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

基本信息

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
项目类别：
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&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos s disease model Alzheimer&apos 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

项目摘要

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.

荧光探针用于检测阿尔茨海默氏症中错误折叠的蛋白质低聚物疾病和相关疾病有大量证据表明，阿尔茨海默氏病（AD）和相关疾病的临床症状与在出现之前的小寡聚物的形成和增殖密切相关突出的后期原纤维和斑块。因此，淀粉样蛋白β低聚物（AβOS）是最直接的用于监测AD的发作和进展的生物标志物。但是，尝试使用此生物标志物有在生物样品中可靠检测AβOS的技术死亡，我们受到了严重的阻碍。虽然低聚物选择性抗体为AβOS提供了重要的见解，但它们的使用并没有延长为了检测体内的低聚物种群，更不用说监测其暂时进化了。总体目标因此，该建议是为了鉴定小的低聚物选择染料来检测AβOS并验证它们在AD和患者组织的动物模型组织中对AβOS以及潜在相关的低聚物的特异性。多个实验室已经观察到体内Aβ组装不仅显示纯粹的乙状结肠，而且还显示双相动力学。我们已经表明，双相动力学的发作与发作直接相关随着单体浓度的增加，原纤维寡聚群的迅速增加。我们在这里提出了从本质上是无寡聚物sigmoidal到低聚物主导的双相动力学的提议为了筛选一些随时可用的荧光染料，以选择其对AβFS和单体的AβOS的选择性。对这种方法的初始测试已经产生了高度有希望的染料候选者。我们的初步数据表明该染料在AD动物模型中特异性染色会染色。尽管非常令人鼓舞，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。在此外，我们试图鉴定多个化学和结构上不同的低聚物选择性染料，以改善将其中一个发展成宠物探测器的可能性，以进行寡聚体的体内成像。因此，我们将扩展我们的 AβO选择性染料的当前筛选到从不同染料类别中选择的较大荧光染料。在平行，我们将仔细检查当前的染料是否可靠地检测到疾病的各个阶段的AβOS，并且在动物模型和患者组织中这样做。有希望的新型AβO选择染料通过我们的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诺言AβO选择性染料，并应用低聚物形成的基本研究，用于开发用于检测AβOS的新测定的基础研究，以及最重要的是，作为对未来的低聚物选择性PET探针的检测部分，用于体内生存的探测患者的低聚物成像。