IL-22-Activated Impacts on Colonic Barrier Function through JAK1/STAT3, SNAI1/ZEB1 and ROCK2/MAPK Signaling.

Overexpression of the transmembrane mucin MUC13, as seen in inflammatory bowel diseases (IBD), could potentially impact barrier function. This study aimed to explore how inflammation-induced MUC13 disrupts epithelial barrier integrity by affecting junctional protein expression in IBD, thereby also considering the involvement of MUC1. RNA sequencing and permeability assays were performed using LS513 cells transfected with and siRNA and subsequently stimulated with IL-22.

Single-day and multi-day exposure to orogastric gavages does not affect intestinal barrier function in mice.

Animals involved in common laboratory procedures experience minor levels of stress. The direct effect of limited amounts of stress on gastrointestinal function has not been reported yet. Therefore, this study aimed to assess the effect of single-day and multi-day orogastric gavages on gut physiology in mice.

Volatile organic compound profiling as a potential biomarker in irritable bowel syndrome: A feasibility study.

Background: Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder for which no diagnostic tools are currently available. Patients are diagnosed using the Rome IV criteria and subtyped into a diarrhea, constipation, or mixed phenotype based on their dominant stool pattern. A recent development in the biomarker area is the analysis of volatile organic compounds (VOCs).

The Effect of Serine Protease Inhibitors on Visceral Pain in Different Rodent Models With an Intestinal Insult.

Serine proteases are believed to play a key role in the origin of abdominal pain in IBD and IBS. We previously demonstrated a reduction of visceral pain in a post-inflammatory IBS rat model after a single intraperitoneal or intracolonic administration of a serine protease inhibitor. The aim of this study was to investigate the efficacy of serine protease inhibition on visceral pain in two different animal models involving a colonic insult based either on acute inflammation or on neonatal irritation.

Local Colonic Administration of a Serine Protease Inhibitor Improves Post-Inflammatory Visceral Hypersensitivity in Rats.

Dysregulation of the protease-antiprotease balance in the gastrointestinal tract has been suggested as a mechanism underlying visceral hypersensitivity in conditions such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). We aimed to study the potential therapeutic role of an intracolonically administered serine protease inhibitor for the treatment of abdominal pain in a post-inflammatory rat model for IBS. An enema containing 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to induce colitis in male Sprague-Dawley rats, whereas controls received a saline solution.

Volatomics in inflammatory bowel disease and irritable bowel syndrome.

Volatile organic compounds (VOCs) are produced by the human metabolism, inflammation and gut microbiota and form the basis of innovative volatomics research. VOCs detected through breath and faecal analysis hence serve as attractive, non-invasive biomarkers for diagnosing and monitoring irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). This review describes the clinical applicability of volatomics in discriminating between IBS, IBD and healthy volunteers with acceptable accuracy in breath (70%-100%) and faecal (58%-85%) samples.

In-Depth Study of Transmembrane Mucins in Association with Intestinal Barrier Dysfunction During the Course of T Cell Transfer and DSS-Induced Colitis.

Background And Aims: There is evidence for a disturbed intestinal barrier function in inflammatory bowel diseases [IBD] but the underlying mechanisms are unclear. Because mucins represent the major components of the mucus barrier and disturbed mucin expression is reported in the colon of IBD patients, we studied the association between mucin expression, inflammation and intestinal permeability in experimental colitis.

Methods: We quantified 4-kDa FITC-dextran intestinal permeability and the expression of cytokines, mucins, junctional and polarity proteins at dedicated time points in the adoptive T cell transfer and dextran sodium sulfate [DSS]-induced colitis models.

Colonoscopy in patients with liver cirrhosis : success and safety issues.

Background: Patients with liver cirrhosis undergo screening colonoscopy before liver transplantation. Screening colonoscopy is subject to specific quality criteria, among which caecal intubation rate. Several factors associated with failed caecal intubation have been identified.

[Chronic constipation and rectal functional investigations].

Chronic constipation is caused by disordered colonic motility, impaired rectal evacuation (dyschezia) or a combination of the two. It is important to distinguish the predominant mechanism of constipation in order to choose the optimal therapy (laxatives or prokinetics versus pelvic floor retraining or surgery). The contribution of dyschezia to constipation can usually be identified by a digital rectal examination, but should, in our opinion, be confirmed by anal manometry, transrectal ultrasonography or defecography.

Role of TRPV1 and TRPA1 in visceral hypersensitivity to colorectal distension during experimental colitis in rats.

The aim of the present study is to investigate the effects of TRPV1 and TRPA1 receptor antagonists and their synergism on the visceromotor responses during experimental colitis in rats. Colitis was induced in rats by a TNBS/ethanol enema at day 0 and was assessed at day 3 using endoscopy, histology and a myeloperoxidase assay. The visceromotor response to colorectal distension (10-80 mmHg) was evaluated in conscious rats before (control condition) and 3 days after 2,4,6-trinitrobenzene sulfonic acid (TNBS) administration (colitis condition).

Involvement of afferent neurons in the pathogenesis of endotoxin-induced ileus in mice: role of CGRP and TRPV1 receptors.

Activation of neuronal reflex pathways by inflammatory mediators is postulated as an important pathogenic mechanism in postoperative ileus. In this study, we investigated the involvement of afferent neurons and more specifically the role of the transient receptor potential vanilloid receptor type 1 (TRPV1) and calcitonin gene-related peptide (CGRP) in endotoxin-induced motility disturbances in mice. Mice were injected with either lipopolysaccharides (LPS) or saline (control) and pre-treated with hexamethonium (blocker of neuronal transmission), capsaicin (neurotoxin), CGRP 8-37 (CGRP antagonist) or BCTC (TRPV1 receptor antagonist).

The role of tachykinins in circular muscle contractility of the murine ileum: a functional investigation.

We investigated the participation of different tachykinin receptors in contractility of circular muscle strips of the mouse ileum using selective NK receptor agonists and antagonists. The NK1 receptor agonist septide (1-100 nM) induced dose-dependent contractions which were reduced by atropine and augmented by L-NNA. L-NNA increased and TTX consecutively reduced contractions to the NK2 receptor agonist beta-A-NKA (1-100 nM).

Functional characterisation of tachykinin receptors in the circular muscle layer of the mouse ileum.

Objectives: Tachykinins are important mediators in neuromuscular signalling but have not been thoroughly characterised in the mouse gut. We investigated the participation of tachykinin receptors in contractility of circular muscle strips of the mouse ileum.

Results: Electrical field stimulation (EFS) of excitatory nonadrenergic noncholinergic (NANC) nerves induced frequency-dependent contractions which were mimicked by substance P (SP).

Functional evidence that ATP or a related purine is an inhibitory NANC neurotransmitter in the mouse jejunum: study on the identity of P2X and P2Y purinoceptors involved.

1. Conflicting views exist on whether ATP is a neurotransmitter in the enteric nervous system. We investigated the role of ATP in enteric transmission in circular muscle strips of the mouse jejunum.