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

• 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
• 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' s Disease; Alzheimer' s disease pathology; Alzheimer' 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

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.

项目摘要/摘要 这项建议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变的博士后职位 治疗学。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特定细胞类型免疫代谢所需的专业知识 在阿尔茨海默病(AD)的背景下影响tau病理和神经炎症的机制。 本研究的目的是研究胆固醇对tau星形胶质细胞内化的影响。 以及随后对神经元健康和生存能力的影响。原代培养的星形胶质细胞和神经元 人源化载脂蛋白E(ApoE)ε3和ε4小鼠将被用来检验总体假设，即 载脂蛋白ε4携带者固有的胆固醇水平增加星形胶质细胞tau内化，引发星形胶质细胞增生症 随后，由于免疫和代谢功能的改变，神经元的健康状况会减弱。 目标1的假设是，较高的星形细胞胆固醇水平会增加tau的内化。为了测试 这将评估用重组tau单体或聚集体刺激的星形胶质细胞tau的变化。 药物调节胆固醇水平前后的内化作用。吞噬细胞抑制药将会是 用来评估内化机制以及比较胆固醇相关的影响 内部化。来自apoEε3和ε4小鼠的星形胶质细胞将被用来比较星形胶质细胞的差异 表达最常见的载脂蛋白E亚型与AD风险亚型。 目标2的假设是，tau反过来增加apoEε4星形胶质细胞炎性细胞因子的分泌。 神经细胞健康状况下降。为了验证这一点，用重组tau刺激的星形胶质细胞将通过一种 多重细胞因子小组以识别炎症性信号。星形细胞条件培养液以及细胞因子 将被用来刺激初级神经元，它们的反应将是 通过新陈代谢、突触和生存能力的测量进行评估。 这些目标的实现将推动直肠疗法相关疾病研究领域的发展，通过确定 胆固醇水平是否调节星形胶质细胞tau的内化，以及是否次级释放 由tau刺激引起的从星形胶质细胞到神经元的致炎细胞因子触发了神经元健康的降低。 了解载脂蛋白E亚型状态对tau相关病理的影响将提高科学知识 阿尔茨海默病进展机制的研究。更具体地说，这一知识将对确定APOE的角色产生影响 ε4的遗传风险通过丧失对神经元的星形胶质细胞支持而增强AD的病理。这些发现 将为确定新的治疗靶点以防止tau增殖、星形胶质细胞增生症、 以及随后的神经退行性变。