Autophagy and esophageal tissue remodeling in EoE

EoE 中的自噬和食管组织重塑

• 批准号: 10298488
• 负责人: Hiroshi Nakagawa
• 金额: $ 48.21万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-18 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10298488
• 关键词: 3-Dimensional; Affect; Antioxidants; Autophagocytosis; Basal Cell; Basal Cell Hyperplasia; Biology; Biopsy; CRISPR/Cas technology; Cell Fate Control; Cell Lineage; Cells; Cellular Stress Response; Cellular biology; Chronic; Clinical; Clonal Expansion; Coupled; Data; Defect; Defense Mechanisms; Desmosomes; Development; Disease; Dose; Down-Regulation; Drug Targeting; Eosinophilic Esophagitis; Epithelial; Esophageal Diseases; Esophageal Stenosis; Esophageal Tissue; Esophagitis; Esophagus; Event; Fibrosis; Flow Cytometry; Genetic; Genetically Engineered Mouse; Growth; Homeostasis; Human; Immune; Impairment; Infiltration; Inflammation; Inflammatory; Interleukin-13; Knowledge; Label; Laboratories; Lamina Propria; Link; Mediating; Mediator of activation protein; Microscopy; Mission; Mitochondria; Mitochondrial DNA; Mitotic; Modeling; Mucous Membrane; Mus; Nature; Organoids; Oxidative Stress; Pathogenesis; Patients; Peptic Esophagitis; Pharmacology; Proteins; Public Health; Publications; Quality of life; Radiation; Reactive Oxygen Species; Research; Role; Signal Transduction; Squamous Epithelium; Stratified Squamous Epithelium; Structure; Tamoxifen; Testing; Tight Junctions; Tissues; United States National Institutes of Health; Validation; base; cytokine; drug testing; experimental study; food allergen; human disease; inflammatory milieu; innovation; insight; keratinocyte; mitochondrial autophagy; mouse model; notch protein; novel; self-renewal; stress reactivity

Project summary Esophageal stratified squamous epithelia comprise proliferative basal cells that undergo terminal differentiation in the suprabasal cell layer. This homeostatic proliferation-differentiation gradient is regulated by Notch signaling that is impaired in eosinophilic esophagitis (EoE), a chronic inflammatory disorder characterized by mucosal eosinophilic infiltration, basal cell hyperplasia (BCH) and subepithelial fibrosis. BCH contributes to a barrier defect that facilitates lamina propria remodeling, culminating in fibrotic esophageal strictures that severely affect patients’ quality of life. While food allergen-activated immune cells and cytokines mediate EoE pathogenesis, the relationship between esophageal epithelial biology and EoE pathogenesis remains elusive. The ongoing project (R01-114436) has established the role of autophagy, a highly conserved cellular stress response, as a fundamental mucosal defense mechanism in EoE. Epithelial autophagy activation involves mitochondrial stress and reactive oxygen species (ROS) induced by proinflammatory EoE-relevant cytokines such as IL-13, which in turn stimulate BCH. BCH features depletion of CD73+ basal cells and reciprocal expansion of CD73- cells with low Notch activity, thereby limiting terminal differentiation. IL-13 promotes BCH by inhibiting Notch while inducing ROS-mediated mitochondrial (mt) damage marked by mtDNA depletion. Moreover, CD73- cells may maintain BCH via Notch-independent epithelial renewal. The overall objective in this competing renewal application is to elucidate the nature of basal cell fate regulation in EoE pathogenesis. The central hypothesis is that EoE-related inflammation influences basal cells’ activity to promote esophageal tissue remodeling. This hypothesis has been formulated based upon strong preliminary data and publications from the applicant’s laboratory and will be pursued through the following interrelated Specific Aims: (1) To elucidate how autophagy activation limits BCH in the EoE inflammatory milieu; (2) To delineate the role of mitochondrial damage in EoE-related BCH; (3) To unravel how Notch signaling protects against tissue remodeling in EoE. The present proposal utilizes a robust murine model of EoE with squamous epithelia- specific autophagy impairment, mtDNA depletion, or Notch inhibition with concurrent basal cell lineage tracing. These approaches are coupled with ex vivo esophageal 3D organoids from EoE mice and patient biopsies to define the mechanistic and functional role of autophagy and mitochondria in basal cell homeostasis. These innovative studies will reveal novel insights into esophageal basal cell biology and tissue remodeling. With genetically engineered mice, 3D organoids and patient biopsies, we will build a comprehensive platform for the development and validation of novel translational applications related to EoE therapy (autophagy activation and mitochondria-targeted antioxidants). These findings may have direct clinical impact in EoE, and potentially other diseases (e.g. GERD) where autophagy, epithelial barrier defects and fibrosis have been implicated.

项目摘要 食管复层鳞状上皮由增殖的基底细胞组成， 在基底上细胞层。这种自我平衡的增殖-分化梯度受Notch调控， 嗜酸性食管炎（EoE）是一种慢性炎症性疾病，其特征是 粘膜嗜酸性粒细胞浸润、基底细胞增生（BCH）和上皮下纤维化。BCH有助于 屏障缺损，促进固有层重塑，最终导致纤维化食管狭窄， 严重影响患者的生活质量。而食物过敏原激活的免疫细胞和细胞因子介导EoE 尽管EoE的发病机制尚未明确，但食管上皮生物学与EoE发病机制之间的关系仍然难以捉摸。 正在进行的项目（R 01 -114436）已经确定了自噬的作用，自噬是一种高度保守的细胞应激 反应，作为一个基本的粘膜防御机制在EoE。上皮细胞自噬激活涉及 促炎性EoE相关细胞因子诱导的线粒体应激和活性氧（ROS） 例如IL-13，其又刺激BCH。BCH的特点是CD 73+基底细胞的耗竭， 扩增具有低Notch活性的CD 73-细胞，从而限制终末分化。IL-13促进BCH 通过抑制Notch，同时诱导ROS介导的线粒体（mt）损伤，以mtDNA耗竭为标志。 此外，CD 73-细胞可以通过Notch非依赖性上皮更新来维持BCH。总体目标是 这种竞争性更新应用是为了阐明EoE发病机制中基底细胞命运调节的性质。 核心假设是EoE相关炎症影响基底细胞的活性，以促进食管癌的发生。 组织重塑这一假设是根据强有力的初步数据和出版物制定的 从申请人的实验室，并将通过以下相互关联的具体目标追求：（1） 阐明自噬激活如何限制EoE炎症环境中的BCH;（2）描述自噬的作用， EoE相关BCH中的线粒体损伤;（3）阐明Notch信号如何保护组织免受 在EoE中重塑。本提案利用了具有鳞状上皮细胞的EoE的稳健小鼠模型， 特异性自噬损伤、mtDNA耗竭或Notch抑制与同时进行的基底细胞谱系追踪。 这些方法与来自EoE小鼠和患者活检的离体食管3D类器官结合， 定义自噬和线粒体在基底细胞稳态中的机制和功能作用。这些 创新的研究将揭示食管基底细胞生物学和组织重塑的新见解。与 基因工程小鼠，3D类器官和患者活检，我们将建立一个全面的平台， 开发和验证与EoE治疗（自噬激活）相关的新型翻译应用 和抗氧化剂）。这些发现可能对EoE有直接的临床影响， 涉及自噬、上皮屏障缺陷和纤维化的其他疾病（例如GERD）。