Development of Orexin-1 Receptor Antagonists to Prevent Drug Relapse

描述(由申请人提供)：本申请是对RFA-DA-07-006的响应，旨在设计、合成和测试相关的临床前模型，潜在的药物成瘾治疗方法。建议的药理学方法是开发新的有效和选择性的食欲素-1(OX1)受体拮抗剂，这些受体拮抗剂可能被证明在预防戒断人类可卡因成瘾者的复发方面有效。为了实现这一目标，我们组建了一支高度积极的研究人员团队，他们在药物发现过程的各个方面和成瘾的动物模型方面都有专业知识。具体目的I将涉及建立一种可靠的基于细胞的OX1受体体外功能分析(和适当的反筛选)，以支持旨在开发新的有效和选择性OX1受体拮抗剂的药物化学计划。具体地说，我们将通过膜电位染料和荧光平板阅读器(FLIPR)在稳定表达人OX1受体的CHO细胞(OX1受体偶联到GQ)中检测激动剂诱导的细胞内钙信号增加的变化。此外，我们将建立一种新的激动剂诱导的、G蛋白无关的受体内化试验，结合高含量成像来定量测量激动剂刺激稳定表达OX1受体的U20S细胞的0X1受体内化。这种内化分析将为钙信号分析提供一个反筛选。特定目标II将利用基于结构-活性关系(SAR)的迭代药物化学计划来发现新的有效和选择性的OX1受体拮抗剂。结构-活性关系将被用来优化新型OX1受体拮抗剂，用于药物代谢和药代动力学(DMPK)和脑渗透特性。特殊目的III将在应激诱导的可卡因复吸恢复模型中测试新型高效和选择性的OX1受体拮抗剂，这些拮抗剂具有良好的DMPK和脑渗透。此外，将在大鼠的颅内自我刺激(ICSS)阈值程序中评估OX1受体拮抗剂阻止复发样行为的内在奖赏特性，以便对具有潜在滥用倾向的化合物进行分类。这样一个综合的多学科研究计划将利用佛罗里达州斯克里普斯公司独特的药物发现能力，并有望产生用于预防人类成瘾者复发的新的治疗实体。

DESCRIPTION (provided by applicant): This application is in response to RFA-DA-07-006 to design, synthesize and test in relevant preclinical models, potential treatments for drug addiction. The pharmacological approach proposed is to develop new classes of potent and selective orexin-1 (OX1) receptor antagonists that may prove efficacious in preventing relapse in abstinent human cocaine addicts. To accomplish this aim, we have assembled a team of highly motivated researchers with expertise in every aspect of the drug discovery process and in animal models of addiction. Specific Aim I will involve establishing a robust in vitro cell-based functional assays for OX1 receptors (and appropriate counter-screens) which can support a medicinal chemistry program aimed at developing new classes of potent and selective OX1 receptor antagonists. Specifically, we will examine changes in agonist-induced increases of intracellular calcium signaling via membrane potential dyes and a fluorescent plate reader (FLIPR) in CHO cells stably expressing human OX1 receptors (OX1 receptors couple to Gq).In addition, we will establish a novel agonist-induced, G-protein-independent, receptor internalization assay coupled with high content imaging to make quantitative measurements of 0X1 receptor internalization upon agonist stimulation in U20S cells stably expressing OX1 receptors. This internalization assay will provide a counter-screen to the calcium signaling assays. Specific Aim II will utilize an iterative medicinal chemistry program based on structure-activity relationships (SAR) to discover new classes of potent and selective OX1 receptor antagonists. Structure-activity relationships will be employed to optimize new classes of OX1 receptor antagonists for drug metabolism and pharmacokinetics (DMPK), and brain penetration properties. Specific Aim III will test new classes of potent and selective OX1 receptor antagonists with favorable DMPK and brain penetration in the rat stress-induced reinstatement model of relapse to cocaine seeking. In addition, the intrinsic rewarding properties of OX1 receptor antagonists that block relapse-like behavior will be assessed in the intracranial self-stimulation (ICSS) thresholds procedure in rats in order to triage compounds with potential abuse liability. Such an integrated multidisciplinary research plan will capitalize on the unique drug discovery capabilities at Scripps Florida, and promises to yield novel therapeutic entities for the prevention of relapse in human addicts.