Validating novel ryanodine receptor-targeted compounds for AD therapeutics

 描述（由申请人提供）：目前，没有有效的策略或治疗方法来保护AD患者的认知功能。最近一系列旨在靶向Aβ加工或炎症通路的失败临床试验突出了探索替代通路的必要性。新型化合物可以有效地保护认知功能，并以不同于以往方法的方式预防疾病进展，这可能提供新的治疗机会。为此，我们开发了>100种小分子化合物，其被设计为兰尼碱受体（RyR）的变构调节剂，RyR是在ER膜上发现的大电导钙通道，作为早期AD或MCI患者的临床测试的候选物。在人类AD患者和AD小鼠模型中，RyR 2表达增加先于淀粉样蛋白沉积、神经元损失和认知障碍。在AD小鼠模型中，增加的RyR诱发的钙释放在树突棘和突触区室中最大，并且有助于突触病理学、增加的淀粉样蛋白和tau病理学、破坏的记忆功能和其他AD定义特征。我们和其他人最近证明，用丹曲林（一种RyR通道稳定剂）治疗AD小鼠，产生了令人兴奋的治疗效果。尽管我们的治疗方案不同，但一致的结果表明钙信号传导正常化（Chakroborty等人，2012 a; Oules等人，2012; Stutzmann等人，2006）、正常突触传递和可塑性表达（Chakroborty等人，2012 a），恢复突触完整性（Stutzmann实验室），降低A水平（Chakroborty等人，2012 a; Oules等人，2012; Peng等人，2012），恢复RyR同种型水平（Chakroborty等人，2012 a; Oules等人，2012），以及改进的存储器测试性能（Oule等人，2012; Peng等人，2012年）。这些数据支持稳定RyR功能的强有力的案例，重点是RyR 2，作为一种治疗策略。本研究的目的是测试和优化将作为RyR通道调节剂的化合物，用于抑制过量的钙释放，同时保持生理功能。中心假设是，用新型小分子化合物稳定RyR介导的钙释放将使钙信号正常化，保护突触功能，并减少组织病理学，从而作为预防AD认知下降的有效治疗策略。这将实现以下目标：1。使用钙成像、电生理学和免疫测定技术鉴定来自人类AD患者的模型细胞和iPSC中的最佳RyR 2稳定化合物。2.在长期治疗的3xTg-AD小鼠模型中证明成功的新型化合物对钙信号传导、突触可塑性和组织病理学的广泛疗效。对公共卫生的意义在于开发有效和新颖的AD治疗方法。

 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.