Neuropeptidomics of Clock-to-Clock Coupling

描述（由申请人提供）：生物学中一个未解决的核心问题是，是什么协调生物体的生物钟？大脑中央生物钟、视交叉上核（SCN）与其他细胞和组织中的生物钟之间的协调丧失与导致睡眠障碍的系统病理有关。这一发现提案的目标是识别连接SCN和[神经胶质]生物钟的肽。对分离培养的外周组织的研究表明，在SCN缺失的情况下，不同组织（包括脑、肝、肺、肌肉、肾、尾[和脾]）的细胞节律仍在继续，但期和周期特性发生了变化。与脱钩，各种组织功能失去了时间一致性以及适当的对齐，以睡眠和觉醒的日常周期。除了扩散因子足以引导许多生物的生物钟外，人们对生物体生物钟的耦合机制知之甚少。事实证明，发现将SCN与（大脑和身体）其他生物钟之间的时间联系起来的耦合因素是很困难的。我们提出了一项研究，在微米尺度上应用先进的分析肽组学技术，结合肽恢复生物钟协调能力的功能测定，这是一种创新的方法。我们的目标是：1)定义和表征SCN驱动的[胶质细胞]节律同步的诱导，2)通过肽组学分析鉴定释放的候选偶联肽，3)确定从SCN释放的候选偶联肽诱导[胶质细胞]时钟同步节律的必要性/充分性，以及4)表征和评估候选偶联肽。这些目标的成功完成将使我们能够在动物模型中测试耦合。内部时钟之间失去同步对健康和长寿是不适应的。目前还没有更好地同步或增强内部时钟耦合的方法。识别有效结合昼夜节律的信号将对代谢综合征、肥胖、心血管压力和随年龄增长的生理衰退的治疗具有重要价值，所有这些都表现为睡眠模式紊乱，每年影响超过1000万美国人。然而，为了实现治疗潜力，必须识别SCN参与其他生物钟的信号，并将其置于时间背景中。公共卫生相关性：本提案旨在确定在睡眠-觉醒周期中提供昼夜节律整合的身体功能神经肽。大脑中央生物钟、视交叉上核（SCN）和其他细胞和组织生物钟之间的协调丧失与导致睡眠障碍的系统病理有关，并且对健康和长寿不适应。识别有效结合整个身体昼夜节律的信号将对代谢综合征、肥胖、心血管压力和随年龄增长的生理衰退的治疗具有重要价值，所有这些都表现为睡眠模式紊乱，每年影响超过1000万美国人；然而，为了实现治疗潜力，必须识别SCN参与其他生物钟的信号，并将其置于时间背景中。

Description (provided by applicant): A central unsolved question in biology is, What coordinates an organism's circadian clocks? Loss of coordination between the central circadian clock in the brain, the suprachiasmatic nucleus (SCN), and circadian clocks in other cells and tissues has been implicated in systems pathologies that lead to sleep disorders. The goal of this discovery proposal is to identify peptides that couple the SCN and [glial] circadian clocks. Studies of peripheral tissues cultured in isolation have revealed that in the SCN's absence, cellular rhythms continue but phase and period properties change in diverse tissues, including brain, liver, lung, muscle, kidney, tail [and spleen]. With decoupling, the various tissue functions lose temporal coherence as well as appropriate alignment to the daily cycle of sleep and wakefulness. Little is known about what couples an organism's circadian clocks, except that diffusible factors are sufficient to entrain many. Discovering coupling factors that communicate time-of-day from SCN to other circadian clocks [in brain and body] has proven difficult. We propose a study applying advanced analytical peptidomic techniques on a micrometer scale coupled with functional determinations of the ability of peptides to restore clock-to-clock coordination, an innovative approach. We aim to: 1) define and characterize induction of SCN-driven synchronization of [glia] rhythms, 2) identify released candidate coupling peptides by peptidomic analysis, 3) determine the necessity/sufficiency of candidate coupling peptides released from the SCN for inducing synchronous rhythms of [glia] clocks, and 4) characterize and evaluate candidate coupling peptides. Successful completion of these aims will poise us for testing coupling in animal models. Loss of synchrony among internal clocks is maladaptive for health and longevity. There are no current approaches to better synchronize or enhance coupling of the internal clocks. Identifying signals that effectively couple circadian rhythms will have major value in treatment of metabolic syndrome, obesity, cardiovascular stress, and physiological decline with aging, all of which manifest with disordered sleep patterns that affect more than 10 million Americans each year. However, to realize therapeutic potential, signals by which the SCN engages other circadian clocks must be identified and placed in temporal context. PUBLIC HEALTH RELEVANCE: This proposal seeks to identify neuropeptides that provide integration of circadian rhythms in body function across the sleep-wake cycle. Loss of coordination between the central circadian clock in the brain, the suprachiasmatic nucleus (SCN), and circadian clocks in other cells and tissues has been implicated in systems pathologies that lead to sleep disorders, and is maladaptive for health and longevity. Identifying signals that effectively couple circadian rhythms throughout the body will have major value in treatment of metabolic syndrome, obesity, cardiovascular stress, and physiological decline with aging, all of which manifest with disordered sleep patterns that affect more than 10 million Americans each year; however, to realize therapeutic potential, signals by which the SCN engages other circadian clocks must be identified and placed in a temporal context.