Effects of proton pump inhibitors on remodeling and fibrosis in eosinophilic esophagitis.

BACKGROUND

Eosinophilic esophagitis (EoE) is a progressive fibrostenotic disease. Although proton pump inhibitors (PPIs) are a first-line EoE treatment due to their anti-inflammatory effects, their effects on remodeling/fibrosis-likely driven in part by TGF-β-remain uncertain.

OBJECTIVES

To elucidate remodeling/fibrosis effects, this study evaluated whether PPIs impact the esophageal transcriptome of PPI-responsive EoE and counteract TGF-β‒induced fibrotic responses in human primary esophageal fibroblasts (HEFs).

METHODS

Prospectively collected paired esophageal biopsies from patients with EoE pre‒/post‒PPI treatment were analyzed by RNA sequencing (RNA-seq). Histologic responsiveness to PPIs was defined as responders (<15 eosinophils/high-power field, n = 10) or nonresponders (≥15 eosinophils/high-power field, n = 9). The ability of PPIs (esomeprazole, omeprazole) to attenuate in vitro, TGF-β‒mediated remodeling/fibrosis in HEFs was analyzed by quantitative PCR, RNA-seq, Western blotting, immunofluorescence, cell migration assays, and reactive oxygen species measurements.

RESULTS

In PPI responders, we identified 746 differentially expressed genes pre‒/post‒PPI treatment (≥2-fold change, P < .05), particularly those enriched in remodeling/fibrosis. In HEFs, TGF-β increased collagen I and α-smooth muscle actin expression via SMAD2/3 phosphorylation; however, PPIs attenuated these responses. RNA-seq revealed that PPIs reversed approximately 30% of TGF-β‒induced changes overlapping with fibrotic responses; 78 genes were concordantly modulated between patient biopsies and HEFs. Functional assays further confirmed that PPIs reduced TGF-β-induced collagen deposition, fibroblast motility, and reactive oxygen species production.

CONCLUSIONS

PPIs modulate remodeling-/fibrosis-related gene expression in patients with EoE and inhibit TGF-β‒induced profibrotic responses in HEFs, supporting antifibrotic potential that may help limit fibrostenotic progression in EoE.