The Role of Pericytes in Brain Hypoperfusion in Alzheimer's Disease Development

周细胞在阿尔茨海默病发展中脑灌注不足中的作用

• 批准号: 10654982
• 负责人: Hongkuan Fan
• 金额: $ 62.07万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-15 至 2028-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10654982
• 关键词: Address; Age Months; Alzheimer' s Disease; Alzheimer' s disease model; Alzheimer' s disease patient; Amyloid; Amyloid beta-Protein; Animals; Antisense Oligonucleotides; Apoptosis; Astrocytes; Blood - brain barrier anatomy; Blood Vessels; Blood brain barrier dysfunction; Blood capillaries; Brain; Brain region; CASP1 gene; CASP3 gene; Cell Adhesion Molecules; Cells; Cerebrovascular Circulation; Cessation of life; Cytometry; Data; Deposition; Development; Disease Progression; Endothelial Cells; Enzyme-Linked Immunosorbent Assay; Extravasation; FLI1 Transcription Factor; FLI1 gene; Functional disorder; Goals; Hippocampus; Histological Techniques; Human; Image; Imaging Techniques; Impaired cognition; Impairment; In Situ Nick-End Labeling; Infiltration; Inflammation Mediators; Inflammatory; Injections; Intrathecal Injections; Knock-out; Learning; Macrophage; Magnetic Resonance Imaging; Measures; Memory; Memory impairment; Microglia; Mus; Neurodegenerative Disorders; Onset of illness; Pericytes; Play; Process; Proteins; Resolution; Role; Superior temporal gyrus; Symptoms; Testing; Tissues; Up-Regulation; Vascular Diseases; abeta accumulation; arterial spin labeling; blood-brain barrier disruption; brain tissue; cerebral capillary; cerebrovascular amyloid; clinically relevant; comparison control; design; hypoperfusion; in vivo; knock-down; monocyte; morris water maze; mouse model; neuroinflammation; neurovascular; neurovascular unit; neutrophil; non-invasive imaging; novel; object recognition; response; therapeutic evaluation; treatment strategy

PROJECT SUMMARY/ABSTRACT Vascular dysfunction, such as decreases in cerebral blood flow (CBF) and disruption of the blood brain barrier (BBB) are early symptoms of Alzheimer’s disease (AD) and could contribute to AD onset and progression. In the brain, specialized cells called pericytes are integral to proper vascular function, as they play a major role in regulating CBF and maintaining BBB integrity. However, the processes that govern pericyte dysfunction and the role of pericytes in decreases of CBF in AD development have not been fully elucidated. Our previous studies have demonstrated that increases in the transcription factor Fli-1 are associated with pericyte dysfunction and viability via up-regulation of caspase-1 expression. Our preliminary data demonstrated that Fli-1 levels were higher in the hippocampus and superior temporal gyrus regions of brain tissue from AD patients compared to controls. Pericytes undergo apoptosis in the hippocampus of AD patients, and pericyte Fli-1 levels were increased in AD patients. In addition, TNF and aggregated amyloid- induced Fli-1 expression in cultured human brain pericytes. Furthermore, amyloid- induced pericyte apoptosis, as evidenced by decreased pericyte viability, increased TUNEL positive cells, and increased expression of apoptosis marker caspase-3. Knockdown of Fli-1 with antisense oligonucleotide Gapmers suppressed amyloid--induced pericyte death, apoptosis, and caspase-3 levels. Thus, increased Fli-1 levels in AD patients may lead to pericyte loss. To determine the cause- effect relationship between increased Fli-1 and AD development, we conducted studies in the 5xFAD mouse model. Fli-1 levels were higher in the hippocampus in 5xFAD mice and corresponded with spatial learning and memory impairment in Novel Object Recognition and Morris Water Maze tests. Injection of Fli-1 Gapmer into the hippocampus significantly decreased Fli-1 and inflammatory mediator levels, mitigated pericye loss and vascular leakage, suppressed adhesion molecule levels, reduced A deposition, and ameliorated spatial learning and memory impairment. These data provide the first evidence that increased Fli-1 levels contribute to AD development. We hypothesize that the transcription factor Fli-1 elevation in Alzheimer's disease leads to pericyte dysfunction and brain hypoperfusion. Three specific aims are proposed to address this hypothesis: Aim 1: Determine how Fli-1 regulates pericyte and neurovascular cell dysfunction in a mouse AD model. Aim 2: Elucidate the mechanisms by which pericyte dysfunction results in brain hypoperfusion and cognitive impairment in a mouse AD model. Aim 3: Test the therapeutic potential of intrathecal administration of Fli-1 Gapmers in mouse AD models. The successful completion of the proposed studies will result in a better understanding of the role of Fli-1 in regulating pericyte dysfunction in AD and the development of a novel treatment strategy for AD.

项目总结/摘要 血管功能障碍，如脑血流量（CBF）减少和血脑屏障破坏 (BBB)是阿尔茨海默病（AD）的早期症状，并可能导致AD的发作和进展。在 在大脑中，被称为周细胞的专门细胞是正常血管功能不可或缺的，因为它们在 调节CBF和维持BBB完整性。然而，控制周细胞功能障碍的过程和 周细胞在AD发展中CBF减少中的作用尚未完全阐明。我们以前的研究 已经证明转录因子Fli-1的增加与周细胞功能障碍有关， 通过上调caspase-1的表达来提高存活率。我们的初步数据表明，Fli-1水平是 在AD患者的脑组织的海马和上级颞回区域中， 对照AD患者海马区周细胞发生凋亡，周细胞Fli-1水平与AD患者海马区周细胞Fli-1水平相关。 AD患者增加。此外，TNF α和聚集的淀粉样蛋白β诱导Fli-1在培养的细胞中表达。 人脑周细胞此外，淀粉样蛋白诱导周细胞凋亡，表现为周细胞减少 存活率、TUNEL阳性细胞增加和凋亡标志物caspase-3表达增加。敲低 Fli-1与反义寡核苷酸Gapmers的联合作用抑制了淀粉样蛋白β诱导的周细胞死亡、凋亡， caspase-3水平。因此，AD患者中增加的Fli-1水平可能导致周细胞损失。为了确定原因- Fli-1增加与AD发展之间的关系，我们在5xFAD小鼠中进行了研究 模型Fli-1在5xFAD小鼠的海马中的水平较高，并且与空间学习相对应， 在新物体识别和Morris水迷宫测试中的记忆损伤。将Fli-1 Gapmer注射到 海马显著降低Fli-1和炎症介质水平，减轻周细胞丢失和血管 渗漏，抑制粘附分子水平，减少A β沉积，改善空间学习， 记忆受损这些数据提供了增加Fli-1水平有助于AD的第一个证据 发展我们假设阿尔茨海默病中转录因子Fli-1的升高导致了 周细胞功能障碍和脑灌注不足。针对这一假设，提出了三个具体目标： 目的1：确定Fli-1如何调节小鼠AD模型中的周细胞和神经血管细胞功能障碍。目标二： 阐明周细胞功能障碍导致脑灌注不足和认知障碍的机制 在小鼠AD模型中。目的3：测试在小鼠中鞘内施用Fli-1缺口体的治疗潜力。 小鼠AD模型。成功完成拟议的研究将使人们更好地了解 Fli-1在调节AD中周细胞功能障碍中的作用以及开发一种新的治疗策略， AD.