Paris Sheré, Zhang Xi, Davis Daniel, Nguyen Anh D, Ustaoglu Ahsen, Genta Robert M, Wang Xuan, Kale Ishani, Ekeanyanwu Rebecca, Leeds Steven, Ward Marc, Podgaetz Eitan, Zhang Qiuyang, Chang Yan, Pan Zui, Woodland Philip J, Sifrim Daniel, Spechler Stuart Jon, Souza Rhonda F
Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center, Dallas, Texas; Center for Esophageal Research, Baylor Scott & White Research Institute, Dallas, Texas.
Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center, Dallas, Texas; Center for Esophageal Research, Baylor Scott & White Research Institute, Dallas, Texas; Baylor Scott & White Center for Medical and Surgical Weight Loss Management, Dallas, Texas.
Gastroenterology. 2025 May;168(5):914-930.e19. doi: 10.1053/j.gastro.2024.12.012. Epub 2024 Dec 24.
BACKGROUND & AIMS: Dilated intercellular space in esophageal epithelium, a sign of impaired barrier function, is a characteristic finding of gastroesophageal reflux disease that is also found in obese patients without gastroesophageal reflux disease. We explored molecular mechanisms whereby adipose tissue products might impair esophageal barrier integrity.
Cultures of visceral fat obtained during foregut surgery from obese and nonobese patients were established. Monolayer and air-liquid interface cultures of human esophageal cells were grown with conditioned medium (CM) from fat cultures. RNA sequencing, enzyme-linked immunosorbent assay, western blot, immunostaining, histology, and analyses of barrier function were performed; inhibitors of hypoxia-inducible factor 2α (HIF-2α [PT2385]), caspase-1 (AC-YVAD-CHO), myosin light chain kinase (Dreverse PIK), and myosin light chain phosphatase (permeant inhibitor of phosphatase 250) were applied; blebbistatin was used to disrupt actin-myosin interactions; N-acetylcysteine was used to scavenge reactive oxygen species.
CM from esophagogastric junction fat of obese patients caused dilated intercellular space with impaired barrier function in esophageal air-liquid interface cultures; these effects were blocked by PT2385. CM from esophagogastric junction fat of obese patients induced reactive oxygen species production that activated HIF-2α in esophageal cells. RNA-sequencing analyses linked CM from esophagogastric junction fat of obese patient-induced HIF-2α increases with innate immune response pathways. Cross-talk between HIF-2α and caspase-1 in esophageal cells led to interleukin 1β secretion, and interleukin 1β/interleukin 1 receptor 1 signaling caused dilated intercellular space with impaired esophageal barrier function via actin-myosin interactions induced by myosin light chain phosphorylation.
We have elucidated molecular mechanisms whereby visceral fat of obese patients can impair esophageal barrier integrity by secreting substances that generate reactive oxygen species, which activate HIF-2α in esophageal epithelial cells. These mechanisms could render the esophagus of obese individuals vulnerable to damage from acid and other noxious agents.
食管上皮细胞间间隙增宽是屏障功能受损的标志，是胃食管反流病的特征性表现，在无胃食管反流病的肥胖患者中也可发现。我们探究了脂肪组织产物可能损害食管屏障完整性的分子机制。
建立了从肥胖和非肥胖患者前肠手术中获取的内脏脂肪培养体系。人食管细胞的单层培养和气液界面培养与来自脂肪培养体系的条件培养基（CM）共同培养。进行了RNA测序、酶联免疫吸附测定、蛋白质印迹法、免疫染色、组织学检查以及屏障功能分析；应用了缺氧诱导因子2α（HIF - 2α [PT2385]）、半胱天冬酶 - 1（AC - YVAD - CHO）、肌球蛋白轻链激酶（Dreverse PIK）和肌球蛋白轻链磷酸酶（磷酸酶250的渗透性抑制剂）的抑制剂；使用blebbistatin破坏肌动蛋白 - 肌球蛋白相互作用；使用N - 乙酰半胱氨酸清除活性氧。
肥胖患者食管胃交界脂肪的CM在食管气液界面培养中导致细胞间间隙增宽且屏障功能受损；这些效应被PT2385阻断。肥胖患者食管胃交界脂肪的CM诱导食管细胞中产生活性氧，从而激活HIF - 2α。RNA测序分析将肥胖患者食管胃交界脂肪诱导的HIF - 2α增加与天然免疫反应途径联系起来。食管细胞中HIF - 2α与半胱天冬酶 - 1之间的相互作用导致白细胞介素1β分泌，白细胞介素1β/白细胞介素1受体1信号传导通过肌球蛋白轻链磷酸化诱导的肌动蛋白 - 肌球蛋白相互作用导致细胞间间隙增宽且食管屏障功能受损。
我们阐明了肥胖患者内脏脂肪通过分泌产生活性氧的物质损害食管屏障完整性的分子机制，这些物质激活食管上皮细胞中的HIF - 2α。这些机制可能使肥胖个体的食管易受酸和其他有害物质的损伤。
