APOE4 Increases Astrocytic Tau Internalization to Promote Alzheimer’s-Related Neuronal Pathology

APOE4 增加星形胶质细胞 Tau 内化，促进阿尔茨海默病相关神经病理学

基本信息

批准号：
10388542
负责人：
Rebecca M Fleeman
金额：
$ 2.37万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-15 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10388542
关键词：
Achievement Affect Age Alleles Alzheimer&apos s Disease Alzheimer&apos s disease pathology Alzheimer&apos s disease risk American Apolipoprotein E Astrocytes Behavior Biological Assay Brain Cells Cellular Neurobiology Characteristics Cholesterol Cholesterol Homeostasis Consequentialism Cytoskeleton Disease Disease Progression Dissociation Environment Genetic Predisposition to Disease Genetic Risk Health Human Immune Impairment Inflammatory Inflammatory Response Knock-in Mouse Knowledge Late Onset Alzheimer Disease Lipids Measures Mentors Metabolic Microglia Microtubule-Associated Proteins Modeling Molecular Neurobiology Mus Nerve Degeneration Neurodegenerative Disorders Neurofibrillary Tangles Neuroglia Neurons Pathologic Pathology Phagocytes Phagocytosis Pharmacology Physiology Play Population Positioning Attribute Postdoctoral Fellow Prevention Process Protein Isoforms Proteins Recombinants Regulation Research Role Scientist Senile Plaques Signal Transduction Source Stimulus Synapses Systems Biology Tauopathies Testing Therapeutic Training Transgenic Mice apolipoprotein E-3 astrogliosis cell type cytokine genetic risk factor hyperphosphorylated tau improved inhibitor methyl-beta-cyclodextrin monomer neuroinflammation novel response tau Proteins tau aggregation therapeutic development uptake

项目摘要

PROJECT SUMMARY/ABSTRACT The aim of this proposal is to provide the trainee, who has a physiology background, with training in molecular and cellular neurobiology and enable her transition to a post-doctoral position in neurodegenerative therapeutics. The rich training environment, which includes a strong mentoring team of diverse scientists, will equip the trainee with the expertise needed to successfully evaluate cell-type-specific immunometabolic mechanisms that impact tau pathology and neuroinflammation in the context of Alzheimer’s disease (AD). The objective of this proposal is to investigate the influence of cholesterol on astrocytic internalization of tau and the subsequent effect this has on neuronal health and viability. Primary astrocyte and neuron cultures from humanized apolipoprotein E (APOE) ε3 and ε4 mice will be used to test the overall hypothesis that the higher cholesterol levels inherent to APOE ε4 carriers increase tau internalization in astrocytes, evoking astrogliosis and subsequent diminished neuronal health via altered immune and metabolic function. The hypothesis of Aim 1 is that higher astrocytic cholesterol levels increase internalization of tau. To test this, astrocytes stimulated with recombinant tau monomers or aggregates will be evaluated for changes in tau internalization before and after pharmacological modulation of cholesterol levels. Phagocytic inhibitors will be used to evaluate the mechanism of internalization as well as to compare cholesterol-related effects on internalization. Astrocytes from APOE ε3 and ε4 mice will be used to compare the differences in astrocytes expressing the most common APOE isoform verses the AD risk isoform. The hypothesis of Aim 2 is that tau increases APOE ε4 astrocytic inflammatory cytokine secretion, in turn decreasing neuronal health. To test this, astrocytes stimulated with recombinant tau will be assayed by a multiplex cytokine panel to identify an inflammatory signature. Conditioned astrocytic media, as well as cytokines identified to have altered expression, will be used to stimulate primary neurons and their responses will be evaluated by metabolic, synaptic, and viability measures. Achievement of these aims will drive the field of tauopathy-related disease research forward by determining whether cholesterol levels modulate internalization of tau in astrocytes, and if secondary release of proinflammatory cytokines from astrocytes to neurons due to tau stimulation triggers diminished neuronal health. Understanding the influence of APOE isoform status on tau-related pathology will improve scientific knowledge of mechanisms of AD progression. More specifically, this knowledge will be impactful in identifying the role APOE ε4 genetic risk plays in potentiating AD pathology through loss of astrocytic support to neurons. These findings will provide rationale for identification of novel treatment targets for prevention of tau propagation, astrogliosis, and subsequent neurodegeneration.

项目概要/摘要该提案的目的是为具有生理学背景的学员提供以下方面的培训：分子和细胞神经生物学，使她能够过渡到神经退行性疾病领域的博士后职位丰富的培训环境，包括由不同科学家组成的强大指导团队，将为学员提供成功评估细胞类型特异性免疫代谢所需的专业知识影响阿尔茨海默病 (AD) 中 tau 病理学和神经炎症的机制。该提案的目的是研究胆固醇对 tau 蛋白星形胶质细胞内化的影响以及这对原代星形胶质细胞和神经元培养物的神经元健康和活力的影响。人源化载脂蛋白 E (APOE) ε3 和 ε4 小鼠将用于检验总体假设，即较高 APOE ε4 携带者固有的胆固醇水平增加星形胶质细胞中 tau 蛋白的内化，引起星形胶质细胞增生以及随后通过免疫和代谢功能损害神经健康。目标 1 的假设是较高的星形细胞胆固醇水平会增加 tau 蛋白的内化。在此，将评估用重组 tau 单体或聚集体刺激的星形胶质细胞的 tau 变化吞噬细胞抑制剂在药物调节胆固醇水平之前和之后内化。用于评估内化机制以及比较胆固醇相关的影响来自 APOE ε3 和 ε4 小鼠的星形胶质细胞将用于比较星形胶质细胞的差异。表达最常见的 APOE 同工型与 AD 风险同工型。目标 2 的假设是 tau 增加 APOE ε4 星形胶质细胞炎症细胞因子的分泌，进而为了测试这一点，将通过重组 tau 刺激的星形胶质细胞进行检测。多重细胞因子面板可识别条件星形胶质细胞介质以及细胞因子。确定具有表达，将用于刺激初级神经元，它们的反应将是通过代谢、突触和活力测量进行评估。这些目标的实现将推动 tau 蛋白病相关疾病研究领域的发展胆固醇水平是否调节星形胶质细胞中 tau 蛋白的内化，以及是否会二次释放由于 tau 蛋白刺激，促炎性细胞因子从星形胶质细胞转移到神经元，导致神经元健康受损。了解 APOE 亚型状态对 tau 相关病理学的影响将提高科学知识更具体地说，这些知识将有助于确定 APOE 的作用。 ε4 遗传风险通过神经元星形胶质细胞支持的丧失而加剧 AD 病理。将为确定预防 tau 增殖、星形胶质细胞增生、以及随后的神经退行性变。