Assessing impaired neuroinflammation associated with Apolipoprotein E4

项目摘要/摘要： 阿尔茨海默病(AD)仍然是全球痴呆症的主要原因，在#年排名第六 美国。虽然大多数AD病例没有明确的遗传原因，但少数遗传风险因素对 正在发展中的AD已被确定。载脂蛋白E(ApoE)是最重要的遗传风险因素之一。 在已鉴定的三种载脂蛋白E亚型中，载脂蛋白E4会增加AD的风险，载脂蛋白E3被认为是 “对照”表型，APOE2已被证明对AD具有保护作用。有趣的是，ApoE已经被证明 与小胶质细胞表面受体相互作用，触发髓样细胞表达的受体2(TREM2)，该受体 也被证明会增加患AD的风险。最近的研究表明，这种相互作用推动了小胶质细胞 在神经变性存在的情况下，基因表达和功能趋向激活的小胶质细胞状态， 提示载脂蛋白E在AD的炎症反应中起作用。虽然AD领域已经建立了ApoE 和TREM2作为AD的风险因素，对这些风险因素的机械性洞察充其量仍然是模糊的。 这个项目的初步结果是，使用肯塔基大学阿尔茨海默病大学的尸检组织 中央脑库，提示ApoE3 AD患者的神经炎性反应与此不同 在无AD的ApoE3患者中发现，提示ApoE3亚型对AD病理有反应。在……里面 相比之下，ApoE4 AD患者往往处于与ApoE3相似的神经炎症状态 没有AD的患者，表明他们对AD的病理不能做出反应。该项目旨在确定 载脂蛋白E亚型对小鼠和人类模型炎症级联反应的影响。我们假设 载脂蛋白E4亚型损害AD患者有益的神经炎性反应，并具有减弱的相互作用 使用TREM2。为了深入研究初步数据突出的差异，将使用两种方法来 确定载脂蛋白E异构体依赖机制的影响。首先，我们将继续调查 通过测定ApoE3/3和ApoE4/4的小胶质细胞形态观察AD尸检脑组织的神经炎性变化 比较阿尔茨海默病患者小胶质细胞的激活状态。我们还将表演纳米弦数字空间 分析AD标志和小胶质细胞周围的蛋白质。这些方法将允许更深层次的 从初步数据中了解这些变化与病理的关系。我们的第二个 方法将使用动物模型靶向TREM2，并研究载脂蛋白E亚型对TREM2的影响 激活。我们将使用磷脂酰丝氨酸和TREM2刺激性抗体来靶向激活TREM2，以允许 更全面地了解载脂蛋白E亚型对TREM2激活的影响。这个项目的总体情况 目的研究载脂蛋白E亚型在神经炎症中的重要性。 举止。总体而言，这项建议提供了足够的时间和极好的设施来获得培训 必要的实验室技术、数据分析、科学交流、手稿写作和指导 为实现我作为一名神经炎症独立研究者的目标奠定了坚实的基础。

PROJECT SUMMARY/ABSTRACT: Alzheimer’s Disease (AD) remains the leading cause of dementia worldwide and 6th leading cause of death in the United States. While the majority of AD cases have no clear genetic cause, a few genetic risk factors for developing AD have been identified. One of the most significant genetic risk factors is Apolipoprotein E (ApoE). Of the three identified ApoE isoforms, ApoE4 confers an increased risk of AD, ApoE3 is believed to be the “control” phenotype, and ApoE2 has been shown to be protective for AD. Interestingly, ApoE has been shown to interact with a surface receptor on microglia, triggering receptor expressed on myeloid cells 2 (TREM2) which has also been shown to confer an increased risk of AD. Recent studies suggest this interaction drives microglial gene expression and function toward an activated microglial state in the presence of neurodegeneration, suggesting a role for ApoE in the inflammatory response seen in AD. While the AD field has established ApoE and TREM2 as risk factors for AD, the mechanistic insights into these risk factors remain murky at best. Preliminary results for this project, using autopsy tissue from the University of Kentucky– Alzheimer’s Disease Center Brain Bank, suggests ApoE3 patients with AD have a neuroinflammatory response differing from that seen in ApoE3 patients without AD, suggesting that the ApoE3 isoform is responding to AD pathology. In contrast, ApoE4 patients with AD tend to be in a state of neuroinflammation similar to that found in ApoE3 patients without AD, suggesting they cannot respond to the AD pathology. This project aims to determine the impact of ApoE isoforms on the inflammatory cascade in both mouse and human models. We hypothesize that the ApoE4 isoform impairs a beneficial neuroinflammatory response in AD and has a weakened interaction with TREM2. To delve into the differences highlighted by the preliminary data, two approaches will be used to determine the impact of the ApoE isoform dependent mechanism. First, we will continue investigating the neuroinflammatory profile of AD autopsy brains by determining microglial morphology in ApoE3/3 and ApoE4/4 patients with AD to compare activation states of the microglia. We will also perform NanoString Digital Spatial Profiling to look at proteins surrounding AD hallmarks and microglia. These approaches will allow for a deeper understanding of how these changes seen from the preliminary data associate with the pathology. Our second approach will use animal models to target TREM2 and investigate the impact ApoE isoforms have on TREM2 activation. We will target TREM2 activation using phosphatidylserine and a TREM2 agonizing antibody to allow for a more comprehensive view of the impact ApoE isoforms have on TREM2 activation. This project overall aims to investigate the importance of ApoE isoforms on neuroinflammation to in an ApoE isoform specific manner. Cumulatively, this proposal provides adequate time and with excellent facilities to acquire training in necessary laboratory techniques, data analysis, scientific communication, manuscript writing, and mentoring to provide a strong foundation to achieve my goal of an independent investigator in neuroinflammation.