Cell autonomous and non-cell autonomous roles of the GWAS risk factor BIN1 in Alzheimer's disease neuropathology

GWAS 危险因子 BIN1 在阿尔茨海默病神经病理学中的细胞自主和非细胞自主作用

• 批准号: 9198396
• 负责人: GOPAL THINAKARAN
• 金额: $ 206.06万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2020-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9198396
• 关键词: Adaptor Signaling Protein; Age; Alleles; Alternative Splicing; Alzheimer' s Disease; Alzheimer' s Disease Pathway; Alzheimer' s disease model; Alzheimer' s disease risk; Amyloid; Amyloidosis; Apoptosis; Attenuated; Behavior; Behavioral; Biological; Brain; Cell Cycle Progression; Cells; Centronuclear myopathy; Complex; Confocal Microscopy; Cytoskeletal Modeling; DNA Repair; DNA Sequence Alteration; Dendrites; Deposition; Disease; Down-Regulation; Drug or chemical Tissue Distribution; Employee Strikes; Endocytosis; Etiology; Exons; Family; Foundations; Fractionation; Future; Genes; Genetic study; Goals; Hippocampal Mossy Fibers; Human; Immunoelectron Microscopy; In Vitro; Individual; Intervention; Investigation; Knock-out; Knockout Mice; Late Onset Alzheimer Disease; Learning; Link; Membrane; Modeling; Mus; Muscular Atrophy; Neonatal; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Oligodendroglia; Pathology; Pathway interactions; Play; Process; Protein Family; Protein Isoforms; Proteins; Reporting; Risk Factors; Rodent; Role; Senile Plaques; Staining method; Stains; Susceptibility Gene; Tauopathies; Testing; Tissues; Transcript; Transgenic Mice; Transgenic Organisms; Translating; Variant; amphiphysin; attenuation; base; cell type; critical period; fly; genome wide association study; gray matter; in vivo; innovation; insight; interest; member; mouse model; myelination; neuronal cell body; neuropathology; novel; novel strategies; prevent; risk variant; tau Proteins; white matter

This proposal focuses on BIN1, one of the recently identified common risk genes within the major susceptibility loci for late-onset Alzheimer's disease (LOAD) (second only to APOE). BIN1 (Bridging INtegrator-1) is a member of a family of adaptor proteins that regulate membrane dynamics in the context of endocytosis and membrane remodeling. Alternate splicing of the 20 exons in BIN1 gene generates ubiquitous and tissue- specific isoforms, which differ in their tissue distribution, subcellular localization, and function. These functions include cell cycle progression, apoptosis, cytoskeletal organization, and DNA repair. An increase of BIN1 expression and alternate splicing of BIN1 have been reported in the brains of individuals with LOAD but how these observations translate to increased risk for AD is entirely not clear. In preliminary studies, we have characterized prominent BIN1 expression in mature oligodendrocytes in the gray and white matter in rodent and the human brain. By generating oligodendrocyte-specific Bin1 conditional knock out (cKO) mice, we confirmed that BIN1 is mainly expressed in mature oligodendrocytes. Interestingly, we observe aberrant BIN1 expression near human senile plaques and BIN1 accrual in amyloid deposits of AD transgenic mouse models. Based on these novel findings, we hypothesize that BIN1 functions in mature oligodendrocytes, and that alteration in BIN1 expression and/or function in oligodendrocytes plays a role in AD-related pathogenic processes and neurodegeneration in a non-cell autonomous manner. We propose the following specific aims to test novel hypothesis related to the role of BIN1 in AD. The Specific Aims of this proposal are: Aim 1: To test the hypothesis that BIN1 cellular expression and localization are altered in AD brain. We will investigate the BIN1 expression and alternate splicing in normal and diseased human brain. We will determine the subcellular localization of BIN1 by fractionation and confocal microscopy, and clarify the ultrastructural BIN1 localization using immunoelectron microscopy. Aim 2: To test the hypothesis that downregulation of BIN1 expression will attenuate amyloid and tau pathology in transgenic mice. We will ascertain whether cell-type specific loss of BIN1 expression in neurons or mature oligodendrocytes will attenuate AD-related neuropathology and behavior deficits in transgenic AD mouse models. Aim 3: To test the hypothesis that BIN1 plays a role in oligodendrocyte differentiation, survival, and maturation, as well as myelination in vivo. We will utilize Bin1 cKO mouse models and cultured oligodendrocytes to test this hypothesis. This proposal is timely, unique, and highly innovative. We believe that our investigation will uncover significant insights on BIN1's function in the brain, characterize novel Bin1 cKO mouse models of interest to the AD field, establish whether attenuation of BIN1 expression provides a novel strategy for disease intervention, and lay the foundation for characterization of BIN1 functional variants linked to AD, and guide future functional characterization of biological pathways and pathogenic mechanisms regulated by this major LOAD risk gene.

该提案的重点是BIN 1，这是最近在晚发性阿尔茨海默病（LOAD）（仅次于APOE）的主要易感基因座中发现的常见风险基因之一。BIN 1（桥接整合子-1）是衔接蛋白家族的成员，其在内吞作用和膜重塑的背景下调节膜动力学。BIN 1基因的20个外显子的选择性剪接产生普遍存在的和组织特异性的异构体，其在组织分布、亚细胞定位和功能上不同。这些功能包括细胞周期进程、细胞凋亡、细胞骨架组织和DNA修复。据报道，在LOAD患者的大脑中，BIN 1表达和BIN 1的可变剪接增加，但这些观察结果如何转化为AD风险增加还完全不清楚。在初步研究中，我们已经在啮齿动物和人脑的灰质和白色物质中的成熟少突胶质细胞中表征了显著的BIN 1表达。通过产生少突胶质细胞特异性Bin 1条件性敲除（cKO）小鼠，我们证实了BIN 1主要在成熟的少突胶质细胞中表达。有趣的是，我们观察到人类老年斑附近BIN 1的异常表达和AD转基因小鼠模型淀粉样蛋白沉积中BIN 1的增加。基于这些新的发现，我们假设BIN 1在成熟的少突胶质细胞中发挥作用，并且BIN 1表达和/或功能的改变在少突胶质细胞中以非细胞自主的方式在AD相关的致病过程和神经退行性变中发挥作用。我们提出了以下具体目标来测试与BIN 1在AD中的作用相关的新假设。目的1：检验BIN 1细胞表达和定位在AD脑中改变的假设。我们将研究BIN 1在正常和患病人脑中的表达和选择性剪接。我们将确定亚细胞定位的BIN 1的分馏和共聚焦显微镜，并澄清超微结构定位的BIN 1使用免疫电子显微镜。目的2：验证BIN 1表达下调将减轻转基因小鼠中淀粉样蛋白和tau蛋白病理的假设。我们将确定在神经元或成熟少突胶质细胞中BIN 1表达的细胞类型特异性缺失是否会减弱转基因AD小鼠模型中AD相关的神经病理学和行为缺陷。目的3：验证BIN 1在体内少突胶质细胞分化、存活和成熟以及髓鞘形成中起作用的假设。我们将利用Bin 1 cKO小鼠模型和培养的少突胶质细胞来验证这一假设。这一建议是及时的，独特的，具有很强的创新性。我们相信，我们的研究将揭示BIN 1在大脑中功能的重要见解，表征AD领域感兴趣的新型BIN 1 cKO小鼠模型，确定BIN 1表达的减弱是否为疾病干预提供了新的策略，并为表征与AD相关的BIN 1功能变体奠定基础，并指导未来的生物学途径和致病机制的功能表征，这一主要的LOAD风险基因调控。