Reshaping ApoE4 and Alzheimer's Brains with ApoE2

项目总结 我们在本申请中提出的研究试图将我们最近对 与人类载脂蛋白E2(APOE2)基因相关的神经保护机制 预防和治疗阿尔茨海默病(AD)的治疗机会。最重要的假设 将人类载脂蛋白2蛋白引入高危载脂蛋白E4和AD大脑是否会积极改变 通过增强大脑的韧性来增强大脑老化的过程或疾病的发病机制 糖酵解代谢，从而改善葡萄糖利用，蛋白质动态平衡，以及 突触活动。在准备工作中，我们实现了对成功至关重要的三个主要里程碑 这一翻译努力的结果是：(1)开发一种生理学的生产方法 具有生物学活性的相关和人类相容的重组APOE2(RhApoE2)糖蛋白 功能可与内源性人类载脂蛋白2相媲美；(2)非侵入性方法的开发 通过调节血-脑钙粘附素相互作用实现重组人载脂蛋白E_2糖蛋白的脑内递送 屏障(BBB)，诱导载脂蛋白E4脑内的神经保护信号；以及(3)新的 分别针对人类散发性(SAD)和家族性AD的人源化敲入小鼠模型 (FAD)，预计将为将替补成功转换为 在床边。拟议的研究将追求三个具体目标。在我们最初成功的基础上， 第一个目标是确定重组人载脂蛋白E_2的最佳治疗方案 糖蛋白将导致重组人载脂蛋白E2在皮质和海马区沉积，并 在不引起不良反应的情况下上调脑糖酵解代谢。该计划的目标是 第二个目的是评估重组人载脂蛋白E_2的治疗效果，结合年龄和 在表达生理的人源化小鼠模型中，性别对与悲伤相关的大脑变化的影响 人ApoE3或ApoE4和人野生型APP蛋白的水平。第三个目标将是 在表达人载脂蛋白E3或载脂蛋白E4生理水平的人源化小鼠模型中进行研究 和人突变型APP蛋白评估重组人载脂蛋白E2对脑的治疗影响 与FAD相关的变化，以及组合如何改变rhApoE2介导的效应 年龄、性别、载脂蛋白E基因和疾病状况。我们对拟议研究的总体目标是 建立以大脑代谢弹性为目标作为疾病改善策略的合理性，以及 生成关于基于rhApoE2的蛋白质疗法是否有可能 发展成为一种有效、安全的AD干预方法。

PROJECT SUMMARY The research we propose in this application seeks to translate our recent understanding of the neuroprotective mechanism associated with the human apolipoprotein E2 (ApoE2) genotype into a therapeutic opportunity to prevent and treat Alzheimer's disease (AD). The overarching hypotheses are that introduction of human ApoE2 protein into high-risk ApoE4 and AD brains positively alters the course of brain aging or disease pathogenesis by bolstering brain resilience through enhanced glycolytic metabolism, which subsequently improves glucose utilization, protein homeostasis, and synaptic activity. In preparation, we have achieved three major milestones critical to the success of this translational endeavor: (1) development of a method for the production of physiologically relevant and human-compatible recombinant ApoE2 (rhApoE2) glycoprotein that possesses biological functionality comparable to endogenous human ApoE2; (2) development of a noninvasive approach for brain delivery of rhApoE2 glycoprotein via modulation of cadherin interactions on the blood-brain barrier (BBB), which induces neuroprotective signaling in ApoE4 brains; and (3) development of novel humanized knock-in mouse models that respectively target human sporadic (sAD) and familial AD (fAD), which are expected to provide high predictive validity for translating bench successes to bedside. The proposed studies will pursue three specific aims. Building on our initial success, the objective of the first aim is to determine the therapeutically optimal regimen for delivery of rhApoE2 glycoprotein that will result in deposition of rhApoE2 throughout cortical and hippocampal regions and upregulation of brain glycolytic metabolism without eliciting adverse reactions. The objective of the second aim is to evaluate the therapeutic impact of rhApoE2 delivery, in combination with age and sex, on brain changes associated with sAD in humanized mouse models that express physiological levels of human ApoE3 or ApoE4 and human wild-type APP proteins. The third aim will be investigated in humanized mouse models that express physiological levels of human ApoE3 or ApoE4 and human mutant APP proteins to evaluate the therapeutic impact of rhApoE2 delivery on brain changes associated with fAD, and how the rhApoE2-mediated effects are modified by a combination of age, sex, ApoE genotype, and disease status. Our overall goals for the proposed research are to establish the plausibility of targeting brain metabolic resilience as a disease-modifying strategy and generate proof of concept as to whether a rhApoE2-based protein therapy can potentially be developed into an effective and safe intervention for AD.