Amniotic fluid modifies esophageal epithelium differentiation and inflammatory responses

The interplay between genetic and environmental factors during pregnancy can predispose to inflammatory diseases postnatally, including eosinophilic esophagitis (EoE), a chronic allergic disease triggered by food. Herein, we examined the effects of amniotic fluid (AF) on esophageal epithelial differentiation and responsiveness to proallergic stimuli. Multiplex analysis of AF revealed the expression of 66 cytokines, whereas five cytokines including IL-4 and thymic stromal lymphopoietin (TSLP) were not detected. Several proinflammatory cytokines including TNFα and IL-12 were highly expressed in the AF from women who underwent preterm birth, whereas EGF was the highest in term birth samples. Exposure of esophageal epithelial cells to AF resulted in transient phosphorylation of ERK1/2 and the transcription of early response genes, highlighting the direct impact of AF on esophageal epithelial cells. In a three-dimensional spheroid model, AF modified the esophageal epithelial differentiation program and enhanced the transcription of IL-13-target genes, including CCL26 and CAPN14, which encodes for a major genetic susceptibility locus for eosinophilic esophagitis. Notably, CAPN14 exhibited upregulation in spheroids exposed to preterm but not term AF following differentiation. Collectively, our findings call attention to the role of AF as a potential mediator of the intrauterine environment that influences subsequent esophageal disorders. 3D esophageal epithelial spheroids were grown from EPC2 cells in Matrigel for 11 days. Spheroids were left untreated or were treated with IL-13 starting from D3. Toatl RNA was extracted from EPC2 cells at D0 (monolayer), D3, and D11 of the differentiation protocol. Spheroids from 2 independent experiments were collected and sequenced.