title: Eosinophilic esophagitis: epithelial mesenchymal transition contributes to esophageal remodeling and reverses with treatment.
abstract: BACKGROUND
  Mechanisms underlying esophageal remodeling with subepithelial fibrosis in subjects with eosinophilic esophagitis (EoE) have not been delineated.
  
  
  OBJECTIVE
  We sought to explore a role for epithelial mesenchymal transition (EMT) in subjects with EoE and determine whether EMT resolves with treatment.
  
  
  METHODS
  Esophageal biopsy specimens from 60 children were immunostained for epithelial (cytokeratin) and mesenchymal (vimentin) EMT biomarkers, and EMT was quantified. Subjects studied had EoE (n = 17), indeterminate EoE (n = 15), gastroesophageal reflux disease (n = 7), or normal esophagus (n = 21). EMT was analyzed for relationships to diagnosis, eosinophil counts, and indices of subepithelial fibrosis, eosinophil peroxidase, and TGF-β immunostaining. EMT was assessed in pretreatment and posttreatment biopsy specimens from 18 subjects with EoE treated with an elemental diet, 6-food elimination diet, or topical corticosteroids (n = 6 per group).
  
  
  RESULTS
  TGF-β1 treatment of esophageal epithelial cells in vitro for 24 hours induced upregulation of mesenchymal genes characteristic of EMT, including N-cadherin (3.3-fold), vimentin (2.1-fold), and fibronectin (7.5-fold). EMT in esophageal biopsy specimens was associated with EoE (or indeterminate EoE) but not gastroesophageal reflux disease or normal esophagus and was correlated to eosinophil counts (r = 0.691), eosinophil peroxidase (r = 0.738), and TGF-β (r = 0.520) immunostaining and fibrosis (r = 0.644) indices. EMT resolved with EoE treatments that induced clinicopathologic remission with reduced eosinophil counts. EMT decreased significantly after treatment by 74.1% overall in the 18 treated subjects with EoE; pretreatment versus posttreatment EMT scores were 3.17 ± 0.82 versus 0.82 ± 0.39 (P < .001), with similar decreases within treatment groups. Pretreatment/posttreatment EMT was strongly correlated with eosinophil counts for combined (r = 0.804, P < .001) and individual treatment groups.
  
  
  CONCLUSIONS
  EMT likely contributes to subepithelial fibrosis in subjects with EoE and resolves with treatments that decrease esophageal inflammation, and its resolution correlates with decreased numbers of esophageal eosinophils.
authors.affiliation: Department of Pediatrics, Children's Memorial Hospital and Northwestern University, Chicago, IL, USA.
authors.forename: Amir F
authors.initials: AF
authors.lastname: Kagalwalla
authors.forename: Noorain
authors.initials: N
authors.lastname: Akhtar
authors.forename: Samantha A
authors.initials: SA
authors.lastname: Woodruff
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Rea
authors.forename: Joanne C
authors.initials: JC
authors.lastname: Masterson
authors.forename: Vincent
authors.initials: V
authors.lastname: Mukkada
authors.forename: Kalyan R
authors.initials: KR
authors.lastname: Parashette
authors.forename: Jian
authors.initials: J
authors.lastname: Du
authors.forename: Sophie
authors.initials: S
authors.lastname: Fillon
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Protheroe
authors.forename: James J
authors.initials: JJ
authors.lastname: Lee
authors.forename: Katie
authors.initials: K
authors.lastname: Amsden
authors.forename: Hector
authors.initials: H
authors.lastname: Melin-Aldana
authors.forename: Kelley E
authors.initials: KE
authors.lastname: Capocelli
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Furuta
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Ackerman
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004035:Diet Therapy; D018450:Disease Progression; D057765:Eosinophilic Esophagitis / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D004804:Eosinophils / Q000378:metabolism* / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects; D004947:Esophagus / Q000187:drug effects / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007633:Keratins / Q000378:metabolism; D008297:Male; D012074:Remission Induction; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
chemical_list: D000305:Adrenal Cortex Hormones; D016212:Transforming Growth Factor beta; D014746:Vimentin; D007633:Keratins