Elucidating the Temporal, Spatial and Cellular Effects of Differential APOE Isoform Expression

项目摘要 载脂蛋白E（APOE）ε4基因携带者患阿尔茨海默病的风险显著增加 疾病（AD）。虽然已经提出了许多理论，但这种关联的原因仍然不清楚。 我自己的研究发现了APOE 4表达对大脑重要过程的新影响， 包括神经元活性、内体-溶酶体系统和生物能调节。然而， 关于这些系统何时、何地以及如何受到差异APOE亚型的影响，仍然存在疑问 表情为了回答这些问题，并获得更全面的了解， APOE同种型表达影响重要的脑过程和通路，我提出了一系列尖端的 在新创建的APOE小鼠模型上进行的实验。通过进行行为实验， 组织学检查，成像和一系列空间多组学实验，该项目旨在定义 不同APOE亚型在大脑中作用的时间、空间和细胞进展。这一切成功都 实验将在幼年（4-6月龄）、老年（14-16月龄）和老年（24-26月龄）中进行 APOE 2、APOE 3和APOE 4-KI小鼠。在目标1中，我们将进行一系列行为测试，包括巴恩斯 迷宫，新物体识别，恐惧条件反射，以及内体-溶酶体的组织学分析 中断、生物能量缺陷和AD病理学标志物的变化。我们还将进行详细的成像 使用fMRI分析观察这些小鼠的活动和结构变化。在目标2中，我们将进行一次- 对这些小鼠进行深入的空间多组学分析，包括空间转录组学和空间 代谢组学/脂质组学。在目标3中，我们将探讨细胞对不同APOE亚型的贡献， 表达，包括新的生物信息学方法和从星形胶质细胞中有条件地敲除APOE， APOE-KI小鼠中的小胶质细胞。我们预计，本文提出的全面研究将揭示重要的APOE 同种型以系统生物学的方式对多种脑过程和通路产生影响，这将大大 增加我们对APOE亚型差异如何影响个体对AD易感性的理解， 这可能导致新的AD治疗策略，特别是在APOE 4携带者中。

Project Summary Carriers of the apolipoprotein E (APOE) ε4 gene are at a significantly increased risk for developing Alzheimer’s disease (AD). Although numerous theories have been proposed, the cause of this association remains unclear. My own research has uncovered novel effects of APOE4 expression on important processes in the brain, including neuronal activity, the endosomal-lysosomal system and bioenergetic regulation. However, substantial questions remain about when, where and how these systems are effected by differential APOE isoform expression. In order to answer these questions and gain a more comprehensive understanding of how differential APOE isoform expression affects vital brain processes and pathways, I propose a series of cutting-edge experiments, performed on a newly created APOE mouse model. By conducting behavioral experiments, histological examinations, imaging and an array of spatial multi-omics experiments, this project aims to define the temporal, spatial and cellular progression of differential APOE isoform effects in the brain. Each of these experiments will be performed on young (4-6 month-old), aged (14-16 month-old), and old (24-26 month-old) APOE2, APOE3 and APOE4-KI mice. In Aim 1, we will conduct a series of behavioral tests, including Barnes maze, novel object recognition, and fear conditioning, as well as a histological analysis for endosomal-lysosomal disruptions, bioenergetic deficits, and changes in AD pathology markers. We will also conduct a detailed imaging analysis using fMRI to observe activity and structural changes in these mice. In Aim 2, we will conduct an in- depth spatial multi-omics analysis on these mice, including spatial transcriptomics and spatial metabolomics/lipidomics. And in Aim 3, we will explore the cellular contributions to differential APOE isoform expression, including a novel bioinformatics approach and conditionally knockout of APOE from astrocytes and microglia in the APOE-KI mice. We anticipate that the full study proposed herein will uncover important APOE isoform effects on multiple brain processes and pathways in a systems-biology manner, which will dramatically increase our understanding of how APOE isoform differences affect an individual’s susceptibility to AD, potentially leading to new therapeutic strategies for AD, especially among APOE4 carriers.