Integrated Signaling and Transcriptional Networks in Circadian Clock Neurons

描述（由申请人提供）：这是一种系统生物学方法，涉及建模，以解决通过光输入调节哺乳动物生物钟相位的机制的重要生物医学问题。生物钟是所有生物体的重要组成部分，对于维持生物体与环境的时间同步以及生物体内部过程的节奏编排至关重要。生物钟功能的破坏会导致睡眠/觉醒周期的中断，并与心肺功能障碍、癌症、胃肠道疾病、抑郁和神经紊乱有关。哺乳动物生物钟受光暗周期影响的分子机制是一个非常重要的问题。充分理解这个函数是很重要的。要开发的方法解决了一个基本的未满足的需求，即理解光激活细胞内信号的机制，从而导致调节哺乳动物细胞功能的转录后果。我们的目标是在自动同步视交叉上核（SCN）昼夜节律细胞中，将光启动信号与视网膜-下丘脑（RHT）光刺激反应中的基因表达联系起来。SCN是主时钟，协调全身的许多生物节律。反映环境和内部状态的输入被传递给SCN细胞受体，SCN细胞受体通过复杂的信号通路与生物钟相互作用，最终使其能够控制节律性生理功能。通过RHT激活的光信号是生物钟功能的所有输入中最具特征的。对光信号的昼夜反应已被发现与昼夜节律相相关。这些效应在同步SCN细胞行为背景下的稳健性，以及文献中关于RHT信号的丰富相关信息，为我们的目标提供了有利的环境。我们的实验策略使用了全基因组表达谱结合药理学信号抑制的析因设计方法。我们将通过整合基因表达数据和启动子信息学来使用转录调控网络分析。这些结果将与现有文献相结合，并用于推导信号通路。然后，我们将实验验证模型结构在不同层次的相互作用。结果将是一个由信号蛋白和转录因子之间的相互作用介导的光信号在SCN中的基因表达效应的实验验证网络-在广泛研究的信号和基因表达领域之间建立新的和直接验证的联系，并在生理学相关的模型系统中这样做。

DESCRIPTION (provided by applicant): This is a systems biology approach involving modeling to approach the significant biomedical question of the mechanisms by light inputs adjust the phase of the mammalian circadian clock. The circadian clock is a critical component of all living organisms and is critical for the maintenance of temporal synchrony of the organism with the environment and rhythmic orchestration of processes within the organism. Disruption of circadian clock function results in disrupted sleep/wake cycles and has been associated with cardiorespiratory dysfunction and cancer, gastrointestinal disorders, depression and altered. The molecular mechanism by which mammalian circadian clocks are entrained to light-dark cycles is a highly significant problem. A full understanding of this function is significant. The approaches to be developed address a fundamental unmet need in understanding the mechanisms by which light activates intracellular signaling that leads to transcriptional consequences which modulate cellular function in mammalian cells. Our objective is to link light-initiated signaling to gene expression in the response of retino-hypothalamic (RHT) light stimulation in auto-synchronized suprachiasmatic nucleus (SCN) circadian cells. The SCN is the master clock, coordinating numerous biological rhythms throughout the body. Inputs reflecting environmental and internal status are transmitted to SCN cell receptors that interact with the clock through complex signaling pathways, ultimately allowing it to control rhythmic physiological functions. Light signaling through RHT activation is the best characterized of all inputs into the circadian clock function. The circadian response to light signaling has been found to be circadian phase-related. The robustness of these effects in the context of synchronous SCN cellular behavior, in conjunction with the wealth of relevant information on RHT signaling from the literature, provides an advantageous environment for our objective. Our experimental strategy uses a factorial design approach to genome-wide expression profiling combined with pharmacological signaling inhibition. We will employ transcriptional regulatory network analysis by integrating gene expression data with promoter informatics. These results will be integrated with existing literature and used to derive signaling pathways. We will then experimentally validate the model structure at the various levels of interaction. The result will be an experimentally verified network of the gene expression effects of light signaling in SCN mediated by interactions between signaling proteins and ultimately transcription factors - making novel and directly validated links between the extensively studied fields of signaling and gene expression, and doing so in a physiologically relevant model system.