Rationale: Eosinophilic esophagitis (EoE) is three times more common in males than females, and mechanism remains unknown. The effect of 17-beta estradiol (E2) in esophageal epithelial cell barrier function was examined, aiming to demonstrate E2 promotes cellular and molecular protective effects in EoE relevant assays.
Methods: Primary human esophageal keratinocyte cells (EPC2) grown in air-liquid interface (ALI) were exposed to IL-13 in the presence and absence of E2 (1-100nM). Transepithelial resistance (TER) was measured using Ussing chambers. Cellular signaling pathways and gene expression related to IL-13 and E2 signaling were analyzed. Expression of E2-related genes (RNAseq) in esophageal samples from male and female EoE patients and controls were examined.
Results: IL-13 stimulation of EPC2 cells decreased TER (Ω.cm2; 2021±516 vs 1258±334; Vehicle vs IL-13; mean±SD; n=10; p<0.001). Pretreatment of EPC2 cells with E2 (100nM) for 24 hours prior to IL-13 exposure abrogated IL-13-induced barrier dysfunction (TER 1291±190 vs 1597±363; Vehicle+IL-13 vs E2+IL-13; mean±SD; n=10; p<0.05). Mechanistically, Western blot analyses showed E2 pretreatment decreased STAT-6 phosphorylation after IL-13 exposure (-0.495 FC; n=3; p<0.05). RNAseq analyses demonstrated IL-13-induced SOCS1 mRNA expression (+6.91 FC, p<0.05) was decreased following E2 pretreatment (-1.96 FC; p<0.05). The E2 modified transcriptome was dysregulated in esophageal samples from EoE patients compared to controls (205/859 genes; 104permutations; FC>1.5; p<0.05).
Conclusions: E2 regulated genes are modified in EoE patients vs controls. E2 attenuates IL-13 induced epithelial barrier dysfunction in EPC2 cells via decreased pSTAT-6 and SOCS1. E2 has potential protective effects in EoE and may contribute to protection against EoE in females.