Specific amyloid-beta oligomer aptamers

描述（由申请人提供）：该提案的中心重点是探索如何填补技术空白-检测活体中的特定A？寡聚体。测量活体中特定A <$寡聚体的新技术的发展将使我们能够研究在临床上可识别的AD迹象出现之前，产生A <$*56、A <$二聚体和A <$三聚体的个体可以活多久。这个项目可以提高我们对启动AD的过程的理解，以及我们在其最早阶段诊断AD的能力，通过确定特定的A？寡聚体是否足够早地出现在AD中，从而成为旨在完全预防疾病的治疗的目标。如果成功，这项工作将使美国和世界上数百万人受益。最近，与拉什大学的研究人员合作，我们发现许多没有认知障碍的老年人的A *56水平升高，如果他们活得更长，他们可能会患上AD。我们还发现，不同的A？寡聚体在AD发展和进展的不同阶段升高。其他研究人员在不同的A？寡聚体的上升和下降中错过了这些复杂的模式，因为他们使用了大量测量A？寡聚体的测试，而没有区分不同的物种。我们假设A <$*56引发AD，其中一个测试是观察A <$*56在大脑中的长期后果。然而，由于我们无法监测活体受试者大脑中的A <$*56，我们将在容易获得的测试样本中测量A <$*56，最好是血液，但也包括脊髓液。使用我们目前的免疫印迹方法，我们可以在大脑和脊髓液中检测到A *56，但在血液中检测不到。这表明血液中的A56水平极低或不存在。然而，在APP转基因小鼠中有间接证据表明A *56存在于血液中。在过去的几年里，Srinand Sreevatsan博士实验室的研究人员开发了DNA适体，能够检测感染羊瘙痒症的绵羊血液中朊病毒蛋白的羊瘙痒症亚型，其水平远低于免疫印迹方法的检测阈值。最近，由罗纳德彼得森博士领导的马约诊所的研究人员完成了对明尼苏达州罗切斯特近2,000名老年居民的招募，对衰老和早期认知问题的遗传、生物标志物和成像方面进行了纵向研究，并同意向我们提供脊髓液和血液样本。在这项挑战资助申请中，我们建议与Sreevatsan博士合作开发检测特定A <$寡聚体的DNA适体，并使用这些适体测量马约诊所队列的脊髓液和血液中不同的A <$寡聚体，包括A <$*56。 公共卫生相关性：该提案的中心焦点探讨了如何填补技术空白--检测活体中特定的A ²低聚物。测量活体中特定A <$寡聚体的新技术的发展将使我们能够研究在临床上可识别的AD迹象出现之前，产生A <$*56、A <$二聚体和A <$三聚体的个体可以活多久。这个项目可以提高我们对启动AD的过程的理解，以及我们在其最早阶段诊断AD的能力，通过确定特定的A？寡聚体是否足够早地出现在AD中，从而成为旨在完全预防疾病的治疗的目标。如果成功，这项工作将使美国和世界上数百万人受益。

DESCRIPTION (provided by applicant): The central focus of this proposal explores how to fill a technological gap - the detection of specific A¿ oligomers in living subjects. The development of new techniques for measuring specific A¿ oligomers in living individuals will enable us to investigate how long individuals that are producing A¿*56, A¿ dimers and A¿ trimers may live before clinically recognizable signs of AD emerge. This project may improve both our understanding of the processes that initiate AD and our ability to diagnose it in its earliest stages, by determining whether specific A¿ oligomers appear early enough in AD to become a target for therapies aimed at preventing the illness altogether. If successful, the work could benefit millions of people in America and the world. Recently, in collaboration with researchers at Rush University, we found that A¿*56 levels were elevated in many elderly individuals with no cognitive impairment who, presumably, would have developed AD had they lived longer. We also showed that distinct A¿ oligomers were elevated in different phases of the development and progression of AD. Other researchers have missed these intricate patterns in the rise and fall of distinct A¿ oligomers, because they used tests which measure A¿ oligomers in bulk, without distinguishing between distinct species. One test of our hypothesis, that A¿*56 initiates AD, is to observe the long-term consequences of A¿*56 in the brain. However, since we cannot monitor A¿*56 in the brains of living subjects, we will instead measure A¿*56 in readily accessible test specimens, preferably blood, but also spinal fluid. Using our current immunoblotting methods we can detect A¿*56 in brain and spinal fluid, but not in blood. This suggests that the levels of A¿*56 in blood are extremely low, or absent. However, there is indirect evidence in APP transgenic mice that A¿*56 is present in the blood. In the past few years, researchers in the laboratory of Dr. Srinand Sreevatsan developed DNA aptamers capable of detecting the scrapie isoform of the prion protein in the blood of scrapie-infected sheep, at levels far below the detection threshold of immunoblotting methods. Lately, researchers at the Mayo Clinic led by Dr. Ronald Petersen completed enrollment of nearly 2,000 elderly residents of Rochester, Minnesota, in a longitudinal study of genetic, biomarker, and imaging aspects of aging and very early cognitive problems, and have agreed to make spinal fluid and blood samples available to us. In this Challenge grant application, we propose to collaborate with Dr. Sreevatsan to develop DNA aptamers which detect specific A¿ oligomers, and to use these aptamers to measure distinct A¿ oligomers, including A¿*56, in the spinal fluid and blood of the Mayo Clinic cohort. PUBLIC HEALTH RELEVANCE: The central focus of this proposal explores how to fill a technological gap - the detection of specific A¿ oligomers in living subjects. The development of new techniques for measuring specific A¿ oligomers in living individuals will enable us to investigate how long individuals that are producing A¿*56, A¿ dimers and A¿ trimers may live before clinically recognizable signs of AD emerge. This project may improve both our understanding of the processes that initiate AD and our ability to diagnose it in its earliest stages, by determining whether specific A¿ oligomers appear early enough in AD to become a target for therapies aimed at preventing the illness altogether. If successful, the work could benefit millions of people in America and the world.