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）：昼夜节律中的缺陷与多种临床疾病有关。新兴证据暗示神经元之间在同步和维持昼夜节律时钟之间进行交流。果蝇果蝇一直是一个强大的模型，旨在阐明时钟的基本机制，其中许多方面与人类高度保守。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。我们最近确定了PDF（PDFR）的G蛋白偶联受体。该受体的识别提供了解决与昼夜节奏起搏器功能有关的中心问题的机会。昼夜节律钟如何驱动下游神经回路以控制行为，例如睡眠和唤醒？ PDF在神经振荡器的耦合中的作用是什么？ PDF重置核心振荡器并驱动节奏行为的机制是什么？该提案的具体目的是：1。在行为和分子昼夜节律中绘制PDF受体功能的细胞底物。关于介导PDF受体作用的昼夜节律行为的神经底物知之甚少。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的PDFR救援，过表达和RNAi敲低。此外，我们将评估PDFR在大脑中的分布。 2。检验PDF信号传导在神经昼夜节律制造者偶联中的作用。为了测定耦合，我们将操纵昼夜节神经网络子集的时钟速度，并在存在或不存在PDF信号传导的情况下分析对互连振荡器的后果。 3。检查PDF重置核心昼夜节律时钟和输出途径的分子机制。我们将检查核心时钟以及cAMP和MAPK信号通路上PDFR丢失的分子后果。使用新型的电生理方法，我们将检查外源性PDF对起搏器和输出神经元电气性能的影响。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。这些研究应阐明昼夜节律行为中PDFR作用必不可少的分子和神经回路。他们还利用了果蝇系统的独特优势，包括易于组织 - 特定的救援研究，在确定的起搏器神经元中操纵时钟的能力以及广泛的遗传资源来检查整个动物中的信号通路和核心时钟。鉴于用哺乳动物系统进行保护，这项工作应提供有关神经肽介导正常和破坏人类疾病的昼夜节律的机制的见解。昼夜节律时钟中的公共卫生相关性缺陷与多种临床疾病有关。神经起搏器及其下游靶标之间的通信是由神经肽介导的。我们将阐明昼夜节律神经肽在同步昼夜节律中的作用，并在简单的动物模型中传达定时信息。鉴于人类的潜在保护，这项工作应洞悉神经肽在人类疾病中介导正常和破坏昼夜节律的机制。