Epithelial glycocalyx degradation mediates surfactant dysfunction in acute respiratory distress syndrome

急性呼吸窘迫综合征中上皮糖萼降解介导表面活性剂功能障碍

基本信息

批准号：
10705837
负责人：
Alicia N Rizzo
金额：
$ 4.21万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-16 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10705837
关键词：
Acute Respiratory Distress Syndrome Affinity Chromatography Anatomy Apical Automobile Driving Award Binding Binding Proteins Biological Assay Biological Markers Bleomycin Blood Circulation Bronchoalveolar Lavage Fluid Clinical Clinical Research Clinical Trials Colorado Complex Critical Care Data Development Devices Disease Drops Electron Microscopy Endothelium Enzymes Epithelial Cells Epithelium Foundations Functional disorder Glycocalyx Glycosaminoglycans Health Heparin Heparin Lyase Heparitin Sulfate Heterogeneity High Pressure Liquid Chromatography Human Hypoxemia Hypoxemic Respiratory Failure Impairment In Vitro Influenza Inhalation Injury Intensive Care Units Intuition Laboratories Lipopolysaccharides Liquid substance Lung Lung Compliance Measurement Measures Mechanical ventilation Mechanics Mediating Medical center Medicine Mentors Methods Modeling Molecular Mus Oligosaccharides Pathogenesis Patient Care Patients Physiology Process Proteins Pulmonary Edema Pulmonary Inflammation Research Research Personnel Respiratory Failure Route Science Severities Structure Surface Syndrome Technology Testing Translating Universities Ventilator Work alveolar epithelium chemical synthesis design dimethylmethylene blue epithelial injury in vivo liquid chromatography mass spectrometry lung injury mouse model novel point of care pressure structural determinants sugar surfactant surfactant function treatment as usual

项目摘要

PROJECT SUMMARY/ABSTRACT Acute respiratory distress syndrome (ARDS), a common cause of respiratory failure in the ICU, is characterized by surfactant dysfunction and impaired lung compliance. Our preliminary data demonstrate that the alveolar epithelial glycocalyx, a layer of glycosaminoglycans that coat the apical surface of the epithelial cells, is damaged in multiple different murine models of ARDS. Additionally, we found that specific enzymatic degradation of the epithelial glycocalyx is sufficient to cause decreased lung compliance and microatelectasis, which appears to be mediated by impaired surfactant function. We have also translated these findings to humans using noninvasively collected airspace fluid obtained from heat moisture exchange filters, which are devices that are used to humidify the airways as part of the usual care of mechanically ventilated patients. Excitingly, we demonstrated that alveolar epithelial glycocalyx degradation, measured by levels of glycosaminoglycans in the airspace fluid, is predictive of duration of mechanical ventilation and degree of hypoxemia. In this proposal, we will determine the mechanisms by which epithelial glycocalyx degradation causes surfactant dysfunction and confirm the translational relevance of these findings in human ARDS patients using noninvasively collected airspace fluid. In Specific Aim 1, we will identify the surfactant protein that binds to the epithelial glycocalyx using heparin affinity chromatography conducted on mouse bronchoalveolar lavage fluid. We will then utilize a heparan sulfate glycoarray to identify the specific heparan sulfate oligosaccharide fragment responsible for this interaction. The functional importance of this interaction will then be tested in mice by administering chemically synthesized surfactant protein-binding oligosaccharides (to competitively displace surfactant from the native alveolar epithelial glycocalyx) and measuring the effects on lung structure and function using design-based stereology, lung mechanics measurements, and constrained sessile drop surfactometry. In Specific Aim 2, we will conduct a pilot observational clinical study in which we will collect both heat moisture exchange filters and advanced lung mechanics data (peak pressure, plateau pressure, driving pressure) from the ventilators of ARDS patients. We will then use this data to test our hypothesis that the quantity of glycosaminoglycans shed into the airspace, measured using a novel point-of-care assay (dimethylmethylene blue), is inversely related to lung compliance in ARDS patients. Given that there are currently no available clinical tests that can predict the course of ARDS, these findings have the potential to become rapidly impactful to patient care in the ICU. This research will be carried out in the highly collaborative Division of Pulmonary Sciences and Critical Care Medicine at the University of Colorado and Denver Health Medical Center. We anticipate that this project will generate data that will both advance the field of translational ARDS research and serve as the foundation for my K08 award application and eventual transition to independent investigator status.

项目概要/摘要急性呼吸窘迫综合征 (ARDS) 是 ICU 呼吸衰竭的常见原因表面活性剂功能障碍和肺顺应性受损。我们的初步数据表明，肺泡上皮糖萼（覆盖上皮细胞顶端表面的一层糖胺聚糖）受损在多种不同的 ARDS 小鼠模型中。此外，我们发现特定的酶促降解上皮糖萼足以导致肺顺应性下降和微肺不张，这似乎是由表面活性剂功能受损介导。我们还使用非侵入性方法将这些发现转化为人类收集从热湿交换过滤器获得的空气空间流体，这些过滤器是用于加湿的装置作为机械通气患者常规护理的一部分。令人兴奋的是，我们证明了肺泡上皮糖萼降解，通过气腔液体中糖胺聚糖的水平来测量，是预测机械通气持续时间和低氧血症程度。在本提案中，我们将确定上皮糖萼降解导致表面活性剂功能障碍的机制并证实使用非侵入性收集的人类 ARDS 患者的这些发现的转化相关性空域流体。在具体目标 1 中，我们将鉴定与上皮糖萼结合的表面活性蛋白使用肝素亲和层析对小鼠支气管肺泡灌洗液进行。然后我们将利用一个硫酸乙酰肝素糖阵列来鉴定造成这种情况的特定硫酸乙酰肝素寡糖片段相互作用。然后，通过给小鼠施用化学物质，测试这种相互作用的功能重要性。合成的表面活性剂蛋白结合寡糖（以竞争性地取代天然的表面活性剂）肺泡上皮糖萼）并使用基于设计的方法测量对肺结构和功能的影响体视学、肺力学测量和约束固着滴表面测量法。在具体目标 2 中，我们将进行一项试点观察性临床研究，其中我们将收集热湿交换过滤器和来自 ARDS 呼吸机的高级肺力学数据（峰值压力、平台压力、驱动压力）患者。然后，我们将使用这些数据来检验我们的假设，即糖胺聚糖的数量流入使用新型即时检测（二甲基亚甲基蓝）测量的空域与肺呈负相关 ARDS 患者的依从性。鉴于目前没有可用的临床测试可以预测病程对于ARDS，这些发现有可能迅速对 ICU 患者的护理产生影响。这项研究将在高度协作的肺科学和重症监护医学部进行科罗拉多大学和丹佛健康医疗中心。我们预计该项目将生成的数据将推动 ARDS 转化研究领域的发展，并作为我的 K08 奖的基础申请并最终过渡到独立调查员身份。