Investigation On The Behavior And Related Neuro-Electrochemistry Of Potential Medications For The Treatment Of Substance Use Disorders.

对治疗物质使用障碍的潜在药物的行为和相关神经电化学的调查。

• 批准号: 10699661
• 负责人: Gianluigi Tanda
• 金额: $ 238.04万
• 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/10699661
• 关键词: Acute; Affinity; Alcohol abuse; Amphetamines; Attention Deficit Disorder; Autophagocytosis; Autoreceptors; Behavior; Behavioral; Behavioral Paradigm; Binding; Body Weight; Brain; Brain Diseases; Brain region; Carbenoxolone; Chemical Structure; Chemosensitization; Clinical; Clinical Research; Clinical Treatment; Clinical Trials; Cocaine; Cocaine Abuse; Cocaine Users; Cocaine use disorder; Collaborations; Computer Models; Corpus striatum structure; Coupling; Crack Cocaine; Data; Diet; Dopamine; Dopamine Receptor; Dose; Drug Design; Drug Prescriptions; Electrochemistry; Electrophysiology (science); Elements; Enzymes; Future; Gap Junctions; Genetic; Genetically Engineered Mouse; Goals; High Fat Diet; Human; Hydroxychloroquine; Impairment; In Vitro; Intravenous; Investigation; Knockout Mice; Measures; Mediating; Medical; Membrane; Metabolic Pathway; Methamphetamine; MicroRNAs; Microdialysis; Modafinil; Molecular; Molecular Conformation; Mus; Nerve; Neurobiology; Neurons; Neurotransmitters; Nucleus Accumbens; Obesity; Optics; Pathologic; Patients; Periodicity; Pharmaceutical Preparations; Pharmacology; Phenotype; Physiological; Play; Population; Pre-Clinical Model; Procedures; Process; Psychological reinforcement; Research; Research Project Grants; Rewards; Ritalin; Rodent; Role; Scanning; Self Administration; Series; Sleep Disorders; Sprague-Dawley Rats; Stimulant; Substance Use Disorder; Synapses; Synaptic Receptors; System; Testing; Therapeutic; Time; Up-Regulation; Wild Type Mouse; Zinc; abuse liability; analog; attenuation; base; cocaine self-administration; cocaine use; comorbidity; conditioned place preference; density; dietary; dopamine transporter; dopaminergic neuron; drug discrimination; drug of abuse; early onset; enantiomer; experimental study; extracellular; in vivo; inhibition of autophagy; inhibitor; insight; methamphetamine use; neural; neurochemistry; neurotransmission; novel; pre-clinical; preclinical study; predictive modeling; psychostimulant; receptor; regional difference; response; reuptake; stimulant abuse; stimulant use disorder; substance use treatment; virtual

The dopamine (DA) transporter (DAT) is the main pharmacologic target of abused psychostimulants like cocaine but also of prescribed medications like modafinil (MOD), which has shown little, if any, propensity for abuse in clinical or preclinical studies. Recently, we have explored the neurochemical and behavioral actions of MOD to better characterize its atypical psychostimulant profile. We found that MOD had a lower potency and efficacy than cocaine in stimulating nucleus accumbens shell (NAS) and core (NAC) DA levels, but, at variance with abused psychostimulants there were no statistically significant regional differences between accumbens subregions. In drug-discrimination studies MOD showed cocaine-like subjective effects at lower doses and earlier onset times than expected based on its DA effects. Those results suggest that non-DA-dependent actions may be playing a role in its unique pharmacological profile. In order to discover a potential non-dopaminergic mechanism for these MOD actions, we compared its behavioral and neurochemical effects with those of methylphenidate, another clinically approved medication that inhibits the neuronal reuptake of DA. We showed that methylphenidate, but not MOD, maintained intravenous self-administration in Sprague-Dawley rats similarly to cocaine. Both MOD and methylphenidate pretreatments potentiated cocaine self-administration. Cocaine, at self-administered doses, stimulated mesolimbic DA levels. This effect was potentiated by methylphenidate, but not by MOD pretreatments, indicating DA-dependent actions for methylphenidate, but not MOD. MOD is known to facilitate electrotonic neuronal coupling by actions on gap junctions. Carbenoxolone, a gap junction inhibitor, antagonized MOD, but not methylphenidate potentiation of cocaine self-administration. Our results indicate that MOD shares mechanisms with cocaine and methylphenidate but has a unique pharmacological profile that includes facilitation of electrotonic coupling and lower abuse liability, which may be exploited in future therapeutic drug design for cocaine use disorder. Though MOD might prove useful as a treatment for specific addicted populations (e.g. heavy crack-cocaine users, or cocaine and methamphetamine addicts without alcohol abuse comorbidity), broader effective medications for psychostimulant use disorders are still an unmet medical need. To this end, several newly synthesized analogs of MOD, for example JJC8-091 and JJC8-088, have been tested in our preclinical models as potential medications for methamphetamine (METH) and cocaine use disorder. JJC8-091 and JJC8-088, were assessed alone and in combination with cocaine to elucidate neurochemical correlates to their divergent behavioral profiles. Despite sharing significant structural similarity, JJC8-088 was more cocaine-like, increasing extracellular DA concentrations in the NAS efficaciously and more potently than JJC8-091. In contrast, JJC8-091 was not self-administered and was effective in blocking cocaine-induced reinstatement to drug seeking. Electrophysiology experiments confirmed that JJC8-091 was more effective than JJC8-088 at inhibiting cocaine-mediated enhancement of DA neurotransmission. Further, when VTA DA neurons in DAT-cre mice were optically stimulated, JJC8-088 produced a significant leftward shift in the stimulation-response curve, similar to cocaine, while JJC8-091 shifted the curve downward, suggesting attenuation of DA-mediated brain reward. Computational models predicted that while JJC8-088 prefers or stabilizes an outward facing conformation of DAT, like cocaine, JJC8-091 stabilizes DAT towards a more occluded conformation. Recently, we have collaborated on a project related to the potential effects of cocaine on neural autophagy in vitro and in vivo. Autophagy inhibitors, i.e. hydroxychloroquine and SBI-0206965, reduce the locomotor stimulant effect of systemic administration of cocaine and its related stimulation of extracellular NAS DA levels in mice. Cocaine-induced autophagy degrades transporters for DA but not serotonin in the NAS. Autophagy inhibition impairs cocaine conditioned place preference in mice. These findings indicate that autophagic degradation of DAT modulates behavioral and neurochemical actions of cocaine. Our research collaborations also include an investigation on the role of the microRNA system on neuronal signaling in mice lacking the translin/trax microRNA-degrading enzyme (Tsn KO mice). We found an altered behavioral and neurochemical response to psychostimulants, and also robust adiposity in the context of normal body weight, suggesting that this phenotype might reflect elevated brain levels of the psychostimulants tested. Analysis of the effect of diet-induced increases in adiposity in wild type mice on brain amphetamine levels also demonstrated that brain amphetamine levels correlate with adiposity. Increased adiposity displayed by Tsn KO mice or by wild type mice fed a high-fat diet correlates with elevated brain amphetamine levels. As amphetamine and its analogues are widely used to treat attention deficit disorder, which is associated with obesity, further studies are warranted to assess the impact of adiposity on amphetamine levels in these patients. In a more recent collaboration, we investigated the role of Zinc in cocaine seeking and abuse vulnerability. Cocaine increases synaptic dopamine (DA) by blocking the DA transporter (DAT). This process regulates cocaine reinforcement, seeking, and abuse. Zn2+ is an essential element that binds to DAT, but the in vivo relevance of this is unknown. We found that cocaine use in humans correlated with Zn2+ content in the striatum, a brain region with high DAT density. In mice, cocaine increased synaptic Zn2+ release in the striatum. Striatal Zn2+ increased cocaines affinity and in vivo potency at the DAT and was required for cocaine-induced DAT upregulation. Finally, genetic or dietary Zn2+ manipulations modulated cocaine efficacy across different behavioral paradigms. These findings reveal new insights into cocaines pharmacological mechanism of action and establish synaptic Zn2+ as a critical environmentally-derived regulator of cocaine abuse vulnerability. Collectively, these data reveal the underlying molecular mechanism at DAT that may be leveraged to rationally optimize leads for the treatment of psychostimulant use disorders.

多巴胺（DA）转运体（DAT）是滥用的精神兴奋剂（如可卡因）的主要药理学靶点，也是处方药（如莫达非尼（MOD））的主要靶点，莫达非尼在临床或临床前研究中几乎没有显示出滥用的倾向。最近，我们探索了MOD的神经化学和行为作用，以更好地表征其非典型精神兴奋剂的特征。我们发现MOD在刺激伏隔核壳（NAS）和核心（NAC） DA水平方面的效力和疗效低于可卡因，但在与滥用精神兴奋剂的差异上，伏隔核亚区之间没有统计学上的显著区域差异。在药物鉴别研究中，MOD在较低剂量和较早起效时间下表现出与可卡因类似的主观效应，这是基于其DA效应的预期。这些结果表明，非da依赖性的作用可能在其独特的药理学特征中发挥作用。为了发现这些MOD作用的潜在非多巴胺能机制，我们将其行为和神经化学作用与哌甲酯进行了比较，哌甲酯是另一种临床批准的抑制神经元再摄取DA的药物。我们发现哌甲酯，而不是MOD，在Sprague-Dawley大鼠中维持静脉自我给药，类似于可卡因。MOD和哌甲酯预处理都增强了可卡因的自我给药。自用剂量的可卡因刺激了中脑边缘的DA水平。这种效应被哌醋甲酯增强，而MOD预处理不增强，这表明哌醋甲酯的作用依赖于da，而不是MOD。MOD已知通过作用于间隙连接促进电紧张神经元耦合。卡贝诺洛酮，一种间隙连接抑制剂，拮抗MOD，但没有哌醋甲酯增强可卡因自我给药。我们的研究结果表明，MOD与可卡因和哌甲酯具有相同的机制，但具有独特的药理学特征，包括促进电紧张偶联和降低滥用倾向，这可能在未来可卡因使用障碍的治疗药物设计中被利用。