Effects of APOE on neuronal network dynamics using multi-electrode arrays

使用多电极阵列进行 APOE 对神经元网络动力学的影响

• 批准号: 8786199
• 负责人: Gustavo A Rodriguez
• 金额: $ 2.56万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8786199
• 关键词: Affect; Aftercare; Aging; Agonist; Alleles; Alzheimer' s Disease; Alzheimer' s disease risk; Apolipoprotein E; Brain; Cell Culture Techniques; Cells; Chemicals; Cholesterol Homeostasis; Complement; Confocal Microscopy; Data Analyses; Development; Disease; Disease susceptibility; E protein; Electrodes; Excitatory Synapse; Forskolin; Genotype; Glycoproteins; Harvest; Health; Human; Impaired cognition; In Vitro; Individual; Inflammation; Knock-in Mouse; LDL-Receptor Related Protein 1; Laboratories; Lead; Learning; Life; Link; Lipids; Lipoprotein (a); Long-Term Effects; Long-Term Potentiation; Measures; Memory; Modeling; Modification; Mus; Nerve Degeneration; Neuroglia; Neurons; Pathogenesis; Pathology; Peptides; Play; Population; Probability; Process; Property; Protein Isoforms; Proteins; Research Proposals; Risk; Risk Factors; Role; Rolipram; Series; Signal Transduction; Site; Synapses; Synaptic plasticity; System; Testing; Therapeutic; Time; Tissues; Vertebral column; Western Blotting; apolipoprotein E-2; apolipoprotein E-3; apolipoprotein E-4; base; cognitive function; density; electrical measurement; genetic risk factor; immunocytochemistry; in vitro Model; indexing; insight; lipid transport; memory process; mimetics; neurodevelopment; neuron development; neurotransmission; novel strategies; promoter; pup; receptor; relating to nervous system; research study; synaptogenesis

DESCRIPTION (provided by applicant): Apolipoprotein E (apoE) is a lipoprotein-associated glycoprotein synthesized in the CNS by glial cells, responsible for lipid transport within the brai. It has also been linked to a variety of CNS functions, including: neurodevelopment, inflammation, and synaptic plasticity. Importantly, APOE is the strongest genetic risk factor for the development of Alzheimer's disease (AD); it affects processes early in disease development and is known to influence normal brain function in the absence of AD pathology. There are three common human alleles: APOE-ε2, APOE-ε3, and APOE-ε4. Compared to non-ε4 carriers, a single copy of the ε4 allele confers an increased risk of 2- to 3-fold, while two ε4 alleles dramatically increase AD risk by 12-fold. At present, the mechanisms underlying apoE4-associated AD risk are unknown. My overarching hypothesis is that APOE genotype affects normal brain function before AD pathogenesis, specifically by affecting the development and network activity of organized neuronal populations in the brain. The objective of this research proposal is to investigate: 1) whether APOE genotype affects the functional development of neuronal networks in vitro; and 2) how apoE affects activity-induced network dynamics and excitatory neurotransmission. To test these objectives, I will first assess the formation and functional properties of neuronal networks in culture using multi-electrode arrays (MEA) (Aim 1). The MEA allows simultaneous measurement of electrical activity at 59 sites in a neuronal culture system. Cortical tissue will be harvested from APOE Targeted Replacement (TR) mice, a knock-in model expressing human APOE in place of murine APOE, and cultured onto MEAs for repeated electrophysiological recording as neuronal networks develop. This in vitro model allows me to test the contribution of each apoE isoform on neuronal networks, effectively reducing confounds present in other cell-based systems. I hypothesize that apoE4 may negatively impact the development of neuronal networks and cause overall decreased network activity compared to apoE2 or apoE3. Next, I will assess the influence of APOE genotype on activity-induced excitation and neuronal network dynamics using chemical Long-Term Potentiation (cLTP) (Aim 2). MEAs allow simple pharmacologic manipulation of apoE levels and signaling during cLTP to mechanistically determine the role apoE isoforms and its receptors play in activity-induced network dynamics. I hypothesize that apoE4 negatively affects cLTP-induced network dynamics. This interdisciplinary proposal represents a novel approach to understanding how APOE genotype contributes to large scale network formation and neuronal population activity. If my hypotheses are correct, then the information gained by these studies will be critical for the development of preventative therapeutics that compensate for apoE4-related brain changes.

描述（由申请人提供）：载脂蛋白 E (apoE) 是一种由神经胶质细胞在中枢神经系统中合成的脂蛋白相关糖蛋白，负责脑内的脂质运输。它还与多种中枢神经系统功能有关，包括：神经发育、重要的是，APOE 是阿尔茨海默病 (AD) 发展的最强遗传风险因素，它影响疾病发展的早期过程，并且已知会影响正常大脑。在没有 AD 病理的情况下，存在三种常见的人类等位基因：APOE-ε2、APOE-ε3 和 APOE-ε4 与非 ε4 携带者相比，ε4 等位基因的单个拷贝会导致 2- 至 3 倍的风险增加。 3 倍，而两个 ε4 等位基因使 AD 风险显着增加 12 倍 目前，apoE4 相关 AD 风险的机制尚不清楚。我的总体假设是 APOE 基因型影响正常。 AD 发病前的大脑功能，特别是通过影响大脑中有组织的神经群体的发育和网络活动来研究：1) APOE 基因型是否影响体外神经网络的功能发育； apoE 如何影响活动诱导的网络动力学和兴奋性神经传递 为了测试这些目标，我将首先使用多电极阵列 (MEA) 评估培养物中神经网络的形成和功能特性（目标 1）。将从 APOE 靶向替代 (TR) 小鼠（一种表达人 APOE 代替小鼠 APOE 的敲入模型）中采集神经元培养系统 59 个位点的电活动测量，并将其培养到 MEA 上以进行重复电生理记录。这个体外模型使我能够测试每种 apoE 同工型对神经网络的贡献，有效减少其他基于细胞的系统中存在的混杂因素，我渴望 apoE4 可能对神经网络产生负面影响。与 apoE2 或 apoE3 相比，神经网络的发育会导致网络活动整体下降。 接下来，我将使用化学长时程增强 (cLTP) 评估 APOE 基因型对活动诱导的兴奋和神经网络动力学的影响（目标 2）。允许在 cLTP 期间对 apoE 水平和信号进行简单的药理学操作，以机械地确定 apoE 亚型及其受体在活动诱导的网络动态中所起的作用，我捕获了 apoE4 的负面影响。这一跨学科的提议代表了一种理解 APOE 基因型如何促进大规模网络形成和神经群体活动的新方法。补偿 apoE4 相关大脑变化的预防性治疗。