Development of Orexin-1 Receptor Antagonists to Prevent Drug Relapse

描述（由申请人提供）：本申请应RFA-DA-07-006的要求，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。提出的药理学方法是开发新型的强效和选择性食欲素-1 （OX1）受体拮抗剂，这些拮抗剂可能有效地防止人类可卡因成瘾者复发。为了实现这一目标，我们组建了一支积极进取的研究团队，他们在药物发现过程和动物成瘾模型的各个方面都有专业知识。我将涉及建立一个强大的体外细胞功能测定OX1受体（和适当的反筛选），这可以支持旨在开发新型有效和选择性OX1受体拮抗剂的药物化学计划。具体来说，我们将通过膜电位染料和荧光板读取器（FLIPR）在稳定表达人OX1受体（OX1受体与Gq偶联）的CHO细胞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、不依赖于g蛋白的受体内化实验，结合高含量成像，定量测量稳定表达OX1受体的U20S细胞在激动剂刺激下的0X1受体内化。这种内化试验将提供钙信号分析的反筛选。Specific Aim II将利用基于结构-活性关系（SAR）的迭代药物化学程序来发现新的有效和选择性OX1受体拮抗剂。结构-活性关系将用于优化新类型的OX1受体拮抗剂的药物代谢和药代动力学（DMPK）以及脑渗透特性。特异性Aim III将在大鼠可卡因寻求复发的应激诱导恢复模型中测试具有有利DMPK和脑渗透的新型强效和选择性OX1受体拮抗剂。此外，阻断复发样行为的OX1受体拮抗剂的内在奖励特性将在大鼠颅内自我刺激（ICSS）阈值程序中进行评估，以筛选具有潜在滥用倾向的化合物。这样一个综合的多学科研究计划将利用佛罗里达斯克里普斯研究所独特的药物发现能力，并有望产生新的治疗实体，以防止人类成瘾者复发。

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.