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.

抽象的 阿尔茨海默氏病（AD）是一种毁灭性的神经退行性疾病，遭受了超过650万美国人的影响。 尽管对淀粉样蛋白β（Aβ）和tau病变进行了数十年的研究，但有效的治疗仍无法触及。 安装广告全基因组协会研究（GWAS）风险基因座提供了理解的机会 疾病生物学并发展有效治疗。多个AD GWAS风险基因（例如APOE）是关键的 对于脂质代谢，对脑健康和疾病至关重要。在压力或衰老大脑中，两者都 星形胶质细胞和小胶质细胞表现出异常的脂质代谢以及脂质滴（LD）的积累。虽然 已知神经胶质LD在很大程度上是神经保护性的，在人神经元中的LD形成及其细胞和分子 后果不太清楚。源自人类诱导多能干细胞的兴奋性神经元（EX） （IPSC），我们已经证明，与星形胶质细胞共同培养的ApoE4 Ex神经元比累积的LD多于 APOE2/3神经元。我们对AD脑的单细胞转录组分析也确定了神经元受损 APOE及其接收器LDLR介导的少突胶质细胞前体细胞（OPC）通信。有趣的是， 最近发现神经胆固醇对于OPC增殖和再生至关重要。因此，我们 假设AD中的异常神经元LD和胆固醇有助于神经元损害并受损 神经元再髓。利用我们在使用IPSC衍生的神经元和皮质器官方面的专业知识作为 脑部疾病的细胞模型，我们将表征细胞类型的LD/胆固醇和 在AD风险等位基因的上下文中，相应的表观基因组/转录组变化。在AIM 1中，确定 神经与LD的脆弱性及其在AD中的临床相关性，我们将共同培养和抑制性（INH）神经元 队列的60个患者特异性IPSC线和测定神经元LD，游离脂肪酸，胆固醇和神经元 形态计量学将与APOE等位基因和非APOE AD多基因风险评分相关。 这些细胞表型也将与患者的纵向血浆脂质水平和其他 临床结果。在AIM 2中，要了解神经脆弱性LD的分子机制，我们将 对AIM 1中使用的相同神经共培养进行单细胞RNA/ATAC序列，以鉴定具有 染色质的可及性和转录与每种细胞类型的细胞LD相关。在AIM 3中，检查 AD风险等位基因对胆固醇介导的神经元 - OPC通信和髓鞘的影响，我们将首先使用 CRISPR编辑以生成带有AD风险等位基因的等源IPSC线，然后将它们区分为 骨髓的大脑器官。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。这项研究将大大提高我们对 AD中神经元脆弱性异常LD和胆固醇的细胞和分子机制。