Partridge, E. | bioRxiv Science

bioRxiv2026

Prostaglandin E2 Reverses Myofibroblast Differentiation in Eosinophilic Esophagitis

Background & AimsUnchecked inflammation in Eosinophilic esophagitis (EoE) leads to esophageal fibrosis and eventual stricture. Differentiated fibroblasts, termed myofibroblasts, are the main effector cells in fibrosis, responsible for secreting extracellular matrix proteins leading to tissue stiffness. Regulating myofibroblasts has not been explored as a therapeutic possibility in the fibrostenotic esophagus. Herein, we aim to investigate the efficacy of Prostaglandin E2 (PGE2) in dedifferentiation of the EoE myofibroblast. MethodsWe evaluated the efficacy and mechanism of myofibroblast dedifferentiation using fetal esophageal fibroblasts (FEF3), patient-derived fibroblasts, and a murine model of EoE. ResultsFibrosis markers (SMA, FN1, and COL1A1) and contractility of myofibroblasts were significantly decreased by PGE2 via the cAMP pathway. PGE2 treatment decreased nuclear accumulation of phospho-Smad2/3-YAP complex and induced phospho-YAP proteasomal degradation. Transcriptome analyses of FEF3 treated with TGF{beta} or PGE2 revealed that the Integrin1 pathway, and specifically thrombospondin 1 (THBS-1), was significantly upregulated by TGF{beta} and downregulated by PGE2, as supported by pseudo-bulk single-cell RNA-seq of EoE biopsies. THBS-1 was shown to be regulated by PGE2 via the cAMP/YAP pathway, and its knockdown induced myofibroblasts dedifferentiation. In a murine model of EoE, Butaprost, agonist of the E-prostanoid G protein-coupled receptor 2, treatment significantly reduced the expression of THBS-1, SMA, and FN1 along with a decrease in YAP nuclear translocation. Additionally, collagen fiber organization in the lamina propria was markedly reduced. ConclusionPGE2 promotes dedifferentiation of myofibroblasts in EoE via the cAMP/YAP/ THBS-1 pathway. Our data suggest that PGE2 is a promising treatment strategy for EoE with stenosis. What You Need to KnowO_ST_ABSBackground and ContextC_ST_ABSIn Eosinophilic esophagitis, unchecked inflammation and tissue stiffness drives fibroblast differentiation and fibrostenosis of the esophagus, yet targeting myofibroblasts as regulators of extracellular matrix deposition in fibrostenotic disease remains clinically unexplored. New FindingsProstaglandin E2 promotes dedifferentiation of myofibroblasts in eosinophilic esophagitis via the cAMP/YAP pathway, with Thrombospondin-1 identified as a critical YAP regulated target driving fibrostenosis. LimitationsThis study focused on fibroblast-specific mechanisms. The effects of PGE2 on esophageal epithelial differentiation, barrier function, and immune cell recruitment in EoE remain to be determined. Clinical Research RelevanceThis study demonstrates proof-of-concept that pharmacological reversal of established fibrosis is achievable in EoE. PGE2 and its EP2-selective agonists represent translatable therapeutic targets for fibrostenotic EoE--a patient population that remains treatment-refractory to current immunosuppressive approaches. Basic Research RelevanceThe cAMP/YAP/THBS-1 signaling in fibroblasts emerges as a critical therapeutic target for esophageal fibrosis. Importantly, this work demonstrates that terminally differentiated myofibroblasts retain remarkable plasticity and can dedifferentiate--challenging the paradigm that fibrosis is irreversible.

cell biology↗

bioRxiv2026

Profibrotic Changes Following Tension Application in a Fetal Lamb Model of Long Gap Esophageal Atresia

IntroductionEsophageal atresia is a common congenital anomaly, occurring in 1 in 3,500 live births. The Foker process has revolutionized the treatment of long gap esophageal atresia (LGEA). It is well established that the Foker process causes tension accelerated growth of the esophagus, but what occurs at the molecular level during tension accelerated growth is still unknown. We aimed to create tension accelerated growth in a fetal lamb model of LGEA in order to answer this question. MethodsFollowing IACUC approval, time-dated fetal lambs (108 to 120 days of gestation) underwent thoracic esophagectomy. Both esophageal ends were ligated and sutured together to create an internal pexy under high tension. Lambs were delivered on postoperative day 2 (POD2) (n=7), POD6 (n=9) or term (n=5). The native esophagus collected at model creation served as control tissue. Specimens were bluntly separated into two layers: inner layer (IL) (epithelium, lamina propria, muscularis mucosa, submucosa) and outer layer (OL) (submucosa, muscle layer, adventitia). RNA sequencing (RNAseq), proteomics, immunohistochemistry, western blotting and real-time qRT-PCR were performed on the specimens. Mann-Whitneys or unpaired t-test were used for statistical analyses. Esophageal fibroblast cell lines established from human biopsy specimens were cultured and stimulated with TGF-beta for in vitro studies on collagen expression. Results23 lambs underwent esophagectomy with tension suture placement at 108 to 120 days gestation. Histologic analysis of tension conditioned compared to control esophagus by trichrome staining demonstrated an increase in collagen deposition in tension conditioned esophagus compared to controls. High throughput bulk RNA sequencing and proteomic analysis were performed with a focus on pathways implicated in fibrosis. GSEA analysis of the inner layer demonstrates upregulation of TGFB signaling, extracellular matrix organization, and collagen deposition at all timepoints. Further analysis was performed to evaluate specific collagen subtypes contributing to this profibrotic phenotype, and COL8A1 and COL12A1 were both significantly upregulated in both RNA and proteomic analysis at all timepoints, with Western blotting confirming up regulation in stretched tissue. In order to evaluate the relationship between TGFB signaling and collagen deposition in the esophagus, we stimulated esophageal fibroblasts with TGFB, qRT-PCR was performed to evaluate the expression of COL8A1, COL12A1, and COL6A3. Expression of all three of these collagen subtypes was noted to be significantly upregulated at all timepoints following TGFB stimulation when compared to non-stimulated controls. ConclusionsTension accelerated growth can safely be achieved in a fetal ovine model of long gap esophageal atresia. Additionally, esophageal atresia can be modeled in the ovine fetus as early as 92 days gestation. Our results demonstrate that esophageal tissue subjected to sustained tension undergoes significant profibrotic changes, as evidenced by upregulation of TGFB signaling, alterations in extracellular matrix organization, and increased collagen deposition. While it is well documented that patients with LGEA have an increased risk of post operative esophageal strictures, these findings provide the first in vivo proof of the role of tension in conferring a profibrotic phenotype in the tension-lengthened esophagus.

developmental biology↗