Role of metabotropic glutamate receptor expression in nicotine dependence

代谢型谷氨酸受体表达在尼古丁依赖中的作用

• 批准号: 8948282
• 负责人: Xia Li
• 金额: $ 19.38万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8948282
• 关键词: Affinity; Agonist; Alcohols; Applications Grants; Attenuated; Autoreceptors; Behavior; Behavioral; Binding; Brain; Cells; Cocaine; Data; Data Reporting; Detection; Development; Dose; Drug Addiction; Effectiveness; Evaluation; Foundations; Future; Gene Transfer; Generations; Genes; Glutamate Receptor; Glutamates; Glycoproteins; Homeostasis; Housekeeping Gene; Immunohistochemistry; In Vitro; Individual; Injection of therapeutic agent; Intravenous; Investigation; Knockout Mice; Laboratories; Lentivirus Vector; Mediating; Messenger RNA; Metabotropic Glutamate Receptors; Molecular; Morbidity - disease rate; Neurons; Nicotine; Nicotine Dependence; Nicotinic Receptors; Nucleus Accumbens; Pharmacotherapy; Prefrontal Cortex; Procedures; Property; Proteins; Psychological reinforcement; Public Health; Publishing; Rattus; Regulation; Reinforcement Schedule; Relative (related person); Research Personnel; Reverse Transcriptase Polymerase Chain Reaction; Role; Self Administration; Self-Administered; Sequence Homology; Site; Source; Subfamily lentivirinae; System; Therapeutic Intervention; Tobacco; Tobacco Dependence; Tobacco smoking; Training; United States National Institutes of Health; Validation; Ventral Tegmental Area; Viral; Viral Vector; Virus; Western Blotting; Work; addiction; base; drug discovery; genetic manipulation; in vivo; innovation; interest; mesolimbic system; metabotropic glutamate receptor 2; metabotropic glutamate receptor 3; metabotropic glutamate receptor 7; monoamine; mortality; neurotransmission; novel; overexpression; presynaptic; promoter; public health relevance; receptor; receptor density; receptor expression; response; reuptake; smoking cessation; tool; transmission process; vector; vector-induced

 DESCRIPTION (provided by applicant): Nicotine dependence, in the form of tobacco smoking, is a major source of preventable morbidity and mortality worldwide. Despite the currently available therapeutic interventions, successful smoking quit rates remain low. Thus, there is an urgent need to develop new and more efficacious treatments. Accumulating evidence suggests a crucial role of excitatory glutamate transmission in the mesocorticolimbic system in mediating nicotine reinforcement, suggesting that glutamate receptors may be innovative targets for the treatment of nicotine addiction. Decreasing glutamate transmission by activation of the presynaptic inhibitory metabotropic glutamate receptor 2/3 (mGluR2/3) attenuates nicotine taking and seeking. However the relative contribution of each receptor (2 vs 3) in nicotine dependence is unknown due to the lack of subtype selective pharmacological tools. Further, little is known regarding the role of the inhibitory presynaptic mGluR7 in nicotine dependence. The only commercially available mGluR7 agonist, AMN082, is far from optimal because of the off-target effects produced by its metabolite. This project seeks to develop the molecular tools that will enable the cell-specific overexpression of these three mGluR subtypes in specific brain sites to allow us to investigate the role of each one of these receptors in nicotine dependence. Lentivirus-mediated genetic manipulations permit the efficient transfer of genes into the brain and sustain long-term regulation of the target receptor(s). This targeted experimental approach allows one to probe the mechanistic basis of nicotine dependence. Work under Specific Aim 1 will generate and validate viral vectors to overexpress mGluR2, 3 and 7 on glutamate terminals in the ventral tegmental area (VTA), a brain site within the mesolimbic system that is critically involved in nicotine dependence and where there is high density of these receptors. Neuron non-specific viral vectors will be generated and validated in vitro to examine the function mediated by vector-expressed mGluRs. Glutamatergic neuron-specific vectors will also be generated. All the vectors will be validated in vivo to examine vector-induced expressions and changes of protein and mRNA levels in the rat brain. Specific Aim 2 will initiate work towards the investigation of the role of each mGluR in the reinforcing and motivational effects of nicotine by using these molecular tools. Specifically, viral vectors will be injected ino the VTA, after which nicotine self-administration will be conducted. We hypothesize that overexpression of mGluR2, 3 or 7 will attenuate nicotine self-administration. In summary, this project will provide novel molecular tools, and then initiate the application of these tools in the investigation of the involvement of mGluR subtypes in nicotine dependence using well-established behavioral rat procedures. Findings from this work will provide the foundation for a future R01 NIH grant application that will systematically explore the role of these mGluRs in different aspects of nicotine dependence.

 描述（由申请人提供）：尼古丁依赖，以吸烟的形式，是全球可预防的发病率和死亡率的主要来源。尽管目前有可用的治疗干预措施，但成功戒烟率仍然很低。因此，迫切需要开发新的和更有效的治疗方法。越来越多的证据表明，兴奋性谷氨酸在介导尼古丁强化的中皮质边缘系统中的传输起着至关重要的作用，这表明谷氨酸受体可能是治疗尼古丁成瘾的创新靶点。通过激活突触前抑制性代谢型谷氨酸受体2/3（mGluR 2/3）减少谷氨酸传递，减弱尼古丁摄入和寻求。然而，由于缺乏亚型选择性药理学工具，每种受体（2 vs 3）在尼古丁依赖中的相对作用尚不清楚。此外，关于抑制性突触前mGluR 7在尼古丁代谢中的作用知之甚少。 依赖唯一的市售mGluR 7激动剂AMN 082由于其代谢产物产生的脱靶效应而远非最佳。该项目旨在开发分子工具，使这三种mGluR亚型在特定大脑部位的细胞特异性过表达，使我们能够研究这些受体中的每一种在尼古丁依赖中的作用。慢病毒介导的遗传操作允许基因有效转移到大脑中并维持对靶受体的长期调节。这种有针对性的实验方法允许人们探索尼古丁依赖的机制基础。具体目标1下的工作将产生和验证病毒载体，以在腹侧被盖区（VTA）的谷氨酸末端过表达mGluR 2，3和7，这是中脑边缘系统内的一个大脑部位，与尼古丁依赖密切相关，并且这些受体的密度很高。将在体外生成并验证神经元非特异性病毒载体，以检查载体表达的mGluRs介导的功能。还将产生谷氨酸能神经元特异性载体。所有的载体将在体内进行验证，以检查载体诱导的表达和蛋白质和mRNA水平在大鼠脑中的变化。具体目标2将通过使用这些分子工具开始研究每种mGluR在尼古丁的增强和激励作用中的作用。具体而言，将病毒载体注射到VTA中，之后将进行尼古丁自我给药。我们假设mGluR 2、3或7的过表达将减弱尼古丁自我给药。总之，本项目将提供新的分子工具，然后启动这些工具在 使用完善的行为大鼠程序研究mGluR亚型在尼古丁依赖中的参与。这项工作的结果将为未来的R 01 NIH拨款申请提供基础，该申请将系统地探索这些mGluRs在尼古丁依赖不同方面的作用。