Fluorescent probes for detection of misfolded protein oligomers in Alzheimer's Disease and related disorders

用于检测阿尔茨海默病和相关疾病中错误折叠蛋白寡聚体的荧光探针

• 批准号: 10604908
• 负责人: David E Kang
• 金额: $ 20.04万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10604908
• 关键词: APP-PS1; Address; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease model; Alzheimer' s disease related dementia; Amyloid; Amyloid beta-Protein; Animal Model; Antibodies; Binding; Biological; Biological Assay; Biological Markers; Categories; Characteristics; Chemicals; Clinical; Data; Dependence; Deposition; Detection; Development; Disease; Dyes; Evolution; Exhibits; Fluorescence; Fluorescent Dyes; Fluorescent Probes; Future; Gentian Violet; Goals; Growth; Human; Image; In Vitro; Kinetics; Label; Laboratories; Link; Monitor; Muramidase; Mus; Normal tissue morphology; Oranges; Outcome; Pathogenicity; Pathologic; Pathology; Patients; Phase; Population; Positron-Emission Tomography; Proliferating; Protocols documentation; Public Health; Role; Sampling; Series; Solid; Solvents; Specificity; Stains; Symptoms; Techniques; Testing; Thioflavin S; Tissues; Transgenic Mice; Transgenic Organisms; Validation; abeta oligomer; amyloid formation; animal tissue; brain tissue; cohort; detection assay; detection method; experimental study; imaging probe; improved; in vivo; in vivo imaging; in vivo monitoring; indexing; innovation; insight; mild cognitive impairment; misfolded protein; monomer; novel; protein oligomer; response; scaffold; screening; success; tau Proteins; tau aggregation

Fluorescent Probes for Detection of Misfolded Protein Oligomers in Alzheimer's Disease and Related Disorder There is significant evidence that the clinical symptoms of Alzheimer’s Disease (AD) and related disorders are closely linked to the formation and proliferation of small oligomers that precede the emergence of the prominent late-stage fibrils and plaques. Therefore, amyloid beta oligomers (AβOs) are the most direct biomarkers for monitoring the onset and progression of AD. Attempts at utilizing this biomarker, however, have been severely hampered by the dearth of techniques for the reliable detection of AβOs in biological samples and tissues. While oligomer-selective antibodies have provided important insights into AβOs, their use doesn't extend to detecting oligomer populations in vivo, let alone monitoring their temporal evolution. The overall objectives of this proposal are therefore to identify small oligomer-selective dyes for the detection of AβOs and to validate their specificity for AβOs, and potentially related oligomers, in tissues of animal models of AD and patient tissue. Multiple laboratories have observed that in vivo Aβ assembly displays not only purely sigmoidal but also biphasic ThT kinetics. We have shown that the onset of biphasic ThT kinetics directly correlates with the onset and rapid increase in prefibrillar oligomer populations with increases in monomer concentrations. Here we propose to use this transition from essentially oligomer-free sigmoidal to oligomer-dominated biphasic kinetics to screen a selection of readily available fluorescent dyes for their selectivity for AβOs over AβFs and monomers. An initial test of this approach already yielded a highly promising dye candidate. Our preliminary data also indicate that this dye specifically stains oligomer deposits in animal models of AD. While very encouraging, the utility of our current oligomer-selective dye requires further validation. In addition, we seek to identify multiple chemically and structurally distinct oligomer-selective dyes to improve the chances to develop one of them into a PET probe for in vivo imaging of oligomers. We will therefore extend our current screen for AβO-selective dyes to a larger set of fluorescent dyes selected from different dye categories. In parallel, we will scrutinize whether the current dye reliably detects AβOs at various stages of the disease, and does so in animal models as well as patient tissues. Promising novel AβO-selective dyes identified through our screening assay will be subjected to the same ex vivo validation of their specificity in tissues. We anticipate that these experiments will yield multiple promising AβO-selective dyes with application for fundamental studies of oligomer formation, for the development of new assays for detecting AβOs ex vivo, and, most importantly, as the detection moiety for a future oligomer-selective PET probe for antemortem in vivo oligomer imaging in patients.

用于检测阿尔茨海默病中错误折叠蛋白质寡聚物的荧光探针 疾病及相关病症 有重要证据表明阿尔茨海默病 (AD) 和相关疾病的临床症状 与出现之前的小寡聚物的形成和增殖密切相关 突出的晚期原纤维和斑块因此，淀粉样β寡聚体（AβO）是最直接的。 然而，已经有人尝试利用这种生物标志物来监测 AD 的发病和进展。 由于缺乏可靠检测生物样品中 AβO 的技术而受到严重阻碍 虽然寡聚物选择性抗体为 AβO 提供了重要的见解，但它们的用途并没有扩展。 检测体内寡聚体群体，更不用说监测它们的时间演变了。 因此，该提案的目的是鉴定用于检测 AβO 的小寡聚物选择性染料并验证 它们对 AD 动物模型组织和患者组织中的 AβO 和潜在相关寡聚体具有特异性。 多个实验室观察到体内 Aβ 组装不仅表现出纯 S 形，而且还表现出 我们已经证明双相 ThT 动力学的发生与发生直接相关。 随着单体浓度的增加，前原纤维寡聚体数量迅速增加。 建议利用这种从基本上无寡聚物的 S 形到寡聚物主导的双相动力学的转变 筛选一系列现成的荧光染料，以确定它们对 AβO 的选择性优于 AβF 和单体。 我们对这种方法的初步测试已经产生了一种非常有前途的候选染料。 表明该染料可以特异性地对 AD 动物模型中的低聚物沉积物进行染色。 虽然非常令人鼓舞，但我们当前的低聚物选择性染料的实用性需要进一步验证。 此外，我们寻求鉴定多种化学和结构不同的低聚物选择性染料，以改善 因此，我们有机会将其中之一开发成用于低聚物体内成像的 PET 探针。 目前对 AβO 选择性染料的筛选已扩展到从不同染料类别中选择的更大组荧光染料。 与此同时，我们将仔细检查当前的染料是否能够可靠地检测疾病各个阶段的 AβO，以及 通过我们的研究，我们在动物模型和患者组织中发现了有前景的新型 AβO 选择性染料。 筛选测定将对其在组织中的特异性进行相同的离体验证。 我们预计这些实验将产生多种有前景的 AβO 选择性染料，并应用于 低聚物形成的基础研究，用于开发离体检测 AβO 的新方法，以及， 最重要的是，作为未来体内死前低聚物选择性 PET 探针的检测部分 患者的寡聚物成像。