Glucocorticoid Receptor Orchestrates Interactions Between Glucocorticoid ‐Responsive and ‐Unresponsive Enhancers to Modulate Gene Expression
Notice bibliographique
Résumé
RATIONALE Glucocorticoids (GCs) are stress hormones that act on the GC receptor (GR; NR3C1) to elicit effects, including repression of inflammatory gene expression. The mechanisms by which GR modulate gene expression are not completely understood. GR binds to thousands of genomic loci, but only regulates the expression of hundreds of genes. Genome‐wide chromatin interaction studies revealed that the proximal promotor of various GC‐regulated genes interacts with multiple distal enhancer elements that harbour GC‐dependent GR binding. The significance of such interactions and the contribution of each locus to the achieved gene expression are yet to be investigated. The current work provides a focused perspective on genomic events that lead to the induction of KLF9 by GCs, a gene expression feature that is highly conserved in multiple cell types. RESULTS GC‐mediated induction of KLF9 was confirmed in the airway epithelial cell lines (A549 and BEAS‐2B), as well as in primary culture of various airway structural cells. This induction was abolished in A549 cells either by pretreating cells with the GR antagonist, Org34517, or by knocking down GR with siRNA. Chromatin immunoprecipitation of GR following GC treatment in A549, BEAS‐2B, and primary human bronchial epithelial (HBE) cells showed GR binding to sites 5.9, 6.7, 25, and 65 kb upstream of the KLF9 gene. Global nascent transcript analysis of BEAS‐2B cells following GC treatment showed marked induction of enhancer RNA (eRNA) from each of these sites. This observation was validated using qPCR in A549 and primary HBE cells. GR binding regions were then cloned upstream to a luciferase reporter to test their enhancer activity due to GCs in isolation from their genomic context. There was a clear distinction between proximal regions (i.e. 5.9 and 6.7 kb from KLF9 promotor) and the distal regions (25 and 65 kb) in terms of basal activity and response to GCs. Proximal regions showed very strong basal reporter activity that was not affected by GC treatment. Distal regions, however, showed minimal basal activity but produced dose‐dependent increase in reporter activity by GCs, which was abolished by mutating the GC response elements (GRE) from these regions. Kinetics of long‐range genomic interactions identified a significant interaction between the distal and the proximal regions in a slightly delayed fashion (4h onward), this was temporally associated with enhanced binding of EP300 (histone acetylase associated with gene activation) to the proximal region. CONCLUSIONS Our data suggests that each GR binding site upstream to KLF9 responds differently to GCs, but all sites may collectively contribute to the basal transcriptional activity, induction, and maintenance of KLF9 expression. Co‐localization of other transcriptional regulators may explain the distinction between different sites. Our data are essential in establishing a model to explain GR genomic binding behaviours and how they correlate with gene expression outcomes, thus providing insights on how to modulate GC actions to achieve clinical benefits. Support or Funding Information Funding: Canadian Institutes of Health Research (CIHR) and Natural Sciences and Engineering Research Council of Canada (NSERC)
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».