Aldh2 and mitochondrial homeostasis in esophageal pathobiology

食管病理学中的 Aldh2 和线粒体稳态

基本信息

批准号：
10159805
负责人：
Hiroshi Nakagawa
金额：
$ 36.45万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-15 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10159805
关键词：
3-Dimensional Acetaldehyde Affect Agonist Alcohol consumption Alcohols Aldehydes Antioxidants Autophagocytosis Benign Biological Assay Biological Models Biology Biopsy CD44 gene CRISPR/Cas technology Carcinogens Cell Line Cells Characteristics Chloroquine Coupled Cytoprotection DNA DNA Adduction DNA Damage Data Defense Mechanisms Dependence Development Diet Disease Drug Metabolic Detoxication Engineering Enzymes Epithelial Epithelial Cells Esophageal Diseases Esophageal Squamous Cell Carcinoma Esophageal mucous membrane Esophagus Ethanol Ethanol Metabolism Exposure to Flow Cytometry Fostering Functional disorder Genetic Genetically Engineered Mouse Goals Homeostasis Human Human Cell Line Human Pathology Immunodeficient Mouse Impairment Individual Injury Intervention Isoenzymes Knowledge Laboratories Lesion Liquid substance Malignant - descriptor Malignant Epithelial Cell Malignant Neoplasms Mediating Metabolism Mission Mitochondria Mus Mutant Strains Mice Mutation Organ Organoids Oxidative Stress Oxides Pathogenesis Pathogenicity Pathology Patients Pharmacology Prevention Protein Isoforms Public Health Publishing Quality Control Reactive Oxygen Species Reporter Research Risk Factors Role Squamous Epithelium Squamous cell carcinoma Structure System Testing Transplantation United States National Institutes of Health Validation Vesicle Wild Type Mouse Xenograft procedure alcohol exposure alcohol pharmacology alcohol response aldehyde dehydrogenases cancer risk cell growth cell injury dietary control experimental study human disease in vivo innovation insight keratinocyte mitochondrial dysfunction neoplastic novel parkin gene/protein premalignant problem drinker tumor tumor growth tumor initiation

项目摘要

PROJECT SUMMARY Esophageal squamous cell carcinoma (ESCC) is the deadliest of all human squamous cell carcinomas with alcohol as a major risk factor. The role of alcohol (ethanol) in the esophageal epithelial cell injury and ESCC pathobiology remains unknown. Ethanol metabolism produces acetaldehyde, a major human carcinogen. Amongst the target organs alcohol drinking may cause diseases, esophagus is unique because it is directly exposed to high concentrations of EtOH and acetaldehyde. Alcohol detoxification involves clearance of acetaldehyde via aldehyde dehydrogenase 2 (Aldh2), the mitochondrial enzyme which breaks down aldehydes. Aldh2 dysfunction increases cancer risk in individuals with polymorphic Aldh2 mutation (Aldh2E487K). In Aldh2-/- and Aldh2E487K mutant mice and Aldh2-depleted human esophageal epithelial cells, alcohol induces mitochondrial damage and oxidative stress with increased DNA adducts formation and DNA damage, suggesting that mitochondrial dysfunction and reactive oxygen species (ROS) may contribute to genetic instability in Aldh2 dysfunctional esophageal epithelial cells. Alcohol-induced oxidative stress is alleviated by autophagy, a cytoprotective mechanism which removes damaged cellular components including dysfunctional mitochondria. Moreover, alcohol stimulates ESCC tumor growth with increased tumor-initiating cells displaying high autophagy and high CD44 expression (CD44H). The long-term goal is to identify esophageal mucosal defense mechanisms that can be manipulated for prevention or therapy of ESCC. The overall objective in this proposal is to clarify how alcohol affects esophageal epithelial cells with Aldh2 dysfunction. This proposal utilizes genetically engineered mouse models, patients' biopsies, human cell lines with altered Aldh2 status via the CRISPR/Cas9-approach, xenograft serial transplantation assays and a novel 3D esophageal organoid system with ethanol exposure and pharmacological interventions as a comprehensive platform to define the mechanistic and functional role of Aldh2 in epithelial response to alcohol exposure. The central hypothesis is that Aldh2 limits alcohol-induced mitochondrial dysfunction, suppressing oxidative stress and ESCC tumor initiation and growth. This hypothesis has been formulated on the basis of strong preliminary data produced in the applicant's laboratory and will be tested by pursuing the following three interrelated Specific Aims: (1) To clarify how mitochondrial Aldh2 limits alcohol-induced esophageal epithelial cell injury; (2) To define how autophagy reduces alcohol-induced mitochondrial damage and oxidative stress; (3) To determine how Aldh2 influences alcohol-induced esophageal neoplastic characteristics. These innovative studies will reveal novel insight into the role of dysfunctional Aldh2 in alcohol-induced oxidative stress and esophageal epithelial cell injury as well as autophagy-mediated cytoprotection in the pathogenesis of ESCC and other alcoholic diseases, both benign and malignant.

项目概要食管鳞状细胞癌 (ESCC) 是所有人类鳞状细胞癌中最致命的一种酒精作为主要危险因素。酒精（乙醇）在食管上皮细胞损伤和食管鳞癌中的作用病理生物学仍然未知。乙醇代谢产生乙醛，一种主要的人类致癌物。在饮酒可能导致疾病的靶器官中，食道是独一无二的，因为它直接暴露于高浓度的乙醇和乙醛。酒精解毒涉及清除通过醛脱氢酶 2 (Aldh2) 产生乙醛，醛脱氢酶 2 是一种分解醛的线粒体酶。 Aldh2 功能障碍会增加具有多态性 Aldh2 突变 (Aldh2E487K) 的个体患癌症的风险。在 Aldh2-/- 中酒精诱导的 Aldh2E487K 突变小鼠和 Aldh2 耗尽的人食管上皮细胞线粒体损伤和氧化应激，增加 DNA 加合物形成和 DNA 损伤，表明线粒体功能障碍和活性氧（ROS）可能有助于遗传 Aldh2 功能失调的食管上皮细胞的不稳定性。酒精引起的氧化应激可通过以下方式缓解：自噬是一种细胞保护机制，可清除受损的细胞成分，包括功能失调的细胞成分线粒体。此外，酒精会刺激食管鳞癌肿瘤生长，增加肿瘤起始细胞的表达高自噬和高 CD44 表达 (CD44H)。长期目标是识别食管粘膜可用于预防或治疗 ESCC 的防御机制。本次活动的总体目标该提案旨在阐明酒精如何影响具有 Aldh2 功能障碍的食管上皮细胞。这个提议利用基因工程小鼠模型、患者活检、Aldh2 状态改变的人类细胞系 CRISPR/Cas9 方法、异种移植连续移植测定和新型 3D 食管类器官系统以乙醇暴露和药理干预作为综合平台来定义 Aldh2 在上皮细胞对酒精暴露的反应中的机制和功能作用。中心假设是 Aldh2 限制酒精引起的线粒体功能障碍，抑制氧化应激和 ESCC 肿瘤起始和成长。这一假设是在强有力的初步数据的基础上提出的申请人的实验室，并将通过追求以下三个相互关联的具体目标进行测试： (1) 阐明线粒体 Aldh2 如何限制酒精引起的食管上皮细胞损伤； (2) 定义如何自噬减少酒精引起的线粒体损伤和氧化应激； (3) 确定Aldh2如何影响酒精诱发的食管肿瘤特征。这些创新研究将揭示新颖的深入了解功能失调的 Aldh2 在酒精诱导的氧化应激和食管上皮细胞中的作用 ESCC 和其他酒精性疾病发病机制中的损伤以及自噬介导的细胞保护，分为良性和恶性。