Exploring CRMP5 as a novel target for Alzheimers disease

探索 CRMP5 作为阿尔茨海默病的新靶点

• 批准号: 10712329
• 负责人: Liberty Francois Ep Moutal
• 金额: $ 37.77万
• 依托单位: SAINT LOUIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-14 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10712329
• 关键词: 3xTg-AD mouse; Acceleration; Administrative Supplement; Adult; Affect; Age; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease model; Alzheimer' s disease patient; Amyloid deposition; Autoantibodies; Autopsy; Awareness; Axon; Behavior; Behavioral; Behavioral Symptoms; Biochemical; Biochemistry; Bioenergetics; Biology; Brain; Breeding; Cause of Death; Cell Death; Cognitive; Data; Dementia; Disease; Down-Regulation; Economic Burden; Electrophysiology (science); Emotional; Functional disorder; Funding; Generations; Grant; Growth; Health; Hippocampus; Human; Human Amyloid Precursor Protein; Immunohistochemistry; Investments; Ion Channel; J20 mouse; Knock-out; Link; Long-Term Potentiation; Measures; Mediator; Medicine; Memory; Memory impairment; Mitochondria; Mus; Mutation; N-Methyl-D-Aspartate Receptors; Nerve Degeneration; Neurites; Neurofibrillary Tangles; Neurons; Pathogenesis; Pathologic; Patients; Peptides; Performance; Population; Positioning Attribute; Postsynaptic Membrane; Prefrontal Cortex; Prevalence; Protein Isoforms; Proteins; Research; Risk; Role; Semaphorin-3A; Senile Plaques; Signal Transduction; Slice; Social Behavior; Socialization; Societies; Symptoms; Synapses; Testing; Tissues; Transgenic Organisms; Tubulin; United States; Up-Regulation; V717F; Western Blotting; Withdrawal; age related; aging population; cohort; dentate gyrus; disease phenotype; familial Alzheimer disease; hyperphosphorylated tau; improved; knock-down; mitochondrial dysfunction; morris water maze; mouse model; neurogenesis; neuron loss; neurotoxicity; new therapeutic target; novel; object recognition; olfactory bulb; overexpression; painful neuropathy; postsynaptic; preclinical study; programs; protein protein interaction; response; social; socioeconomics; transcriptome sequencing; tubulin polymerization inhibitor; β-amyloid burden

ABSTRACT Alzheimer’s disease (AD) is a devastating disease that bears a huge emotional and socio-economic burden. Because of the aging population of our societies, the increasing risks of developing Alzheimer and the lack of proper disease-mitigating strategy, AD is now viewed as a global and urgent crisis. In this proposal, we suggest a new therapeutic target: Collapsin Response Mediator Protein (CRMP)-5, an inhibitor of tubulin polymerization and neurite outgrowth. The rationale here is that targeting proteins that restrict neuronal connectivity of the hippocampus, a prime region of neuronal loss in AD, could prove a valid strategy to mitigate neurotoxicity in AD and decrease its burden. In the hippocampus CRMP5 interacts with tubulin in the growing axon thus halting its growth and negatively regulates neurogenesis. In brains from AD patients, CRMP5 expression is increased in the hippocampus and in the pre-frontal cortex. This supplement builds on the observations that (i) CRMP5 expression was increased in the 3xTg mouse model of AD, (ii) increased CRMP5 expression reduced socialization in 3xTg-AD mice, (iii) CRMP5 knockdown rescued social performance in 3xTg-AD mice, (iv) CRMP5 increases mitochondrial fragmentation, thereby participating in the known dysfunction of mitochondria in the AD brain, (v) CRMP5 controls the post-synaptic expression of GluN2B, an ion channel implicated in AD-induced memory impairment. These results show that CRMP5 upregulation is a pathological feature participating to AD however the function for CRMP5 in the pathogenesis of AD remains unknown. Within this supplement, we will test the effect of CRMP5 knockout on memory impairment and social withdrawal as well as neuronal function in a mouse model of AD. To do so, we will breed a J20 mouse line, which overexpresses human amyloid precursor protein (APP) with two mutations (Swedish and Indiana mutations) linked to familial AD, with our current CRMP5 KO line. We will compare our J20–crmp5-/-compared to J20–crmp5wt mice by evaluating their cognitive behaviors using the novel object recognition and Morris water maze tests and their social behavior using the three-chamber paradigm test. We will assess Aβ burden, as well as synaptic integrity in the hippocampus and pre-frontal cortex. We will also evaluate neuronal loss by immunoblotting using markers of necroptosis, contributing to cell death in human and AD mice models. Mitochondrial dysfunction, an underlying mechanism of AD pathophysiology, will be assessed by cellular bioenergetic profiling and Aβ burden in the mitochondria. Using electrophysiology, we will test synaptic functionality by measuring long-term potentiation (LTP) in hippocampal and prefrontal cortex slices. We expect that knock-down of CRMP5 in the J20 mouse will result in reduced AD phenotypes, defined by (i) increasing memory and social behaviors, (ii) decreasing amyloid plaques burden, (iii) improving mitochondria function, (iv) decreasing neuronal death, and (v) enhancing synaptic integrity and function. This Administrative Supplement request in response to NOT-AG-22-025 will help kickstart a larger and more comprehensive study to evaluate the targeting of CRMP5 to decrease the burden of AD symptoms.

抽象的 阿尔茨海默病（AD）是一种毁灭性的疾病，带来巨大的情感和社会经济负担。 由于我们社会人口老龄化，患阿尔茨海默病的风险不断增加，而且缺乏 如果采取适当的疾病缓解策略，AD 现在被视为一场全球性的紧迫危机。在本提案中，我们建议 新的治疗靶点：塌陷反应介导蛋白 (CRMP)-5，一种微管蛋白聚合抑制剂 和神经突生长。这里的基本原理是，靶向限制神经元连接的蛋白质 海马体是 AD 神经元丢失的主要区域，可能被证明是减轻 AD 神经毒性的有效策略 并减轻其负担。在海马体中，CRMP5 与正在生长的轴突中的微管蛋白相互作用，从而阻止其生长 生长并对神经发生进行负调节。在 AD 患者的大脑中，CRMP5 表达增加 海马体和前额皮质。本补充建立在以下观察基础上：(i) CRMP5 AD 3xTg 小鼠模型中的表达增加，(ii) CRMP5 表达增加减少 3xTg-AD 小鼠的社交能力，(iii) CRMP5 敲除挽救了 3xTg-AD 小鼠的社交表现，(iv) CRMP5 增加线粒体碎片，从而参与 AD 中已知的线粒体功能障碍 大脑，(v) CRMP5 控制 GluN2B 的突触后表达，GluN2B 是一种与 AD 诱导相关的离子通道 记忆障碍。这些结果表明CRMP5上调是参与AD的病理特征 然而，CRMP5 在 AD 发病机制中的功能仍不清楚。在本补充文件中，我们将 测试 CRMP5 敲除对记忆障碍、社交退缩以及神经元功能的影响 AD小鼠模型。为此，我们将培育 J20 小鼠品系，该小鼠品系过度表达人类淀粉样蛋白前体 具有与家族性 AD 相关的两种突变（瑞典突变和印第安纳突变）的蛋白质 (APP)，以及我们目前的 CRMP5 KO线。我们将通过评估 J20–crmp5-/- 与 J20–crmp5wt 小鼠的认知行为来比较它们 使用新颖的物体识别和莫里斯水迷宫测试及其使用三室的社会行为 范式测试。我们将评估 Aβ 负荷以及海马体和前额皮质的突触完整性。 我们还将使用坏死性凋亡标记物通过免疫印迹评估神经元损失，从而导致细胞死亡 在人类和 AD 小鼠模型中。线粒体功能障碍是 AD 病理生理学的一个潜在机制， 通过细胞生物能量分析和线粒体中的 Aβ 负荷进行评估。利用电生理学，我们 将通过测量海马和前额皮质的长时程增强 (LTP) 来测试突触功能 切片。我们预计 J20 小鼠中 CRMP5 的敲低将导致 AD 表型减少，定义为 通过（i）增加记忆力和社会行为，（ii）减少淀粉样斑块负担，（iii）改善 线粒体功能，（iv）减少神经元死亡，（v）增强突触完整性和功能。这 响应 NOT-AG-22-025 的行政补充请求将有助于启动更大、更多的 评估 CRMP5 减轻 AD 症状负担的综合研究。