Pulmonary endothelial glycocalyx degradation causes ARDS during sepsis

脓毒症期间肺内皮糖萼降解导致 ARDS

基本信息

批准号：
8209145
负责人：
Eric Peter Schmidt
金额：
$ 12.83万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-01 至 2016-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8209145
关键词：
Adult Respiratory Distress Syndrome Affect Anticoagulants Attenuated Beta-glucuronidase Biological Assay Blood Blood Circulation Blood Vessels Cell physiology Chest Clinical Complement Critical Illness Data Development Disease Dose Edema Endothelial Cells Endothelium Enzymes Figs - dietary Floods Functional disorder Glycocalyx Glycoproteins Glycosaminoglycans Goals Heparin Heparitin Sulfate Imaging Techniques Immunofluorescence Immunologic In Vitro Infection Inflammation Mediators Investigation Knock-out Lipopolysaccharides Liquid substance Lung Maps Measures Mechanical Stress Mediating Mediator of activation protein Microscopic Microscopy Modeling Mus Nature Nitric Oxide Patients Pattern Permeability Physiological Physiology Production Proteoglycan Pulmonary Circulation Pulmonary vessels Reaction Time Regional Perfusion Role Sepsis Severities Stretching Structure Surface TNF gene Testing Therapeutic Thick Transgenic Mice Tumor Necrosis Factor-alpha United States Venous Wild Type Mouse cytokine heparanase heparinase III in vivo in vivo Model inhibitor/antagonist intraperitoneal intravital microscopy mortality mouse model novel prevent response septic shear stress sugar therapeutic target

项目摘要

7. PROJECT SUMMARY/ABSTRACT The acute respiratory distress syndrome (ARDS) is a severe (> 30% mortality) critical illness that affects over 190,000 patients in the United States each year. Despite over 40 years of study, little is known about how this disease develops, and no specific treatment exists. While sepsis is a well-known cause of ARDS, the mechanisms underlying the development of septic ARDS are uncertain. A key step in the development of ARDS is dysfunction of the pulmonary endothelial barrier, which separates blood from the lung interstitium. Studies of the systemic (non-pulmonary) vasculature have revealed that proper endothelial barrier function is dependent on an intact glycocalyx-a thin layer of proteoglycans, glycoproteins, and glycosaminoglycans lining the vascular lumen. Emerging data suggest that inflammatory mediators of sepsis degrade the systemic endothelial glycocalyx, causing barrier dysfunction. The role of the pulmonary endothelial glycocalyx in sepsis and ARDS, however, has been unexplored. We hypothesize that sepsis induces pulmonary endothelial glycocalyx degradation, leading to barrier dysfunction and ARDS. As glycocalyx structure is often aberrant in-vitro, this hypothesis will be explored using ex-vivo and in-vivo models: the isolated, perfused mouse lung and closed-chest, intravital mouse lung microscopy. The dose-response and time course of lipopolysaccharide (LPS, a model of sepsis) induced pulmonary glycocalyx degradation will be determined. The vascular segmental (arterial vs. microvascular vs. venous) pattern of glycocalyx loss will be mapped using multiphoton intravital microscopy and compared to the segmental pattern of endothelial hyperpermeability during sepsis. The role of tumor necrosis factor ¿ and heparanase will be explored as mediators of LPS-induced glycocalyx loss, using pharmacologic inhibitors and transgenic mouse models. The therapeutic benefit of heparin, an inhibitor of heparanase, will be explored. In summary, this investigation promises a better understanding of a poorly-understood structure (the pulmonary endothelial glycocalyx) with relevance to a common clinical condition (sepsis-associated ARDS) via a combined physiologic (isolated, perfused mouse lung) and specialized microscopic (multiphoton intravital microscopy) approach. Furthermore, this investigation identifies heparanase as an attractive therapeutic target in a disease that yet lacks specific treatment.

7. 项目概要/摘要急性呼吸窘迫综合征 (ARDS) 是一种严重（死亡率 > 30%）的危重疾病，每年影响超过 190,000 名美国患者，尽管研究已超过 40 年，但人们对此知之甚少。关于这种疾病是如何发展的，并且没有具体的治疗方法，而脓毒症是众所周知的原因。 ARDS，脓毒症 ARDS 发展的潜在机制尚不确定。 ARDS 发生的一个关键步骤是肺内皮屏障功能障碍，对全身（非肺）脉管系统的研究表明，它可以将血液与肺间质分离。适当的内皮屏障功能依赖于完整的糖萼——一层薄薄的蛋白聚糖，新的数据表明，血管腔内的糖蛋白和糖胺聚糖与炎症有关。脓毒症介质会降解全身内皮糖萼，引起屏障功能障碍。然而，脓毒症和急性呼吸窘迫综合征（ARDS）中的肺内皮糖萼的作用尚未被探索。我们认为脓毒症会诱导肺内皮糖萼降解，从而导致屏障由于糖萼结构在体外通常是异常的，因此将使用该假设来探讨。离体和体内模型：分离的灌注小鼠肺和闭胸活体小鼠肺显微镜观察脂多糖（LPS，脓毒症模型）诱导的剂量反应和时间过程。将确定肺糖萼的降解情况（动脉、微血管、血管）。静脉）糖萼损失模式将使用多光子活体显微镜进行绘制，并与脓毒症期间内皮细胞通透性过高的节段模式肿瘤坏死因子的作用 ¿和将使用药物抑制剂和方法探索乙酰肝素酶作为 LPS 诱导的糖萼丢失的介质转基因小鼠模型将探讨肝素（乙酰肝素酶抑制剂）的治疗效果。总之，这项研究有望更好地理解一个鲜为人知的结构（肺内皮糖萼）与常见临床状况（脓毒症相关 ARDS）相关结合生理学（分离的、灌注的小鼠肺）和专门的显微镜（多光子活体此外，这项研究确定乙酰肝素酶是一种有吸引力的治疗方法。目标是一种尚缺乏特异性治疗的疾病。