Flow-Induced Endothelial Innate Immunity and Atherosclerosis Susceptibility

血流诱导的内皮先天免疫和动脉粥样硬化易感性

• 批准号: 9185542
• 负责人: John YJ Shyy
• 金额: $ 43.79万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-05 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9185542
• 关键词: Animal Experiments; Apolipoprotein E; Atherosclerosis; Binding; Biosensor; Blood Circulation; Blood Vessels; Blood flow; CASP1 gene; Characteristics; Core Protein; Data; Endothelial Cells; Endothelium; Etiology; Event; FHA Domain; Family; Fluorescence Resonance Energy Transfer; Foundations; Functional disorder; Goals; Immune response; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Interleukin-1 beta; Interleukin-18; Knock-in; Knock-in Mouse; Knock-out; Knowledge; Light; Link; Localized Disease; Mechanics; Mediator of activation protein; Molecular; Monitor; Natural Immunity; Pattern; Phenotype; Phosphorylation; Physiological; Post-Translational Protein Processing; Predisposition; Proteins; Reporter; Reporting; Risk Factors; Role; SRE-2 binding protein; Signal Transduction; Stimulus; TNF Receptor-Associated Factors; Testing; Threonine; Transactivation; Transcriptional Activation; Trees; Vascular Endothelial Cell; atherogenesis; base; bioimaging; cytokine; disorder prevention; endothelial dysfunction; in vivo; macrophage; marenostrin; monocyte; mouse model; receptor; research study; response; shear stress; spatiotemporal; tool; vascular inflammation

Project Summary Atheroprone flow-induced endothelial dysfunction, characterized by enhanced inflammatory response, is an early vascular event leading to the focal distribution of atherosclerosis. Despite the causality between atheroprone flow pattern and endothelial dysfunction, key molecular events linking mechanical stimuli to the pro-inflammatory phenotype of vascular endothelial cells (ECs) and the consequent susceptibility to atherogenesis remain poorly understood. We recently demonstrated that atheroprone flow activates sterol regulatory element binding protein 2 (SREBP2) in ECs, which induces the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome through transcriptional induction (i.e., Signal 1) and higher-order assembly (i.e., Signal 2). Such unresolved EC innate immune response leads to endothelial dysfunction and ensuing atherosclerosis. We have also identified that atheroprone flow induces TRAF-interacting protein with a forkhead-associated (FHA) domain (TIFA). Newly performed experiments indicate that SREBP2 transcriptionally upregulates TIFA and inflammasome components (Signal 1), and that phosphorylated TIFA Threonine-9 (TIFA pT9) oligomerizes TIFA leading to the higher-order assembly of NLRP3 inflammasome (Signal 2). These observations provide the foundation for the guiding hypothesis that atheroprone flow, through transcriptional induction and post-translational modification of TIFA, activates NLRP3 inflammasome in the endothelium, which contributes to atherosclerosis susceptibility. Three Specific Aims are proposed to test this hypothesis. Specific Aim 1 will elucidate the molecular mechanism by which atheroprone flow primes the induction of the NLRP3 inflammasome through Signal 1. In vitro flow channel experiments with oscillatory shear stress (OS) simulating atheroprone flow will be used to elucidate the transcriptional cascade of SREBP2-TIFA-NLRP3 inflammasome that respond to atheroprone flow. Specific Aim 2 will delineate the molecular basis by which atheroprone flow activates the NLRP3 inflammasome via Signal 2. Specifically, mechanobiology and FRET-based bioimaging will be used to investigate the role of TIFA pT9 in the higher-order assembly of NLRP3 inflammasome in ECs in response to atheroprone flow. Specific Aim 3 will investigate the role of atheroprone flow-activated SREBP2-TIFA-NLRP3 inflammasome in endothelial dysfunction, leading to atherosclerosis in vivo. We will examine endothelial function, vascular inflammation, and atherosclerosis in EC-SREBP2-/-, TIFA-/-, and TIFA T9A knock-in mice with or without an ApoE-/- background. The proposed experimental approaches that combine vascular, mechanobiological, biosensor, and animal experiments will systemically analyze the mechano and molecular basis of atheroprone flow-induced innate immune response in ECs and its functional relevance to atherosclerosis susceptibility.

项目摘要 Atheroprone流量诱导的内皮功能障碍，其特征在于增强的炎症反应，是一种炎症反应。 早期血管事件导致动脉粥样硬化灶性分布。尽管因果关系 动脉粥样硬化酮流动模式和内皮功能障碍，关键分子事件连接机械刺激， 血管内皮细胞（EC）的促炎表型和随之而来的对 对动脉粥样硬化形成仍然知之甚少。我们最近证明了阿色罗酮流激活固醇 调节元件结合蛋白2（SREBP 2）在内皮细胞中，诱导NOD样受体家族，pyrin 结构域3（NLRP 3）炎性体通过转录诱导（即，信号1）和高阶 组件（即，信号2）。这种未解决的EC先天免疫应答导致内皮功能障碍， 继而发生动脉粥样硬化。我们还发现，动脉粥样硬化酮流诱导TRAF相互作用蛋白， 叉头相关结构域（FHA）。新进行的实验表明，SREBP 2 转录上调TIFA和炎性体组分（信号1），磷酸化TIFA ThreeThrin-9（TIFA pT 9）寡聚化TIFA，导致NLRP 3炎性体的高阶组装 （信号2）。这些观察结果为指导性假设提供了基础， 通过TIFA的转录诱导和翻译后修饰，激活NLRP 3 内皮中的炎性小体，其有助于动脉粥样硬化的易感性。三个具体 目的是为了检验这一假设。具体目标1将阐明分子机制， atheroprone流动通过信号1引发NLRP 3炎性小体的诱导。体外流道 振荡剪切应力（OS）模拟动脉粥样硬化流动的实验将用于阐明 SREBP 2-TIFA-NLRP 3炎性体的转录级联反应，其响应于动脉粥样硬化酮流动。具体 目的2将描述动脉粥样硬化酮流动激活NLRP 3炎性小体的分子基础， 信号2。具体而言，机械生物学和基于FRET的生物成像将用于研究TIFA的作用 内皮细胞中NLRP 3炎性小体的高阶组装中的pT 9对动脉粥样硬化酮流动的响应。具体 目的3将研究动脉粥样硬化酮流动激活的SREBP 2-TIFA-NLRP 3炎性小体在炎症反应中的作用。 内皮功能障碍，导致体内动脉粥样硬化。我们将检查内皮功能，血管 炎症和动脉粥样硬化在EC-SREBP 2-/-、TIFA-/-和TIFA T9 A敲入小鼠中的表达， ApoE-/-背景。所提出的实验方法，联合收割机血管，机械生物学， 生物传感器和动物实验将系统地分析动脉粥样硬化酮的机制和分子基础 内皮细胞中流动诱导的先天免疫应答及其与动脉粥样硬化易感性的功能相关性。