Epithelial glycocalyx degradation mediates surfactant dysfunction in acute respiratory distress syndrome

上皮糖萼降解介导急性呼吸窘迫综合征中表面活性剂功能障碍

基本信息

批准号：
10386057
负责人：
Alicia N Rizzo
金额：
$ 5.01万
依托单位：
UNIVERSITY OF COLORADO DENVER
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：
2022-03-01 至 2022-09-15
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10386057
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 Chemicals Clinical Clinical Research Clinical Trials Colorado Complex Critical Care Data Development Devices Disease Drops Electron Microscopy Endothelium Enzymes Epithelial Epithelial Cells Foundations Functional disorder Glycocalyx Glycosaminoglycans Health Heparin Heparin Lyase Heparitin Sulfate Heterogeneity High Pressure Liquid Chromatography Human Humidifier 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 base design dimethylmethylene blue epithelial injury in vivo liquid chromatography mass spectrometry lung injury mouse model novel point of care pressure 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.

项目摘要/摘要急性呼吸窘迫综合征（ARDS）是ICU中呼吸衰竭的常见原因表面活性剂功能障碍和肺合顺顺性受损。我们的初步数据表明肺泡上皮糖脂是覆盖上皮细胞顶部表面的一层糖胺聚糖，已损坏在多种不同的鼠模型中。此外，我们发现特定的酶促降解上皮糖脂足以导致肺依从性降低和微催化性，这似乎是由表面活性剂功能受损介导。我们还使用无创的将这些发现转化为人类从热湿交换过滤器获得的收集的空域流体，这些液体是用于加湿的设备呼吸道是机械通风患者通常护理的一部分。令人兴奋的是，我们证明了肺泡上皮糖脂降解，通过空域液中的糖胺聚糖水平测量，是预测机械通气持续时间和低氧血症程度。在此提案中，我们将确定上皮糖脂降解引起表面活性剂功能障碍的机制并确认这些发现在人类ARDS患者中使用无创收集的转化相关性空域流体。在特定的目标1中，我们将确定与上皮糖蛋白结合的表面活性剂蛋白使用在小鼠支气管肺泡灌洗液上进行的肝素亲和色谱法。然后，我们将使用一个硫酸乙酰肝素糖果实确定负责此的特定硫酸乙酰肝素寡糖片段相互作用。然后，将通过化学施用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（竞争性地置换了天然的表面活性剂肺泡上皮糖脂）并使用基于设计的基于设计的肺结构和功能的影响立体学，肺力学测量和狭窄的无孔滴表面测量法。在特定的目标2中，我们将进行一项试点观察性临床研究，我们将同时收集热水分交换过滤器和高级肺力学数据（峰值压力，高原压力，驾驶压力）来自ARDS的呼吸机患者。然后，我们将使用这些数据来检验我们的假设，即糖胺聚糖的数量被散发到使用新型护理测定法（二甲基甲基蓝）测量的空域与肺部相关 ARDS患者的合规性。鉴于目前尚无可用的临床测试可以预测该课程在ARDS中，这些发现有可能对ICU的患者护理迅速影响。这项研究将在高度合作的肺科学和重症监护医学的协作部门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数据两者都将推进转化ARDS研究的领域，并作为我的K08奖的基础申请和最终过渡到独立调查员状态。