Intestinal Epithelial AMPK Does Not Protect Against High Dose DSS‐Induced Colitis in Mice
Notice bibliographique
Résumé
AMP‐Activated Protein Kinase (AMPK) is a master regulator of cellular energy status whose activity requires α1 and α2 isoforms of the catalytic subunit. Recent evidence suggested AMPK protects against DSS‐induced colitis using villin‐Cre AMPKα1 knockout mice and nonspecific pharmacological activators. However, previous studies have not tested if both AMPKα isoforms are required for protection as α1/α2 double‐knockout is embryonic lethal in mice. Moreover, we previously showed AMPKα1 protein is increased in AMPKα2−/− mice, potentially confounding conclusions. Furthermore, the role of intestinal epithelial AMPK in inflammatory responses remains poorly understood. The goals of this study were to determine if AMPK is necessary for intestinal homeostasis and to confirm if intestinal epithelial AMPK is required for protection against colitis in a mouse model. Methods Intestinal epithelial‐specific deletion of both AMPK catalytic isoforms (AMPKα ΔIEC KO ) was generated by crossing villin‐Cre recombinase mice with Prkaa1 and Prkaa2 floxed mice (AMPKα fl/fl ). Barrier integrity and function were assessed histologically, by 40 kDa FITC‐dextran (FD4) intestinal permeability assay and by agonist stimulation of chloride secretion ex vivo in Ussing chambers. Colitis was induced with 5% dextran sulfate sodium (DSS) in drinking water for 5 days, followed by 3 days of water. Body weight, stool consistency and hemoccult were recorded daily to determine disease activity index scores. Intestinal permeability during colitis was determined by FD4 permeability. Mice were euthanized according to institutional IACUC protocols. Tissues were fixed in 4% paraformaldehyde for imaging or flash frozen for protein and RNA analysis. Results Unchallenged AMPKα ΔIEC KO mice showed no histologic changes in intestinal integrity, nor any significant change in intestinal permeability or agonist‐stimulated chloride secretion. Mice administered 5% DSS developed severe colitis indicated by dramatic weight loss and increased disease activity index score compared to untreated controls. Colitis induced similar levels of colonic shortening and increased intestinal permeability in both floxed and AMPKα ΔIEC KO mice, however AMPK‐regulated pro‐inflammatory gene expression was unchanged compared to untreated controls. Despite the lack of an overt phenotypic difference in AMPKα ΔIEC KO mice compared to AMPKα fl/fl mice, we did observe significant differences in protein expression. The tight junction protein claudin 2 was significantly decreased in proximal colon of AMPKα ΔIEC KO mice compared to AMPKα fl/fl mice without DSS challenge. Untreated and DSS‐treated AMPKα ΔIEC KO mice had decreased levels of the apoptosis markers cleaved caspase 3 in ileum, and PARP in proximal colon respectively, while cleaved caspase 3 was increased in distal colon compared to matched AMPKα fl/fl mice. Conclusion Loss of AMPK alone altered levels of claudin 2 and apoptotic markers in intestinal epithelial cells but did not alter DSS‐induced colitis severity. Support or Funding Information NIH 2R01DK091281 (DFM) This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
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) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 0,002 |
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 ».