Investigating the cause of cerebral blood flow reductions in a mouse model of frontotemporal dementia

探讨额颞叶痴呆小鼠模型脑血流量减少的原因

• 批准号: 10525598
• 负责人: Oliver Bracko
• 金额: $ 41.08万
• 依托单位: UNIVERSITY OF MIAMI CORAL GABLES
• 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 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10525598
• 关键词: Alzheimer' s Disease; Alzheimer' s disease model; Antibodies; Behavioral Assay; Blood - brain barrier anatomy; Blood Cells; Blood Vessels; Blood capillaries; Blood flow; Candidate Disease Gene; Cell surface; Cells; Cerebrovascular Circulation; Characteristics; Cognitive deficits; Data; Data Set; Databases; Dementia; Development; Disease; Endothelial Cells; Endothelium; Fluorescence; Frontotemporal Dementia; Functional Imaging; Functional disorder; Gene Proteins; Grant; Image; Imaging Device; Impaired cognition; Impairment; Individual; Inflammation; Label; Leukocytes; Light; Link; Measures; Membrane; Microcirculation; Microglia; Microvascular Dysfunction; Modeling; Molecular; Molecular Abnormality; Mus; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Obstruction; Oxidative Stress; PGRN gene; Pathologic; Pathology; Pathway Analysis; Pathway interactions; Patients; Pericytes; Pharmaceutical Preparations; Prefrontal Cortex; Protein Analysis; Proteomics; Reporter; Resolution; Role; Severities; Short-Term Memory; Site; Symptoms; Thinness; Tissues; Wild Type Mouse; Work; cell type; constriction; density; excitotoxicity; experimental study; fluorescence imaging; imaging approach; improved; in vivo; in vivo Model; in vivo imaging; insight; loss of function mutation; mouse model; multiphoton imaging; multiple omics; neurovascular unit; neutrophil; new therapeutic target; novel; novel therapeutic intervention; novel therapeutics; protein degradation; transcriptome; transcriptome sequencing; transcriptomics; two-photon; vascular contributions; vascular inflammation

Summary: Substantial reductions in brain blood flow are found in patients and mouse models of neurodegenerative diseases, including frontotemporal dementia (FTD). These blood flow reductions likely contribute to disease symptoms and progression, but the mechanism remains unknown. Recently, two new mechanisms contributing to brain blood flow reductions in Alzheimer's disease were proposed. Interestingly, both capillary stalling and pericyte constriction are associated with microvasculature dysfunction. In preliminary experiments, the PI has shown that capillary stalling found in Alzheimer's disease mice, also occurs in Progranulin (PGRN) deficient mice, a model for FTD. Thus, the project proposed here will investigate the contribution of stalled blood flow and pericyte constriction in capillaries to brain blood flow reductions. Further, this project aims to elucidate the mechanism behind these phenomena using transcriptome analyses and cell-surface proteomics of microvessels from PGRN-deficient mice. The pathology and region predicted to suffer from blood flow reductions in the PGRN deficient mice is the prefrontal cortex, which can be readily studied with the two-photon excited fluorescence imaging tools used previously by the PI. Preliminary data suggests that PRGN-deficient mice display increased capillary stalling caused by white blood cells adhered to the endothelium. For Aim 1, we will use high-resolution, multiphoton, in vivo imaging approaches to structurally and functionally determine blood flow rates in individual capillaries, measure capillary stalling and pericyte constriction, and their interplay. This data will identify the cause of brain blood flow reduction associated with FTD. Aim 2 will elucidate the molecular mechanism linking vascular inflammation to brain blood flow reductions in PGRN-deficient mice by using transcriptomic and cell-surface proteomics to profile microvessels. These experiments will generate two datasets that will allow us to pinpoint molecular aberrations in microvessels of PGRN deficient mice. The data will also shed light on the role of vascular inflammation and vascular obstructions contributing to blood flow reductions. Selected genes and proteins identified in these screens will be independently confirmed and later further analyzed by functional in vivo multiphoton imaging, labeling antibodies, inhibiting drugs, and/or cell-type-specific mouse models. We predict that candidate genes and proteins will be involved in vascular inflammation and associated with oxidative stress, blood-brain barrier breakdown, protein degradation, and lysosomal dysfunction. The idea of capillary stalling is new, and - if confirmed -, could represent a mechanism contributing to brain blood flow reductions in neurodegenerative disease in general, and not just specifically to FTD. If correct, novel therapeutic strategies targeting microvascular inflammation could be developed to improve brain blood flow in patients with FTD and possibly in other neurogenerative diseases with reductions in brain blood flow.

总结：在脑出血患者和小鼠模型中发现了脑血流量的大量减少。 神经退行性疾病，包括额颞叶痴呆（FTD）。这些血流量的减少 有助于疾病症状和进展，但机制仍不清楚。 最近，两个新的机制，有助于脑血流量减少阿尔茨海默氏病， 提出了有趣的是，毛细血管停滞和周细胞收缩都与微血管有关， 功能障碍在初步实验中，PI表明阿尔茨海默病中发现了毛细血管停滞 小鼠，也发生在颗粒蛋白原（PGRN）缺陷小鼠（FTD模型）中。因此，这里提出的项目 将研究停滞的血流和毛细血管中的周细胞收缩对脑血流的贡献 减少。此外，该项目旨在阐明这些现象背后的机制， 转录组分析和细胞表面蛋白质组学的PGRN缺陷小鼠的微血管。 预测在PGRN缺陷型小鼠中遭受血流减少的病理和区域是 前额叶皮层，这可以很容易地研究与双光子激发荧光成像工具使用 此前，PI初步数据表明，PRGN缺陷小鼠显示毛细血管停滞增加 由粘附在内皮上的白色血细胞引起。对于目标1，我们将使用高分辨率，多光子， 体内成像方法在结构上和功能上确定单个毛细血管中的血流速率， 测量毛细血管停滞和周细胞收缩，以及它们之间的相互作用。这些数据将确定 FTD相关的脑血流量减少。 目的2将阐明血管炎症与脑血流量减少之间的分子机制， 通过使用转录组学和细胞表面蛋白质组学来分析微血管的PGRN缺陷小鼠。这些 实验将产生两个数据集，这将使我们能够精确定位微血管中的分子畸变， PGRN缺陷小鼠。这些数据还将阐明血管炎症和血管炎性反应的作用。 导致血流减少的阻塞。在这些筛选中鉴定的选定基因和蛋白质 将被独立确认，随后通过功能性体内多光子成像、标记 抗体、抑制药物和/或细胞类型特异性小鼠模型。我们预测候选基因和 蛋白质将参与血管炎症并与氧化应激、血脑屏障 分解、蛋白质降解和溶酶体功能障碍。 毛细血管停滞的想法是新的，如果得到证实，可能代表了一种有助于大脑的机制。 一般神经退行性疾病的血流量减少，而不仅仅是FTD。如果正确的话， 可以开发针对微血管炎症的新治疗策略来改善脑血流量， FTD患者和可能存在脑血流减少的其他神经退行性疾病患者的脑血流。