Murray, M. G. | bioRxiv Science

bioRxiv2025

Interleukin-13-mediated alterations in esophageal epithelial mitochondria contribute to tissue remodeling in eosinophilic esophagitis

BackgroundThe significance of mitochondria in EoE pathobiology remains elusive. ObjectiveTo determine the impact of EoE inflammatory mediators upon mitochondrial biology in esophageal epithelium, the mechanisms mediating these effects, and their functional significance to EoE pathobiology. MethodsMitochondria were evaluated in human biopsies, MC903/Ovalbumin-induced murine EoE, and human esophageal keratinocytes. Esophageal keratinocytes were treated with EoE-relevant cytokines and JAK/STAT inhibitor ruxolitinib. To deplete mitochondria, 3D organoids generated from TFAMloxp/loxp mice were subjected ex vivo to Cre or siRNA against Transcription factor A, mitochondria (TFAM) was transfected into esophageal keratinocytes. Mitochondrial respiration, membrane potential, and superoxide levels were measured. ResultsWe find evidence of increased mitochondria in esophageal epithelium of patients with EoE and mice with EoE-like inflammation. In esophageal keratinocytes, IL-4 and IL-13 increase mitochondrial mass. IL-13 increases mitochondrial biogenesis in a JAK/STAT-dependent manner. In 3D organoids, IL-13 limits squamous cell differentiation (SCD), and this is blunted upon TFAM depletion. IL-13 decreases mitochondrial respiration and superoxide level, although mitochondria remain intact. IL-13-mediated suppression of superoxide was abrogated upon TFAM depletion in esophageal keratinocytes. ConclusionsWe report that increased mitochondrial mass is a feature of EoE. Among EoE-relevant cytokines, IL-13 is the primary driver of increased mitochondrial mass in esophageal keratinocytes by promoting mitochondrial biogenesis in a JAK/STAT-dependent manner. IL-13-mediated accumulation of mitochondria impairs SCD in esophageal keratinocytes and also suppresses oxidative stress, a factor that is known to induce SCD. These findings identify a novel mechanism through which IL-13 promotes EoE-associated epithelial remodeling. Clinical ImplicationThese findings further lay a foundation for exploration of level of esophageal epithelial mitochondria as a predictive biomarker for response to dupilumab. Capsule summaryIL-13 promotes mitochondrial biogenesis in esophageal epithelium, contributing to impaired squamous cell differentiation.

molecular biology↗

bioRxiv2021

Single cell transcriptomic analysis reveals cellular diversity of murine esophageal epithelium and age-associated mitochondrial dysfunction

Stratified squamous epithelium of the esophagus is comprised of basal keratinocytes that execute a terminal differentiation program in overlying suprabasal and superficial cell layers. Although morphologic progression coupled with expression of specific molecular markers has been characterized along the esophageal epithelial differentiation gradient, the molecular heterogeneity within the cell types along this trajectory has yet to be classified at the level of single cell resolution. To explore the molecular characteristics of esophageal keratinocytes along the squamous differentiation continuum, we performed single cell RNA-Sequencing transcriptomic profiling of 7,972 cells from murine esophageal epithelial sheets. We identified 8 distinct cell clusters in esophageal epithelium, unveiling an unexpected level of diversity, particularly among basal cells. We further mapped the cellular pathways and lineage trajectories within basal, suprabasal, and superficial clusters as well as within the heterogeneous basal cell populations, providing a comprehensive molecular view of esophageal epithelial cells in the context of squamous differentiation. Finally, we explored the impact of tissue aging upon esophageal epithelial cell clusters and demonstrated that mitochondrial dysfunction is a feature of aging in normal esophageal epithelium. These studies provide an unparalleled molecular perspective on murine esophageal keratinocytes that will serve as a valuable resource for dissecting cell type-specific roles in esophageal biology under conditions of homeostasis, aging, and tissue pathology.

molecular biology↗