Dopamine D2 Receptor Mutations and Hyperkinetic Movement Disorders

多巴胺 D2 受体突变和多动性运动障碍

• 批准号: 10640977
• 负责人: KIM Arthur NEVE
• 金额: --
• 依托单位: PORTLAND VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10640977
• 关键词: Adolescence; Affect; Agonist; Arrestins; Benign; Binding; Biological; Brain; Cells; Cervical Dystonia; Characteristics; Chorea; Clinical; Cognitive deficits; Cyclic AMP; Cytoplasm; DRD2 gene; Data; Dependence; Disease; Dopamine D2 Receptor; Dopamine Receptor; Dystonia; Electrophysiology (science); Exhibits; Exons; Face; Family; Functional disorder; G-Protein-Coupled Receptors; GTP-Binding Proteins; Gait abnormality; Generations; Genetic Polymorphism; Goals; Heterozygote; Human; Impairment; Kinetics; Knock-in Mouse; Lead; Learning; Link; Location; Mediating; Mental disorders; Midbrain structure; Modeling; Motor; Movement; Movement Disorders; Mus; Mutation; Neostriatum; Neurologic Dysfunctions; Neurologic Symptoms; Outcome; Parkinson Disease; Pathogenicity; Phosphorylation; Phosphotransferases; Positioning Attribute; Potassium Channel; Property; RNA Splicing; Receptor Activation; Regulation; Role; Schizophrenia; Severities; Signal Transduction; Single Nucleotide Polymorphism; Slice; Spasm; Substance Use Disorder; System; Transmembrane Domain; Variant; Viral; Work; autosome; clinical phenotype; de novo mutation; dopamine system; dopaminergic neuron; early onset; genetic variant; in silico; in vivo; inward rectifier potassium channel; member; molecular dynamics; motor impairment; mouse model; mutant; nervous system disorder; neuroprotection; neuropsychiatric symptom; neuropsychiatry; novel; protein activation; receptor; receptor expression; receptor function; recruit; societal costs; therapeutic target

Project Summary Dopamine receptors are the primary therapeutic targets for a variety of neurological and psychiatric disorders, including schizophrenia, Parkinson’s disease, and many other movement disorders. The five subtypes of dopamine receptors (D1-D5) are members of the superfamily of G protein-coupled receptors. This proposal is focused on the D2 receptor and, in particular, on two novel DRD2 allelic variants that are linked to hyperkinetic movement disorders. An important distinction between the two variants is that subjects with the mutation M374R have more severe dysfunction with an earlier onset than those with the mutation I212F. The three aims will use a variety of approaches to compare and contrast the effects of the two mutations on D2 receptor function. Our overall goal is to determine which changes to receptor function are pathogenic, and which are benign or even potentially neuroprotective. D2-I212F exhibits increased constitutive activation of G proteins, increased sensitivity to low concentrations of agonist, decreased arrestin binding, slow kinetics for regulation of potassium channels, and inefficient expression. We will determine if the more severe clinical outcome caused by the M374R mutation is explained by qualitatively similar changes that differ only in magnitude, or if there are qualitative differences with I212F. In Aim 1 we will assess arrestin binding and G protein activation by the two novel variants, expanding our characterization to all D2 receptor-activated Gα subtypes and exploring the role of receptor phosphorylation. In Aim 2 we will carry out in silico studies of receptor activation. In Aim 3 we will create a knock-in mouse model of heterozygous expression of D2-M374R. We will evaluate the functional properties of D2-M374R in midbrain dopamine neurons by slice electrophysiology, using first viral expression of D2-M374R, and then the knock-in mice as they become available. We will also evaluate gait abnormalities in the knock-in mice, and quantify D2 receptor expression in midbrain and neostriatum. The aims proposed here will quantify the effect of these novel polymorphisms on the function and expression of the D2 receptor in cells and in mouse brain and should provide a biological explanation for manifestation of neurological dysfunction in humans with these variants.

项目摘要 多巴胺受体是多种神经和精神疾病的主要治疗靶点， 包括精神分裂症、帕金森氏症和许多其他运动障碍。五种亚型 多巴胺受体（D1-D5）是G蛋白偶联受体超家族的成员。这项建议是 集中在D2受体，特别是两个新的DRD 2等位基因变异，与运动过度相关， 运动障碍这两种变体之间的一个重要区别是， M374 R突变的患者比I212 F突变的患者具有更严重的功能障碍，且发病更早。三个目标 将使用多种方法来比较和对比两种突变对D2受体的影响 功能我们的总体目标是确定受体功能的哪些变化是致病的，哪些是 良性的甚至是潜在的神经保护性的D2-I212 F表现出增加的G蛋白的组成型活化， 对低浓度激动剂的敏感性增加，抑制蛋白结合减少， 钾通道和低效表达。我们将确定是否更严重的临床结果导致 由M374 R突变解释为定性相似的变化，只是在幅度上不同，或者如果有 与I212 F的质量差异。在目标1中，我们将评估抑制蛋白结合和G蛋白激活的两个 新的变体，将我们的特征扩展到所有D2受体激活的Gα亚型，并探索其作用 受体的磷酸化。在目标2中，我们将进行受体激活的计算机模拟研究。在目标3中， 建立D2-M374 R杂合表达的敲入小鼠模型。我们将评估功能 使用首次病毒表达，通过切片电生理学测定中脑多巴胺神经元中D2-M374 R的特性 的D2-M374 R，然后当它们变得可用时进行基因敲入小鼠。我们还将评估步态异常， 敲入小鼠，并定量中脑和新纹状体中的D2受体表达。这里提出的目标 将量化这些新型多态性对细胞中D2受体功能和表达的影响 和小鼠脑中，并应提供一个生物学解释的神经功能障碍的表现， 有这些变异的人