The role of TREM2 in Alzheimer's disease pathogenesis

TREM2在阿尔茨海默病发病机制中的作用

基本信息

批准号：
8783748
负责人：
Taylor Reagan Jay
金额：
$ 4.27万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-01-01 至 2017-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8783748
关键词：
Affect Alzheimer&apos s Disease Alzheimer&apos s disease model Alzheimer&apos s disease risk Amyloid Protein AA Amyloid beta-Protein Anti-Inflammatory Agents Anti-inflammatory Area Binding Biological Assay Biological Response Modifiers Brain Cell Line Cellular Stress Cessation of life Chaperonin 60 Coupled Data Deposition Development Disease Equilibrium Fellowship Flow Cytometry Heat shock proteins Hippocampus (Brain)Human Immune Immune response Immunohistochemistry Immunoprecipitation Impaired cognition Impairment In Vitro Inflammation Inflammatory Inflammatory Response Late Onset Alzheimer Disease Lead Ligands Location Memory Microglia Microspheres Mus Mutation Myeloid Cells Neurons Pathogenesis Pathology Patients Performance Phagocytosis Phenotype Play Prevalence Production Proteins Published Comment Radial Risk Role Signal Transduction Slice Specificity Staining method Stains Stress Surface Testing Therapeutic Intervention Time Transgenic Mice Up-Regulation Water Western Blotting amyloid pathology arm behavior test cognitive change conditioned fear cytokine early onset extracellular high risk immune function loss of function mutation mouse model nervous system disorder neuroinflammation neuron loss novel object recognition prevent public health relevance receptor response spatiotemporal tau Proteins theories therapeutic development uptake

项目摘要

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a devastating neurological disease that affects millions of people across the globe. The pathology of this disease is characterized by the accumulation of the beta amyloid (A?) protein into extracellular plaques and the intracellular accumulation of the microtubule associated protein tau. Inflammation has also been shown to play an important role in pathology, a theory supported by the recent discovery of mutations in the immune regulating protein TREM2 in AD patients. While it is known that TREM2 is important in suppressing inflammation and promoting phagocytosis, its exact role in AD is unclear. Our preliminary data suggests that TREM2 binds to Hsp60, a pro-inflammatory immune regulator that is increased in response to cellular stress. Because of their opposing actions on inflammation, we predict that Hsp60 biases TREM2 to interact with downstream components that block its anti-inflammatory function. We also show that Hsp60 levels are increased in neurons containing elevated levels of intraneuronal A? in a mouse model of AD. We predict that Hsp60 downregulates TREM2 activity in areas where cellular stress is high, thereby promoting inflammation at the specific time and in the specific location where cellular stress is occurring. Without TREM2, we predict that the balance in inflammation will tip toward proinflammatory responses and that inflammation will no longer be localized to areas of cellular stress. In order to determine the role of TREM2 in AD, we will first examine the role of Hsp60-TREM2 signaling in vitro. Using microglia cultured from WT or transgenic mice lacking TREM2, we will be able to determine the TREM2-dependent effects of Hsp60 treatment on cytokine production using qRT-PCR and phagocytosis, using a fluorescent microsphere uptake assay coupled with flow cytometry. We also aim to determine the changes in TREM2 and Hsp60 expression and localization during the progression of pathology in the 5xFAD AD mouse model using immunohistochemistry, Western blotting, and flow cytometry. We expect that expression of Hsp60 will increase in neurons early in pathology, and that TREM2 will be upregulated globally to re-set the balance of inflammation. Finally, we will look at the effect of the constitutive loss of TREM2 on pathology in AD mice. We expect that these mice will have increased production of pro- inflammatory cytokines and decreased phagocytic capacity. Consequently, when pathology in these mice is determined using ThioS staining for plaque number, and NeuN staining to assay neuronal loss, TREM2-/- 5xFAD mice will show earlier and more severe changes. We also predict earlier cognitive decline in AD mice which lack TREM2 in tests such as novel object recognition, radial arm water maze and fear conditioning. Through these studies, we hope to gain a better understanding of the role of TREM2 in AD and provide a novel avenue for the development of therapeutic interventions for AD patients.

描述（由申请人提供）：阿尔茨海默病（AD）是一种毁灭性的神经系统疾病，影响着全球数百万人。该疾病的病理学特征是β淀粉样蛋白(Aβ)积累到细胞外斑块中以及微管相关蛋白tau在细胞内积累。炎症也被证明在病理学中发挥着重要作用，这一理论得到了最近发现的 AD 患者免疫调节蛋白 TREM2 突变的支持。虽然众所周知 TREM2 在抑制炎症和促进吞噬作用方面很重要，但其在 AD 中的确切作用尚不清楚。我们的初步数据表明，TREM2 与 Hsp60 结合，Hsp60 是一种促炎性免疫调节剂，在细胞应激反应中会增加。由于它们对炎症的作用相反，我们预测 Hsp60 会偏向 TREM2 与阻断其抗炎功能的下游成分相互作用。我们还发现，神经元内 A? 水平升高的神经元中 Hsp60 水平升高。在 AD 小鼠模型中。我们预测 Hsp60 会下调细胞应激高区域的 TREM2 活性，从而促进细胞应激发生的特定时间和特定位置的炎症。如果没有 TREM2，我们预测炎症的平衡将倾向于促炎症反应，并且炎症将不再局限于细胞应激区域。为了确定 TREM2 在 AD 中的作用，我们首先检查 Hsp60-TREM2 信号在体外的作用。使用从缺乏 TREM2 的 WT 或转基因小鼠培养的小胶质细胞，我们将能够使用 qRT-PCR 和吞噬作用，使用荧光微球摄取测定与流式细胞术相结合，确定 Hsp60 治疗对细胞因子产生的 TREM2 依赖性影响。我们还旨在使用免疫组织化学、蛋白质印迹和流式细胞术确定 5xFAD AD 小鼠模型病理进展过程中 TREM2 和 Hsp60 表达和定位的变化。我们预计 Hsp60 的表达将在病理早期的神经元中增加，并且 TREM2 将全面上调以重新设定炎症平衡。最后，我们将研究 TREM2 的组成性缺失对 AD 小鼠病理学的影响。我们预计这些小鼠促炎细胞因子的产生会增加，而吞噬能力会下降。因此，当使用 ThioS 染色测定斑块数量并使用 NeuN 染色测定神经元损失来确定这些小鼠的病理学时，TREM2-/- 5xFAD 小鼠将显示出更早、更严重的变化。我们还预测缺乏 TREM2 的 AD 小鼠在新物体识别、径向臂水迷宫和恐惧条件反射等测试中会出现早期认知能力下降。通过这些研究，我们希望更好地了解TREM2在AD中的作用，并为AD患者的治疗干预措施的开发提供新的途径。