Multidimensional mapping of vulnerable cell types in humanized Alzheimer's disease mouse models

摘要 阿尔茨海默病(AD)的特征是进行性神经变性和淀粉样蛋白b的聚集 (AB)和tau。不同脑区和某些细胞类型对AD病理的选择性易感性已被证实 已经成立了。然而，关于其背后的疾病相关机制，仍有许多未知之处。 不同的反应。我们之前已经使用单细胞转录组进行了无偏见的 人类阿尔茨海默病(AD)脑内脆弱和抵抗神经元亚型的特征(19个兴奋性和24个 抑制亚型；约490,000个核，多区域数据集)。这一特征揭示了早期转录 抑制性中间神经元的变化，特别是在表达受体酪氨酸激酶c-Kit的人群中。 使用我们的新方法通过流式细胞仪分离和分析带有tau聚合体的神经元SoMAS，我们还量化了 20种主要新皮质神经元亚型对形成神经原纤维缠结(NFT)的易感性。 尽管中间神经元被证明对NFT的形成普遍具有抵抗力，但它们也不能幸免于死亡。我们的工作 在人脑中突出了共同和不同的抗体和tau相关致病因子的存在 机制，以及需要多维方法来确定AD的脆弱性。这 一项提案寻求进一步表征抗体和tau蛋白病易感性的细胞类型特异性特征 在新开发的敲门(KI)人源化AD小鼠模型中。我们将检验早期变化的假设 在特定的GABA能抑制中间神经元中，包括c-Kit细胞，与网络有关 人源化AD小鼠模型中的功能障碍、早期蛋白质聚集和认知缺陷。建模 抗体和tau之间的致病相互作用，我们将使用表达人源化抗体的小鼠模型，而不是或 家族性阿尔茨海默病(FAD)突变和表达人MAPT的小鼠模型 与紧张症有关。在目标1中，我们将结合单细胞RNA-和atac-seq应用于tau和tau基因。 慢性脑电/肌电记录显示小鼠不含Tau的SoMAS的行为和电生理特征 并通过标准和机器学习分析的行为。在目标2中，我们将使用空间多重组学与单一- 细胞和亚细胞分辨率，以绘制与抗体相关的特定细胞类型的脆弱性和细胞-细胞相互作用 和tau蛋白病。在目标3中，我们将确定抗体和/或tau是否会改变分子、细胞和电路 脆弱c-Kit中间神经元的特性。在所有目标中，我们将整合我们的多元组学和功能数据，并 将我们的老鼠和之前产生的人类数据进行比较，以确定进化上保守的或物种- 特定的细胞类型行为。这些目标的完成将提供一个与人类疾病相关的、大规模的 多组学数据集有助于揭示与单抗和单抗相关的神经退变机制 Tau蛋白病症。

ABSTRACT Alzheimer’s disease (AD) is characterized by progressive neurodegeneration and the aggregation of amyloid-b (Ab) and tau. The selective vulnerability of different brain regions and some cell types to AD pathology has been established. However, much remains unknown regarding the disease-relevant mechanisms underlying this differential response. We have previously used single-cell transcriptomics to perform an unbiased characterization of vulnerable and resistant neuronal subtypes in the human AD brain (19 excitatory and 24 inhibitory subtypes; ~490,000 nuclei, multi-region dataset). This characterization revealed early transcriptional changes in inhibitory interneurons, particularly in a population expressing the receptor tyrosine kinase c-Kit. Using our novel method to isolate by FACS and profile neuronal somas with tau aggregates, we also quantified the susceptibility of 20 major neocortical neuronal subtypes to the formation of neurofibrillary tangles (NFTs). Although interneurons proved generally resistant to NFT formation, they were not spared from death. Our work in the human brain highlights the existence of shared and distinct Ab- and tau-associated pathogenic mechanisms as well as the need for a multidimensional approach to characterizing vulnerability in AD. This proposal seeks to further characterize cell type-specific signatures of vulnerability to Ab and tau proteinopathies in newly developed knock-in (KI) humanized mouse models of AD. We will test the hypothesis that early changes in specific populations of GABAergic inhibitory interneurons, including c-Kit cells, are associated with network dysfunction, early protein aggregation, and cognitive deficits in humanized AD mouse models. To model pathogenic interactions between Ab and tau, we will use mouse models expressing humanized Ab without or with familial AD (FAD) mutations and mouse models expressing human MAPT without or with a mutation associated with tauopathy. In Aim 1, we will apply combined single-cell RNA- and ATAC-seq to tau-bearing and tau-free somas from mice characterized behaviorally and electrophysiologically by chronic EEG/EMG recordings and by standard and machine learning-analyzed behavior. In Aim 2, we will use spatial multiomics with single- cell and subcellular resolution to map cell-type-specific vulnerabilities and cell-cell interactions in relation to Ab and tau proteinopathies. In Aim 3, we will determine if Ab and/or tau alter the molecular, cellular, and circuit properties of vulnerable c-Kit interneurons. In all aims, we will integrate our multiomics and functional data and compare our mouse and previously-generated human data to identify evolutionarily conserved or species- specific cell type behaviors. The completion of these aims will provide a human disease-relevant, large-scale multiomics dataset instrumental to unravelling the mechanisms of neurodegeneration associated with Ab and tau proteinopathies.