Microglial function of GWAS risk factor BIN1 in Alzheimer's disease pathogenesis and inflammatory signaling

GWAS危险因子BIN1在阿尔茨海默病发病机制和炎症信号传导中的小胶质细胞功能

• 批准号: 10524611
• 负责人: Srikant Rangaraju
• 金额: $ 225.05万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-15 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10524611
• 关键词: Ablation; Acute; Adaptor Signaling Protein; Age; Alternative Splicing; Alzheimer' s Disease; Alzheimer' s disease risk; Amyloid; Apolipoprotein E; Binding; Biochemical; Brain; Brain Diseases; Cerebrum; Coupling; Data; Data Set; Disease; Disease Progression; Disease associated microglia; Disease model; Endocytosis; Enhancers; Event; Foundations; Functional disorder; Future; Gene Expression; Genes; Goals; Human; IRF1 gene; Immune signaling; Impairment; In Vitro; Inflammatory; Inflammatory Response; Injections; Interferons; Investigation; Knockout Mice; Label; Late Onset Alzheimer Disease; Lipopolysaccharides; Mass Spectrum Analysis; Mediating; Membrane; Microglia; Microscopy; Modeling; Molecular; Molecular Analysis; Mus; Neurodegenerative Disorders; Neurons; Pathogenesis; Pathogenicity; Pathology; Pathway interactions; Phenotype; Play; Predisposition; Proteins; Proteomics; Recycling; Regulation; Reporting; Research; Risk Factors; Role; Seeds; Signal Pathway; Signal Transduction; Single Nucleotide Polymorphism; Synaptic Vesicles; TREM2 gene; Tauopathies; Testing; Time; Tissues; Transcript; Transgenic Organisms; Up-Regulation; Variant; Wild Type Mouse; abeta deposition; amyloid pathology; cell type; cerebral amyloidosis; conditional knockout; genome wide association study; in vivo; innovation; insight; large scale data; multidisciplinary; neuroinflammation; neuropathology; novel; prevent; protein expression; receptor; response; risk variant; tau Proteins; transcriptomics; vesicular release; β-amyloid burden

PROJECT SUMMARY BIN1, an adaptor protein encoded by the second most common susceptibility GWAS risk factor of late-onset AD, regulates membrane dynamics in the context of endocytosis, membrane remodeling, and synaptic vesicle release. Large-scale expression datasets have reported high-level BIN1 expression in microglia, and AD- associated BIN1 SNPs are thought to alter BIN1 expression through a microglia-specific enhancer. However, the precise functional role(s) of microglial BIN1 in regulating AD pathophysiology has not been investigated systematically. Our central hypothesis is that microglial BIN1 plays an essential role in neuroinflammatory signaling through which BIN1 influences AD pathophysiology. Our preliminary studies show that the loss of Bin1 expression in vitro (cultured microglia) and in vivo (microglia-specific cKO mice) profoundly impairs proinflammatory gene expression and the upregulation of several disease-associated microglia (DAM) genes. Our transcriptomic profiling identified BIN1 as a homeostatic microglial regulator with a non-redundant role in activating proinflammatory response upstream of Apoe, Trem2, and Tyrobp, and upstream of PU.1 and IRF1. BIN1 was predicted to regulate type 1 and 2 interferon responses in microglia in vitro and in vivo. Collectively, these findings offer important insights into microglial BIN1 function, demonstrating its significance in brain inflammatory response. The overall objective of this proposal is to explore BIN1’s role in microglia further, especially in the context of AD pathogenesis, and gain molecular insights. The goal of Aim 1 is to generate 5XFAD:Bin1 cKO mice to elucidate microglial BIN1 function in the modulation of cerebral amyloid burden and amyloid-associated pathophysiology. We will conduct detailed biochemical, molecular, and neuropathological characterization and perform transcriptomics profiling of neuroinflammation and DAM transition to understand BIN1’s role in microglial response to amyloid pathology. Aim 2 studies seek to generate PS19:Bin1 cKO mice to elucidate the involvement of microglial BIN1 function in tau pathophysiology and pathology propagation using detailed neuropathology and comprehensive biochemical, proteomics, and molecular analyses. Aim 3 studies will investigate the mechanistic role of BIN1 as a crucial regulator of early inflammatory signaling events in microglia. We will use unbiased and hypothesis-driven approaches to define the microglial BIN1 interactome and elucidate how BIN1 and its binding partners are reorganized in a context-dependent manner to facilitate immune signaling via key microglial receptors. This timely and unique proposal is highly innovative. Our strategy to use microglia-specific inducible Bin1 cKO mice represents the most direct in vivo approach to rigorously investigate how microglial BIN1 regulates AD pathophysiology and gain insights using comprehensive transcriptomics, proteomics, and interactome characterization. We believe that the successful completion of the proposed research will fill significant gaps in our understanding of BIN1 as a risk factor for LOAD and guide future functional characterizations of molecular pathways and pathogenic mechanisms regulated by this major LOAD risk gene.

项目摘要 BIN 1是由晚发性AD的第二大最常见易感性GWAS风险因子编码的衔接蛋白， 在胞吞作用、膜重塑和突触囊泡的背景下调节膜动力学 release.大规模的表达数据集已经报道了小胶质细胞中高水平的BIN 1表达，而AD- 相关的BIN 1 SNP被认为通过小胶质细胞特异性增强子改变BIN 1表达。然而，在这方面， 尚未研究小胶质细胞BIN 1在调节AD病理生理学中的精确功能作用 系统地我们的中心假设是小胶质细胞BIN 1在神经炎症反应中起重要作用。 BIN 1通过其影响AD病理生理学的信号传导。我们的初步研究表明，Bin 1的丢失 体外（培养的小胶质细胞）和体内（小胶质细胞特异性cKO小鼠）表达严重损害 促炎基因表达和几种疾病相关小胶质细胞（DAM）基因的上调。 我们的转录组学分析鉴定了BIN 1作为一种稳态小胶质细胞调节因子，在细胞凋亡中具有非冗余作用。 激活Apoe、Trem 2和Tyrobp上游以及PU.1和IRF 1上游的促炎反应。 BIN 1被预测在体外和体内调节小胶质细胞中的1型和2型干扰素应答。总的来说， 这些发现为小胶质细胞BIN 1的功能提供了重要的见解，证明了它在大脑中的重要性。 炎症反应。这项提案的总体目标是进一步探索BIN 1在小胶质细胞中的作用， 特别是在AD发病机制的背景下，并获得分子见解。目标1的目标是生成 5XFAD：Bin 1 cKO小鼠，以阐明小胶质细胞BIN 1在调节脑淀粉样蛋白负荷中的功能， 淀粉样蛋白相关的病理生理学。我们会进行详细的生化分子和神经病理学检查 表征并进行神经炎症和DAM转换的转录组学分析，以了解 BIN 1在小胶质细胞对淀粉样蛋白病理反应中的作用目的2研究寻求产生PS19：Bin 1 cKO小鼠， 使用以下方法阐明小胶质细胞BIN 1功能在tau病理生理学和病理传播中的参与 详细的神经病理学和全面的生化、蛋白质组学和分子分析。Aim 3研究 将研究BIN 1作为早期炎症信号事件的关键调节因子的机制作用， 小胶质细胞我们将使用无偏和假设驱动的方法来定义小胶质细胞BIN 1相互作用组， 阐明BIN 1及其结合伙伴如何以上下文依赖的方式重组，以促进免疫 通过关键的小胶质细胞受体传递信号。这一及时而独特的建议具有很强的创新性。我们的战略是 小胶质细胞特异性诱导型Bin 1 cKO小鼠代表了严格研究的最直接体内方法 小胶质细胞BIN 1如何调节AD病理生理学并使用综合转录组学获得见解， 蛋白质组学和相互作用组表征。我们认为，成功完成拟议的 研究将填补我们对BIN 1作为LOAD风险因素的理解的重大空白，并指导未来的功能 分子途径和致病机制的表征由这个主要的LOAD风险基因调控。