Endothelial Injury in Endotoxin-Induced Acute Renal Failure

内毒素引起的急性肾衰竭中的内皮损伤

• 批准号: 8265931
• 负责人: PATRICK N CUNNINGHAM
• 金额: $ 32.33万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8265931
• 关键词: Actins; Acute; Acute Kidney Failure; Address; Affect; Animal Experiments; Apoptosis; Award; Blood Circulation; Blood Pressure; Blood Vessels; Blood flow; Caspase; Caspase Inhibitor; Cell Adhesion Molecules; Cell Culture Techniques; Cells; Clinical; Coagulation Process; Complication; Conscious; Data; Development; Devices; Endothelial Cells; Endothelium; Endotoxemia; Endotoxins; Event; Functional disorder; Implant; In Vitro; Infection; Inflammation; Inflammatory; Injury; Kidney; Kidney Transplantation; Knock-out; Knockout Mice; Lead; Leukocytes; Measurement; Mediating; Mediation; Mediator of activation protein; Mentors; Modeling; Molecular; Monitor; Morbidity - disease rate; Mus; Myosin Light Chain Kinase; NF-kappa B; NFKB Signaling Pathway; Outcome; Pathogenesis; Pathway interactions; Patients; Play; Process; Protein Isoforms; Renal Blood Flow; Renal function; Role; Scientist; Sepsis; Signal Transduction; Small Interfering RNA; Stimulus; Syndrome; TNF gene; TNFRSF1A gene; Testing; Time; Transcription Factor AP-1; Transgenic Mice; Transplantation; United States National Institutes of Health; Vascular Permeabilities; Vascular resistance; Work; analog; caspase-8; defined contribution; hemodynamics; in vivo; inhibitor/antagonist; kidney cell; kidney vascular structure; mortality; mouse model; overexpression; public health relevance; receptor; research study; response; septic; sphingosine 1-phosphate; tool; vascular inflammation

DESCRIPTION (provided by applicant): Acute renal failure affects approximately 5% of all hospitalized patients, causing great morbidity and mortality, and commonly results from sepsis. Preliminary data indicate that LPS-induced ARF, a model of septic renal dysfunction, depends on the action of TNF on its receptor TNFR1 in the kidney, and is associated with renal endothelial apoptosis, inflammation, and vascular leak both in vivo and in vitro. Specific Aim 1 will use primary culture of mouse renal endothelial cells (ECs) to determine the mechanisms of TNF-induced endothelial barrier dysfunction, via use of pharmacologic inhibitors and an siRNA approach, and will study the effect on cytoskeletal disruption caused by TNF. Specific Aim 2 will determine the role of this endothelial barrier dysfunction in the course of LPS-induced acute renal failure (ARF) using transgenic mice overexpressing and deficient in the endothelial isoform of myosin light chain kinase (MLCK). Sphingosine-1-phosphate analogues, which maintain endothelial barrier integrity, will also be administered to determine the effect on LPS-induced ARF. Renal cross-transplantation will be used as a tool to define the contribution of renal as opposed to systemic endothelial injury, and chronically implanted blood pressure and renal flowprobe devices will allow real-time measurement of intrarenal hemodynamics in response to the above manipulations in the setting of endotoxemia. Specific Aim 3 will test the hypothesis that TNF-induced caspase activation amplifies renal endothelial inflammation, and will define mechanisms through which this cross-talk occurs, which may involve MLCK and other cytoskeletal events. Specific Aim 4 will use endothelial-specific knockout mice lacking caspase-8, and endothelial-specific transgenic mice with nonfunctional NF-?B, to distinguish the respective contributions of endothelial apoptosis and inflammation to the outcome of LPS-induced ARF. Together, this project will develop tools which should allow greater understanding of the importance and mechanism of endothelial injury and its role in septic ARF. PUBLIC HEALTH RELEVANCE: Acute kidney failure (ARF) is a common complication in hospitalized patients that leads to great morbidity and mortality, and commonly results from overwhelming infection. This project tests the hypothesis that injury and inflammation to kidney endothelial cells, which line the blood vessels, are an important cause of ARF. In this proposal, animal experiments using strains with altered endothelial functions and cell culture experiments will provide greater understanding of the mechanisms involved in ARF, which should eventually lead to more rational and targeted therapies for this syndrome.

描述（由申请人提供）：急性肾功能衰竭影响大约 5% 的住院患者，导致很高的发病率和死亡率，通常由败血症引起。初步数据表明，LPS诱导的ARF是脓毒症肾功能不全的模型，依赖于TNF对其肾脏受体TNFR1的作用，并且与体内和体外的肾内皮细胞凋亡、炎症和血管渗漏相关。具体目标 1 将使用小鼠肾内皮细胞 (EC) 的原代培养物，通过使用药物抑制剂和 siRNA 方法来确定 TNF 诱导的内皮屏障功能障碍的机制，并将研究 TNF 对细胞骨架破坏的影响。具体目标 2 将使用过度表达和缺乏肌球蛋白轻链激酶 (MLCK) 内皮亚型的转基因小鼠来确定这种内皮屏障功能障碍在 LPS 诱导的急性肾衰竭 (ARF) 过程中的作用。还将施用维持内皮屏障完整性的 1-磷酸鞘氨醇类似物，以确定对 LPS 诱导的 ARF 的影响。肾交叉移植将被用作定义肾脏相对于全身内皮损伤的贡献的工具，并且长期植入的血压和肾流量探针装置将允许实时测量肾内血流动力学，以响应内毒素血症情况下的上述操作。具体目标 3 将检验 TNF 诱导的 caspase 激活会放大肾内皮炎症的假设，并将定义这种串扰发生的机制，其中可能涉及 MLCK 和其他细胞骨架事件。具体目标 4 将使用缺乏 caspase-8 的内皮特异性基因敲除小鼠和具有无功能 NF-κB 的内皮特异性转基因小鼠，以区分内皮细胞凋亡和炎症对 LPS 诱导的 ARF 结果的各自贡献。该项目将共同开发工具，让人们更好地了解内皮损伤的重要性和机制及其在脓毒性 ARF 中的作用。 公共卫生相关性：急性肾衰竭 (ARF) 是住院患者的常见并发症，导致很高的发病率和死亡率，通常是由大量感染引起的。该项目检验了这样的假设：血管内皮细胞的损伤和炎症是 ARF 的一个重要原因。在该提案中，使用内皮功能改变的菌株进行的动物实验和细胞培养实验将有助于人们更好地了解 ARF 的机制，从而最终为该综合征提供更合理、更有针对性的治疗方法。