Cell-free hemoglobin-oxidized LDL-LOX-1 axis and microvascular hyperpermeability during sepsis

脓毒症期间无细胞血红蛋白氧化的 LDL-LOX-1 轴和微血管通透性过高

• 批准号: 10739620
• 负责人: Jamie E Meegan
• 金额: $ 14.02万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10739620
• 关键词: Abbreviations; Acute Lung Injury; Acute Respiratory Distress Syndrome; Adherens Junction; Antibodies; Apoptotic; Atherosclerosis; Automobile Driving; Binding; Blood Vessels; CREB1 gene; Cardiovascular Diseases; Cell Separation; Cells; Cessation of life; Clinical; Cyclic AMP-Responsive DNA-Binding Protein; Data; Edema; Endothelial Cells; Endothelium; Erythrocytes; Filtration; Functional disorder; Generations; Goals; Haptoglobins; Hemoglobin; Human; Immune response; Infection; Inflammation Mediators; Inflammatory; Injections; Injury; Laboratories; Lectin; Lectin Receptors; Link; Lipoproteins; Low Density Lipoprotein oxidation; Lung; MAP Kinase Gene; Matrix Metalloproteinases; Measures; Mediating; Membrane Proteins; Mentors; Metalloproteases; Microvascular Dysfunction; Mitogens; Molecular; Morbidity - disease rate; Mus; Organ; Oxidants; Pathogenesis; Pathologic; Pathway interactions; Patients; Peer Review; Peptide Hydrolases; Permeability; Phase; Phosphotransferases; Physiological; Plasma; Plasma Cells; Positioning Attribute; Preparation; Prevention strategy; Proteins; Receptor Signaling; Regulation; Research; Resolution; Role; Sepsis; Signal Pathway; Signal Transduction; Small Interfering RNA; Technical Expertise; Testing; Tight Junctions; Tissues; Training; Up-Regulation; Vascular Endothelial Cell; Vascular Endothelium; Writing; career; cell injury; clinically relevant; endothelial dysfunction; ex vivo perfusion; inhibitor; lung injury; lung microvascular endothelial cells; model development; mortality; mouse model; new therapeutic target; novel; oxidation; oxidized LDL receptors; oxidized low density lipoprotein; p38 Mitogen Activated Protein Kinase; polymicrobial sepsis; programs; receptor; septic patients; skills; systemic inflammatory response; targeted treatment; translational study; treatment strategy

PROJECT SUMMARY/ABSTRACT Sepsis, a dysregulated host response to infection with high morbidity and mortality, is characterized by a systemic inflammatory response and widespread vascular hyperpermeability leading to edema, organ dysfunction, and death. Lung vascular hyperpermeability in sepsis contributes to acute respiratory distress syndrome (ARDS), with no specific prevention or treatment strategies. Disruption of the microvascular endothelial cell (MVEC) barrier is a critical pathological feature of sepsis-induced lung injury driven by circulating inflammatory mediators, oxidants, and proteolytic enzymes. Our group has shown that plasma cell- free hemoglobin (CFH), released during sepsis due to red blood cell fragility, is a mechanistic driver of acute lung injury through induction of lung MVEC hyperpermeability. However, the cellular and molecular mechanisms are unknown. One potential mechanism by which CFH may disrupt the MVEC barrier is through its known ability to oxidize low-density lipoprotein (oxLDL). OxLDL binds and signals through its major endothelial receptor lectin-like oxidized LDL receptor 1 (LOX-1) to cause endothelial dysfunction. LOX-1 activation has been implicated in cardiovascular diseases such as atherosclerosis but its involvement in MVEC hyperpermeability during sepsis is unknown. Our preliminary data from patients with sepsis show that circulating CFH and oxLDL are tightly correlated with each other, MVEC injury markers, and mortality. However, little is known regarding LOX-1 receptor signaling leading to hyperpermeability, especially in the context of sepsis-induced injury to the lung microvasculature. This proposal aims to test the central hypothesis that MVEC hyperpermeability and lung injury during sepsis are mediated through oxidation of LDL by CFH to induce LOX-1 receptor signaling and ectodomain shedding. My career and long-term research goals are to establish an independent academic research program to identify novel signaling mechanisms regulating microvascular endothelial hyperpermeability during sepsis that can be targeted therapeutically for treatment of sepsis-induced organ dysfunction. During the mentored phase of this proposal, I will develop new physiologically relevant and translationally significant technical skills like ex vivo perfused human lung, lung filtration coefficient, endothelial cell isolation, and tissue-specific mouse model development, as well as gain expertise in lipoprotein and membrane protein pathophysiology. I will also enhance my proficiency in laboratory management, mentoring, peer review and writing. I have assembled a superb mentoring team to help me achieve these new skills and my career goals. The proposed research and training in this application will be crucial preparation for my transition to an independent academic research career and position me well to achieve my goal of becoming a leader in mechanistic and translational studies of microvascular dysfunction in sepsis.

项目概要/摘要 脓毒症是宿主对感染的反应失调，具有高发病率和死亡率，其特点是 全身炎症反应和广泛的血管通透性过高导致水肿、器官 功能障碍和死亡。脓毒症时肺血管通透性过高导致急性呼吸窘迫 综合征（ARDS），没有具体的预防或治疗策略。破坏微血管 内皮细胞（MVEC）屏障是脓毒症引起的肺损伤的一个关键病理特征 循环炎症介质、氧化剂和蛋白水解酶。我们的小组已经证明浆细胞- 由于红细胞脆性，脓毒症期间释放的游离血红蛋白（CFH）是急性发作的机制驱动因素。 通过诱导肺 MVEC 通透性过高造成肺损伤。然而，细胞和分子 机制尚不清楚。 CFH 破坏 MVEC 屏障的一种潜在机制是通过 其已知的氧化低密度脂蛋白（oxLDL）的能力。 OxLDL 通过其主要结合并发出信号 内皮受体凝集素样氧化 LDL 受体 1 (LOX-1) 导致内皮功能障碍。液氧-1 激活与动脉粥样硬化等心血管疾病有关，但它也参与 MVEC 脓毒症期间的通透性过高尚不清楚。我们对脓毒症患者的初步数据表明 循环 CFH 和 oxLDL 彼此、MVEC 损伤标志物和死亡率密切相关。 然而，对于导致通透性过高的 LOX-1 受体信号传导知之甚少，尤其是在 脓毒症引起的肺微血管损伤的背景。该提案旨在检验中央 脓毒症期间 MVEC 通透性过高和肺损伤是通过 LDL 氧化介导的假设 通过 CFH 诱导 LOX-1 受体信号传导和胞外域脱落。 我的职业和长期研究目标是建立一个独立的学术研究计划 确定脓毒症期间调节微血管内皮渗透性过高的新信号机制 可以作为治疗脓毒症引起的器官功能障碍的靶向治疗。在辅导阶段 根据这个提案，我将开发新的生理相关且具有转化意义的技术技能，例如 体内灌注人肺、肺过滤系数、内皮细胞分离和组织特异性小鼠模型 发展，并获得脂蛋白和膜蛋白病理生理学方面的专业知识。我也会 提高我在实验室管理、指导、同行评审和写作方面的熟练程度。我组装了一个 优秀的指导团队帮助我实现这些新技能和我的职业目标。拟议的研究和 该应用程序的培训将是我过渡到独立学术研究的重要准备 职业生涯并使我能够很好地实现成为机械和转化研究领导者的目标 脓毒症的微血管功能障碍。