide Archive (ENA) under accession number PRJEB50651.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was 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:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Frederic Antonio Carvalho, PhD, Academic Research, Department of Pharmacology, INSERM 1107 NeuroDOL/University of Clermont Auvergne, 28 Place Henri Dunant, Clermont-Ferrand 63000, France. frederic.carvalho@inserm.fr
Received: March 15, 2022
Peer-review started: March 15, 2022
First decision: May 29, 2022
Revised: June 9, 2022
Accepted: July 5, 2022
Article in press: July 5, 2022
Published online: August 7, 2022
ARTICLE HIGHLIGHTS
Research background
Chronic abdominal pain associated to irritable bowel syndrome (IBS) is strongly related to stress and is the most common cause for gastroenterology consultation. Brain/gut/microbiota trialogue alterations are suspected to be involved in colonic hypersensitivity (CHS), responsible for chronic abdominal pain. It is also associated with abnormal intestinal permeability and intestinal dysbiosis, which can alter colon homeostasis leading to abnormal activation of the innate immunity that promotes CHS, perhaps involving the toll-like receptors (TLRs), which play a central role in innate immunity.
Research motivation
The breakdown of the relationship between TLRs and gut microbiota could contribute to the development of IBS. Thus, because of correlation between IBS and early life adverse events, our study investigated the impact of neonatal maternal separation (NMS) paradigm on intestinal homeostasis, fecal microbiota composition and CHS development in mice as well as the association with TLRs expression.
Research objectives
A better characterization of mechanisms associated with CHS is important for the establishment of new potential pharmacological targets.
Research methods
In our study, we used a referenced CHS animal model, the NMS paradigm, which mimics deleterious events in childhood that can induce a wide range of chronic disorders during adulthood. In addition, we have evaluated colonic sensitivity of NMS mice by colorectal distension (CRD) coupled with intracolonic pressure variation measurement. Fecal microbiota composition was analyzed by 16S rRNA sequencing from weaning to CRD periods. TLR mRNA expression was evaluated in colonocytes.
Research results
This study, based on the preclinical mouse model of NMS, demonstrated that around 50% of NMS mice exhibited increased intestinal permeability and CHS associated with intestinal dysbiosis. In particular, a significant increased amount of flagellated bacteria was observed in the NMS mice with CHS. In association, only tlr5 mRNA expression was increased in colonocytes of NMS mice with CHS.
Research conclusions
Taken together, our results suggest a pathophysiological continuum between intestinal dysbiosis and CHS, with a role for TLR5.
Research perspectives
TLR5 signaling upon recognition of flagellin is relevant in visceral pain through both direct and indirect mechanisms, and application of TLR5-specific antagonists could potentially reversed CHS in non-inflammatory visceral pain context.
