A283 ROLE OF IMMUNOGLOBULIN E IN ABDOMINAL PAIN DUE TO INTERACTIONS BETWEEN DIET AND STRESS IN A MODEL OF IBS
Bibliographic record
Abstract
Abstract Background Food and stress are common triggers of symptoms in IBS patients. We previously showed in a murine model of IBS that exposure to a food antigen during a period of psychological stress leads to visceral hypersensitivity in both the ileum and colon upon re-exposure to the food antigen. This was inhibited by blocking mast cells and histamine receptors, suggesting that mast cell activation is involved in this increased pain signaling. However, it is unknown if immunoglobulin E (IgE) is involved in the activation of mast cells leading to visceral hypersensitivity. Purpose Determine the role of IgE in the increased pain signaling in ileum and colon of mice re-exposed to ovalbumin after an initial exposure to ovalbumin during chronic stress. Method Balb/c mice underwent water avoidance stress (WAS) for 10 days and were exposed to ovalbumin (OVA) from days 2-10. Five weeks later, mice were re-exposed to ovalbumin for two weeks (WAS/OVA+OVA mice). Mice were injected with anti-mouse IgE or isotype control antibody (1 mg/kg, i.p.) just prior and during ovalbumin re-exposure. Ex-vivo extracellular afferent recordings from nerves innervating the ileum were obtained to assess changes in mechanosensitivity. Ileum and colonic supernatants were also collected. Dorsal root ganglion neurons (DRG) from control mice (n = 12) were incubated with ileal and colonic supernatants. The excitability of these neurons was assessed by measuring the rheobase (minimum current required to evoke an action potential; lower rheobase=increased excitability) using perforated patch clamp. Data were analyzed by unpaired t-test or two-way ANOVA with Sidak’s post hoc test. Result(s) WAS/OVA+OVA mice treated with anti-IgE antibody had decreased mechanosensitivity of ileal nerves following lumen distention compared to WAS/OVA+OVA mice treated with isotype control antibody (7.7 ± 0.65 vs 12.9 ± 1.04 Hz, p = 0.034, n = 9 and 8 mice, respectively). Ileal supernatants from anti-IgE treated WAS/OVA+OVA mice evoked lower excitability (higher rheobase) in DRG neurons than neurons incubated with supernatants from isotype control treated WAS/OVA+OVA mice (rheobase: 89.2 ± 4.7 vs 71.9 ± 5.1 pA, p= 0.018). Colonic supernatants showed similar effects of the anti-IgE treatment (rheobase: 95.5 ± 4.4 vs 76.7 ± 5.4 pA, p = 0.01). Conclusion(s) IgE is involved in the increased pain signaling observed in both ileum and colon induced by antigen re-exposure following an initial stress-food antigen interaction. This suggests that IgE-mediated mast cell activation in response to food antigens may be a mechanism of meal-induced pain in IBS patients. Please acknowledge all funding agencies by checking the applicable boxes below Other Please indicate your source of funding; Department of Medicine, Translational Medicine Grant, Queen's University Disclosure of Interest None Declared
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".