Pulsatile exposure to simulated reflux leads to changes in gene expression in a 3D model of oesophageal mucosa.
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.
Kroto Research Institute, North Campus, University of Sheffield, Sheffield, UK.
Nicola H
NH
Green
Zoe
Z
Nicholls
Paul R
PR
Heath
Jonathan
J
Cooper-Knock
Bernard M
BM
Corfe
Sheila
S
MacNeil
Jonathan P
JP
Bury
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D001471:Barrett Esophagus / Q000378:metabolism / Q000473:pathology*; D001647:Bile Acids and Salts / Q000378:metabolism / Q000494:pharmacology*; D001655:Bile Reflux / Q000150:complications; D002460:Cell Line; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000378:metabolism / Q000473:pathology*; D004947:Esophagus / Q000378:metabolism / Q000473:pathology; D005764:Gastroesophageal Reflux / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D051557:Hepatocyte Nuclear Factor 4 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009092:Mucous Membrane / Q000378:metabolism / Q000473:pathology; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D020033:Protein Isoforms; D013655:Taurochenodeoxycholic Acid / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D001647:Bile Acids and Salts; C496592:HNF4A protein, human; D051557:Hepatocyte Nuclear Factor 4; D016328:NF-kappa B; D020033:Protein Isoforms; D014157:Transcription Factors; D013655:Taurochenodeoxycholic Acid
Barrett's metaplasia; HNF4alpha; acid; oesophageal adenocarcinoma; reflux; taurochenodeoxycholate; tissue engineering