Durability of Epithelial Defects in Crohn's Disease Intestine

项目摘要/摘要 克罗恩病是一种衰弱的进行性胃肠道炎症性疾病。中的缺陷 上皮细胞被认为是克罗恩病进展的原因之一。然而，生物驱动因素和 上皮性缺陷的发生机制尚不清楚。如果继发性上皮细胞缺陷发生在 患者存在炎症和改变的微生物群暴露，针对这些暴露进行治疗 将被预测为解决上皮缺陷。或者，如果上皮缺陷是原发的或持久性的 克罗恩病进展的贡献者，尽管接受了治疗，但预计它们仍将持续，因为目前没有 治疗的目标是上皮细胞。本项目旨在区分这两种模型，以改进克罗恩的 疾病预后。我们已经确定了两种与微绒毛功能障碍相关的量化上皮缺陷 克罗恩病回肠组织缺乏组织学炎症，提示微绒毛缺陷可能是 克罗恩病进展的持久贡献者。微绒毛是上皮细胞顶端的膜突起 增加吸收表面积并为酶的浓缩提供物理位置的细胞， 转运蛋白和宿主防御蛋白对肠道内环境的稳定至关重要。微绒毛或某些微绒毛的丢失 定位蛋白与微绒毛包涵体病、极早起病的炎症性肠病、 还有肠病。对于这个项目，我们建议跟踪体内定量的微绒毛缺陷(前后)。 治疗)和体外(从炎症/微生物暴露中去除上皮)。我们已经开发出一种 主要假设上皮微绒毛缺陷将在克罗恩病患者亚群中持久存在 更具攻击性的病程。在目标1中，我们将研究微绒毛缺陷在体内的持久性。 使用现有的纵向样本和来自儿科风险克罗恩病队列和对照的数据 研究对象。我们预测微绒毛缺陷在进展性疾病患者中更有可能持续存在 行为、缺乏抗肿瘤坏死因子反应和要求手术。我们还将执行关联分析 微绒毛缺陷的表型、临床参数和微生物组特征，以确定我们潜在的 改进患者分类。在目标2中，我们将研究体外培养的微绒毛缺损的持久性。 取自克罗恩病的人肠上皮椭球样线和对照患者的活检组织。我们的 初步分析表明，微绒毛缺陷将在椭圆线的子集中持久存在。我们会 检验耐久的椭圆形微绒毛缺陷是否与脂代谢下降有关，脂代谢是一种关键的肠细胞 根据我们的初步分析，预计功能将会下降。总体而言，这个项目将决定 微绒毛缺陷是导致克罗恩病进展的持久的上皮因素。此外，它还将开始 确定最有可能从个性化治疗中受益的克罗恩病患者亚群 恢复上皮细胞功能的方法。

PROJECT SUMMARY/ABSTRACT Crohn’s disease is a debilitating and progressive inflammatory disease of the gastrointestinal tract. Defects in epithelial cells are thought to contribute to Crohn’s disease progression. However, the biological drivers and mechanisms of epithelial defects are not well understood. If epithelial cell defects occur secondary to the inflammatory and altered microbiome exposures present in the patient, treatments targeting these exposures would be predicted to resolve the epithelial defects. Alternatively, if epithelial defects are primary or durable contributors to Crohn’s disease progression, they would be predicted to persist despite treatment, as no current treatments target the epithelium. This project aims to distinguish these two models in order to improve Crohn’s disease prognosis. We have identified two quantitative epithelial defects related to microvillar dysfunction in Crohn’s disease ileal tissues lacking histological inflammation, suggesting that microvillar defects could be durable contributors to Crohn’s disease progression. Microvilli are apical membrane protrusions on epithelial cells that increase surface area for absorption and provide a physical location for the enrichment of enzymes, transporters, and host defense proteins critical for intestinal homeostasis. Loss of microvilli or certain microvillar localized proteins is associated with microvillus inclusion disease, very-early onset inflammatory bowel disease, and enteropathy. For this project, we propose to track the quantitative microvillar defects in vivo (pre- and post- treatment) and in vitro (epithelium removed from inflammatory/microbial exposures). We have developed an overarching hypothesis that epithelial microvillar defects will be durable in a Crohn’s disease patient subset with a more aggressive disease course. In Aim 1, we will investigate the durability of the microvillar defects in vivo using existing longitudinal samples and data from the pediatric RISK Crohn’s disease cohort and control subjects. We predict that the microvillar defects are more likely to persist in patients with progressive disease behavior, lack of anti-TNF response, and requirement for surgery. We will also perform association analysis with the microvillar defect phenotypes, clinical parameters, and microbiome profiles to identify ways we can potentially improve patient subsetting. In Aim 2, we will investigate the durability of the microvillar defects in vitro using human intestinal epithelial spheroid lines derived from Crohn’s disease and control patient biopsy tissues. Our preliminary analysis indicates that the microvillar defects will be durable in a subset of spheroid lines. We will test if durable spheroid microvillar defects are associated with decreased lipid metabolism, a critical enterocyte function predicted to be decreased by our preliminary analysis. Overall, this project will determine whether microvillar defects are durable epithelial contributors to Crohn’s disease progression. In addition, it will begin to identify the Crohn’s disease patient subset that would be most likely to benefit from a personalized therapeutic approach to restore epithelial cell function.