Slow-onset long-acting dopamine transport inhibitors for treating drug addiction

用于治疗药物成瘾的缓效长效多巴胺转运抑制剂

• 批准号: 9353055
• 负责人: Eliot Gardner
• 金额: $ 10.18万
• 依托单位: NATIONAL INSTITUTE ON DRUG ABUSE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9353055
• 关键词: Agonist; Animal Model; Animals; Area; Attenuated; Behavior; Behavioral Mechanisms; Behavioral Paradigm; Binding; Biochemical; Biological Assay; Brain; Chemical Structure; Chemicals; Cocaine; Cocaine Dependence; Computer Assisted; Cues; Data; Development; Dopamine; Dose; Drug Addiction; Drug Design; Drug Kinetics; Electrical Stimulation of the Brain; Exposure to; Extinction (Psychology); Goals; Habits; Heroin; High Pressure Liquid Chromatography; Hour; Human; Hunger; Immunoblotting; In Vitro; Injection of therapeutic agent; Intravenous; Investigation; Laboratory Animals; Laboratory Rat; Lead; Ligand Binding; Light; Locomotion; Measures; Methadone; Microdialysis; Modafinil; Modeling; Molecular; Molecular Models; Motor Activity; Neurotransmitters; Nicotine; Nicotine Dependence; Nucleus Accumbens; Opiates; Patients; Pattern; Pharmaceutical Preparations; Pharmacotherapy; Polymerase Chain Reaction; Procedures; Proteins; Psychological reinforcement; Psychostimulant dependence; RNA; Rattus; Relapse; Reporting; Research; Reverse Transcription; Rewards; Running; Sampling; Self Administration; Self-Administered; Stress; Techniques; Testing; Time; Western Blotting; Work; addiction; analog; clinical efficacy; craving; design; dopamine transporter; drug discrimination; drug seeking behavior; extracellular; in vivo; inhibitor/antagonist; molecular modeling; monoamine; mu opioid receptors; novel; pharmacophore; piperidine; pre-clinical; preference; psychostimulant; research study; screening; transport inhibitor

We had previosuly shown that our lead proof-of-concept slow-onset long-acting dopamine transporter (DAT) inhibitor - CTDP30640 - enhances electrical brain-stimulation reward, enhances extracellular dopamine in the reward-related nucleus accumbens locus in the brain, stimulates locomotor activity, and significantly reduces intravenous cocaine self-administration in laboratory rats - all with a very pronounced slow-onset long-acting profile of action. During this same period, we extended our research in this area to include two additional compounds that we designed and synthesized de novo using computer-assisted molecular drug design and a pharmacophore DAT model that we ourselves developed - CTDP31345 and CTDP31346. Because of the high degree of similarity between the chemical structures of CTDP31345 and CTDP31346, a decision was made to run only one of those two compounds through a full range of preclinical animal screening paradigms - namely, CTDP31345. We found that CTDP31345 enhances electrical brain-stimulation reward, enhances extracellular dopamine in the reward-related nucleus accumbens locus in the brain, stimulates locomotor activity, and significantly reduces intravenous cocaine self-administration in laboratory rats - all with a very pronounced slow-onset long-acting profile of action. On a less promising note, we found that CTDP31345 generalizes to cocaine in the drug-discrimination animal behavioral paradigm, produces dramatic locomotor sensitization, and triggers relapse to cocaine-seeking behavior in laboratory rats who have been pharmacologically detoxified and behaviorally extinguished from their prior intravenous cocaine-taking habits. We further found that CTDP31345 itself supports intravenous self-administration, albeit at a much lower rate than cocaine. As we had previously seen with compound CTDP30640, the effects of compound CTDP31345 are additive with those of cocaine. This prompted us to explore the relationship between the fast-onset short-acting opiate heroin and the slow-onset long-acting opiate methadone, the latter of which is well-known to have clinical efficacy as an anti-addiction medication for patients addicted to opiates. We reasoned that investigating the heroin-methadone relationship in our preclinical animal models might shed light on medication development stratgies for cocaine and other psychostimulants. We found that - in contrast to the relationship between cocaine and CTDP30640 or CTDP31345 - methadone pretreatment: 1) dose-dependently inhibited intravenous heroin self-administration with a clear behavioral extinction pattern, 2) dose-dependently inhibited heroin-enhanced brain-stimulation reward, and 3) dose-dependently inhibited heroin-enhanced nucleus accumbens levels of the reward-related and relapse-related neurotransmitter dopamine as measured by in vivo brain microdialysis. This suggests a functional antagonism by methadone of heroin's actions, which may be explained by methadone's ability to produce cellular internalization of the mu opioid receptor. These data suggest that in order to be fully successful, potential anti-cocaine medications should more fully emulate methadone's action - i.e., functionally antagonizing cocaine's actions (perhaps by inducing conformational changes in the dopamine transporter) while at the same time blocking the transporter in a cocaine-like manner (but with slow-onset long-lasting pharmacokinetics) so as to substitute for cocaine and remediate the brain chemical deficiency believed to underlie cocaine "hunger" and cocaine craving. In addition, we believe that the facts that our compounds CTDP30640 and CTDP31345 show much slower onsets and much longer durations of action (e.g., 96 hours following a single injection) than other DAT inhibitors developed as potential anti-addiction pharmacotherapies (e.g., GBR12909) demonstrate the validity of our pharmacophore drug design model, our molecular drug design procedures, and our medication development strategy. On a purely molecular drug design level, during the reporting period we successfully designed and synthesized new slow-onset long-duration piperidine analogs with increased selectivity for the dopamine transporter, resulting in a new test compound - CTDP32476. During the present reporting period, we found the following: 1) that in vitro ligand binding assays show CTDP32476 to be a potent and selective DAT inhibitor; 2) that CTDP32476 is a competitive inhibitor of cocaine binding to the DAT; 3) that systemic administration of CTDP32476 alone produced a slow-onset, long-lasting increase in nucleus accumbens extracellular dopamine; 4) that systemic administration of CTDP32476 alone produced a slow-onset, long-lasting increase in locomotion; 5) that systemic administration of CTDP32476 alone produced a slow-onset, long-lasting increase in electrical brain-stimulation reward; 6) that drug-naive rats do not self-administer CTDP32476; 7) that, in substitution testing, cocaine self-administration rats display a progressive reduction in CTDP32476 self-administration with an extinction pattern of drug-taking behavior, suggesting significantly lower addictive potential than cocaine; 8) that pretreatment with CTDP32476 inhibits cocaine self-administration; 9) that pretreatment with CTDP32476 inhibits cocaine-associated cue-induced relapse to drug-seeking; 10) that pretreatment with CTDP32476 inhibits cocaine-enhanced extracellular nucleus accumbens dopamine. These findings suggest that CTDP32476 is a unique DAT inhibitor that not only could satisfy "drug hunger" through its slow-onset long-lasting DAT inhibitor action, but also render subsequent administration of cocaine ineffectual - thus constituting a novel and unique compound with translational potential as an agonist therapy for treatment of cocaine addiction. In addition, during the present reporting period we studied modafinil as a potential anti-addiction pharmacotherapeutic compound. Specifically, we used animal models of self-administration and in vivo brain microdialysis to study the pharmacological actions of R-modafinil and S-modafinil on nicotine-taking and nicotine-seeking behavior, and mechanisms underlying such actions. We found that R-modafinil is more potent and effective than S-modafinil in attenuating nicotine self-administration in laboratory rats. Further, we found that R-modafinili: 1) inhibits intravenous nicotine self-administration; 2) inhibits nicotine-induced relapse to nicotine-seeking behavior; and 3) inhibits nicotine-associated cur-induced drug-seeking behavior. R-modafinil alone neither sustained self-administration in rats previously self-administering nicotine not reinstated extinguished nicotine-seeking behavior. In vivo brain microdialysis experiments showed that R-modafinil alone produced a slow-onset moderate increase in nucleus accumbens dopamine. Pretreatment with R-modafinil dose-dependently blocked nicotine-enhanced nucleus accumbens dopamine in both naive and nicotine self-administering rats, suggesting a dopamine-dependent mechanism underlying mitigation of nicotine's effects. These findings support further investigation of R-modafinil for treatment of nicotine dependence in humans.

我们之前已经证明，我们的主要概念证明慢效长效多巴胺转运体（DAT）抑制剂CTDP30640可以增强脑电刺激奖励，增强大脑中与奖励相关的伏隔核的细胞外多巴胺，刺激运动活动，并显着减少实验室大鼠静脉注射可卡因的自我给药-所有这些都具有非常明显的慢效长效作用。在同一时期，我们扩展了我们在该领域的研究，包括我们使用计算机辅助分子药物设计和我们自己开发的药效团DAT模型重新设计和合成的另外两种化合物- CTDP31345和CTDP31346。由于CTDP31345和CTDP31346的化学结构高度相似，我们决定只运行这两种化合物中的一种，即CTDP31345，通过全面的临床前动物筛选模式。我们发现CTDP31345增强脑电刺激奖励，增强大脑中与奖励相关的伏隔核的细胞外多巴胺，刺激运动活动，并显着减少实验室大鼠静脉注射可卡因的自我给药-所有这些都具有非常明显的缓慢起效的长效作用。在一个不太乐观的情况下，我们发现CTDP31345在药物识别动物行为范式中可以推广到可卡因，产生戏剧性的运动致敏，并在药理学上解毒和行为上从先前静脉注射可卡因的习惯中消失的实验室大鼠中引发可卡因寻求行为的复发。我们进一步发现CTDP31345本身支持静脉自我给药，尽管比可卡因低得多。正如我们之前在化合物CTDP30640中看到的那样，化合物CTDP31345的作用与可卡因的作用是叠加的。这促使我们探索快效短效阿片类药物海洛因与慢效长效阿片类药物美沙酮之间的关系，后者作为阿片类药物成瘾患者的抗成瘾药物具有众所周知的临床疗效。我们认为，在我们的临床前动物模型中研究海洛因和美沙酮的关系可能会为可卡因和其他精神兴奋剂的药物开发策略提供启示。我们发现，与可卡因与CTDP30640或CTDP31345 -美沙酮预处理的关系相反：1)剂量依赖性地抑制静脉注射海洛因自我给药，具有明显的行为消失模式；2)剂量依赖性地抑制海洛因增强的脑刺激奖励；3)剂量依赖性地抑制海洛因增强的伏隔核奖励相关和复发相关的神经递质多巴胺水平，通过体内脑微透析测量。这表明美沙酮对海洛因的作用具有功能性拮抗作用，这可以用美沙酮产生细胞内化mu阿片受体的能力来解释。这些数据表明，为了完全成功，潜在的抗可卡因药物应该更充分地模仿美沙酮的作用，即，在功能上对抗可卡因的作用（可能是通过诱导多巴胺转运体的构象变化），同时以类似可卡因的方式阻断转运体（但具有缓慢的持久药代动力学），以替代可卡因，并纠正被认为是导致可卡因“饥饿”和可卡因渴望的大脑化学物质缺乏。此外，我们相信，我们的化合物CTDP30640和CTDP31345比其他作为潜在抗成瘾药物治疗（如GBR12909）开发的DAT抑制剂表现出更慢的起效和更长的作用持续时间（例如，单次注射后96小时），这一事实证明了我们的药效团药物设计模型、分子药物设计程序和药物开发策略的有效性。在纯分子药物设计水平上，在报告期间，我们成功地设计和合成了新的慢效长效哌啶类似物，增加了多巴胺转运体的选择性，从而产生了新的测试化合物CTDP32476。在本报告期间，我们发现：1)体外配体结合试验表明CTDP32476是一种有效的选择性DAT抑制剂；2) CTDP32476是可卡因与DAT结合的竞争性抑制剂；3) CTDP32476全身单独给药可使伏隔核细胞外多巴胺缓慢、持久地增加；4) CTDP32476全身单独给药可产生缓慢发作、持久的运动增加；5) CTDP32476全身单独给药可产生慢起、持久的脑电刺激奖励增加；6)未给药大鼠不自我给药CTDP32476；7)在替代试验中，可卡因自我给药大鼠CTDP32476自我给药呈递进式减少，且服药行为呈灭绝模式，成瘾潜力明显低于可卡因；8) CTDP32476预处理抑制可卡因自我给药；9) CTDP32476预处理可抑制可卡因相关线索诱导的药物寻求复发；10) CTDP32476预处理可抑制可卡因增强的伏隔核胞外多巴胺。这些发现表明，CTDP32476是一种独特的DAT抑制剂，不仅可以通过其慢效持久的DAT抑制剂作用来满足“药物饥饿”，而且还可以使后续的可卡因给药无效，从而构成一种具有翻译潜力的独特化合物，可作为治疗可卡因成瘾的激动剂疗法。此外，在本报告期间，我们研究了莫达非尼作为一种潜在的抗成瘾药物治疗化合物。具体而言，我们使用自我给药和体内脑微透析的动物模型来研究r -莫达非尼和s -莫达非尼对尼古丁摄入和尼古丁寻求行为的药理作用及其作用机制。我们发现r -莫达非尼比s -莫达非尼更有效和有效地减弱实验室大鼠的尼古丁自我给药。此外，我们发现R-modafinili: 1)抑制静脉尼古丁自我给药；2)抑制尼古丁诱导的尼古丁寻求行为的复发；3)抑制尼古丁相关的curc诱导的药物寻求行为。单用r -莫达非尼既不能维持先前自我服用尼古丁的大鼠的自我服用，也不能恢复已消失的尼古丁寻求行为。体内脑微透析实验表明，r -莫达非尼单独使用可使伏隔核多巴胺缓慢、中度升高。r -莫达非尼预处理剂量依赖性阻断尼古丁增强的幼年和尼古丁自我给药大鼠伏隔核多巴胺，提示多巴胺依赖机制可能减轻尼古丁的影响。这些发现支持了r -莫达非尼治疗人类尼古丁依赖的进一步研究。