Dopamine signal transduction in striatal neurons in Parkinson’s disease

帕金森病纹状体神经元的多巴胺信号转导

• 批准号: 10353674
• 负责人: Stella M Papa
• 金额: $ 50.05万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-23 至 2024-03-19
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10353674
• 关键词: Address; Adverse effects; Animal Model; Antiparkinson Agents; Behavioral; Cell physiology; Cells; Chronic; Corpus striatum structure; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyclic GMP; Cyclic Nucleotides; Data; Disease; Disease Progression; Disease model; Dopamine; Dopamine D1 Receptor; Dopamine D2 Receptor; Dopamine Receptor; Enterobacteria phage P1 Cre recombinase; Enzyme Activation; Enzymes; Equilibrium; Foundations; Goals; Guanosine Monophosphate; Immunoblotting; Implant; Injections; Involuntary Movements; L-DOPA induced dyskinesia; Lesion; Levodopa; Mediating; Mediator of activation protein; Midbrain structure; Modeling; Molecular; Molecular Target; Motor; Neurons; Nucleotides; Oxidopamine; Parkinson Disease; Parkinsonian Disorders; Pathway interactions; Patients; Periodicity; Pharmacology Study; Physiological; Play; Primates; Protein Kinase; Rattus; Receptor Activation; Recombinant adeno-associated virus (rAAV); Regulation; Research; Resolution; Rodent Model; Role; Second Messenger Systems; Signal Transduction; Specificity; Symptoms; System; Technology; Testing; Time; Transgenic Organisms; Viral Vector; Virus; abnormal involuntary movement; base; behavior test; disability; enzyme pathway; functional outcomes; improved; improved mobility; inhibitor/antagonist; motor behavior; motor control; motor deficit; motor impairment; motor symptom; nigrostriatal pathway; novel; optogenetics; overexpression; parkinsonian model; parkinsonian rodent; phosphoric diester hydrolase; programs; protein kinase A kinase; receptor expression; response; therapeutic target; transgene expression

Project Summary Parkinson’s disease (PD) is characterized by motor abnormalities primarily caused by loss of midbrain dopamine (DA) cells, whose principal function is to modulate the striatal neuron activity. DA replacement with L-Dopa produces significant improvement of motor deficits, but over time the overall efficacy of L-Dopa declines. Together disease progression and chronic dopaminergic treatment induces maladaptive plasticity in striatal projection neurons (SPNs), which results in altered responses to DA inputs. DA signaling in SPNs is transduced by various molecular cascades following DA receptor activation. The first step in these cascades is the regulation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) syntheses. These cyclic nucleotides activate their dependent protein kinases PKA and PKG, which are key mediators in multiple cell functions. Thus, DA modulation of SPNs is largely transduced by the cAMP-PKA and cGMP-PKG pathways. However, the roles of these enzyme pathways for DA responses after neurons have undergone significant maladaptive plasticity changes are not known. Furthermore, there may be different functional outcomes from activation of these enzyme pathways in distinct SPN subpopulations. Based on our pharmacological studies targeting nucleotide levels that suggest a key role of the cGMP-PKG pathway, we propose to explore the impact of manipulating PKG activity selectively in SPN subpopulations. This study of DA signal transduction in SPN subpopulations is aimed at identifying key cellular mechanisms that can be targeted to improve the efficacy of dopaminergic therapies. This project has two specific aims consisting of behavioral and physiological analyses in rodent models of PD including chronic stages. In the first aim, we will manipulate the activity of PKG in selective neuronal subtypes. For this purpose, we will use transgenic rats expressing a Cre system, and then inject viral vectors to overexpress PKG in direct or indirect SPNs. A battery of behavioral tests will be used to assess the role of the PKG pathway in the motor impairment of parkinsonian models as well as its reversal by dopaminergic stimulation. In the second aim, we will analyze the neuronal activity in response to overexpression of PKG, which will allow us to establish physiological correlates of behavioral results. For these recordings, we will also use transgenic rats and apply optogenetics to identify direct and indirect SPNs. Our approach includes the use of novel animal models and technologies to address key pathophysiologic mechanisms of DA signal transduction in PD. The main objectives of these exploratory studies are (I) to reveal particular roles of the cGMP-PKG pathway depending on the cellular subtype, and (II) to generate foundation data for continuation of this important research program. The long-term goal of the program is developing new strategies to alleviate the motor impairment of patients during the long course of PD.

项目摘要 帕金森病（PD）的特征是主要由中脑多巴胺丢失引起的运动异常 (DA)细胞，其主要功能是调节纹状体神经元活动。用L-多巴替代DA 产生运动缺陷的显著改善，但随着时间的推移，L-多巴的总体功效下降。 疾病进展和慢性多巴胺能治疗共同诱导纹状体适应不良可塑性 投射神经元（SPN），这导致对DA输入的反应改变。SPN中的DA信号转导 通过DA受体激活后的各种分子级联反应。这些级联的第一步是监管 环磷酸腺苷（cAMP）和环磷酸鸟苷（cGMP）的合成。这些 环核苷酸激活其依赖性蛋白激酶PKA和PKG，这是多个细胞中的关键介质。 细胞功能。因此，SPN的DA调节主要通过cAMP-PKA和cGMP-PKG途径转导。 然而，这些酶通路在神经元发生显著变化后DA反应中的作用， 适应不良的可塑性变化是未知的。此外，可能有不同的功能结果， 在不同的SPN亚群中这些酶途径的激活。根据我们的药理学研究 靶向核苷酸水平，表明cGMP-PKG途径的关键作用，我们建议探索影响 在SPN亚群中选择性地操纵PKG活性。本研究探讨了多巴胺在SPN中的信号转导 亚群的目的是确定关键的细胞机制，可以有针对性地提高疗效， 多巴胺能疗法 本计画有两个特定的目标，包括啮齿类动物模型的行为与生理分析 包括慢性期在内的PD。在第一个目标中，我们将在选择性的神经元中操纵PKG的活性， 亚型。为此，我们将使用表达Cre系统的转基因大鼠，然后注射病毒载体， 在直接或间接SPN中过度表达PKG。一组行为测试将用于评估 帕金森病模型运动障碍中PKG通路的变化及多巴胺能刺激的逆转作用。 在第二个目标中，我们将分析PKG过表达引起的神经元活动，这将允许 我们建立行为结果的生理相关性。对于这些记录，我们也将使用转基因 大鼠，并应用光遗传学来识别直接和间接的SPN。我们的方法包括使用新的动物 解决PD中DA信号转导的关键病理生理机制的模型和技术。的 这些探索性研究的主要目的是（I）揭示cGMP-PKG通路的特殊作用 取决于细胞亚型，和（II）为继续这项重要研究提供基础数据 程序.该计划的长期目标是制定新的策略，以减轻运动障碍， 患者在长期的PD过程中。