Glutamate receptors and human neurological disease

该R35研究计划提案将使用电生理、分子和结构方法来 探索与神经系统疾病相关的兴奋性突触功能的多个方面。我们将重点关注 突触后谷氨酸受体功能特性的阐明和调控。我们会带上 利用低温电子显微镜、遗传学、机器人学和受体生物学的同步进展来解决以下问题 以前是无法进入的。四种方法将解决我们对突触理解中的关键差距 功能，并提供与治疗相关的神经疾病洞察。 首先，我们将探讨地区性不耐受对健康人群变异的功能和临床意义。 以及与新发疾病相关的谷氨酸受体突变，最常见的发现于GRIN1， GRIN2A、GRIN2B、GRIN2D是基因组中耐受性最差的基因之一。我们将建立 健康个体的等位基因频率与功能改变之间的关系，这是顺序上必要的 了解这些基因中SNPs作为疾病危险因素的潜在作用。对这些稀有变种的评估 也将为精确医学提供机会，并促进我们对受体功能的理解。 第二，我们将为概念验证研究开发新的化合物，以确定新的治疗策略 神经紊乱。我们将合成激动剂效力和通道开放的亚单位选择性调节剂 评估未被研究的NMDA受体亚单位(例如，GluN2C，GluN2D)在脑内神经回路中作用的概率 皮质、丘脑和纹状体。我们将确定NMDA调节剂的作用部位和作用机制 受体，并使用药物化学来改善协作中的脑渗透、效力和溶解性 和丹尼斯·利奥塔一起在埃默里大学上化学课。我们将使用我们开发的药理学工具来获得洞察力 用于治疗癫痫、中风、帕金森氏症和阿尔茨海默病。 第三，我们通过开发两类化合物的SAR来探索NMDA受体的偏向调节器 这会改变离子通道的选择性。这些化合物代表了第一个例子，表明一种药理 调整剂可以改变通道渗透特性，表明调制器可以调整不同的功能 NMDA受体。这些化合物具有作为神经保护剂的巨大潜力，可以减少阳离子通量。 没有与受体阻断相关的副作用，我们将在缺血模型中对其进行体内评估。 第四，我们将结合通过对区域不容忍的遗传分析获得的信息， 变构调节和结构生物学的新进展促进了我们对其机制的理解 将谷氨酸结合转化为通道开放。这些实验将重点放在 控制通道开放的蛋白质，这是我们的变构调节剂和常见的 与疾病相关的人类突变的地点。我们将合作进行低温电子显微镜和结晶学 研究确定调节剂的结合部位，以及通道结构和功能的关键特征。

This R35 Research Program proposal will use electrophysiological, molecular, and structural approaches to probe multiple aspects of excitatory synaptic function that are relevant for neurological disease. We will focus on the elucidation and modulation of the functional properties of postsynaptic glutamate receptors. We will take advantage of coincident advances in cryoEM, genetics, robotics, and receptor biology to address questions that were previously inaccessible. Four approaches will address critical gaps in our understanding of synaptic function and provide therapeutically-relevant insight into neurological disease. First, we will explore the functional and clinical implications of regional intolerance for variation in the healthy population as well as de novo disease-associated glutamate receptor mutations, most commonly found in GRIN1, GRIN2A, GRIN2B, GRIN2D, genes that are among the least tolerant in the genome. We will establish the relationship in healthy individuals between allelic frequency and functional changes, which is necessary in order to understand the potential role of SNPs in these genes as disease risk factors. Evaluation of these rare variants will also provide opportunities for precision medicine, and advance our understanding of receptor function. Second, we will develop novel compounds for proof-of-concept studies to identify new therapeutic strategies for neurological disorders. We will synthesize subunit-selective modulators of agonist potency and channel open probability to assess the roles of understudied NMDA receptor subunits (e.g. GluN2C, GluN2D) in circuits in cortex, thalamus, and striatum. We will determine the site and mechanism of action of modulators of NMDA receptors, and use medicinal chemistry to improve brain penetration, potency, and solubility in collaboration with Dennis Liotta in Chemistry at Emory. We will use the pharmacological tools that we develop to gain insight into the treatment of epilepsy, stroke, Parkinson’s disease, and Alzheimer’s disease. Third, we explore biased modulators of NMDA receptors by developing the SAR of two classes of compounds that alter ion channel selectivity. These compounds represent the first example whereby a pharmacological agent can alter channel permeation properties, demonstrating that modulators can tune distinct functions of the NMDA receptor. These compounds hold enormous potential as neuroprotectants that diminish cation flux without side effects associated with receptor blockade, which we will evaluate in vivo in models of ischemia. Fourth, we will combine information obtained through genetic analysis of regional intolerance, mechanism of allosteric modulation, and new advances in structural biology to advance our understanding of the mechanisms that convert glutamate binding to channel opening. These experiments will focus on the shared regions of the protein that control channel opening, which are the key sites of action of our allosteric modulators and common sites for disease-associated human mutations. We will collaboratively perform cryoEM and crystallographic studies to determine the binding site for modulators, as well as key features of channel structure and function.