Dissect the mechanisms of selective regional vulnerability in Lewy Body Dementias via comparative snRNA-seq analysis

项目摘要 路易体病是一种高度异质性的神经退行性疾病，包括帕金森氏病 帕金森病（PD）、帕金森病痴呆（PDD）和路易体痴呆（DLB）。LBD是 其特征在于蛋白质α-突触核蛋白在神经元细胞体（路易体）中的异常聚集， 神经突，目前认为是疾病的常见原因。路易体沉积开始 在PD的尾侧脑干，但在DLB病例的新皮质。起始α-突触核蛋白的区域差异 沉积与相应区域的神经元损失相关-黑质中的多巴胺神经元 (SN)和新皮质中身份不明的神经元，以及以神经元为主的独特临床表现 运动症状在PD，而早期痴呆在DLB。为什么某些特定的神经元和大脑区域 在疾病发作时受到影响，而邻近的细胞和区域没有？这是一个基本问题， 该提案将通过新的基因组学技术解决神经退行性疾病领域， 生物信息学工具。在最初的试点研究中，使用单核RNA测序（snRNA-seq）分析，我们 发现了一种新的疾病相关星形胶质细胞（DAA）亚群，并证明DAA有助于 炎症、淀粉样蛋白病理学和神经退行性疾病发病机制增加， 实质星形胶质细胞在AD和PD脑中均具有受损的功能。此外，我们发现， 三个小胶质细胞亚群，类似于，但与标记基因表达谱不同， 常规静息（M0）、M1和M2激活的小胶质细胞。我们观察到小胶质细胞的功能缺陷， 在所有小胶质细胞亚群和独特的上调炎症通路在PD提示共同的 和PD特异性神经变性机制。这些数据为我们提供了一个独家机会， 分析这些胶质细胞亚群与选择性区域和神经元脆弱性之间的关系， 不同的疾病。在目标1中，我们将确定患者额叶皮层（FC）和SN中的脆弱神经元类型 PD、PDD和DLB。在目标2中，我们将检验星形胶质细胞/小胶质细胞功能障碍是脑缺血的基础这一假设。 LBD的选择性区域脆弱性机制。在目标3中，我们将检验以下假设： 神经元和星形胶质细胞/小胶质细胞之间的相互作用是选择性神经元 LBD的弱点。我们的研究将为深入了解选择性神经元凋亡的分子机制提供理论依据。 和地区性的弱点。此外，我们的研究还将为神经元的功能研究提供分子生物学标记和工具。 细胞类型特异性保护和靶向星形胶质细胞/小胶质细胞亚群分离和操作。 此外，我们的研究将提供区分PD、PDD和DLB的分子生物标志物，这是非常重要的。 这在今天是一个重要但相当大的挑战。

Project Summary Lewy body diseases (LBDs) are highly heterogeneous neurodegenerative disorders including Parkinson's disease (PD), Parkinson's disease dementia (PDD), and dementia with Lewy bodies (DLB). LBDs are characterized by the abnormal aggregation of the protein α-synuclein in neuronal cell bodies (Lewy Body) and neurites which are currently considered to be the common cause of the diseases. Lewy Body deposition starts in the caudal brainstem of PD but in the neocortex of DLB cases. The regional differences of initial α-synuclein deposition correlate with neuronal loss in the corresponding regions - dopamine neurons in the substantia nigra (SN) and neurons of unknown identity in the neocortex, and the unique clinical manifestations with a predominant motor symptom in PD whereas early dementia in DLB. Why some particular neurons and brain regions are affected at the disease onset, whereas the neighboring cells and regions not? This is a fundamental question in the field of neurodegenerative diseases that this proposal will address via novel genomics technologies and bioinformatics tools. In an initial pilot study, using single nucleus RNA-sequencing (snRNA-seq) analyses, we identified a novel disease-associated astrocyte (DAA) subpopulation and demonstrated that DAA contributed to increased inflammation, amyloid pathology, and neurodegenerative disease pathogenesis whereas parenchymal astrocytes had compromised functionality in both AD and PD brains. Additionally, we identified three microglia subpopulations that were similar to but with marker gene expression profiles distinct from the conventional resting (M0), M1, and M2 activated microglia. We observed deficient microglia functionality shared across all microglia subpopulations and uniquely up-regulated inflammatory pathways in PD suggesting common and PD-specific mechanisms of neurodegeneration. These data provide us with an exclusive opportunity to analyze the relationships between these glia subpopulations and selective regional and neuronal vulnerability in different diseases. In Aim 1, we will identify vulnerable neuronal types in the frontal cortex (FC) and SN of patients with PD, PDD, and DLB. In Aim 2, we will test the hypothesis that astrocyte/microglia dysfunction underlies the mechanism of the selective regional vulnerability of LBD. In Aim 3, we will test the hypothesis that dysregulated interactions between neurons and astrocytes/microglia underlie the mechanism of the selective neuronal vulnerability of LBD. Our study will provide deep insights into the molecular mechanisms of selective neuronal and regional vulnerability in LBDs. Besides, our study will provide molecular biomarkers and tools for neuron cell-type-specific protection and targeted astrocyte/microglia subpopulation isolation and manipulation. Furthermore, our study will provide molecular biomarkers for distinguishing PD, PDD, and DLB, which is very important but a considerable challenge today.