Resolving selective vulnerability and disease progression in human Alzheimer's brain via single-cell RNA-seq

摘要 阿尔茨海默病（AD）的有效治疗是迫切需要的。现有的方法主要 未能改善症状或改变疾病进展，部分原因是我们对 疾病的发病机制。以前的神经病理学和神经影像学研究有助于 建立AD的组织病理学标志和特定脑区域的参与。但 不同的神经元和非神经元细胞类型对AD的选择性脆弱性和潜在的分子 其机制在很大程度上仍然未知。我们假设神经元和非神经元细胞亚群 类型有助于独特的AD，并提出使用单细胞转录组学在人脑中，以确定 这些细胞类型和导致AD病理学的潜在分子机制。虽然应用这个 创新技术对人类大脑是具有挑战性的，人类AD大脑对于理解 不同细胞类型对疾病的贡献，识别最早的致病事件，揭示 神经保护途径，并定义病理学的传播。我们将研究早期和晚期受影响的大脑 皮层区域，包括内嗅皮层、联合皮层和初级感觉皮层， 疾病进展的全谱（Braak I-VI期）和年龄匹配的健康对照。这一战略 将提供一个全面的景观脆弱和弹性的细胞类型，他们的转录组变化， 以及变化随时间的推移和在皮层区域的传播。在目标1中，我们将使用单核RNA- 用于神经元、神经胶质细胞（小胶质细胞、星形胶质细胞和胶质细胞）的无偏鉴定和转录组分析的测序。 少突胶质细胞）和血管细胞。在目标2中，我们将测试不同分子定义的假设， 皮质-皮质和皮质-丘脑投射神经元的亚群选择性地对 退化在目标3中，我们将使用我们的新方法研究与tau病理学相关的分子变化。 开发了用于纯化和分析带有神经元缠结的单个神经元的测定。这些研究将 生成人类神经元缠结的第一个单细胞转录组谱，并提供对神经元缠结的深入了解。 tau介导的神经变性机制。总之，我们的研究将提供一个公正和强大的 识别AD中的脆弱和弹性细胞类型，并深入了解其分子机制 选择性的弱点。这些数据将为科学界提供宝贵的资源， 基于细胞类型的疾病建模和药物发现。

ABSTRACT Effective therapies for Alzheimer’s disease (AD) are urgently needed. The existing approaches have largely failed to improve symptoms or modify disease progression, in part because of our incomplete understanding of the disease pathogenesis. Previous neuropathology and neuroimaging studies have been instrumental in establishing the histopathological hallmarks of AD and the involvement of specific brain regions. However, the selective vulnerability of distinct neuronal and non-neuronal cell types to AD and the underlying molecular mechanisms remain largely unknown. We hypothesize that subpopulations of neuronal and non-neuronal cell types contribute distinctively to AD and propose the use of single-cell transcriptomics in human brain to identify these cell types and the underlying molecular mechanisms leading to AD pathology. Although applying this innovative technology to human brain is challenging, human AD brain is crucial for understanding the contributions of distinct cell types to disease, identifying the earliest pathogenic events, uncovering neuroprotective pathways, and defining the spread of pathology. We will study early- and late-affected cerebral cortical regions, including entorhinal, association, and primary sensory cortices, from subjects encompassing the full spectrum of disease progression (Braak stages I–VI) and age-matched healthy controls. This strategy will provide a comprehensive landscape of the vulnerable and resilient cell types, their transcriptome changes, and the spread of changes over time and across cortical regions. In Aim 1 we will use single-nucleus RNA- sequencing for the unbiased identification and transcriptome profiling of neurons, glia (microglia, astrocytes, and oligodendrocytes), and blood vessel cells. In Aim 2 we will test the hypothesis that distinct molecularly defined subpopulations of cortico-cortical and cortico-thalamic projection neurons are selectively vulnerable to degeneration. In Aim 3 we will examine the molecular changes associated with tau pathology using our newly developed assay for purifying and profiling single neurons bearing neurofibrillary tangles. These studies will generate the first single-cell transcriptome profiling of human neurons with tangles and provide insight into the tau-mediated mechanisms of neurodegeneration. Together, our studies will provide an unbiased and robust identification of the vulnerable and resilient cell types in AD and insight into the molecular mechanisms underlying the selective vulnerabilities. These data will provide a valuable resource to the scientific community for improved cell-type-based disease modeling and drug discovery.