A253 RETINOIC ACID RECEPTOR ALPHA IS A NEGATIVE REGULATOR OF INTESTINAL EPITHELIAL TSLP GENE EXPRESSION
Bibliographic record
Abstract
We have recently described decreased myeloid cell numbers in the large and small intestines of intestinal-specific Retinoic Acid Receptor (RAR) alpha-deficient mice (Villin-Cre RAR-/-mice). We therefore hypothesized that Retinoic Acid (RA) and its receptors may regulate the expression of intestinal Thymic Stromal Lymphopoietin (TSLP), an important cytokine involved in Th2-type immunity known to play critical roles in the maintenance of peripheral CD4+T cell homeostasis via the modulation of activation/maturation of myeloid cells and decreased IL-12 production. Importantly, TSLP levels are decreased in Crohn’s disease (CD) where inflammation is driven by IL-12. Furthermore, there is epidemiologic data suggesting that the RAR agonist all-trans retinoic acid (ATRA, Accutane©) may be protective in CD. To determine whether retinoic Acid is a positive regulator of TSLP expression via activation of RAR alpha in Intestinal Epithelial Cells (IECs). We examined TSLP expression in the colons of Villin-Cre RAR-/-mice. Epithelial cells were isolated from the crypts and surface colonic epithelium and RNA isolated and analyzed via qRT-PCR. TSLP expression in the surface colonic epithelium was compared to that of wild-type littermates. In order to determine whether changes in TSLP expression were due to cell intrinsic effects, we sought to generate a RARalpha IEC knockout cell line. Using CRISPR/CAS9 we targeted exon 5 in the open reading frame of the RARalpha gene in Mode-K murine IECs. Targeted cells were selected in puromycin, cloned and CRISPR cleavage confirmed using Surveyor assays. Knockdown of RARalpha was assessed using RARluciferase assays. TSLP expression in surface colonic epithelium was elevated 2.3 fold in RARalpha villin-cre mice compared to wild type litter mates. In contrast, crypt TSLP expression was unchanged, as expected given absence of Cre expression in this compartment. We successfully generated partial RARalpha deficient Mode-K cells based on the results of Surveyor assays and RAR-luciferase activity assays. TSLP expression was elevated 2.3 fold in the Mode-K RARalpha CRISPR clones versus parent Mode-K cells. TSLP expression is controlled at least in part by RAR alpha in colonic IECs where it may act as a repressor of TSLP promoter transactivation. This suggests that retinoic acid, a dietary factor, may influence myeloid and T cell function via effects on epithelial TSLP expression and suggests a mechanism whereby Accutane©(ATRA) may affect CD. CCCCumming School of Medicine
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".