Novel misfolded proteins in ADRD: proteomics, genetics, and clinical-pathological correlations

阿尔茨海默病和相关痴呆(ADRD)的不同病理机制仍然存在 不完全理解。目前还没有完美的动物模型来研究这些疾病。已知的四个反常 错误折叠的蛋白质通常是通过对患有ADRD的大脑进行神经病理检查来检测的：Aβ，Tau， TdP-43和/或α-突触核蛋白。我们的初步数据表明，有更多的致病蛋白 等待鉴定的物种。这些蛋白质的特征可能与 ADRD的诊断和治疗策略。这项研究项目的目标是确定 ADRD中以前未表征、错误折叠和异常加工的蛋白质；解决基因变异 通过新的错误折叠的蛋白质调节痴呆症的严重性和异质性； 进行临床-病理对照，重点研究这些新的蛋白质，以识别与新疾病相关的新疾病 病理性生物标记物。我们将利用肯塔基大学广告中心(UK-ADC)的资源 生物库和肯塔基大学蛋白质组学核心基金，以执行以下具体目标： 具体目标1.分析人杏仁核不溶于洗涤剂的蛋白质提取物(速冻) 在尸检中)，以调查在ADRD中是否可以检测到尚未确定特征的错误折叠蛋白。 来自洗涤剂不溶于洗涤剂的、尿素可溶的杏仁核蛋白部分的多肽将被询问。 使用质谱学。我们手头有来自40名UK-ADC受试者的杏仁核，其中包括一个 临床和病理特征的谱系。免疫组织化学和生化研究将 为进一步研究确定最佳候选蛋白质(目标2和3)。 具体目标2.使用外显子测序构建稳健和协调的数据库以定位 ADRD中与新的错误折叠蛋白相关的遗传区。我们将测试两者之间的关联 痴呆症和编码候选错误折叠蛋白的基因中罕见的外显子(“错义”)遗传变异 (目标1)。遗传学数据加上丰富的神经病理内表型和纵向临床数据将 能够洞察推动痴呆症的新机制。大规模数据集(NACC、ADGC、ADSP)将 聚合和协调以测试基于临床和神经病理的遗传驱动因素 关注新的候选基因的内表型。候选目标基因已经被识别出来。 具体目标3.建立新的错误折叠的临床-病理相关性 ADRD中的蛋白质病。我们将测试潜在的新型蛋白质病之间的关联(来自 目的1)对于认知障碍，考虑已知标记物Aβ、tau、α突触核蛋白和tdp-43，以及 脑血管病理学。我们有370个样本可用于分析(包括性别)来自英国-ADC， 它应该有统计学上的力量来检验我们的假设，即小说的存在和严重性 错误折叠的蛋白质病理与认知障碍有关。

The heterogeneous pathologies of Alzheimer's disease and related dementias (ADRD) are still incompletely understood. There is no perfect animal model to study these diseases. Four known aberrantly misfolded proteins are commonly detected via neuropathologic examination of brains with ADRD: Aβ, Tau, TDP-43, and/or α-Synuclein. Our preliminary data indicate that there are more pathogenic protein species awaiting identification. Characterization of these proteins may be relevant to the development of both diagnostic and therapeutic strategies for ADRD. The goals of this research project are to identify previously uncharacterized, misfolded, and aberrantly processed proteins in ADRD; to resolve gene variants that modulate the severity and heterogeneity of dementia through the novel misfolded proteins; and, to perform clinical-pathological correlation, focusing on these novel proteins, to identify new disease-associated pathologic biomarkers. We will leverage the resources of the University of Kentucky AD Center (UK-ADC) biobank and the University of Kentucky Proteomics Core Facility, to execute the following Specific Aims: Specific Aim 1. Analyse detergent-insoluble protein extracts from human amygdala (snap-frozen at autopsy) to investigate whether as yet uncharacterized misfolded proteins are detectable in ADRD. Polypeptides from the detergent-insoluble, urea-soluble protein fractions of amygdala will be interrogated using mass spectrometry. We have on-hand amygdalae from 40 UK-ADC subjects which incorporate a spectrum of clinical and pathologic features. Immunohistochemistry and biochemical studies will be performed to determine the best candidate proteins for additional studies (Aims 2 and 3). Specific Aim 2. Construct a robust and harmonized database with exonic sequencing to localize genetic regions associated with novel misfolded proteins in ADRD. We will test the association between dementia and rare, exonic (`mis-sense') genetic variants in genes that encode candidate misfolded proteins (Aim 1). Genetics data augmented with rich neuropathologic endophenotypes and longitudinal clinical data will enable insights into novel mechanisms that drive dementia. Large-scale datasets (NACC, ADGC, ADSP) will be aggregated and harmonized to test the genetic drivers of clinical and neuropathology-based endophenotypes focusing on novel candidate genes. Candidate target genes have already been identified. Specific Aim 3. Establish the clinical-pathologic correlation for the novel misfolded proteinopathies in ADRD. We will test the association between the potential novel proteinopathies (from Aim 1) with cognitive impairment, factoring in known markers Aβ, tau, α-Synuclein, and TDP-43, as well as cerebrovascular pathologies. We have 370 samples available for analyses (both sexes) from the UK-ADC, which should be statistically powered to test our hypothesis that the presence and severity of novel misfolding protein pathologies are associated with cognitive impairment.