Dlgap2 as a Regulator of Alzheimer's Disease Related Cognitive Declines Via Synaptic Modifications

项目摘要 到目前为止，围绕着调节神经元的遗传和神经机制， 认知恢复力对阿尔茨海默病（AD）。如果不更好地理解这些机制， 在AD面前，开发提高认知寿命的治疗方法仍然是有限的。我们最近 一项已发表的工作，利用人-鼠跨物种分析，确定了突触后基因Dlgap 2 （椎间盘大相关蛋白2）作为年龄和AD相关认知能力下降的潜在介导因素， 树突棘形态的变化，这与其他以前的工作调查棘作为一个 AD相关认知恢复力的中介。我这项工作的长期目标是确定Dlgap 2是否是一个 AD相关认知功能下降的真正修饰剂，并更好地理解Dlgap 2在 AD进展过程中的突触功能障碍。我采用的新方法是调节 Dlgap 2在AD发病机制模型小鼠海马神经元中的表达。使用新设计的 腺相关病毒（AAV）携带Dlgap 2与神经元特异性启动子，我将过表达Dlgap 2在 AD小鼠的CA 1区。迄今为止，这是首次研究Dlgap 2在AD相关认知功能中的作用。 下降我推测海马锥体神经元中Dlgap 2表达的增加将增强海马锥体神经元中Dlgap 2的表达。 CA 1中突触和树突棘重塑，并最终促进对因果关系的认知恢复。 在我们的易感AD小鼠模型中的突变。我将通过评估以下变化的影响来检验这一假设： dlgap 2在3种不同生物学尺度认知老化中的表达。1)我将测量认知结果， 青年（6个月）和老年人的工作记忆、短时记忆和长时记忆的脑区依赖性结构域 （14个月）在两种性别中过表达Dlgap 2的AD小鼠。2)在同样的小鼠中，我将确定 Dlgap 2在CA 1神经元中的过表达导致EPSP峰电位耦合和/或长时程突触后电位的增加。 通过使用离体全细胞电流钳记录增强。这些录音会告诉我 AD中Dlgap 2的过表达通过修饰与突触可塑性的相互作用而增强突触可塑性。 NMDAr/AMPAR和突触后密度。3)为了研究Dlgap 2对突触结构的影响，我将 成像树突棘形态学，AD相关认知衰退的修饰剂，CA 1神经元过度表达 Dlgap2.这里提出的工作将有助于促进我的培训目标，以获得新的技能和知识 包括与以下有关的：新的行为测定、电生理学、荧光显微镜、树突状细胞 脊柱成像和一般湿实验室技能此外，这项拟议的工作将大大有助于我完善我的 科学的沟通技巧，项目管理技巧，以及促进我的职业发展。

PROJECT SUMMARY To date, there is a significant knowledge gap surrounding the genetic and neuronal mechanisms that regulate cognitive resilience to Alzheimer’s Disease (AD). Without a better understanding of these mechanisms, developing therapeutics to enhance cognitive longevity in the face of AD will remain limited. Our recently published work, which utilized human-mouse cross-species analysis, identified the post-synaptic gene Dlgap2 (Discs large associated protein 2) as a potential mediator of age- and AD-related cognitive decline through changes to dendritic spine morphology, which concurs with other previous work investigating spines as a mediator of AD-related cognitive resilience. My long-term goal for this work is to determine if Dlgap2 is a genuine modifier of AD-related cognitive decline, and to build a better understanding of the role of Dlgap2 in synaptic dysfunction during the progression of AD. The novel approach that I am employing is to modulate Dlgap2 expression in hippocampal neurons of mice that model AD pathogenesis. Using a newly designed Adeno-Associated Virus (AAV) carrying Dlgap2 with and neuron specific promotor, I will overexpress Dlgap2 in the CA1 of AD mice. To date this is the first work to investigate the role of Dlgap2 in AD-related cognitive decline. I hypothesize that increasing expression of Dlgap2 in hippocampal pyramidal neurons will enhance synaptic and dendritic spine remodeling in CA1 and, ultimately, promote cognitive resilience to causal mutations in our susceptible AD mouse model. I will test this hypothesis by evaluating the impact of changes in Dlgap2 expression on cognitive aging on 3 different biological scales. 1) I will measure cognitive outcomes in the hippocampal-dependent domains of working, short-term and long-term memory of young (6mo) and aged (14mo) AD mice that overexpress Dlgap2 across both sexes. 2) In the same mice, I will determine if overexpression of Dlgap2 in CA1 neurons results in an increase in EPSP spike coupling and/or Long-term potentiation by using ex vivo whole-cell current-clamp recordings. These recordings will inform me if overexpression of Dlgap2 in AD reinforces synaptic plasticity via modifications to interactions between NMDAr/AMPAr and the postsynaptic density. 3) To investigate the effect of Dlgap2 on synaptic structure, I will image dendritic spine morphology, a modifier of AD-related cognitive decline, of CA1 neurons that overexpress Dlgap2. The work proposed here will help facilitate my training goals to acquire new skills and knowledge including those pertaining to: new behavioral assays, electrophysiology, fluorescent microscopy, dendritic spine imaging, and general wet lab skills. Additionally, this proposed work will greatly assist me in refining my scientific communication skills, project management skills, and furthering my career development.