The Role of KCa3.1 in Neuroinflammation in Alzheimer Disease

KCa3.1 在阿尔茨海默病神经炎症中的作用

• 批准号: 8630956
• 负责人: Izumi Maezawa
• 金额: $ 31.29万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-30 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8630956
• 关键词: Affect; Age-Months; Alzheimer' s Disease; Amyloid; Amyloid beta-Protein; Behavioral; Brain; Brain Injuries; Breeding; Calcium-Activated Potassium Channel; Cells; Chemotaxis; Clinical Trials; Cognitive deficits; Data; Dementia; Deposition; Development; Disease; Elderly; Face; Functional disorder; Future; Gene Expression; Genes; Genetic; Goals; Grant; Immune; Immunosuppressive Agents; In Vitro; Individual; Infection; Inflammation Mediators; Inflammatory; Inflammatory Response; Inhibitory Concentration 50; Ischemic Stroke; Knock-out; Laboratories; Leukocytes; Measures; Mediating; Memory impairment; Microglia; Modeling; Molecular Profiling; Mus; Neurons; Nitric Oxide; Outcome; Pathogenesis; Pathology; Patients; Phagocytosis; Pharmaceutical Preparations; Phenotype; Play; Production; Proteins; Public Health; Reaction; Reactive Oxygen Species; Recording of previous events; Regulation; Rodent; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Therapeutic; Time; Transgenic Mice; chemokine; cytokine; cytotoxic; improved; in vivo; inhibitor/antagonist; interest; killings; macrophage; meetings; migration; mild cognitive impairment; mouse model; neuroinflammation; neurotoxic; neurotoxicity; new therapeutic target; novel strategies; patch clamp; preclinical study; prevent; public health relevance; small molecule; therapeutic target; tool; uptake

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is the most common cause of dementia in the elderly. To meet the public health challenge posed by AD, a goal set by the National Alzheimer's Project Act is to prevent or treat AD by 2025. Therefore currently there is an urgent need for new therapeutic target discovery and corresponding compound development. A protein deposited in AD brains called amyloid-beta (Abeta) has been hypothesized to play a critical role in AD pathogenesis. Abeta can activate microglia to clear Abeta but at the same time also stimulate microglia to release cytotoxic substances that cause neuronal damage. Using the small molecule TRAM-34, which was synthesized by our group, as a pharmacological tool we recently demonstrated that the calcium-activated potassium channel KCa3.1 plays an important role in microglia activation and microglial neurotoxicity. In vivo evidence indicates that blockade of KCa3.1 by TRAM-34 can inhibit microglia-mediated neuronal killing without affecting their migration and phagocytotic activities. Relevant to AD, our results suggest that TRAM-34 blocks the neurotoxicity induced by Abeta-activated microglia, but does not inhibit their beneficial function of phagocytosing Abeta. KCa3.1 blockade, therefore, is a potential new approach for the treatment of AD. With the help of this grant we wish to perform proof-of-principle studies to validate KCa3.1 as a novel therapeutic target for reducing microglia-mediated neurotoxicity and microglial dysfunction in Alzheimer's disease (AD), through the following three Specific Aims: Aim-1: Determine the effect of KCa3.1 blockade on Ab-induced microglial activation. We will treat cultured microglia with Abeta aggregates (oligomer and fibril) and evaluate the effect of KCa3.1 blockade by TRAM-34 treatment (Aim-1a) or genetic knockout (Aim-1b) on chemotactic and phagocytotic activities, signaling pathways, and the production of chemokines, cytokines, reactive oxygen species, and nitric oxide. Aim-2: Assess the contribution of KCa3.1 to AD-like pathology and cognitive deficits seen in the APPswe/PS1dE9 (APP-PS1) model using the genetic knockout approach. We will cross-breed APP-PS1 mice with KCa3.1-/- mice and evaluate whether KCa3.1 reduction affects neuropathological and behavioral abnormalities in APP-PS1 mice. We will further determine if KCa3.1 reduction can alleviate microglial dysfunction seen in APP-PS1 mice. Aim-3: Validate KCa3.1 as a therapeutic target for AD by performing preclinical studies with TRAM-34. We will determine if a 2-month course of TRAM-34, a selective inhibitor of KCa3.1, administered to APP-PS1 mice will reduce neuroinflammation, alleviate microglial dysfunction, and improve the neuropathological and behavioral outcomes of APP-PS1 mice. Because KCa3.1 blockade is relatively safe, our preclinical studies will have translational significance for future developmen of drugs for treating individuals with mild cognitive impairment or AD through inhibition of detrimental microglia functions.

描述（由申请人提供）：阿尔茨海默病（AD）是老年痴呆症的最常见原因。为了应对AD带来的公共卫生挑战，《国家阿尔茨海默病项目法案》设定的目标是到2025年预防或治疗AD。因此，目前迫切需要发现新的治疗靶点和开发相应的化合物。沉积在AD脑中的称为淀粉样蛋白-β（Abeta）的蛋白质已被假设在AD发病机制中起关键作用。Abeta可以激活小胶质细胞以清除Abeta，但同时也刺激小胶质细胞释放细胞毒性物质，导致神经元损伤。使用我们小组合成的小分子TRAM-34作为药理学工具，我们最近证明了钙激活钾通道KCa3.1在小胶质细胞活化和小胶质细胞神经毒性中起着重要作用。体内证据表明，通过TRAM-34阻断KCa 3.1可以抑制小胶质细胞介导的神经元杀伤，而不影响它们的迁移和吞噬活性。关于AD，我们 结果表明，TRAM-34阻断由A β激活的小胶质细胞诱导的神经毒性，但不抑制它们吞噬A β的有益功能。因此，KCa 3.1阻断是治疗AD的一种潜在的新方法。在这项资助的帮助下，我们希望进行原理验证研究，以验证KCa3.1作为减少阿尔茨海默病（AD）中小胶质细胞介导的神经毒性和小胶质细胞功能障碍的新型治疗靶点，通过以下三个具体目标：目标-1：确定KCa3.1阻断对Ab诱导的小胶质细胞激活的影响。我们将用Abeta聚集体（寡聚体和原纤维）处理培养的小胶质细胞，并评估通过TRAM-34处理（Aim-1a）或基因敲除（Aim-1b）阻断KCa3.1对趋化和吞噬活性、信号传导通路以及趋化因子、细胞因子、活性氧和一氧化氮产生的影响。目标二：使用基因敲除方法评估KCa3.1对APPswe/PS1 dE 9（APP-PS1）模型中观察到的AD样病理和认知缺陷的贡献。我们将APP-PS1小鼠与KCa3.1-/-小鼠杂交，并评估KCa3.1减少是否会影响APP-PS1小鼠的神经病理学和行为异常。我们将进一步确定KCa3.1减少是否可以减轻APP-PS1小鼠中观察到的小胶质细胞功能障碍。目的-3：通过使用TRAM-34进行临床前研究，将KCa3.1作为AD的治疗靶点。我们将确定给予APP-PS1小鼠2个月的TRAM-34（一种KCa3.1的选择性抑制剂）是否会减少神经炎症，缓解小胶质细胞功能障碍，并改善APP-PS1小鼠的神经病理学和行为结果。由于KCa3.1阻断相对安全，我们的临床前研究将对未来开发通过抑制有害的小胶质细胞功能治疗轻度认知障碍或AD的药物具有转化意义。