Molecular regulation of pulmonary tight junctions

肺紧密连接的分子调节

基本信息

批准号：
8831000
负责人：
MICHAEL H. KOVAL
金额：
$ 38.42万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-01 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8831000
关键词：
Acute Acute Lung Injury Adenovirus Vector Adult Respiratory Distress Syndrome Affect Air Alcohol abuse Alcohol consumption Alcohols Alveolar Alveolus Biological Models Bleomycin Cell model Cells Cessation of life Chronic Cultured Cells Data Dietary Alcohol Diffusion Edema Elements Epithelial Epithelial Cells Epithelium Floods Fluid Balance Functional disorder Goals In Vitro Incidence Inflammation Injury Ions Laboratories Learning Ligation Liquid substance Lung Lung diseases Measures Mechanics Molecular Outcome Pathologic Pathway interactions Patients Permeability Predisposition Process Proteins Public Health Pulmonary Edema Pump Puncture procedure Regulation Research Respiratory Failure Respiratory physiology Role Sepsis Series Severities Site Structure Syndrome System Testing Therapeutic Tight Junctions alcohol effect alcohol response alveolar epithelium chronic alcohol ingestion claudin 4 extracellular improved in vivo in vivo Model lung injury mortality prevent problem drinker protective effect public health relevance response seal small molecule solute tool water diffusion

项目摘要

DESCRIPTION (provided by applicant): Acute Respiratory Distress Syndrome (ARDS) is characterized by compromised epithelial function in the terminal alveolus leading to airspace flooding, respiratory failure, and increased mortality. While much has been learned about the pathophysiology of ARDS in the past four decades, the mortality rate remains unacceptably high at ~50%. Surviving ARDS correlates with the ability to maintain lung fluid clearance which, in turn, requires a healthy air-liquid barrier in the lung. This barrier is maintained in large part b alveolar epithelial tight junctions, structures at cell-cell contact sites which form a selectively permeable seal to regulate paracellular diffusion of water, ions and solutes. My laboratory has identified specific roles for proteins known as claudins in regulating alveolar epithelial tight junction permeability. However, the downstream effects of claudin dysregulation in response to acute lung injury (ALI) and ARDS have not been fully elucidated. In addition, chronic alcohol abuse worsens the incidence and severity of ARDS. We have found that chronic dietary alcohol ingestion alters alveolar epithelial claudin expression which correlates with impaired barrier function. Here, molecular tools developed by my laboratory combined with cultured cell and model injury systems will be used to understand how claudin dysregulation affects the progression of ARDS in response to ALI. The project will define mechanistic roles for alveolar epithelial claudins, including claudin-4 and claudin-18 which correlate with improved lung fluid clearance and claudin-5 which is upregulated in the alcoholic lung and associates with impaired alveolar barrier function. A series of adenovectors were developed which allows manipulation of claudin expression by cultured primary alveolar epithelial cells and lung epithelia in vivo. This approach will be used to measure the effects of increasing claudin-4, claudin-5 or claudin-18 expression on alveolar epithelial barrier function. The effects of increasing claudin-4, claudin-5 or claudin-18 on lung fluid clearance in vivo will be assessed and correlated changes to tight junction composition during ALI due to two distinct model systems: 1) intratracheal administration of bleomycin and 2) cecal ligation and puncture to induce sepsis. We will also assess the ability of claudin-4 and claudin-18 to reverse the deleterious effects of alcoholic lung syndrome which exacerbate the pathologic consequences of ALI. Measuring the effects of altered alveolar claudin composition on tight junction permeability and turnover in diverse ALI model systems will be used to evaluate therapeutic strategies with the potential to strengthen alveolar barrier function and lessen susceptibility to ARDS.

描述（由申请人提供）：急性呼吸窘迫综合征（ARDS）的特征是末端肺泡中的上皮功能受损，导致空域洪水，呼吸衰竭和死亡率增加。尽管过去四十年中有关ARDS的病理生理学已经了解了很多，但死亡率仍然不可接受地高约50％。存活的ARDS与维持肺液清除率的能力相关，这反过来又需要在肺中具有健康的空气屏障。该障碍在很大的部分中保持肺泡上皮紧密连接，在细胞 - 细胞接触位点的结构有选择性地形成A 可渗透密封以调节水，离子和溶质的细胞细胞扩散。我的实验室已经确定了被称为克劳丁蛋白的蛋白质的特定作用，在调节肺泡上皮紧密连接性中。然而，尚未完全阐明Claudin失调对急性肺损伤（ALI）和ARD的下游作用。此外，慢性酒精滥用使ARDS的发病率和严重程度恶化。我们发现，慢性饮食摄入量会改变与屏障功能受损相关的肺泡上皮表达。在这里，由我的实验室开发的分子工具与培养的细胞和模型损伤系统相结合，将用于了解Claudin失调如何影响ALI的ARDS进展。该项目将定义肺泡上皮claudins的机械作用，包括Claudin-4和Claudin-18，它们与改善的肺液清除率和Claudin-5相关，这些肺液和Claudin-5在酒精肺中被上调，并与肺泡屏障功能受损相关。开发了一系列的腺苷酸，可以通过体内培养的原发性肺泡上皮细胞和肺上皮来操纵克劳丁表达。该方法将用于测量增加Claudin-4，Claudin-5或Claudin-18表达对肺泡上皮屏障功能的影响。将评估Claudin-4，Claudin-5或Claudin-18对体内肺液清除率的影响，并将由于两个不同的模型系统而在ALI期间与紧密连接组成的变化进行评估：1）气管内给药Bleomycin和2）2）Cecal结扎和盲肠结扎和诱导Sepsis。我们还将评估Claudin-4和Claudin-18的能力扭转酒精肺的有害作用综合征加剧了阿里的病理后果。测量改变肺泡claudin组成对各种ALI模型系统紧密连接渗透性的影响和离职率将用于评估治疗策略，以增强肺泡屏障功能并降低对ARD的敏感性。