Novel Specific Ligands for ABeta Oligomers

描述（由申请人提供）：该项目旨在开发一类新型分子，其与被认为导致阿尔茨海默病（AD）的淀粉样蛋白（A）的神经毒性形式特异性和高亲和力相互作用。到目前为止，AD还没有治愈方法，目前的治疗方法只能中度和暂时缓解症状。AD的临床诊断的敏感性为~85%，而确诊仅在死后实现。AD的有效诊断和治疗可能需要敏感和特异性的工具，用于早期检测和干预导致AD发展的神经毒性过程。 新分子，称为适体，将使用已被证明产生对多种靶标具有高亲和力和特异性的配体的成熟方法从10（15）个DNA序列的文库中选择。AD领域的一个难题是相关靶标是A的亚稳态组装体，其难以研究和分离。我们将克服这一困难，采用光化学交联技术，以前在我们的实验室开发，以稳定这些组件。该方法能够定量纯化单个组装体。 该项目包括以下步骤：首先，将产生对神经毒性A？组装体具有高亲和力和高特异性的适体。其次，我们将开发一种基于适体的诊断技术，并将使用这种技术来分析AD患者和健康个体的脑脊液样本。第三，我们将评估适体在神经元细胞培养物中抑制A？神经毒性作用的能力，作为开发基于适体的药物治疗AD的第一步。使用这种系统的方法，我们希望获得具有高亲和力和高特异性的亚稳态，神经毒性A？组件的适配体，并使用这些适配体作为新的，基于机制的工具，AD诊断和治疗。

DESCRIPTION (provided by applicant): This project aims to develop a novel class of molecules that interact specifically and with high affinity with neurotoxic forms of amyloid ¿-protein (A¿), which are believed to cause Alzheimer's disease (AD). To date, AD has no cure and current treatments yield only moderate and temporary relief of symptoms. The clinical diagnosis of AD has sensitivity of ~85%, whereas a definite diagnosis is achieved only post mortem. Effective diagnosis and treatment for AD likely will require sensitive and specific tools for early detection of, and intervention against the neurotoxic processes that lead to development of AD. The new molecules, termed aptamers, will be selected from a library of 10(15) DNA sequences using well established methods that have been shown to yield ligands with high affinity and specificity for a large variety of targets. A difficult problem in the AD field is that the relevant targets are metastable assemblies of A¿, which are difficult to study and isolate. We will overcome this difficulty employing a photochemical cross-linking technique previously developed in our laboratory to stabilize these assemblies. This method enables quantitative purification of individual assemblies. The project includes the following steps: First, aptamers with high affinity and high specificity for neurotoxic A¿ assemblies will be generated. Second, we will develop an aptamer-based diagnostic technique and will use this technique to analyze cerebrospinal fluid samples from patients with AD and from healthy individuals. Third, we will assess the capability of the aptamers to inhibit the neurotoxic effect of A¿ in cultures of neuronal cells as a first step towards development of aptamer-based drugs for treatment of AD. Using this systematic approach, we expect to obtain aptamers with high affinity and high specificity for the metastable, neurotoxic A¿ assemblies and to use these aptamers as novel, mechanism-based tools for AD diagnostics and therapeutics.