Neuronal Vulnerability to Lipid Droplets and Cholesterol in Alzheimer's Disease

阿尔茨海默病中神经元对脂滴和胆固醇的脆弱性

• 批准号: 10644533
• 负责人: Jubao Duan
• 金额: $ 69.14万
• 依托单位: NORTHSHORE UNIVERSITY HEALTHSYSTEM
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2028-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10644533
• 关键词: ATAC-seq; Affect; Age; Aging; Alleles; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease patient; Alzheimer' s disease risk; Alzheimer’s disease biomarker; American; Amyloid beta-Protein; Astrocytes; Biological Assay; Biology; Brain Diseases; Cell Communication; Cell Differentiation process; Cell Line; Cell Nucleus; Cell Proliferation; Cell Survival; Cell model; Cells; Cellular Assay; Cerebrum; Cholesterol; Cholesterol Esters; Cholesterol Homeostasis; Chromatin; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Coculture Techniques; Data; Dementia; Demyelinations; Disease; Disease Progression; Fatty Acids; Genes; Genetic; Genetic Risk; Genetic Transcription; Goals; Homeostasis; Human; Image; Impairment; Individual; Induced pluripotent stem cell derived neurons; Lesion; Lipids; Mediating; Microglia; Modeling; Molecular; Nerve Degeneration; Neurodegenerative Disorders; Neuronal Dysfunction; Neurons; Nonesterified Fatty Acids; Oligodendroglia; Organoids; Outcome; Patients; Phenotype; Plasma; Proteins; RNA; Research; Role; Small Nuclear RNA; Stress; Synapses; Toxic effect; Triglycerides; aging brain; aging population; apolipoprotein E-4; brain health; cell type; clinical phenotype; clinically relevant; cohort; dementia risk; effective therapy; epigenomics; excitatory neuron; genome wide association study; genome-wide analysis; induced pluripotent stem cell; lipid metabolism; multiple omics; myelination; nerve stem cell; neural; neuroprotection; neuropsychiatry; normal aging; oligodendrocyte precursor; polygenic risk score; receptor; remyelination; repaired; risk variant; tau Proteins; transcriptomics; triacsin C

ABSTRACT Alzheimer's disease (AD) is a devastating neurodegenerative disorder that afflicts over 6.5 million Americans. Despite decades of research on amyloid-β (Aβ) and Tau lesions, effective treatment remains out of reach. Mounting AD genome-wide association studies (GWAS) risk loci provide opportunities for understanding disease biology and developing effective treatment. Multiple AD GWAS risk genes, such as APOE, are pivotal for lipid metabolism that is essential to brain health and disease. Under stress or in the aging brain, both astrocytes and microglia show abnormal lipid metabolism and accumulation of lipid droplets (LD). Although glial LD are known to be largely neuroprotective, LD formation in human neurons and its cellular and molecular ramifications are less clear. With excitatory neurons (Ex) derived from human induced pluripotent stem cells (iPSC), we have shown that APOE4 Ex neurons co-cultured with astrocytes accumulated more LD than APOE2/3 neurons. Our single-cell transcriptomic analysis of AD brain also identified an impaired neuron- oligodendrocyte precursor cell (OPC) communication mediated by APOE and its receptor LDLR. Interestingly, neural cholesterol was recently found to be essential to OPC proliferation and remyelination. We thus hypothesize that abnormal neuronal LD and cholesterol in AD contribute to neuronal damage and impaired neuron remyelination. Leveraging our expertise on using iPSC-derived neurons and cortical organoids as cellular models for brain disorders, we will characterize the cell type vulnerability to LD/cholesterol and the corresponding epigenomic/transcriptomic changes in the context of AD risk alleles. In Aim 1, to determine the neural vulnerability to LD and its clinical relevance in AD, we will co-culture Ex and Inhibitory (Inh) neurons of a cohort of 60 patient-specific iPSC lines, and assay neural LD, free fatty acids, cholesterol, and neural morphometrics, which will then be associated with APOE alleles and non-APOE AD polygenic risk scores. These cellular phenotypes will also be correlated with patients’ longitudinal plasma lipid levels and other clinical outcomes. In Aim 2, to understand molecular mechanisms underlying neural vulnerability to LD, we will perform single-cell RNA/ATAC-sequencing on the same neural co-cultures used in Aim 1 to identify genes with chromatin accessibility and transcription correlated with cellular LD in each cell type. In Aim 3, to examine the effect of AD risk alleles on cholesterol-mediated neuron-OPC communication and myelination, we will first use CRISPR editing to generate isogenic iPSC lines carrying AD risk alleles and then differentiate them into myelinating cerebral organoids. We will examine the effects of AD risk alleles on neuronal cholesterol levels as well as the OPC proliferation and neuron myelination. This study will significantly advance our understanding of the cellular and molecular mechanisms of neuronal vulnerability to abnormal LD and cholesterol in AD.

摘要 阿尔茨海默病（AD）是一种毁灭性的神经退行性疾病，困扰着超过650万美国人。 尽管对淀粉样蛋白-β（Aβ）和Tau病变进行了数十年的研究，但有效的治疗仍然遥不可及。 越来越多的AD全基因组关联研究（GWAS）风险位点提供了了解 疾病生物学和开发有效的治疗方法。多种AD GWAS风险基因，如APOE，是关键 对大脑健康和疾病至关重要的脂质代谢。在压力下或在老化的大脑中， 星形胶质细胞和小胶质细胞表现出异常的脂质代谢和脂滴（LD）的积累。虽然 已知神经胶质LD在很大程度上具有神经保护作用，人神经元中的LD形成及其细胞和分子生物学特性。 后果还不太清楚。用来自人诱导多能干细胞的兴奋性神经元（Ex） 我们已经证明，与星形胶质细胞共培养的APOE 4 Ex神经元比与星形胶质细胞共培养的APOE 4 Ex神经元积累了更多的LD。 APOE 2/3神经元。我们对AD大脑的单细胞转录组学分析也发现了一个受损的神经元- APOE及其受体LDLR介导的少突胶质前体细胞（OPC）通讯。有趣的是， 最近发现神经胆固醇对于OPC增殖和髓鞘再生是必需的。我们因此 假设AD中异常神经元LD和胆固醇有助于神经元损伤和受损 神经元髓鞘再生利用我们在使用iPSC衍生的神经元和皮质类器官方面的专业知识， 脑疾病的细胞模型，我们将描述细胞类型对LD/胆固醇的脆弱性和 AD风险等位基因背景下的相应表观基因组/转录组变化。在目标1中，确定 神经对LD的脆弱性及其在AD中的临床相关性，我们将共培养前和抑制（Inh）神经元， 60个患者特异性iPSC系的队列，并测定神经LD、游离脂肪酸、胆固醇和神经内分泌。 形态计量学，然后将其与APOE等位基因和非APOE AD多基因风险评分相关联。 这些细胞表型也将与患者的纵向血浆脂质水平和其他相关性相关。 临床结果。在目标2中，为了了解LD神经脆弱性的分子机制，我们将 对目标1中使用的相同神经共培养物进行单细胞RNA/ATAC测序，以鉴定具有以下特征的基因： 染色质可及性和转录与每种细胞类型中的细胞LD相关。在目标3中，为了检查 AD风险等位基因对胆固醇介导的神经元-OPC通讯和髓鞘形成的影响，我们将首先使用 CRISPR编辑以产生携带AD风险等位基因的等基因iPSC系，然后将它们分化为 髓鞘化脑类器官我们将研究AD风险等位基因对神经元胆固醇水平的影响， 以及OPC增殖和神经元髓鞘形成。这项研究将大大促进我们对 AD中神经元对异常LD和胆固醇的易损性的细胞和分子机制。