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

项目摘要/摘要 血管功能障碍，如脑血流量减少和血脑屏障破坏 血脑屏障(BBB)是阿尔茨海默病(AD)的早期症状，可能导致AD的发生和发展。在 大脑中称为周细胞的特殊细胞对正常的血管功能是不可或缺的，因为它们在 调节脑血流量，维护血脑屏障完整性。然而，控制周细胞功能障碍的过程和 周细胞在阿尔茨海默病发生发展中降低脑血流量中的作用尚未完全阐明。我们之前的研究 已经证明转录因子Fli-1的增加与周细胞功能障碍和 通过上调caspase-1的表达而存活。我们的初步数据显示Fli-1水平是 与AD患者相比，AD患者脑组织中海马区和颞上回区域的表达更高 控制。AD患者海马区周细胞发生凋亡，周细胞Fli-1水平明显升高。 在AD患者中升高。此外，肿瘤坏死因子和聚集性淀粉样蛋白-诱导培养的细胞表达Fli-1。 人脑周细胞。此外，淀粉样蛋白-诱导周细胞凋亡，周细胞减少为证据。 TUNEL阳性细胞数增加，凋亡标记物caspase-3表达增加。击倒 Fli-1与反义寡核苷酸Gapmer联合抑制淀粉样蛋白诱导的周细胞死亡、凋亡和 Caspase-3水平。因此，AD患者Fli-1水平升高可能导致周细胞丢失。为了确定原因- Fli-1升高与AD发生发展的作用关系，我们在5xFAD小鼠中进行了研究 模特。5xFAD组小鼠海马区的Fli-1水平较高，且与空间学习和 新物体识别和Morris水迷宫测试中的记忆障碍。Fli-1Gapmer注射入脑内 海马区显著降低Fli-1和炎症介质水平，减轻眼周和血管丢失 渗漏，抑制黏附分子水平，减少A沉积，并改善空间学习和 记忆力受损。这些数据首次提供了Fli-1水平升高导致AD的证据 发展。我们假设转录因子Fli-1在阿尔茨海默病中的升高导致 周细胞功能障碍和脑低灌流。为了解决这一假设，我们提出了三个具体目标： 目的1：确定Fli-1对AD模型小鼠周细胞和神经血管细胞功能障碍的调节作用。目标2： 阐明周细胞功能障碍导致脑低灌注和认知功能障碍的机制 在小鼠AD模型中。目的3：检测鞘内注射Fli-1 Gapmer对小鼠的治疗作用 鼠标AD模型。成功完成拟议的研究将有助于更好地了解 Fli-1在阿尔茨海默病周细胞功能障碍中的作用及其治疗策略的研究进展 广告。

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.