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: 10403425
• 负责人: Johanna Elizabeth Tomorsky
• 金额: $ 6.98万
• 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 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10403425
• 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 随着我们人口的老龄化，阿尔茨海默病(AD)正变得越来越普遍，其特点是 严重的记忆力丧失和认知障碍。神经元突触的修剪有助于 阿尔茨海默病的病理改变，是认知功能下降的最佳相关因素。低聚淀粉样蛋白和β-淀粉样蛋白 神经炎症机制可导致AD中突触的修剪。而神经元和免疫细胞 已被证明相互作用驱动修剪，这种相互作用下游的神经元信号不是很好 明白了。这项提议的一个主要目标是确定驱动突触的神经元信号机制。 常染色体显性遗传性阿尔茨海默病小鼠模型在两个年龄和不同条件下的修剪 聚集的淀粉样β蛋白与免疫激活。 突触修剪在整个发育过程中都是自然发生的，其中一个假设是发育 修剪机制在阿尔茨海默病中调节失调。沙茨实验室令人惊讶地发现，与生俱来的 免疫受体PirB在神经元中表达，并在突触修剪发育过程中发挥作用。在……里面 此外，成年小鼠的PirB基因敲除，无论是全局的还是单独的兴奋性神经元，都有助于快速生长 新的突触，并重新开启关键的周期样突触可塑性。PirB及其人类同源物LilrB2， 两者都被证明以高亲和力结合淀粉样β蛋白，而生殖系全局PirB基因敲除被证明是 在AD的APP/PS1鼠标模型中防止记忆丢失。而全球生殖系淘汰赛 保护性，在治疗的背景下，确定PirB阻断在正常情况下的效果也是重要的 饲养处于疾病发展不同阶段的成年小鼠。此外，虽然沙茨实验室发现了一种 连接PirB和突触修剪的信号通路，通过cofilin的去磷酸化，没有其他信号 在APP/PS1小鼠中，已经研究了PirB下游的通路。 在这里，我建议检验阿尔茨海默病模型小鼠神经元基因表达失调的假设 并且可以用PirB KO恢复，防止突触丢失。提出的实验应该能确定 阿尔茨海默病模型小鼠神经元和PirB下游突触的新信号通路。我还提议 在正常饲养的成年APP/PS1小鼠体内阻断PirB以确定PirB/LilrB2的治疗潜力 公元后的封锁。我主要关注疾病发展的两个阶段：1)早期，斑块形成之前，但当 据报道，突触和记忆障碍，以及2)斑块形成和免疫增强后的晚期 激活。这项提案的中心目标是使用转录、生化、电生理和 行为学技术阐明阿尔茨海默病PirB/LilrB2下游信号通路 PirB阻断对APP/PS1模型小鼠记忆丧失的治疗潜力。这样做的长期目标是 研究有助于我们理解导致突触修剪的信号机制。 阿尔茨海默病，作为寻找潜在治疗方法和治疗靶点的第一步。