title: NF-κB is activated in oesophageal fibroblasts in response to a paracrine signal generated by acid-exposed primary oesophageal squamous cells.
abstract: Oesophageal exposure to duodenogastro-oesophageal refluxate leads to reflux oesophagitis and is implicated in the development of Barrett's metaplasia (BM). NF-κB signalling in epithelial cells is associated with the activation of transcription factors believed to be central to BM development, whilst NF-κB activation in fibroblasts plays a critical role in matrix remodelling. Our aim was to study the effects of acid exposure on NF-κB activation in primary human oesophageal fibroblasts (HOFs) and primary and immortalized oesophageal squames and to investigate any epithelial/stromal interactions in the response of these cells to acid. Primary HOFs and primary and immortalized oesophageal epithelial cells were exposed to acid (pH 7 - pH 4 ≤ 120 min) in single or pulsed treatments. Conditioned medium from epithelial cells following acid exposure was also applied to fibroblasts. Cell viability was determined by MTT-ESTA. NF-κB activation was determined by cellular localization of NF-κB/p65 visualized by immunofluorescence. Conditioned medium from oesophageal epithelial cells, subjected to pH 5 pulsatile exposure, activated NF-κB in fibroblasts, with some inter-patient variability, but these conditions did not directly activate NF-κB in the epithelial cells themselves. Significant NF-κB activation was seen in the epithelial cells but only with greater acidity and exposure times (pH 4, 60-120 min). Our findings show that acid exposure can cause indirect activation of stromal cells by epithelial-stromal interactions. This may contribute to the pathogenesis of oesophageal diseases, and the inter-patient variability may go some way to explain why some patients with reflux oesophagitis develop BM and others do not.
authors.affiliation: Kroto Research Institute, North Campus, University of Sheffield, Sheffield, UK. n.h.green@sheffield.ac.uk
authors.forename: Nicola H
authors.initials: NH
authors.lastname: Green
authors.forename: Qizhi
authors.initials: Q
authors.lastname: Huang
authors.forename: Bernard M
authors.initials: BM
authors.lastname: Corfe
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Bury
authors.forename: Sheila
authors.initials: S
authors.lastname: MacNeil
mesh_terms: D000143:Acids / Q000494:pharmacology*; D002450:Cell Communication / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects; D004947:Esophagus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016328:NF-kappa B / Q000378:metabolism*; D019899:Paracrine Communication / Q000187:drug effects* / Q000502:physiology*; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects
chemical_list: D000143:Acids; D017077:Culture Media, Conditioned; D016328:NF-kappa B