Introduction

Disorders of gut-brain interaction (DGBIs), such as functional dyspepsia and irritable bowel syndrome, are chronic gastrointestinal disorders with recurrent and bothersome abdominal symptoms. Although incompletely understood, immune activation, particularly involving eosinophils and mast cells, and visceral hypersensitivity have been implicated in their pathophysiology.

Aims & Methods

Using the normoglycemic Biobreeding diabetes-prone (BBDP-N) rat, we aim to 1) characterise the immune activation in jejunal and colonic mucosa and to 2) study the effect of budesonide, a local anti-inflammatory corticosteroid, on gut physiology and sensitivity.
90-day-old BBDP-N and Biobreeding diabetes-resistant (control) rats underwent a 28-day treatment with budesonide (0.5 mg/kg/day) or vehicle. Eosinophils and mast cells were identified by staining jejunal and colonic sections with Chromotrope 2R and anti-mast cell protease 2 antibody, respectively. To assess their activity, eosinophil peroxidase (EPO) and β-hexosaminidase levels were measured. Jejunal and colonic segments were mounted in modified Ussing chambers, and permeability was assessed by the transmucosal passage of a fluorescently labelled 20 and 4kDa dextran molecule (FITC-Dx4/20), and the transepithelial electrical resistance (TEER). Sensitivity to isobaric colorectal distension was assessed(1): the ∆ area under the curve (AUC) of the visceromotor response (VMR) to wall tension was calculated at baseline and after treatment. Depending on the normality of the data, an unpaired t-test or Mann-Whitney test was performed.

Results

Comparing vehicle-treated groups, the BBDP-N rats had higher numbers of jejunal eosinophils (1366.0±201.3 vs. 561.7±55.3 eosinophils/mm²; p<0.01) and mast cells (1151.0±136.7 vs. 549.1±44.8 mast cells/mm²; p<0.001), whereas only colonic eosinophil numbers were higher (222.7±40.4 vs. 128.9±14.5 eosinophils/mm²; p=0.03). Additionally, EPO levels were higher in the BBDP-N rats in both regions (jejunum: 59.4±9.8 vs. 4.4±3.0 µg/g tissue; p<0.01 & colon: 82.0±23.6 vs. 1.6±1.1 µg/g tissue; p<0.01), with no difference in mast cell activation. Following budesonide treatment, eosinophil (jejunum, BBDP-N: 167.3±53.6 vs. 1366.0±201.3 eosinophils/mm²; p<0.001 & control: 220.1±43.7 vs. 561.7±55.3 eosinophils/mm²; p<0.01, colon: BBDP-N: 58.2±11.9 vs. 222.7±40.4 eosinophils/mm²; p<0.01 & control: 78.1±14.4 vs. 128.9±14.5 eosinophils/mm²; p=0.01) and mast cell (jejunum: BBDP-N: 418.8±51.0 vs. 1151.0±136.7 mast cells/mm²; p<0.001 & control: 305.4±67.6 vs. 549.1±44.8 mast cells/mm²; p=0.01, colon: BBDP-N: 146.5±19.1 vs. 262.6±37.5 mast cells/mm²; p<0.01 & control: 137.4±17.8 vs. 244.9±29.4 mast cells/mm²; p<0.01) levels decreased in both groups in both regions. Colonic eosinophil activation was also reduced in BBDP-N rats (21.5±9.7 vs. 82.0±23.6 µg/g tissue; p=0.05), with no effect on mast cell activation. Jejunal permeability, assessed by 20kDa passage was increased in vehicle-treated BBDP-N rats (258.0±51.5 vs. 132.0±25.1 pmol/cm²; p=0.03). Budesonide treatment significantly increased colonic TEER in BBDP-N rats (73.2±4.3 vs. 38.3±4.1 Ω.cm²; p<0.001). Colonic sensitivity to distention was significantly reduced in BBDP-N following the treatment (-20.1±17.2 vs. 207.0±85.5 mV/s x mmHg.cm; p=0.02).

Conclusion

In conclusion, our work shows the importance of eosinophil and mast cell predominant immune activation in visceral hypersensitivity in a well-characterised preclinical model of DGBI. Anti-inflammatory treatments should be re-evaluated in DGBI with intestinal eosinophil and mast cell infiltration.

References

1: Meleine M et al. Neurogastroenterology and motility, 2019.

Introduction

Emerging evidence suggests that poor oral health may play a role in gastrointestinal carcinogenesis through inflammatory and microbiome-mediated mechanisms. However, its association with esophageal cancer remains insufficiently explored.

Aims & Methods

We aimed to assess the association of oral health indicators and oral hygiene behaviors with esophageal cancer risk using both dental health screening and claims-based data. We conducted a population-based case-control study using the Korean National Health Insurance Service (NHIS) database and the National Health Screening (NHS) records. To enhance the reliability of our study, we examined oral hygiene from two complementary perspectives: (1) oral health assessed through dental examinations and questionnaires in the NHS database and (2) periodontal disease status determined based on a claim-based analysis of the NHIS database. Individuals newly diagnosed with esophageal cancer were identified and matched at a 1:4 ratio to cancer-free controls through rigorous propensity score (PS) matching based on sociodemographic factors, comorbidities, lifestyle behaviors, and laboratory parameters. Oral health variables were assessed using national dental screening program data (status of decayed, missing, and filled teeth; gingivitis severity; dental calculus; and self-reported oral hygiene practices) and NHIS claims data identifying periodontal disease using ICD-10 codes and procedure codes. Multivariable-adjusted conditional logistic regression analyses were performed to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

Results

After PS matching, the oral health analysis included 4,238 cancer cases and 16,904 controls, while the claim-based periodontal disease analysis comprised 18,905 cancer cases and 75,604 matched controls in the final analysis. In multivariable analysis, missing teeth (adjusted OR, 1.16; 95% CI, 1.08–1.25) and inadequate oral hygiene behaviors—including brushing fewer than three times daily (aOR, 1.14; 95% CI, 1.07–1.23), infrequent toothbrushing before bedtime (aOR, 1.08; 95% CI, 1.00–1.16), infrequent use interdental cleaning tools (aOR, 1.10; 95% CI, 1.01–1.19), and dental visits in the past year (aOR, 1.09; 95% CI, 1.02–1.16)—were significantly associated with an increased risk of esophageal cancer. Additionally, claim-based periodontal disease was independently associated with elevated risk (aOR, 1.05; 95% CI, 1.01–1.09). Subgroup analyses revealed consistent associations across smoking and obesity strata, while sex-, age-, and alcohol-stratified analyses demonstrated differential patterns.

Conclusion

This study provides comprehensive, population-based evidence that both clinically assessed dental health indicators and behavioral oral hygiene practices are associated with esophageal cancer risk. The integration of screening-based and claims-based data enhances the validity of the findings and highlights oral health as a potential modifiable risk factor for esophageal cancer prevention.

Introduction

Spasmolytic polypeptide expressing metaplasia (SPEM) is a cell repair lineage and is a very important phenotype of gastric mucosal injury and precancerous lesion.
Previously, parietal cells loss is considered as the first step and followed with chief cells transdiffernation to induce SPEM. But whether chief cells initial loss cause SPEM
needs to be further investigation. Acidic mammalian chitinase (CHIA) belongs to the 18 glycosidase family and is highly expressed in the chief cells. Our previous study showed that CHIA deficiency in the chief cells is the key event to induce SPME to progress to gastric cancer (Liu et al., DDW 2023 and 2024). However, the molecular role of CHIA in the development of SPEM is need further investigated.

Aims & Methods

Electron microscopy, qRT-PCR and single-cell sequencing (scRNA-seq) technology, as well as histopathological and immunofluorescence (IF) stainning with specific markers were performed in chief cells specific CHIA knockout mouse model (CHIA^rox/rox-GIF-Dre) and wild-type mice(CHIA^rox/rox), and in CHIA over - expression mice (CHIA ^rox/rox - GIF - Dre + rAAv - CHIA) and the control group (CHIA ^rox/rox - GIF - Dre + rAAv - control).

Results

Compared with CHIA^rox/rox mice, histological analysis and scRNA-seq technology data showed that loss of chief cells with increased M2 macrophage infiltration and final SPEM formation, but remaining of parietal cells in CHIA^rox/rox-GIF-Dre mice. Electron microscopy showed CHIA deficiency in mice resulted in endoplasmic reticulum was dilated and swollen, as well as the mitochondrial membrane was discontinuous of chief cells, followed with the accumulation of endoplasmic reticulum stress marker, including PERK, XBP-1, eIF2α/P-eIF2α, and GRP78, together with upregulation of pyroptosis-related marker, including NLRP3, ACS, GSDMD, NEK7, Caspase1, Caspase11, IL-1β, and IL-18, which was detected by qRT-PCR. These data indicating that target CHIA deletion caused chief cells pyroptosis. Furthermore, qRT-PCR analysis showed that CHIA deficiency caused the activation of IL33/IL-13 circuit in the mucosa of mice. Moreover, double immunofluorescence staining confirmed that upregulation and colocalization of IL-33 induced M2 macrophage polarization markers, including F4/80 and CD163⁺ with NLRP3 in the base of gastric mucosal of CHIA^rox/rox-GIF-Dre mice when compared with CHIA^rox/rox mice.Notably, CHIA ^rox/rox - GIF - Dre + rAvv - CHIA mice reversed the above process compared with controls.

Conclusion

Chief cells specific CHIA deficiency resulted in endoplasmic reticulum stress mediate NLRP3 inflammasome activation to induce chief cells proptosis.
Chief cells initial loss is sufficient and the key step to activate IL-33/ST2-M2 macrophage polarization axis to induce SPEM, which is independent of parietal cells loss.