Define molecular events driving selective neuronal death in multiple neurodegenerative diseases by snRNA-seq

项目摘要 尽管进行了数十年的研究，但目前阿尔茨海默氏症的神经退变机制 阿尔茨海默病(AD)和帕金森病(PD)仍然存在争议，没有治疗方法可以 预防、减缓或阻止疾病进展。神经退行性疾病有两个基本原因 一般特征。1)与这种疾病相关的病理只影响特定的 神经元(“选择性神经元脆弱性”)；2)病理随着时间的推移而恶化，影响更大 以一种刻板的和可预测的方式在各地区开展工作。发现调控的关键途径 神经元对变性的这种不同的易感性为发现 新的药物靶点和有前景的神经保护治疗策略的发展。 然而，选择性神经元和局部脆弱性的潜在机制是 很难解剖，因为我们区分不同神经元亚群的能力有限。 黑质多巴胺能神经元的缺失是帕金森病的帕金森病的特征 运动症状，如僵硬和震颤。AD的SN也有神经元丢失[8，9]， 然而，帕金森病患者通常没有运动症状。脑内多巴胺能神经元 黑质是高度异质性的[10]，帕金森病的多巴胺能神经元的丢失。 不同轴之间的异质性[11-14]。目前尚不清楚是否相同数量的神经元 在AD和PD中丢失，以及神经元丢失的机制是否在 两种疾病。神经炎症-激活神经免疫细胞(如小胶质细胞)进入 促炎状态--是AD和PD共同的病理因素。然而， 不同小胶质细胞亚群的分子同一性及神经炎症在脑出血中的作用 选择性神经元死亡仍不清楚。因此，我们建议使用单核rna-seq。 (SnRNA-seq)，一种无偏见的方法来识别和表征不同的细胞群体 组织，以剖析选择性神经元死亡的机制。具体地说，我们的特定 目标是：目标1：描述和验证细胞异质性、细胞和 阿尔茨海默病、帕金森病患者黑质神经元和小胶质细胞转录水平的变化 患者和年龄匹配的对照组。目标2：剖析细胞组成的机制 阿尔茨海默病和帕金森病的转录组异常。我们的研究将提供1)分子标记 以及用于靶向神经元和小胶质细胞亚群分离和操作的工具；2)更好 了解不同神经元和小胶质细胞亚群的动态变化及其 阿尔茨海默病和帕金森病的转录改变及其可能的调控机制；3)高表达 有信心将新的候选基因和途径作为开发有效免疫疗法的靶点 或者神经保护策略。

Project Summary Despite decades of research, currently the mechanisms of neurodegeneration in Alzheimer’s disease (AD) and Parkinson Disease (PD) remain controversial and there are no therapies can prevent, slow, or halt disease progression. Neurodegenerative diseases have two fundamental general characteristics. 1) The pathology associated with the disease only affects particular neurons (‘selective neuronal vulnerability’); 2) The pathology worsens with time and impacts more regions in a stereotypical and predictable fashion. The discovery of key pathways that regulate this differential susceptibility of neurons to degeneration holds great potential for the discovery of novel drug targets and the development of promising neuroprotective treatment strategies. However, the mechanisms underlying selective neuronal and regional vulnerability have been difficult to dissect because of our limited ability to distinguish different neuronal subpopulations. Loss of dopaminergic neurons in the SN is a hallmark of PD which underlies the parkinsonian motor symptoms such as rigidity and tremor. Neuronal loss also occurs in the SN of AD [8, 9], however, often without co-occurring parkinsonian motor symptoms. Dopaminergic neurons within the SN are highly heterogeneous [10] and the loss of the dopaminergic neurons in PD is heterogeneous across different axes [11-14]. It is unclear whether the same population of neurons were lost in AD and PD and whether the mechanisms of neuronal loss are shared between the two diseases. Neuroinflammation - activation of the neuroimmune cells (e.g. microglia) into proinflammatory states - are shared pathological contributors in AD and PD. However, the molecular identity of different microglia subpopulations and the role of neuroinflammation in the selective neuronal death remain unclear. Therefore, we propose to use single nucleus RNA-seq (snRNA-seq), an unbiased approach to identify and characterize distinct cell populations in tissues, to dissect the mechanisms underlying selective neuronal death. Specifically, our specific aims are: Aim 1: Characterize and validate cellular heterogeneity, cellular and transcriptomic changes of neuron and microglia from the SN brain tissues of AD, PD patients and age-matched controls. Aim 2: Dissect the mechanisms of cell composition and transcriptome dysregulation in AD and PD. Our study will provide 1) molecular markers and tools for targeted neuronal and microglia subpopulation isolation and manipulation; 2) better understanding of the dynamic change of different neuronal and microglia subpopulation, their transcriptomic changes and the putative regulatory mechanisms in AD and PD; 3) high- confidence new candidate genes and pathways as targets to develop effective immunotherapies or neuroprotective strategies.