Regulation of Inflammation by the Fibrinolytic System

纤溶系统对炎症的调节

• 批准号: 10693590
• 负责人: STEVEN L. GONIAS
• 金额: $ 39.5万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-10 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10693590
• 关键词: Address; Adult; Alteplase; Alternative Splicing; Alzheimer' s Disease; Anti-Inflammatory Agents; Apolipoprotein E; Astrocytes; Attenuated; Automobile Driving; Binding; Brain; Breeding; Cell surface; Cells; Clinical; Colitis; Data; Disease; Disease Progression; Elements; Fibrinolysis; Functional disorder; Funding; Gene Deletion; Gene Expression; Genes; Genetic Polymorphism; Goals; Grant; Human; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Response; Interferon Type II; Knockout Mice; LDL-Receptor Related Protein 1; Ligands; Lipopolysaccharides; Lipoprotein Receptor; Lipoproteins; MAPT gene; Macrophage; Mediating; Membrane; Membrane Microdomains; Metalloproteases; Microglia; Mus; Mutate; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; NGFR Protein; Natural Immunity; Nerve Degeneration; Neurofibrillary Tangles; Neurons; Oligodendroglia; Pathogenesis; Pathologic; Pathway interactions; Peptide Hydrolases; Peripheral; Phosphorylation; Physiology; Plasminogen Activator; Play; Post-Translational Protein Processing; PrP; Probability; Proteins; Receptor Signaling; Regulation; Role; Signal Pathway; Signal Transduction; Sodium Dextran Sulfate; System; TLR2 gene; TLR4 gene; TLR7 gene; Tauopathies; Testing; Toll-like receptors; Transgenic Mice; United States National Institutes of Health; Work; alpha 2-Glucoproteins; central sensitization; exosome; extracellular; extracellular vesicles; glial activation; in vivo; inhibitor; injured; knockout gene; monocyte; mouse model; mutant; neuroinflammation; novel; pain processing; parent grant; promoter; receptor; response; tau aggregation; tau function; tau interaction

Project Summary/Abstract Low Density Lipoprotein Receptor-related Protein-1 (LRP1) functions as an endocytic and cell-signaling receptor for the fibrinolysis protease, tissue-type plasminogen activator (tPA). Binding of tPA to LRP1 in macrophages generates an anti-inflammatory response in which the activity of multiple Toll-like Receptors is attenuated. This response requires LRP1 co-receptors, including the NMDA Receptor, which is essential. Because LRP1 has numerous structurally and functionally diverse ligands, it is extremely important to understand whether different ligands generate distinct signaling responses. The microtubule-associated protein, TAU, is a recently identified LRP1 ligand which accumulates in the CNS in various forms of neurodegeneration and is a major driver of the pathophysiology observed in Alzheimer's Disease (AD). Using cultured macrophages, we have shown that TAU elicits responses that are distinct from those elicited from tPA; in fact, TAU functions as an LRP1-dependent pro- inflammatory factor. Neuro-inflammation is highly important in AD and we hypothesize that interaction of TAU with microglial LRP1 in the brain is a major driver of microglial activation, neuro-inflammation, and AD pro- gression. Mechanistically, we have evidence that TAU activates pathways that release LRP1 from the cell surface, converting the anti-inflammatory membrane-anchored receptor into a highly pro-inflammatory soluble derivative (shed LRP1). The major goal of this supplement to parent grant R01 HL136395 is to test our hypo- thesis that the receptor system under study in the parent grant is subjugated by TAU in the CNS to drive neuro- inflammation in AD. Two specific aims are proposed. In Specific Aim 1, we will characterize the interaction of TAU with LRP1 in cultured microglia and test the hypothesis that this interaction stimulates LRP1 shedding, which activates microglia and promotes inflammation. Although our previous work suggests that the activities of LRP1 ligands are conserved in macrophages and microglia, it is imperative that we test this hypothesis directly in microglia. The effects of TAU on LRP1 shedding, microglial physiology, cell-signaling, and inflammatory mediator expression will be considered. Microglia will be isolated from adult conditional gene knock-out mice to confirm the role of LRP1 and test whether co-receptors are involved. In Specific Aim 2, we will study the effects of microglial LRP1 on neuro-inflammation and the pathophysiology that develops in transgenic mice that express the P301S mutant of human TAU. These mice develop spontaneous TAU aggregates that are eventually lethal and neuro-inflammation plays a central role in the pathogenesis of disease. Neutralization of LRP1 expression in microglia in these mice will be accomplished by breeding with mice in which Lrp1 is deleted conditionally under the control of promoter systems active in microglia. These studies represent an important extension of R01 HL136395 with significant potential to generate an independent NIH-funded grant focusing on a completely novel pathway for neuro-inflammation in AD.

项目总结/摘要 低密度脂蛋白受体相关蛋白-1（LRP 1）作为内吞和细胞信号受体发挥作用 纤溶蛋白酶，组织型纤溶酶原激活剂（tPA）。巨噬细胞中tPA与LRP 1的结合 产生抗炎反应，其中多种Toll样受体的活性减弱。这 反应需要LRP 1辅助受体，包括NMDA受体，这是必不可少的。因为LRP 1具有 许多结构和功能上不同的配体，理解是否不同是非常重要的。 配体产生不同的信号传导应答。微管相关蛋白TAU是最近发现的一种新的微管相关蛋白。 LRP 1配体以各种形式的神经变性在CNS中积累，并且是神经变性的主要驱动因素。 在阿尔茨海默病（AD）中观察到的病理生理学。使用培养的巨噬细胞，我们已经表明，TAU 与tPA引起的反应不同的诱发反应;事实上，TAU作为LRP 1依赖性前体发挥作用， 炎症因子神经炎症在AD中非常重要，我们假设TAU的相互作用 脑中的小胶质细胞LRP 1是小胶质细胞活化、神经炎症和AD前体的主要驱动因素。 格雷辛。从机制上讲，我们有证据表明TAU激活了从细胞中释放LRP 1的途径 表面，将抗炎膜锚定受体转化为高度促炎的可溶性 衍生物（脱落LRP 1）。本补充父母补助金R 01 HL 136395的主要目标是测试我们的低血糖， 论文认为，受体系统正在研究中的父母赠款是屈从于TAU在中枢神经系统，以驱动神经元， AD炎症提出了两个具体目标。在具体目标1中，我们将描述 TAU与LRP 1在培养的小胶质细胞中的相互作用，并测试这种相互作用刺激LRP 1脱落的假设， 从而激活小胶质细胞并促进炎症虽然我们以前的工作表明， LRP 1配体在巨噬细胞和小胶质细胞中是保守的，我们必须直接验证这一假设 在小胶质细胞中。TAU对LRP 1脱落、小胶质细胞生理学、细胞信号传导和炎症的影响 将考虑中介表达。将从成年条件基因敲除小鼠中分离小胶质细胞 以确认LRP 1的作用，并测试是否涉及辅助受体。在具体目标2中，我们将研究 小胶质细胞LRP 1对转基因小鼠神经炎症和病理生理学的影响， 表达人TAU的P301 S突变体。这些小鼠产生自发的TAU聚集体， 最终致命的神经炎症在疾病的发病机制中发挥着核心作用。中和 这些小鼠中小胶质细胞中LRP 1的表达将通过与LRP 1缺失的小鼠交配来实现 在小胶质细胞中有活性的启动子系统的控制下。这些研究代表了一个重要的 R 01 HL 136395的扩展，具有产生独立NIH资助赠款的巨大潜力，重点是 AD中神经炎症的全新途径。