Novel Specific Ligands for ABeta Oligomers

描述(由申请人提供)：该项目旨在开发一种新型分子，它与神经毒性形式的淀粉样蛋白(A？)特异地相互作用，并具有高亲和力，被认为是导致阿尔茨海默病(AD)的原因。到目前为止，阿尔茨海默病还没有治愈方法，目前的治疗只能产生中度和暂时的症状缓解。临床诊断AD的敏感性约为85%，而只有在尸检后才能得到明确的诊断。AD的有效诊断和治疗可能需要敏感和特定的工具来早期发现并干预导致AD发展的神经毒性过程。 新分子被称为适配子，将使用成熟的方法从10(15)个DNA序列库中选择，这些方法已被证明对各种靶标产生具有高亲和力和特异性的配体。AD领域的一个难题是，相关靶点是Aβ的亚稳集合体，很难研究和分离。我们将克服这一困难，利用我们实验室以前开发的光化学交联技术来稳定这些组件。这种方法可以对单个组件进行定量提纯。 该项目包括以下步骤：首先，将产生具有高亲和力和高特异性的神经毒素A？组件的适配子。其次，我们将开发一种基于适体的诊断技术，并将使用该技术分析AD患者和健康人的脑脊液样本。第三，我们将评估适配子在神经细胞培养中抑制A的神经毒性作用的能力，作为开发基于适配子的治疗AD药物的第一步。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？组件的适体，并将这些适体用作AD诊断和治疗的新的、基于机制的工具。

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.