Pulsatile exposure to simulated reflux leads to changes in gene expression in a 3D model of oesophageal mucosa

Int J Exp Pathol. 2014 Jun;95(3):216-28. doi: 10.1111/iep.12083. Epub 2014 Apr 8.

Abstract

Oesophageal exposure to duodenogastroesophageal refluxate is implicated in the development of Barrett's metaplasia (BM), with increased risk of progression to oesophageal adenocarcinoma. The literature proposes that reflux exposure activates NF-κB, driving the aberrant expression of intestine-specific caudal-related homeobox (CDX) genes. However, early events in the pathogenesis of BM from normal epithelium are poorly understood. To investigate this, our study subjected a 3D model of the normal human oesophageal mucosa to repeated, pulsatile exposure to specific bile components and examined changes in gene expression. Initial 2D experiments with a range of bile salts observed that taurochenodeoxycholate (TCDC) impacted upon NF-κB activation without causing cell death. Informed by this, the 3D oesophageal model was repeatedly exposed to TCDC in the presence and absence of acid, and the epithelial cells underwent gene expression profiling. We identified ~300 differentially expressed genes following each treatment, with a large and significant overlap between treatments. Enrichment analysis (Broad GSEA, DAVID and Metacore™; GeneGo Inc) identified multiple gene sets related to cell signalling, inflammation, proliferation, differentiation and cell adhesion. Specifically NF-κB activation, Wnt signalling, cell adhesion and targets for the transcription factors PTF1A and HNF4α were highlighted. Our data suggest that HNF4α isoform switching may be an early event in Barrett's pathogenesis. CDX1/2 targets were, however, not enriched, suggesting that although CDX1/2 activation reportedly plays a role in BM development, it may not be an initial event. Our findings highlight new areas for investigation in the earliest stages of BM pathogenesis of oesophageal diseases and new potential therapeutic targets.

Keywords: Barrett's metaplasia; HNF4alpha; acid; oesophageal adenocarcinoma; reflux; taurochenodeoxycholate; tissue engineering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology*
  • Barrett Esophagus / metabolism
  • Barrett Esophagus / pathology*
  • Bile Acids and Salts / metabolism
  • Bile Acids and Salts / pharmacology*
  • Bile Reflux / complications
  • Cell Line
  • Cells, Cultured
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Esophageal Neoplasms / metabolism
  • Esophageal Neoplasms / pathology*
  • Esophagus / metabolism
  • Esophagus / pathology
  • Gastroesophageal Reflux / metabolism
  • Gastroesophageal Reflux / pathology
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic / drug effects*
  • Hepatocyte Nuclear Factor 4 / genetics*
  • Hepatocyte Nuclear Factor 4 / metabolism
  • Humans
  • Hydrogen-Ion Concentration
  • Mucous Membrane / metabolism
  • Mucous Membrane / pathology
  • NF-kappa B / genetics
  • NF-kappa B / metabolism*
  • Oligonucleotide Array Sequence Analysis
  • Protein Isoforms
  • Taurochenodeoxycholic Acid / pharmacology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Bile Acids and Salts
  • HNF4A protein, human
  • Hepatocyte Nuclear Factor 4
  • NF-kappa B
  • Protein Isoforms
  • Transcription Factors
  • Taurochenodeoxycholic Acid

Supplementary concepts

  • Adenocarcinoma Of Esophagus

Associated data

  • GEO/GSE45380