Article Text

other Versions

PDF
Original article
Autophagy mediates epithelial cytoprotection in eosinophilic oesophagitis
  1. Kelly A Whelan1,2,
  2. Jamie F Merves3,4,
  3. Veronique Giroux1,2,
  4. Koji Tanaka1,2,
  5. Andy Guo1,2,
  6. Prasanna M Chandramouleeswaran1,2,
  7. Alain J Benitez5,
  8. Kara Dods3,
  9. Jianwen Que6,
  10. Joanne C Masterson7,
  11. Shahan D Fernando7,
  12. Bridget C Godwin3,4,
  13. Andres J Klein-Szanto8,
  14. Kudakwashe Chikwava4,9,
  15. Eduardo D Ruchelli4,9,
  16. Kathryn E Hamilton1,2,
  17. Amanda B Muir3,4,
  18. Mei-Lun Wang3,4,
  19. Glenn T Furuta7,
  20. Gary W Falk1,
  21. Jonathan M Spergel4,5,
  22. Hiroshi Nakagawa1,2
  1. 1Gastroenterology Division, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
  2. 2Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA
  3. 3Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
  4. 4Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
  5. 5Division of Allergy and Immunology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
  6. 6Center for Human Development and Division of Digestive and Liver Diseases, Department of Medicine, Columbia University Medical Center, New York, New York, USA
  7. 7Section of Pediatric Gastroenterology, Hepatology and Nutrition, Digestive Health Institute, University of Colorado Denver School of Medicine, Aurora, Colorado, USA
  8. 8Histopathology Facility and Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
  9. 9Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
  1. Correspondence to Dr Hiroshi Nakagawa, Gastroenterology Division, University of Pennsylvania, 421 Curie Blvd., 956 BRB, Philadelphia, PA 19104-4863, USA; nakagawh{at}mail.med.upenn.edu

Abstract

Objective The influence of eosinophilic oesophagitis (EoE)-associated inflammation upon oesophageal epithelial biology remains poorly understood. We investigated the functional role of autophagy in oesophageal epithelial cells (keratinocytes) exposed to the inflammatory EoE milieu.

Design Functional consequences of genetic or pharmacological autophagy inhibition were assessed in endoscopic oesophageal biopsies, human oesophageal keratinocytes, single cell-derived ex vivo murine oesophageal organoids as well as a murine model recapitulating EoE-like inflammation and basal cell hyperplasia. Gene expression, morphological and functional characterisation of autophagy and oxidative stress were performed by transmission electron microscopy, immunostaining, immunoblotting, live cell imaging and flow cytometry.

Results EoE-relevant inflammatory conditions promoted autophagy and basal cell hyperplasia in three independent murine EoE models and oesophageal organoids. Inhibition of autophagic flux via chloroquine treatment augmented basal cell hyperplasia in these model systems. Oesophageal keratinocytes stimulated with EoE-relevant cytokines, including tumour necrosis factor-α and interleukin-13 exhibited activation of autophagic flux in a reactive oxygen species-dependent manner. Autophagy inhibition via chloroquine treatment or depletion of Beclin-1 or ATG-7, augmented oxidative stress induced by EoE-relevant stimuli in murine EoE, oesophageal organoids and human oesophageal keratinocytes. Oesophageal epithelia of paediatric EoE patients with active inflammation displayed increased autophagic vesicle content compared with normal and EoE remission subjects. Functional flow cytometric analysis revealed autophagic flux in human oesophageal biopsies.

Conclusions Our findings reveal for the first time that autophagy may function as a cytoprotective mechanism to maintain epithelial redox balance and homeostasis under EoE inflammation-associated stress, providing mechanistic insights into the role of autophagy in EoE pathogenesis.

  • OESOPHAGITIS
  • CELL BIOLOGY
  • EPITHELIAL CELLS
  • INFLAMMATION

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.