Disease Model Development and Phenotyping Project

疾病模型开发和表型鉴定（ESTA）项目 在最初的资助期间，该研究所创建和评估了40多个新模型，其中包括33个LOAD- 相关等位基因这包括一组平台菌株，其并入人源化AP 0 E4、Trem 2 * R47 H和Trem 2 * R47 H。 人源化Aβ序列。通过IU/JAX/PITT模型评价了4至24个月的平台菌株- AD表型分析管道，包括PET/CT、多组学（转录组学、蛋白质组学和代谢组学）， 神经病理学和液体生物标记物分析。第一个平台菌株LOAD 1（APOE 4双纯合子 和Trem 2 * R47 H）主要表现出年龄依赖性效应和很少的基因型特异性效应。为我们的第二 平台菌株LOAD 2（APOE 4、Trem 2 * R47 H和hAβ的三重纯合子），我们将高脂肪/高糖 饮食（HFD）组作为环境危险因素。与对照小鼠相比，在12个月时，HFD喂养的LOAD 2 小鼠表现出不溶性Aβ42水平升高，下托神经元丢失，长时程增强减少， (LTP)海马棘密度降低。除了平台模型，24个假定的遗传模型 将生物信息学和数据管理核心（BDMC）识别的风险变体引入LOAD 1 或通过CRISPR/Cas9检测LOAD 2，并通过将脑转录组与加速药物进行比较进行评估 AD（AMP-AD）数据。推定的风险变体位于先前鉴定的两个基因中（例如， Abca 7、CR 1、Plcg 2、Mthfr和Epha 1）以及新的AD风险基因。通过这项工作，Abca 7 * A1527 G， Plcg 2 * M28 L和Mthfr* 677 C>T优先用于通过我们的表型分析管道进行全面表征。 总的来说，这些数据支持我们的总体假设，即与负荷相关的遗传和/或 在没有家族性AD（fAD）突变的情况下，环境风险因素将在以下人群中诱导标志性AD病理学： 小鼠，并因此创建用于临床前测试的改进的小鼠模型。在更新中，我们将继续 评估新的LOAD模型，重点关注临床前测试核心（PTC）的识别模型。 为了实现这一目标，我们的表型分析管道得到了加强，并结合了一个组合的横截面和 纵向设计，广泛的生物标志物分析，MRI，另外的PET配体（例如，治疗神经炎症， 突触损失）、数字空间分布以及突触和认知评估。我们将首先完成 表征三种优先的LOAD菌株，以及表征一种新的平台模型LOAD 3（三重 APOE 4、hAβ和人源化MAPT等位基因的纯合型），有和没有HFD（Aim 1）。 TAU的过度磷酸化和聚集是LOAD的标志性病理学，在我们目前的研究中不存在。 菌株因此，我们接下来将评估四种MAPT变体（N279 K，P301 L，R406 W和S320 F）， 预测增加对TAU病理学的易感性（目的2）。最后，没有一个单一的LOAD模型可以 代表人类负载的异质性，因此我们将评估基于以下内容的新型负载模型： 多基因风险分析（BDMC，目标3）。该研究将继续与BDMC和临床前试验协同作用 核心（PTC）开发更精确的LOAD小鼠模型，并启动临床前测试。

PROJECT SUMMARY DISEASE MODEL DEVELOPMENT AND PHENOTYPING (DMP) PROJECT In the initial funding period, the DMP created and evaluated more than forty new models incorporating 33 LOAD- relevant alleles. This included a set of platform strains that incorporated humanized APOE4, Trem2*R47H and humanized Aβ sequence. Platform strains were evaluated from 4 to 24 months through the IU/JAX/PITT MODEL- AD phenotyping pipeline that included PET/CT, multi-omics (transcriptomics, proteomics and metabolomics), neuropathology, and fluid biomarker analysis. The first platform strain, LOAD1 (double homozygous for APOE4 and Trem2*R47H) showed primarily age-dependent affects and few genotype-specific effects. For our second platform strain, LOAD2 (triple homozygous for APOE4, Trem2*R47H and hAβ), we included a high fat/high sugar diet (HFD) group as an environmental risk factor. Compared to control mice, at 12 months, HFD-fed LOAD2 mice showed elevated levels of insoluble Aβ42, loss of neurons in the subiculum, reduced long-term potentiation (LTP), and reduced spine densities in the hippocampus. In addition to the platform models, 24 putative genetic risk variants identified by the Bioinformatics and Data Management core (BDMC) were introduced into LOAD1 or LOAD2 by CRISPR/Cas9 and evaluated by comparing brain transcriptomes to Accelerated Medicines Partnerships in AD (AMP-AD) data. The putative risk variants were located in both previously identified (e.g., Abca7, CR1, Plcg2, Mthfr and Epha1) as well as novel AD risk genes. Through this work, Abca7*A1527G, Plcg2*M28L and Mthfr*677C>T were prioritized for full characterization through our phenotyping pipeline. Collectively, these data support our overarching hypothesis that combinations of LOAD-relevant genetic and/or environmental risk factors, in the absence of familial AD (fAD) mutations, will induce hallmark AD pathologies in mice and therefore create improved mouse models for preclinical testing. In the renewal we will continue to evaluate novel LOAD models, with an increased focus on identifying models for the preclinical testing core (PTC). To achieve this, our phenotyping pipeline has been enhanced and incorporates a combined cross-sectional and longitudinal design, extensive biomarker analysis, MRI, additional PET ligands (e.g., for neuroinflammation and synapse loss), digital spatial profiling, and synaptic and cognitive assessment. We will first complete characterization of three prioritized LOAD strains as well as characterize a novel platform model LOAD3 (triple homozygous for APOE4, hAβ and a humanized MAPT allele) with and without HFD (Aim 1). Hyperphosphorylation and aggregation of TAU is a hallmark pathology for LOAD and absent in our current strains. Therefore, we will next evaluate four MAPT variants (N279K, P301L, R406W and S320F) that are predicted to increase susceptibility to TAU pathology (Aim 2). Finally, no single LOAD model is expected to represent the heterogeneity of human LOAD and we will therefore evaluate novel LOAD models based on polygenic risk analysis (BDMC, Aim 3). The DMP will continue to synergize with the BDMC and Preclinical Test Core (PTC) to develop more precise mouse models of LOAD and initiate preclinical testing.