Intercellular Signaling in the Circadian Clock

生物钟中的细胞间信号传导

• 批准号: 8078194
• 负责人: Ravi Allada
• 金额: $ 32.37万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8078194
• 关键词: Acute; Address; Adult; Animal Model; Animals; Back; Behavior; Behavior Control; Behavioral; Biological Assay; Biological Neural Networks; Brain; Cell Line; Cells; Circadian Rhythms; Clinical; Communication; Couples; Coupling; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Defect; Disease; Drosophila genus; Employee Strikes; Enhancers; Feedback; Feeds; Fluorescent in Situ Hybridization; G-Protein-Coupled Receptors; Health; Human; Immunofluorescence Immunologic; Label; MAP Kinase Gene; MAPK Signaling Pathway Pathway; Mammals; Maps; Mediating; Membrane; Modeling; Molecular; Molecular Genetics; Neuroanatomy; Neurons; Neuropeptides; Output; Pacemakers; Pathway interactions; Phenotype; Pigments; Publishing; RNA Interference; Resources; Role; Signal Pathway; Signal Transduction; Sleep; Speed; System; Techniques; Time; Tissues; Work; circadian pacemaker; electrical property; fly; genetic analysis; genetic manipulation; genetic resource; human disease; insight; intercellular communication; interest; mutant; neural circuit; novel; overexpression; receptor; receptor function; relating to nervous system; research study

DESCRIPTION (provided by applicant): Defects in circadian clocks have been implicated in a variety of clinical disorders. Emerging evidence implicates communication between neurons in synchronizing and sustaining circadian clocks. The fruit fly Drosophila has been a powerful model to elucidate the underlying mechanisms of clocks, many aspects of which are highly conserved with humans. In the fruit fly, the neuropeptide PIGMENT DISPERSING FACTOR (PDF) is central to synchronizing neural pacemakers and regulating neural outputs. We have recently identified the G-protein coupled receptor for PDF (PDFR). The identification of this receptor affords an opportunity to address central questions related to circadian pacemaker function. How do circadian clocks drive downstream neural circuits to control behavior, such as sleep and wake? What is the role of PDF in coupling of neural oscillators? What are the mechanisms by which PDF resets core oscillators and drives rhythmic behaviors? The specific aims of the proposal are: 1. To map the cellular substrates of PDF receptor function in behavioral and molecular circadian rhythms. Remarkably little is known about the neural substrates that mediate PDF receptor action in circadian behavior. To address this issue, we will use tissue-specific PDFR rescue, overexpression, and RNAi knockdown in circadian and potential downstream neural circuits. In addition, we will assess the distribution of PDFR in the brain. 2. To examine the role of PDF signaling in coupling of neural circadian pacemakers. To assay coupling, we will manipulate the speed of the clock in subsets of the circadian neural network and assay the consequences on interconnected oscillators in the presence or absence of PDF signaling. 3. To examine the molecular mechanisms by which PDF resets the core circadian clock and output pathways. We will examine the molecular consequences of loss of PDFR on the core clock as well as cAMP and MAPK signaling pathways. Using novel electrophysiological approaches, we will examine the effects of exogenous PDF on electrical properties of pacemaker and output neurons. We will analyze genetic interactions between PDF/PDFR, core clock, cAMP/MAPK, and membrane excitability mutants. These studies should elucidate the molecular and neural circuitry essential for PDFR action in circadian behavior. They also exploit the unique advantages of the Drosophila system, including the ease of tissue- specific rescue studies, the ability to manipulate the clock in identified subsets of pacemaker neurons, and the extensive genetic resources to examine signaling pathways and the core clock in the whole animal. Given the conservation with mammalian systems, this work should provide insights into the mechanisms by which neuropeptides mediate normal and disrupted circadian rhythms in human disease. PUBLIC HEALTH RELEVANCE Defects in circadian clocks have been implicated in a variety of clinical disorders. Communication between neural pacemakers and to their downstream targets is mediated by neuropeptides. We will elucidate the role of a circadian neuropeptide in synchronizing circadian clocks and communicating timing information in a simple animal model. Given the potential conservation with humans, this work should provide insight into the mechanisms by which neuropeptides mediate normal and disrupted circadian rhythms in human disease.

描述（由申请人提供）：生物钟缺陷与多种临床疾病有关。新的证据表明神经元之间的通信可以同步和维持生物钟。果蝇是阐明生物钟基本机制的有力模型，生物钟的许多方面对于人类来说是高度保守的。在果蝇中，神经肽色素分散因子 (PDF) 对于同步神经起搏器和调节神经输出至关重要。我们最近发现了 PDF 的 G 蛋白偶联受体 (PDFR)。这种受体的识别为解决与昼夜节律起搏器功能相关的核心问题提供了机会。生物钟如何驱动下游神经回路来控制行为，例如睡眠和醒来？ PDF 在神经振荡器耦合中的作用是什么？ PDF 重置核心振荡器并驱动节律行为的机制是什么？该提案的具体目标是： 1. 绘制 PDF 受体功能在行为和分子昼夜节律中的细胞底物图谱。对于在昼夜节律行为中介导 PDF 受体作用的神经底物，人们知之甚少。为了解决这个问题，我们将在昼夜节律和潜在的下游神经回路中使用组织特异性 PDFR 救援、过度表达和 RNAi 敲低。此外，我们还将评估 PDFR 在大脑中的分布。 2. 研究 PDF 信号在神经节律起搏器耦合中的作用。为了分析耦合，我们将操纵昼夜节律神经网络子集中的时钟速度，并分析在存在或不存在 PDF 信号的情况下对互连振荡器的影响。 3. 研究PDF重置核心生物钟和输出通路的分子机制。我们将研究 PDFR 缺失对核心时钟以及 cAMP 和 MAPK 信号通路的分子后果。使用新颖的电生理学方法，我们将研究外源 PDF 对起搏器和输出神经元电特性的影响。我们将分析 PDF/PDFR、核心时钟、cAMP/MAPK 和膜兴奋性突变体之间的遗传相互作用。这些研究应该阐明 PDFR 在昼夜节律行为中发挥作用所必需的分子和神经回路。他们还利用果蝇系统的独特优势，包括易于进行组织特异性救援研究、操纵已识别的起搏神经元亚群中的时钟的能力，以及用于检查整个信号通路和核心时钟的广泛遗传资源。动物。考虑到哺乳动物系统的保守性，这项工作应该提供对神经肽介导人类疾病中正常和扰乱的昼夜节律的机制的见解。公共卫生相关性 生物钟缺陷与多种临床疾病有关。神经起搏器与其下游目标之间的通讯是由神经肽介导的。我们将在简单的动物模型中阐明昼夜节律神经肽在同步生物钟和传达计时信息中的作用。考虑到对人类的潜在保护作用，这项工作应该可以深入了解神经肽在人类疾病中介导正常和扰乱的昼夜节律的机制。