Interplay between meningeal lymphatics, high-density lipoproteins and border macrophages in cerebral amyloid angiopathy

脑淀粉样血管病中脑膜淋巴管、高密度脂蛋白和边界巨噬细胞之间的相互作用

• 批准号: 10674681
• 负责人: Gwendalyn J Randolph
• 金额: $ 57.84万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10674681
• 关键词: ATP binding cassette transporter 1; Address; Affect; Alzheimer' s Disease; Amyloid beta-Protein; Behavior; Bile fluid; Blood; Blood Circulation; Blood Vessels; Blood flow; Brain; Cell membrane; Cells; Cerebral Amyloid Angiopathy; Cerebral hemisphere hemorrhage; Cholesterol; Chronic; Coupling; Data; Dendritic Cells; Deposition; Disease; Disease Progression; Endocytosis; Experimental Models; Genetic; Health; High Density Lipoproteins; Hour; Human; Image; Impairment; Investigational Therapies; Knock-in Mouse; Laboratories; Leptomeninges; Lesion; Light; Link; Lipoproteins; Liquid substance; Literature; Liver; Lymph; Lymphatic; Macrophage; Mediating; Mediator; Membrane Transport Proteins; Meningeal; Meningeal lymphatic system; Meninges; Modeling; Mus; Natural Immunity; Organ; Penetration; Peptides; Phagocytosis; Phenotype; Plasma; Process; Proteins; Role; Signal Transduction; Site; Testing; Therapeutic Intervention; Thinness; Tissues; Tunica Adventitia; Vascular Diseases; abeta deposition; apolipoprotein E-4; arteriole; blood-brain barrier crossing; brain parenchyma; confocal imaging; cranium; epidemiology study; improved; interest; interstitial; intravital imaging; lymph flow; lymphatic circulation; lymphatic vasculature; monocyte; mouse model; neuroimmunology; porcine model; restraint; reverse cholesterol transport; spatial relationship; tool; trafficking; two-photon; vascular inflammation; β-amyloid burden

ABSTRACT – project 3 The Randolph lab studies vascular inflammation and has a long-standing interest in the egress of cells and molecules that impact chronic vascular diseases. With a track record in studying the trafficking of monocytes (and the cells they become), we later began studying the transit of apoA1-enriched high-density lipoprotein (HDLA1) through tissues. We demonstrated that liver-derived HDLA1 leaves most tissue parenchyma through lymphatics to mediate reverse cholesterol transport, a process whereby cholesterol from cells in various body organs is picked up by HDLA1 and returned to the liver for disposal in bile. Reverse cholesterol transport regulates macrophage phenotype in various diseases, as macrophages readily accumulate cholesterol. On the other hand, macrophages also efficiently transfer cholesterol to HDLA1 via the membrane transporter ABCA1 in a process called cholesterol efflux. If cholesterol efflux is impaired, for example from reduction of HDLA1, cholesterol accumulates in signaling domains at the plasma membrane to affect the phenotype and activation status of macrophages. Overall, macrophages and lymphatics provide two distinct means for tissue clearance of metabolites, debris, and other mediators--one via endocytosis or phagocytosis and the other via fluid transport--and HDLA1 bridges these mechanisms. We have developed and validated a knock-in mouse line expressing photoactivatable GFP linked to apoA1, to quantitatively track endogenous HDLA1 after photo- activating a tissue of interest. Although little HDLA1 crosses the blood-brain barrier to enter the brain, HDLA1 enters the meningeal interstitium. Indeed, preliminary data reveal that the HDLA1 can be tagged by shining 405 nm light on the thinned skullbone as the HDLA1 passes through the meninges. Phototagged meningeal HDLA1 reaches the blood circulation one hour later, but only under conditions when the meningeal draining lymphatic vasculature is intact. Epidemiological studies in cerebral amyloid angiopathy (CAA), a disease broadly associated with Alzheimer’s disease (AD) and characterized by A deposition in the adventitia of the penetrating and meningeal arterioles, identify HDLA1 levels as inversely correlated with cerebral hemorrhage associated with CAA. A connection between HDLA1 and CAA is directly supported by genetic and experimental therapeutic interventions in mice. However, detailed mechanistic studies to unravel how HDLA1 affects CAA have not been conducted. Using the 5XE4fl/fl murine model of CAA developed by the Holtzman laboratory, we will herein focus on unraveling the role of HDLA1 in CAA by coupling use of our HDLA1 phototag tool with approaches to interrogate its connection to lymphatic and blood flow (aim 1), to monocyte/macrophage phenotype (aim 2), and to disease progression overall (aim 3). We here will test the hypothesis that HDLA1 restrains CAA and that its meningeal transit is impaired during CAA. By contrast, in states of health, we propose that it functionally maintains meningeal interstitial flow into lymphatics by interacting with and governing the phenotype of meningeal macrophages, including parenchymal border macrophages (PBM).

摘要 – 项目 3 伦道夫实验室研究血管炎症，长期以来对细胞的流出和 影响慢性血管疾病的分子。在研究单核细胞贩运方面拥有良好记录 （以及它们变成的细胞），我们后来开始研究富含 apoA1 的高密度脂蛋白的转运 (HDLA1) 通过组织。我们证明，肝源性 HDLA1 通过以下途径离开大部分组织实质： 淋巴管介导胆固醇逆向运输，这是胆固醇从身体各个细胞中排出的过程 器官被 HDLA1 拾取并返回肝脏并在胆汁中处理。胆固醇逆向转运 调节各种疾病中的巨噬细胞表型，因为巨噬细胞很容易积聚胆固醇。上 另一方面，巨噬细胞还通过膜转运蛋白 ABCA1 有效地将胆固醇转移至 HDLA1 一个称为胆固醇流出的过程。如果胆固醇流出受损，例如 HDLA1 减少， 胆固醇在质膜的信号传导域中积聚，影响表型和激活 巨噬细胞的状态。总体而言，巨噬细胞和淋巴管提供两种不同的组织清除方式 代谢物、碎片和其他介质——一种通过内吞作用或吞噬作用，另一种通过液体 传输——HDLA1 桥接了这些机制。我们开发并验证了敲入小鼠品系 表达与 apoA1 连接的可光激活 GFP，以定量追踪光后内源性 HDLA1 激活感兴趣的组织。虽然 HDLA1 很少能穿过血脑屏障进入大脑，但 HDLA1 进入脑膜间质。事实上，初步数据显示 HDLA1 可以通过闪亮 405 进行标记 当 HDLA1 穿过脑膜时，纳米光照射在变薄的颅骨上。光标记脑膜 HDLA1 一小时后到达血液循环，但前提是脑膜引流淋巴管 脉管系统完好无损。脑淀粉样血管病（CAA）的流行病学研究，一种广泛的疾病 与阿尔茨海默病 (AD) 相关，其特征是 A 沉积在外膜中 穿透动脉和脑膜动脉，确定 HDLA1 水平与脑出血呈负相关 与 CAA 相关。 HDLA1 和 CAA 之间的联系得到遗传和实验的直接支持 对小鼠的治疗干预。然而，详细的机制研究揭示了 HDLA1 如何影响 CAA 尚未进行。使用 Holtzman 实验室开发的 5XE4fl/fl CAA 小鼠模型，我们 本文将重点通过将我们的 HDLA1 照片标签工具与 询问其与淋巴和血流（目标 1）、与单核细胞/巨噬细胞的联系的方法 表型（目标 2），以及总体疾病进展（目标 3）。我们在这里将检验 HDLA1 的假设 抑制 CAA 且其脑膜转运在 CAA 期间受损。相比之下，在健康状态下，我们 提出它通过与 和 相互作用来功能性地维持脑膜间质流入淋巴管 控制脑膜巨噬细胞的表型，包括实质边界巨噬细胞（PBM）。