Validating novel ryanodine receptor-targeted compounds for AD therapeutics

 描述(申请人提供)：目前，尚无有效的策略或治疗方法来保护AD患者的认知功能。最近一系列针对Aβ处理或炎症途径的失败临床试验强调了探索替代途径的必要性。能够以不同于以往方法的方式有效地保护认知功能和防止疾病进展的新型化合物可能提供新的治疗机会。为此，我们开发了设计为兰尼定受体(RyR)变构调节剂的&gt；100小分子化合物，兰尼定受体(RyR)是一种发现在内质网膜上的大电导钙通道，可用于早期AD或MCI患者的临床测试。在人类AD患者和AD小鼠模型中，RyR2表达增加先于淀粉样蛋白沉积、神经元丢失和认知损害。在AD小鼠模型中，RyR诱导的钙释放增加在树突棘和突触间隔最大，并与突触病理、淀粉样蛋白和tau病理增加、记忆功能障碍和其他AD定义特征有关。我们和其他人最近证明，用丹曲林治疗AD小鼠，一种RyR通道稳定剂，产生了令人兴奋的治疗效果。尽管我们的治疗方案不同，但一致的结果显示钙信号转导正常化(Chakroborty等人，2012a；Oules等人，2012；Stutzmann等人，2006)，突触传递和可塑性表达正常(Chakroborty等人，2012a)，突触完整性恢复(Stutzmann实验室)，A水平降低(Chakroborty等人，2012a；Oules等人，2012；Peng等人，2012)，RyR异构体水平恢复(Chakroborty等人，2012a；Oules等人，2012)，记忆测试中的表现有所改善(Oule等人，2012；Peng等人，2012)。这些数据支持稳定RyR功能的有力证据，重点是RyR2，作为一种治疗策略。这项研究的目的是测试和优化将作为RyR通道调节器的化合物，在保持生理功能的同时抑制过度的钙释放。中心假说是，用新的小分子化合物稳定RyR介导的钙释放将使钙信号正常化，保护突触功能，减少组织病理学，从而成为预防AD认知功能下降的有效治疗策略。这将通过以下目标来完成：1.使用钙成像、电生理和免疫分析技术在模型细胞和人类AD患者的IPSC中寻找最佳的RyR2稳定化合物。2.在慢性治疗3xTg-AD小鼠模型上，展示了成功的新化合物对钙信号、突触可塑性和组织病理学的广泛疗效。对公众健康的意义在于开发一种有效的、新颖的治疗AD的方法。

 DESCRIPTION (provided by applicant): Currently, there are no effective strategies or treatments to preserve cognitive function in AD patients. The recent series of failed clinical trias designed to target Aβ processing or inflammatory pathways highlight the need to explore alternative pathways. Novel compounds that can effectively preserve cognitive function and prevent disease progression in a manner distinct from previous approaches could provide new therapeutic opportunities. To this end, we developed >100 small molecule compounds designed as allosteric modulators of the ryanodine receptor (RyR), a large conductance calcium channel found on the ER membrane, as candidates for clinical testing in early AD or MCI patients. In both human AD patients and AD mouse models, increased RyR2 expression precedes the amyloid deposition, neuronal loss, and cognitive impairments. In AD mouse models, increased RyR-evoked calcium release is greatest in dendritic spines and synaptic compartments, and contributes synaptic pathology, increased amyloid and tau pathology, disrupted memory function, and other AD-defining features. We and others have recently demonstrated that treating AD mice with dantrolene, a RyR channel stabilizer, resulted in exciting therapeutic effects. Although our treatment regimens differed, the consistent results demonstrate normalized calcium signaling (Chakroborty et al., 2012a; Oules et al., 2012; Stutzmann et al., 2006), normal synaptic transmission and plasticity expression (Chakroborty et al., 2012a), restored synaptic integrity (Stutzmann lab), reduced A levels (Chakroborty et al., 2012a; Oules et al., 2012; Peng et al., 2012), restored RyR isoform levels (Chakroborty et al., 2012a; Oules et al., 2012), and improved performance on memory tests (Oule et al., 2012; Peng et al., 2012). These data support a strong case for stabilizing RyR function, with a focus on RyR2, as a therapeutic strategy. The objective of this study is to test and optimize compounds that will function as RyR channel regulators, serving to suppress excessive calcium release while maintaining physiological functions. The central hypothesis is that stabilizing RyR-mediated calcium release with novel small molecule compounds will normalize calcium signaling, preserve synaptic function, and reduce histopathology, thus serving as an effective therapeutic strategy to prevent cognitive decline in AD. This will be accomplished with the following Aims: 1. Identify optimal RyR2 stabilizing compounds in model cells and iPSC from human AD patients using calcium imaging, electrophysiological and immunoassay techniques. 2. Demonstrate broad efficacy of successful novel compounds on calcium signaling, synaptic plasticity and histopathology in chronically treated 3xTg-AD mouse models. The significance to public health is the development of an effective and novel treatment for AD.