In situ cryo-electron tomography of ß-amyloid and tau in post-mortem Alzheimer's disease brain
In situ cryo-electron tomography of ß-amyloid and tau in post-mortem Alzheimer's disease brain
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阿尔茨海默病死后大脑中的 α-淀粉样蛋白和 tau 蛋白原位冷冻电子断层扫描
DOI：
10.1101/2023.07.17.549278
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Gilbert M
中科院分区：
文献类型：
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作者：
Gilbert M
大多数神经退行性疾病的定义性病理特征是蛋白质组装成淀粉样蛋白，形成疾病特异性结构。在阿尔茨海默病（AD）中，其特征在于淀粉样蛋白-β（Aβ）和具有AD特异性构象的tau的沉积。淀粉样蛋白在人脑中的原位结构尚不清楚。在这里，使用低温荧光显微镜（cryoFM）靶向冷冻切片，冷冻聚焦离子束扫描电子显微镜（cryoFIB-SEM）抬出和冷冻电子断层扫描（cryoET），我们确定了新鲜死后AD供体脑中β-淀粉样蛋白和tau病理的组织内结构。β-淀粉样蛋白斑块含有以平行阵列排列的原纤维和原丝的混合物和网格状结构，其中一些是分支的。细胞外囊泡、细胞外液滴和开放的脂质双层片定义了淀粉样斑块的非淀粉样成分。相比之下，tau包涵体的特征在于无分支的细丝簇。每个簇内细丝的亚断层扫描平均值显示了不同的结构，包括双螺旋扭曲的成对螺旋细丝（PHF）和慢性创伤性脑病（CTE）样tau细丝，它们位于病理学的两个显微镜区域内，相距约1.1 μm。一个集群内的细丝彼此相似，但集群之间的不同，表明原纤维异质性的空间组织和亚细胞组织环境的影响。本文概述的针对人类供体组织内特定蛋白质的原位结构方法可应用于广泛的神经退行性疾病。
A defining pathological feature of most neurodegenerative diseases is the assembly of proteins into amyloid that form disease-specific structures. In Alzheimer’s disease (AD) this is characterised by the deposition of amyloid-β (Aβ) and tau with AD-specific conformations. Thein situstructure of amyloid in the human brain is unknown. Here, using cryogenic fluorescence microscopy (cryoFM)-targeted cryo-sectioning, cryo-focused ion beam scanning electron microscopy (cryoFIB-SEM) liftout and cryo-electron tomography (cryoET), we determined the in-tissue structure of β-amyloid and tau pathology in fresh post-mortem AD donor brain. β-amyloid plaques contained a mixture of fibrils and protofilaments arranged in parallel arrays and lattice-like structures, some of which were branched. Extracellular vesicles, extracellular droplets and open lipid bilayer sheets defined non-amyloid constituents of amyloid plaques. In contrast, tau inclusions were characterised by clusters of unbranched filaments. Subtomogram averaging of filaments within each cluster revealed distinct structures including variably twisted paired helical filaments (PHF) and chronic traumatic encephalopathy (CTE)-like tau filaments that were situated ∼1 μm apart within two microscopic regions of pathology. Filaments within a cluster were similar to each other, but different between clusters, showing that fibril heterogeneity is spatially organised and influenced by the subcellular tissue environment. Thein situstructural approaches outlined here for targeting specific proteins within human donor tissues have applications to a broad range of neurodegenerative diseases.