Kinetics of Ligand Binding in Dopamine D1 Receptor Biased Signaling

多巴胺 D1 受体偏向信号传导中配体结合动力学

基本信息

批准号：
9973218
负责人：
John A Allen
金额：
$ 23.7万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-15 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9973218
关键词：
Acute Adenylate Cyclase Agonist Arrestins Attention Attention deficit hyperactivity disorder Automobile Driving Behavior Binding Biological Assay Biological Availability Brain Brain Diseases Catechols Cell Line Cocaine Corpus striatum structure Cyclic AMP Disease Dopamine Dopamine D1 Receptor Elements Evaluation Exhibits Foundations Future G Protein-Coupled Receptor Signaling G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits, Gs GTP-Binding Proteins Goals Huntington Disease Impaired cognition In Vitro Kinetics Knockout Mice Lead Legal patent Ligand Binding Ligands Locomotion Measurable Mediating Membrane Mental disorders Metabolism Mus Neural Pathways Neuraxis Neurologic Oral Outcome Parkinson Disease Penetration Pharmaceutical Preparations Play Preparation Production Property Receptor Signaling Reporting Research Research Project Grants Rewards Role Schizophrenia Second Messenger Systems Short-Term Memory Signal Transduction Signaling Protein Specificity Structure Substance Use Disorder Testing Therapeutic Translational Research Validation arrestin 2 base beta-arrestin clinical application desensitization design in vivo innovation motor control neurotransmission novel novel drug class novel therapeutics pre-clinical prevent radioligand receptor receptor binding receptor function response side effect therapeutic development

项目摘要

Inadequate dopamine (DA) neurotransmission in brain neural pathways is a pathophysiological underpinning of many disabling neurologic and psychiatric illnesses including substance use disorders, attention deficit hyperactivity disorder and cognitive impairments in schizophrenia. The DA D1 receptor (D1R) is a G protein- coupled receptor (GPCR) identified as playing a central role in motor control, reward, attention and working memory. While activation of the D1R could provide a valuable therapeutic strategy for treating diverse brain disorders, undesirable properties of established catechol ligands have prevented therapeutic development for over 40 years. Our research group recently solved this catechol problem and reported the first non-catechol D1R selective agonists that have unprecedented drug-like properties. Many GPCRs, including the D1R, can signal not only through G proteins, but also via G protein-independent interactions with other signaling proteins including, most prominently, β-arrestins. Unexpectedly, several of the novel non-catechol D1R agonists show biased signaling activity via G proteins, without engagement of β-arrestins. This G protein biased signaling by novel D1R agonists may result in superior activation and/or reduced side effect profiles relative to unbiased D1R agonists, providing the innovative opportunity to fine tune D1R activity for neurotherapeutics. Historically, GPCR ligands have been optimized based on their potency, efficacy and specificity; however, another crucial parameter that impacts receptor signaling is the duration of ligand binding to the receptor (i.e., binding kinetics). We hypothesize that the duration of ligand binding is a key mechanism that determines signaling bias of selective D1R agonists towards G proteins versus β-arrestin signaling. The goal of this research project is to validate and quantify the biased agonist activity of these novel D1R agonists and evaluate if faster ligand-receptor binding kinetics is a mechanism driving biased signaling. Aim 1 will use a combination of approaches including functional D1R signaling assays, competition and kinetic binding assays to define a scale of signaling bias for D1R agonists and the kinetic binding parameters (Koff, Kon) for unbiased and biased agonists. We will then correlate these kinetic binding parameters of agonists to β-arrestin-mediated signaling outcomes of desensitization and internalization. Aim 2 will determine if faster binding kinetics drive non-catechol D1R agonist efficacy in vivo. We will assess kinetic binding parameters (Koff, Kon) for unbiased and biased non-catechol D1R agonists from mouse striatal membranes and compare the functional efficacy of D1R agonists on cocaine-induced locomotor behavior using wildtype and β-arrestin2 knockout mice. This research project will expand our highly limited appreciation of ligand properties and mechanisms governing D1R biased signaling. If we discover that the duration of agonist binding is a mechanism underlying biased D1R signaling, we will provide a defining and measurable ligand property to aid in the design of biased agonists. This project will also validate the relevance and potential usefulness of G protein biased agonism for D1R function.

脑神经通路中多巴胺 (DA) 神经传递不足是许多致残性神经和精神疾病，包括物质使用障碍、注意力缺陷精神分裂症中的多动症和认知障碍 DA D1 受体 (D1R) 是一种 G 蛋白。耦合受体（GPCR）被认为在运动控制、奖励、注意力和工作中发挥着核心作用而 D1R 的激活可以为治疗不同的大脑提供有价值的治疗策略。疾病，已建立的儿茶酚配体的不良特性阻碍了治疗的发展我们的研究小组最近解决了这个儿茶酚问题并报告了第一个非儿茶酚 D1R。具有前所未有的药物样特性的选择性激动剂，包括 D1R 在内的许多 GPCR 都可以发出信号。不仅通过 G 蛋白，还通过 G 蛋白独立的与其他信号蛋白的相互作用出乎意料的是，一些新型非儿茶酚 D1R 激动剂显示出最突出的 β-arrestins。通过 G 蛋白偏向信号传导，无需 β-抑制蛋白参与。相对于无偏 D1R，新型 D1R 激动剂可能会产生更好的激活作用和/或减少副作用激动剂，为神经治疗药物微调 D1R 活性提供了创新机会。配体已根据其效力、功效和特异性进行了优化；然而，另一个关键参数影响受体信号传导的是配体与受体结合的持续时间（即结合动力学）。排除了配体结合的持续时间是决定选择性信号偏向的关键机制 D1R 激动剂针对 G 蛋白与 β-arrestin 信号传导的对比本研究项目的目标是验证和验证。量化这些新型 D1R 激动剂的偏向激动剂活性，并评估配体-受体结合是否更快动力学是一种驱动偏向信号传导的机制，目标 1 将使用包括功能在内的多种方法的组合。 D1R 信号传导测定、竞争和动力学结合测定，以确定 D1R 激动剂的信号传导偏差范围以及无偏激动剂和有偏激动剂的动力学结合参数（Koff、Kon），然后我们将这些关联起来。激动剂与β-抑制蛋白介导的脱敏信号转导结果的动力学结合参数目标 2 将确定更快的结合动力学是否会驱动非儿茶酚 D1R 激动剂的体内功效。将评估来自小鼠的无偏和有偏非儿茶酚 D1R 激动剂的动力学结合参数（Koff、Kon）纹状体膜并比较 D1R 激动剂对可卡因诱导的运动行为的功能功效使用野生型和 β-arrestin2 敲除小鼠该研究项目将扩大我们高度有限的认识。如果我们发现激动剂的持续时间，配体特性和控制 D1R 偏向信号传导的机制。结合是偏向 D1R 信号传导的潜在机制，我们将提供定义且可测量的配体该项目还将验证相关性和潜力。 G 蛋白偏向激动对 D1R 功能的有用性。