Identification of Old-Age-Associated Alzheimer's Disease Drug Targets

描述(申请人提供)：到目前为止，老年是大多数神经退行性疾病的最大风险因素，但很少有人尝试确定这些疾病中任何一种与衰老相关的治疗目标，包括阿尔茨海默氏症(AD)。在过去的十年中，Salk实验室开发了神经细胞培养药物筛选试验，这些试验基于与衰老相关的中枢神经系统病理，包括营养支持丧失、能量代谢降低、氧化损伤和细胞内聚集蛋白的积累。将这些分析与迭代药物化学结合使用，制成了一种特别有效的化合物，称为J147，在上述所有分析中都具有神经保护作用，EC50在低纳摩尔范围内。该化合物还可增强年轻和极老(30mo)小鼠的记忆，改善老年(23mo)AD转基因小鼠的认知功能和突触结构，并延长果蝇的寿命。由于J147在缺乏淀粉样蛋白通路中任何已知AD药物靶点的多种细胞培养模型中防止细胞死亡，因此它一定作用于与淀粉样蛋白通路无关并有助于其治疗效果的高度相关的分子靶点(S)和靶通路。鉴于J147在多种不同功能、与年龄相关的毒性测试中具有神经保护作用，它应该是 有可能定义共同的、共享的神经保护途径(S)，然后将其用作确定AD治疗的新治疗靶点的基础。这一提出的用于识别药物靶标的化学生物学方法最早于1785年从毛地黄中分离出地高辛，随后于1806年从罂粟中分离出吗啡，并于1897年从水杨酸中分离出阿司匹林。这些分子不仅对医学做出了巨大的贡献，而且是分别涉及Na-K-ATP泵、阿片受体和环氧合酶的分子通路和药物靶点的++鉴定的关键因素，导致了一系列今天应用于临床的衍生药物。这项申请的总体目标是使用基于J147化合物的化学生物学方法来识别和验证AD治疗和预防的新的、与衰老相关的靶点。这将通过分子生物学和蛋白质组学来确定在多种毒性测试中导致神经保护的共同分子信号通路，并通过化学和蛋白质组学来分离J147的分子靶点(S)。体内靶标验证将部分在动物模型中进行， 并不偏向于家族性AD/淀粉样蛋白途径，而是反映了人类衰老和AD的大部分方面，即衰老加速的SAMP8小鼠。

DESCRIPTION (provided by applicant): Old age is by far the greatest risk factor for the majority of neurodegenerative diseases, yet few attempts have been made to identify aging-associated therapeutic targets for any of these diseases, including Alzheimer's dementia (AD). During the last ten years the Salk laboratories have developed nerve cell culture drug screening assays that are based upon old-age-associated CNS pathologies, including the loss of trophic support, reduced energy metabolism, oxidative damage, and the accumulation of intracellular aggregated proteins. Using these assays in conjunction with iterative medicinal chemistry, an exceptionally potent compound, called J147, was made that is neuroprotective in all of the above assays with EC50s in the low nanomolar range. This compound also enhances memory in young and very old (30 mo) mice, improves cognitive function and synaptic structure in old (23 mo) AD transgenic mice, and extends the life span of flies. SinceJ147 prevents cell death in multiple cell culture models that lack any of the recognized AD drug targets of the amyloid pathway, it must be acting on highly relevant molecular target(s) and target pathways that are unrelated to the amyloid pathway and that contribute to its therapeutic efficacy. Given that J147 is neuroprotective in multiple, functionally distinct, age-associated toxicity assays, it should be possible to define common, shared neuroprotective pathway(s) which will then be used as the basis for identifying new therapeutic targets for the treatment of AD. This proposed chemical biology approach to identify drug targets originated in 1785 with the isolation of digoxin from foxglove, followed by morphine from poppies in 1806, and aspirin from salicylic acid in 1897. Not only did these molecules make tremendous contributions to medicine, they also were the key factors in the ++ identification of the molecular pathways and drug targets involving the Na -K -ATP pump, opiate receptors, and the cyclooxygenase enzymes, respectively, leading to a succession of derivative drugs that are in the clinic today. The overall goal of this application i to use a chemical biology approach based upon the J147 compound to identify and validate novel, old-age-associated targets for AD treatment and prevention. This will be done by using molecular biology and proteomics to define the shared molecular signaling pathways that lead to neuroprotection in multiple toxicity assays, and chemistry and proteomics to isolate the molecular target(s) of J147. In vivo target validation will be done in part in an animal model that is not biased toward the familial AD/amyloid pathway, but rather reflects most aspects of human aging and AD, the senescence-accelerated SAMP8 mice.