Regulation of mitochondrial DNA homeostasis and neuroinflammation by Fascin in Alzheimer’s Disease

阿尔茨海默病中肌成束蛋白对线粒体 DNA 稳态和神经炎症的调节

• 批准号: 10435974
• 负责人: Yongchao Charles Ma
• 金额: $ 218.75万
• 依托单位: LURIE CHILDREN'S HOSPITAL OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10435974
• 关键词: Actins; Affect; Age; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease patient; American; Amyloid; Biogenesis; Brain; Bundling; Cells; Complex; DNA; Data; Defect; Development; Disease; Dominant-Negative Mutation; Emotional; Extravasation; F-Actin; Filopodia; Goals; Hippocampus (Brain); Homeostasis; Impairment; Inflammasome; Inflammatory; Knockout Mice; Laboratories; Learning; Mediating; Membrane; Memory impairment; Microfilaments; Microglia; Mitochondria; Mitochondrial DNA; Mus; Neoplasm Metastasis; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Oxidative Phosphorylation; Oxidative Stress; Pathogenesis; Pathogenicity; Pathologic; Persons; Phenotype; Physiological; Play; Process; Proteins; Regulation; Role; Symptoms; Testing; Tissues; Transgenic Mice; Transgenic Organisms; Tumor Cell Invasion; Virus; Voltage-Dependent Anion Channel; base; brain tissue; cancer cell; cell motility; cost; crosslink; cytokine; disease phenotype; effective therapy; fascin; human old age (65+); in vivo; inducible gene expression; insight; mitochondrial dysfunction; mouse model; neuroinflammation; neuron loss; novel; novel therapeutic intervention; respiratory; therapeutic development

Project Summary/Abstract Alzheimer’s disease (AD), the most common neurodegenerative disorder, affects one in ten people age 65 and older. Due to limited understanding of mechanisms underlying AD pathogenesis, there is no effective treatment for this devastating disease. The goal of this application is to investigate an unexpected role for actin bundling protein Fascin in regulating mitochondrial nucleoid DNA (mtDNA) homeostasis, oxidative phosphorylation (OXPHOS), mitochondrial oxidative stress, neuroinflammation, and neurodegeneration, as well as how dysregulation of these processes contributes to AD pathogenesis. Fascin is an actin bundling protein essential for the cross-linking of actin filaments into compact and rigid bundles. The current paradigm posits that Fascin promotes cell migration and tumor invasion by generating protrusive membrane structures such as filopodia. We recently made the surprising finding that depletion of Fascin disrupts mitochondrial F-actin bundling, which in turn causes abnormal mitochondrial respiratory complex biogenesis and impaired mitochondrial OXPHOS, suggesting a novel role of Fascin in the regulation of mitochondrial function. Mechanistically the mitochondrial dysfunction in Fascin depleted cells was due to increased mtDNA aggregation and leakage. Given that mtDNA can robustly induce inflammasome activation and inflammatory cytokine expression, Fascin deficiency may play an unexpected role in causing neuroinflammation. Importantly, we found that Fascin is cleaved into a 37kDa functionally dominant-negative form in the brains of AD patients and AD mouse models. Virus-mediated expression of Fascin in AD mouse hippocampus mitigated disease symptoms. In addition, Fascin knockout mice we generated showed profound mitochondrial defects and significant loss of neurons in the brain. Based on these preliminary data, we hypothesize that Fascin controls mitochondrial function and mtDNA homeostasis in the brain. Fascin functional deficiency in AD leads to significant mitochondrial defects, neuroinflammation and neurodegeneration. To test the hypothesis, in Aim 1 we will define the role of Fascin in regulating mitochondrial function, mtDNA homeostasis, neuroinflammation and neuronal cell death in the mouse brain in vivo. In Aim 2 we will investigate the functional deficiency of Fascin caused by proteolytic cleavage during the course of AD pathogenesis using brain tissues from AD patients and mouse models, and to elucidate mechanisms underlying how Fascin functional deficiency causes mtDNA leakage, oxidative stress, neuroinflammation, and degeneration. In Aim 3 we will study the effects of transgenic expression of Fascin on alleviating AD pathological phenotypes and disease symptoms in mice. Successful completion of the proposed studies will reveal Fascin’s novel role in regulating mitochondrial function, mtDNA homeostasis, neuroinflammation and neurodegeneration. Investigating Fascin functional deficiency in AD will help understand disease pathogenic mechanisms and facilitate therapeutic development.

项目总结/摘要 阿尔茨海默病（AD）是最常见的神经退行性疾病，每10个人中就有1个患有AD。 65岁以上由于对AD发病机制的了解有限，目前还没有有效的治疗方法。 治疗这种毁灭性的疾病。该应用程序的目标是调查一个意想不到的角色， 肌动蛋白捆绑蛋白Fascin在调节线粒体类核DNA（mtDNA）稳态、氧化 磷酸化（OXPHOS）、线粒体氧化应激、神经炎症和神经变性， 以及这些过程的失调如何导致AD发病。 肌成束蛋白是一种肌动蛋白成束蛋白，在肌动蛋白丝交联成致密刚性结构中起重要作用 捆起来。目前的范式假定Fascin通过产生细胞因子来促进细胞迁移和肿瘤侵袭。 膨胀的膜结构，如丝状伪足。我们最近有了一个惊人的发现， Fascin破坏线粒体F-肌动蛋白捆绑，这反过来又导致异常的线粒体呼吸 复杂的生物合成和受损的线粒体OXPHOS，表明Fascin在调节中的新作用 线粒体的功能。从机制上讲，Fascin耗竭细胞中的线粒体功能障碍是由于 线粒体DNA聚集和渗漏增加。鉴于mtDNA可以强烈诱导炎性小体激活， 和炎症细胞因子表达，Fascin缺乏可能在引起炎症反应中发挥意想不到的作用。 神经炎症重要的是，我们发现Fascin被切割成一个37 kDa的功能显性负调控蛋白， 在AD患者和AD小鼠模型的大脑中形成。病毒介导Fascin在AD小鼠中的表达 海马减轻了疾病症状。此外，我们产生的Fascin敲除小鼠显示出深刻的 线粒体缺陷和脑中神经元的显著损失。根据这些初步数据，我们 假设成束蛋白控制脑中线粒体功能和mtDNA稳态。Fascin AD中的功能缺陷导致显著的线粒体缺陷、神经炎症和 神经变性为了验证这一假设，在目标1中，我们将定义Fascin在调节细胞凋亡中的作用。 线粒体功能，线粒体DNA稳态，神经炎症和神经元细胞死亡， vivo.在目的2中，我们将研究在细胞周期中由蛋白水解切割引起的Fascin的功能缺陷。 使用来自AD患者和小鼠模型的脑组织的AD发病机制的过程，并阐明 Fascin功能缺陷如何导致mtDNA渗漏，氧化应激， 神经炎症和变性。在目的3中，我们将研究Fascin的转基因表达对细胞凋亡的影响。 减轻小鼠AD病理表型和疾病症状。 成功完成拟议的研究将揭示Fascin在调节线粒体中的新作用。 功能，线粒体DNA稳态，神经炎症和神经变性。研究Fascin功能 缺乏AD将有助于了解疾病的致病机制，并促进治疗的发展。