Disruption of neuronal signaling in Alzheimer’s disease and rescue by manipulating the innate immune receptor PirB

阿尔茨海默病神经元信号传导的破坏以及通过操纵先天免疫受体 PirB 进行挽救

• 批准号: 10231468
• 负责人: Johanna Elizabeth Tomorsky
• 金额: $ 6.64万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10231468
• 关键词: APP-PS1; Acute; Adult; Affinity; Age; Alleles; Alzheimer' s Disease; Alzheimer' s disease model; Alzheimer' s disease pathology; Amyloid beta-Protein; Astrocytes; Automobile Driving; Behavioral; Behavioral Paradigm; Binding; Biochemical; Cells; Cessation of life; Crystallization; Development; Disease Progression; Dominant-Negative Mutation; Electrophysiology (science); Electroporation; Functional disorder; Gene Expression; Gene Proteins; Genes; Goals; Histocompatibility; Homologous Gene; Human; Immune; Immune signaling; Immunoglobulins; Immunologic Receptors; Impaired cognition; Inflammation; Injury; Knock-out; Lead; Length; Ligands; Link; LoxP-flanked allele; Mass Spectrum Analysis; Measures; Memory; Memory Loss; Memory impairment; Microglia; Mus; Neurofibrillary Tangles; Neurons; Pathologic; Pathway interactions; Pattern; Phosphorylation; Population; Prosencephalon; Protein Dephosphorylation; Proteins; Recombinant Proteins; Reporting; Research; RiboTag; Role; Signal Pathway; Signal Transduction; Structure; Synapses; Synaptic plasticity; Synaptosomes; Tamoxifen; Techniques; Testing; Therapeutic; Time; Transgenes; abeta accumulation; aged; autosomal dominant Alzheimer' s disease; calmodulin-dependent protein kinase II; cell type; cofilin; conditional knockout; critical period; druggable target; excitatory neuron; experimental study; follow-up; hyperphosphorylated tau; immune activation; in utero; knock-down; macrophage; mouse model; nanomolar; neuroinflammation; neuron loss; neurotransmission; new growth; novel; oAβ; prevent; rapid growth; receptor; response; small hairpin RNA; synaptic function; synaptic pruning; therapeutic target; transcriptome sequencing; transcriptomics

Project Summary Alzheimer’s disease (AD) is becoming more prevalent as our population ages and is characterized by devastating memory loss and cognitive impairment. The pruning of neuronal synapses contributes to the pathology of AD and is the best correlate of cognitive decline. Both oligomeric amyloid beta and neuroinflammatory mechanisms can lead to synapse pruning in AD. While neurons and immune cells have been shown to interact to drive pruning, the neuronal signaling downstream of this interaction is not well understood. A major goal of this proposal is to determine neuronal signaling mechanisms driving synapse pruning in mouse models of autosomal dominant AD at two ages and under varying conditions of both aggregated amyloid beta and immune activation. Synapse pruning occurs naturally throughout development, and one hypothesis is that developmental pruning mechanisms are dysregulated in AD. The Shatz lab made the surprising discovery that the innate immune receptor, PirB, is expressed in neurons and has roles in synapse pruning over development. In addition, PirB knockout in adult mice, either globally or in excitatory neurons alone, facilitates the rapid growth of new synapses and re-opens critical period-like synaptic plasticity. PirB and its human homologue, LilrB2, have both been shown to bind amyloid beta at high affinities, and germline global PirB knockout was shown to protect against memory loss in the APP/PS1 mouse model of AD. While global germline knockout was protective, in a therapeutic context, it is also important to determine the effect of PirB blockade in normally reared adult mice at various stages of disease progression. In addition, while the Shatz lab identified a signaling pathway linking PirB to synapse pruning, via the dephosphorylation of cofilin, no other signaling pathways have been examined downstream of PirB in APP/PS1 mice. Here, I propose to test the hypothesis that neuronal gene expression is dysregulated in AD model mice and can be restored with PirB KO, protecting against synapse loss. The experiments proposed should identify new signaling pathways in neurons and at synapses downstream of PirB in AD model mice. I also propose to block PirB in normally reared adult APP/PS1 mice to determine the therapeutic potential of PirB/LilrB2 blockade in AD. I focus on two stages of disease progression: 1) early, before plaque formation but when synaptic and memory deficits have been reported, and 2) late, after plaque formation and heightened immune activation. The central goal of this proposal is to use transcriptomic, biochemical, electrophysiological, and behavioral techniques to elucidate signaling pathways downstream of PirB/LilrB2 in AD and demonstrate the therapeutic potential of PirB blockade to ‘treat’ memory loss in APP/PS1 model mice. The long-term aim of this research is to contribute to our understanding of the signaling mechanisms leading to synaptic pruning in Alzheimer’s disease, as a first step toward finding potential therapies and therapeutic targets.

项目摘要 随着人口年龄的年龄，阿尔茨海默氏病（AD）变得越来越普遍，其特征是 毁灭性的记忆力丧失和认知障碍。神经元突触的修剪有助于 AD的病理是认知能力下降的最佳相关性。两种低聚淀粉样ββ和 神经炎症机制可能导致AD中的突触修剪。而神经元和免疫细胞具有 他被证明可以相互作用以驱动修剪，这种相互作用的下游神经元信号不好 理解。该提案的主要目标是确定驱动突触的神经元信号传导机制 在两个年龄的常染色体显性AD的小鼠模型中修剪，在两者的不同条件下 聚集的淀粉样β和免疫激活。 突触修剪在整个开发过程中自然发生，一个假设是发展 AD中的修剪机制失调。 Shatz Lab令人惊讶的发现是先天的 免疫接收器PIRB在神经元中表达，并且在触发性方面的发育方面具有作用。在 另外，仅在全球或仅兴奋性神经元中的成年小鼠中的PIRB敲除，便有助于快速生长 新的突触和重新打开关键时期的合成可塑性。 PIRB及其人类同源物Lilrb2， 两者都显示在高亲和力下结合淀粉样蛋白β，生殖线全球PIRB敲除已显示为 预防AD的APP/PS1鼠标模型中的内存丢失。而全球种系淘汰是 保护性，在治疗性的情况下，确定PIRB封锁的效果正常也很重要 在疾病进展的各个阶段饲养的成年小鼠。另外，Shatz Lab确定了 通过Cofilin的去磷酸化，将PIRB连接到突触修剪的信号通路，没有其他信号传导 在APP/PS1小鼠中，PIRB下游检查了途径。 在这里，我建议测试以下假设：AD模型小鼠神经元基因表达失调 可以使用PIRB KO恢复，以防止突触损失。提出的实验应确定 AD模型小鼠PIRB下游神经元和突触的新信号通路。我也建议 正常饲养的成人应用/PS1小鼠中的PIRB块，以确定PIRB/LILRB2的治疗潜力 广告中的块。我专注于疾病进展的两个阶段：1）早期，牙菌斑形成之前 已经报道了突触和记忆的定义，2）晚期，牙菌斑形成和免疫力增强后 激活。该建议的核心目标是使用转录组，生化，电生理和 在AD中阐明PIRB/LILRB2下游的信号通路的行为技术并证明了 PIRB阻滞的治疗潜力“治疗” APP/PS1模型小鼠中的记忆丧失。长期目标 研究是有助于我们理解导致突触修剪的信号传导机制 阿尔茨海默氏病，是寻找潜在疗法和治疗靶标的第一步。