Filaggrin and tight junction proteins are crucial for IL-13-mediated esophageal barrier dysfunction

作者：Liping Wu, Tadayuki Oshima, Min Li, Toshihiko Tomita, Hirokazu Fukui, Jiro Watari, Hiroto Miwa · 发表于：American Journal of Physiology-Gastrointestinal and Liver Physiology · 年份：2018 · DOI：10.1152/ajpgi.00404.2017 · 被引用次数：67 · 研究领域：Eosinophilic Esophagitis、IL-33, ST2, and ILC Pathways、Food Allergy and Anaphylaxis Research

Eosinophilic esophagitis (EoE) is an allergy-mediated disease that is accompanied by IL-13 overexpression and an impaired esophageal barrier. Filaggrin (FLG) and tight junction (TJ) proteins are considered to contribute to epithelial barrier function. However, their functional involvement in EoE has not been elucidated. Here, we aimed to determine the IL-13-mediated barrier dysfunction and expression of TJ-related proteins in EoE and to characterize interactions among TJ-related proteins involved in the barrier function of the esophageal epithelium. Biopsy specimens from EoE patients were analyzed. Primary human esophageal epithelial cells (HEECs) were cultured using an air-liquid interface (ALI) system. The permeability of TJs was assayed by biotinylation. Transepithelial electrical resistance (TEER) was measured after stimulation with IL-13 and after siRNA silencing of FLG expression. FLG and TJ genes and proteins were assessed by quantitative RT-PCR, Western blot analysis, and immunofluorescent staining. The biotinylation reagent diffused through the paracellular spaces of whole stratified epithelial layers in EoE biopsy samples. The TEER decreased in ALI-cultured HEECs after IL-13 stimulation. Although the protein level of FLG decreased, that of the TJ proteins increased in the mucosa of EoE biopsy samples and in ALI-cultured HEECs after IL-13 stimulation. IL-13 altered the staining patterns of TJ proteins and the epithelial morphology. FLG siRNA transfection significantl...