Novel bivalent multifunctional ligands towards Alzheimer's disease

描述（由申请人提供）：阿尔茨海默病（AD）是一种毁灭性的神经退行性疾病，是痴呆症的主要原因。新出现的证据表明，淀粉样蛋白肽（A¿o）的小而可溶性低聚物是AD患者认知障碍的主要毒性物质。此外，越来越多的证据表明，氧化应激、生物金属平衡失调和神经炎症也可能导致AD的病理。许多针对这些危险因素的小分子已经被开发出来，并在临床前和临床试验中进行了测试，然而，它们都没有被FDA批准作为ad修饰剂。这可能表明，另一种有前途的策略是使用多功能配体同时解决这些风险因素。此外，越来越多的证据强调了细胞膜/脂筏（CM/LR）在AD病理中的重要作用，并且CM/LR与所有已确定的AD危险因素有关。这表明，通过将这一因素纳入分子设计中，可以利用这种关系开发具有战略意义的多功能药物。本提案的总体目标是验证和开发更有效的二价多功能A¿o寡聚化抑制剂（BMAOIs），该抑制剂含有具有内在抗氧化/金属螯合功能的多功能A¿o抑制剂和CM/LR锚定片段作为进一步临床前研究的先导化合物。本应用的中心假设是，这些BMAOIs将锚定在CM/LR内部或附近的多功能A¿o抑制剂部分，在那里A¿寡聚、Ab/生物金属相互作用和氧化应激发生，以增加其局部浓度和可及性，从而提高其效率。我们实验室的初步研究已经达到了BMAOIs策略的概念验证，并确定了两个有希望进一步优化的先导化合物。提出了三个具体的目标来实现我们在这个应用程序中的目标。在目标1中，将基于新鉴定的先导化合物设计和合成一系列BMAOIs，以修饰和优化间隔结构域、CM/LR锚定结构域和a¿o抑制剂结构域。在目标2中，设计的BMAOIs将在各种体外实验中进行评估，包括抑制与人类神经母细胞瘤MC65细胞保护活性相关的A¿O形成，以及对分化的SH-SY5Y和小鼠原代神经元的神经保护作用。BMAOIs与CM/LR的共定位也将在MC65细胞和小鼠原代神经元中进行研究。此外，还将测试所选BMAOIs的抗氧化性能和金属络合性能。在目标3中，将评估通过目标2选择标准的强效BMAOIs对转基因TgCRND8小鼠的认知和A¿病理的影响。这项研究具有创新性，因为我们正在寻找一类新的靶向a¿o，氧化应激，a¿o /生物金属相互作用和CM/LR的BMAOIs作为新的药理工具和潜在的ad修饰剂。这项研究的结果将是一种新颖的、经过验证的、可用的BMAOIs策略，并最终有利于AD的药物治疗。

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a devastating neurodegenerative disorder and the leading cause of dementia. Emerging evidence has recognized small, soluble oligomers of amyloid-¿-peptide (A¿Os) as the major toxic species for cognition impairment in AD. Furthermore, evidence has been accumulating that oxidative stress, biometal dyshomeostasis, and neuroinflammation may also contribute to the pathology of AD. Numerous small molecules targeting each of these risk factors have been developed and tested in preclinical and clinical trials, however, none of them has been approved by FDA as AD-modifying agents. This may suggest that one of the alternative and promising strategies is to use multifunctional ligands to tackle these risk factors simultaneously. Furthermore, evidence has increasingly underscored the important roles of cell membrane/lipid rafts (CM/LR) in the pathology of AD and CM/LR have been implicated to associate with all the identified risk factors in AD. This indicates that this relationship can be exploited therapeutically to develop strategic distinct multifunctional agents by incorporating this factor into molecular design. The overall goa of this proposal is to validate and develop more potent bivalent multifunctional A¿ oligomerization inhibitors (BMAOIs) that contain a multifunctional A¿O-inhibitor with intrinsic antioxidant/metal chelating functions and a CM/LR anchor moiety as lead compounds for further preclinical studies. The central hypothesis of this application is that these BMAOIs will anchor the multifunctional A¿O-inhibitor moiety inside, or in the vicinity of, CM/LR where A¿ oligomerization, Ab/biometal interactions, and oxidative stress occur to increase its local concentration and accessibility, thus enhancing its efficiency. Preliminary studies in our laboratory have reached the proof-of- concept of the BMAOIs strategy and resulted in the identification of two promising lead compounds for further optimization. Three specific aims are proposed to achieve our objective in this application. In aim 1, a series of BMAOIs will be designed and synthesized based on the newly identified lead compounds to modify and optimize the spacer domain, CM/LR anchor domain and A¿O-inhibitor domain. In aim 2, the designed BMAOIs will be evaluated in various in vitro assays including inhibition of A¿O formation in association with protective activity in human neuroblastoma MC65 cells as well as neuroprotective effects on differentiated SH-SY5Y and mouse primary neurons. The co-localization of BMAOIs with CM/LR will also be investigated in MC65 cells and mouse primary neurons. In addition, antioxidant and metal complexation properties of selected BMAOIs will be tested. In aim 3, potent BMAOIs that passed the selection criteria of aim 2 will be evaluated for their effects on cognition and A¿ pathology in transgenic TgCRND8 mice. The proposed research is innovative because we seek a new class of BMAOIs targeting A¿Os, oxidative stress, A¿/biometal interactions and CM/LR as novel pharmacological tools and potential AD-modifying agents. The outcome of this study would be a novel, validated, BMAOIs strategy available and ultimately benefit pharmacotherapy for AD.