Role of Astrocyte EAAT2/GLT1 Failure in Alzheimer's Disease Pathogenesis

星形胶质细胞 EAAT2/GLT1 故障在阿尔茨海默病发病机制中的作用

基本信息

批准号：
10594014
负责人：
David G Cook
金额：
$ 72.64万
依托单位：
SEATTLE INST FOR BIOMEDICAL/CLINICAL RES
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-01 至 2026-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10594014
关键词：
Acceleration Address Adenovirus Vector Affect Age Alzheimer&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos s disease patient Amyloid Amyloid beta-42 Anabolism Anatomy Astrocytes Automobile Driving Autopsy Back Binding Brain Brain Pathology Brain region Cells Complement Data Dependovirus Disease Drug Metabolic Detoxication Dysmorphology Electrophysiology (science)Equilibrium Extracellular Space Failure Family Functional disorder Gene Expression Genetic Glial Fibrillary Acidic Protein Glutamate Transporter Glutamates Glutamine Goals Hippocampus Homeostasis Impaired cognition Interneurons Intervention Knowledge Lentivirus Lentivirus Vector Measures Mediating Memory Metabolic Methods Molecular Target Morphology Mus Neurons Neurotransmitters Occupations Pathogenesis Pathogenicity Pathology Pathway interactions Play Positioning Attribute Process Property Proteins Publishing Pyramidal Cells Recovery Reporting Research Role Slice Specificity Synapses Synaptic Transmission System Testing Toxic effect Work astrogliosis cognitive function excitotoxicity extracellular gamma-Aminobutyric Acid in vivo insight mild cognitive impairment mind control mouse model neuron loss neuropathology neurotoxic neurotransmission novel patch clamp prevent response single-cell RNA sequencing synergism tau Proteins tau expression tau-1 transcriptomics translational potential transmission process uptake

项目摘要

Astrocytes are ideally positioned to support neuronal/synaptic needs for trophic factors, metabolic homeostasis, and protection from toxicity. While reactive astrogliosis is a prominent feature of AD, this offers very limited insight about how astrocytes influence the disease process or how they may be harmed. One of the most important functions of astrocytes is to clear extracellular glutamate to prevent excitotoxicity. Glutamate taken up by astrocytes is also used as a metabolic substrate for biosynthesis of other neuro- transmitters like GABA. Thus, there are at least two major ways astrocytic glutamate clearance protects the brain. In cortex and hippocampus, the glutamate transporter Slc1a2 (also called GLT1 or EAAT2) plays the most important role in glutamate clearance. Most, but not all Slc1a2 is in astrocytes. Our research team has shown that: (i) Slc1a2 is disturbed in AD; (ii) Slc1a2 loss in an AD mouse model accelerates onset of cognitive impairment; (iii) A42 slows synaptically-released glutamate uptake in hippo- campal slices; and (iv) mice with reduced astrocytic Slc1a2 display significant transcriptomic overlaps with AD. These data complement strong work from other groups and collectively argue that Slc1a2 dysfunction may play an important role in AD. However, additional critical questions need to be answered to better understand how astrocytic Slc1a2 may interact with A42 and tau pathology. Specifically, is there pathogenic synergy among these processes? In AD more needs to be uncovered about the relationship between neurons and the fine (often GFAP-negative) astrocytic processes expressing nearly all Slc1a2 in the brain—an anatomical relationship that is crucial to their function. In addition, there is insufficient data supporting the hypothesis that astrocytic Slc1a2 can play a contributing or causal role in exacerbating A42 and tau pathology. The goal of this project is to fill these knowledge gaps. First, we will use novel mice with reduced Slc1a2 specifically in astrocytes; and with adenoviral vectors (AAVs) expressing A42 and tauP301L, dissect the in vivo molecular interactions between these pathogenic pathways. We will address whether astrocytes are lost in response to A42 and/or tau. We will use a novel lentivirus system expressing Slc1a2, which infects astrocytes, to test whether specifically rescuing astrocytic Slc1a2 ameliorates neuropathology, as well as Slc1a2 function. Second, using state-of-the art patch clamp methods that directly measure astrocyte glutamate clearance, dissect how Slc1a2 loss, A42, and tau expression interact to affect astrocytic glutamate clearance. We will address how these pathogenic processes influence astrocytic Slc1a2 that regulate synaptic network excitability by supporting GABAergic transmission. Third, using well-characterized postmortem brains from control, prodromal, and AD patients we will test the potential translational significance of the glutamate transporter and astrocyte neuropathology we have reported and is suggested by our new preliminary data. Together, these data hold promise of advancing our knowledge of Slc1a2 as a potential molecular target for intervention in AD.

星形胶质细胞的位置是支持营养因素，代谢的神经元/突触需求稳态和免受毒性的保护。虽然反应性星形胶质细胞增多症是AD的重要特征，但这提供了关于星形胶质细胞如何影响疾病过程或如何受到伤害的洞察力非常有限。星形胶质细胞最重要的功能之一是清除细胞外谷氨酸，以防止兴奋性毒性。星形胶质细胞接收的谷氨酸也被用作代谢底物，用于其他神经的生物合成像加巴这样的发射器。那至少有两种主要方式星形胶质细胞谷氨酸清除保护脑。在皮质和海马中，谷氨酸转运蛋白SLC1A2（也称为GLT1或EAAT2）播放在谷氨酸清除中最重要的作用。大多数但并非所有SLC1A2都在星形胶质细胞中。我们的研究小组表明：（i）SLC1A2在AD中受到干扰；（ii）AD鼠标模型中的SLC1A2损失加速认知障碍的发作；（iii）A42在河马中减慢了突触发行的谷氨酸摄取校园切片；（iv）降低星形胶质细胞SLC1A2的小鼠与AD显示出明显的转录组重叠。这些数据完成了其他小组的强大工作，并共同认为SLC1A2功能障碍可能在广告中起重要作用。但是，需要回答其他关键问题，以更好地理解星形细胞SLC1A2如何与A42和TAU病理相互作用。具体而言，是否存在致病性协同作用在这些过程中？在广告中，需要发现有关神经元与神经元之间关系的信息精细（通常是GFAP阴性的）星形胶质细胞过程，几乎表达大脑中的所有SLC1A2 - 一种解剖学关系对他们的功能至关重要。此外，没有足够的数据支持以下假设星形胶质细胞SLC1A2可以在加剧A42和TAU病理学中起贡献或因果关系。该项目的目的是填补这些知识空白。首先，我们将使用减少SLC1A2的新颖小鼠特别是星形胶质细胞；并用表达A42和taup301l的腺病毒载体（AAVS）剖析这些致病途径之间的体内分子相互作用。我们将解决星形胶质细胞是否丢失对A42和/或tau的响应。我们将使用一种表达SLC1A2的新型慢病毒系统，该系统感染了星形胶质细胞，为了测试专门营救星形胶质细胞SLC1A2是否可以改善神经病理学以及SLC1A2功能。其次，使用直接测量星形胶质细胞谷氨酸清除率的最先进的斑块夹方法，剖析SLC1A2丢失，A42和Tau表达如何相互作用以影响星形胶质细胞谷氨酸清除率。我们将解决这些致病过程如何影响调节突触网络兴奋性的星形细胞SLC1A2 通过支持GABA能传播。第三，使用控制良好的验尸大脑，前脚和AD患者我们将测试谷氨酸转运蛋白和我们已经报告的星形胶质细胞神经病理学，并由我们的新初步数据提出。在一起，这些数据有望提高我们对SLC1A2的了解，作为干预AD的潜在分子靶标。