A Human Barrett's Esophagus Organoid System Reveals Epithelial-Mesenchymal Plasticity Induced by Acid and Bile Salts.

Overview

abstract

The pathogenesis of subsquamous intestinal metaplasia (SSIM), in which glands of Barrett's esophagus (BE) are buried under esophageal squamous epithelium, is unknown. In a rat model of reflux esophagitis, we found that columnar-lined esophagus developed via a wound healing process involving epithelial-mesenchymal plasticity (EMP) that buried glands under ulcerated squamous epithelium. To explore a role for reflux-induced EMP in BE, we established and characterized human Barrett's organoids, and sought evidence of EMP after treatment with acidic bile salts (A&B). We optimized media to grow human BE organoids from immortalized human Barrett's cells and from BE biopsies from 7 patients, and we characterized histologic, morphologic, and molecular features of organoid development. Features and markers of EMP were explored following organoid exposure to A&B, with and without a collagen I (COL1) matrix to simulate a wound healing environment. All media successfully initiated organoid growth, but advanced DMEM/F12 (aDMEM) was best at sustaining organoid viability. Using aDMEM, organoids comprising non-goblet and goblet columnar cells that expressed gastric and intestinal cell markers were generated from BE biopsies of all 7 patients. Following A&B treatment, early-stage Barrett's organoids exhibited EMP with loss of membranous E-cadherin and increased protrusive cell migration, events significantly enhanced by COL1. Using human BE biopsies, we have established Barrett's organoids that recapitulate key histologic and molecular features of BE to serve as high-fidelity BE models. Our findings suggest that reflux can induce EMP in human BE, potentially enabling Barrett's cells to migrate under adjacent squamous epithelium to form SSIM.