Molecular pathways connecting sleep, stress, metabolism and longevity

项目摘要/摘要 果蝇的基因筛查发现了显著缩短夜间- 白天和白天的睡眠。受这些突变影响的基因在血脑中表达- 苍蝇神经膜下神经胶质细胞屏障形成及形态和生物物理改变 屏障的属性。我们发现了其中一些基因之间的新的遗传相互作用 突变：令人惊讶的是，某些突变组合恢复了睡眠和血脑屏障 功能。我们建议进行进一步的研究，以揭示连接它们之间的分子通路 基因产物，并阐明它们对睡眠和屏障功能的贡献。我们发现 在野生型果蝇中，血脑屏障的开启和关闭有节奏，需要 生物钟。我们还发现，屏障通透性与睡眠密切相关 需要：睡眠不足会打开障碍，但睡眠恢复则会关闭障碍。什么是存在 以这样一种动态的方式跨越障碍进行交换？神经系统功能受到保护 通过一个陡峭的K浓度梯度分离血淋巴和脑。在我们提议的 研究我们将开发工具来量化高时间跨过血脑屏障的K流量 在活体苍蝇中的分辨率。睡眠和清醒的发作是否与这些离子有关？ 交换？这样的测量是否揭示了清醒/睡眠行为的特征 使用标准的运动活动监测是否明显？我们的研究还表明，睡眠 变种人减少了寿命，但这种方式可以通过时间控制访问 食物。这些影响需要生物钟，我们将确定哪些组织是 负责这种反应，以及寿命的恢复是否依赖于睡眠恢复。 长期暴露在心理压力源下会对两者产生深远而持久的影响 身体和精神健康，并经常伴随着严重的睡眠损失。慢性 社会隔离提供了一种方法，可以很容易地应用心理压力源 延长的时间，我们观察到总睡眠、白天睡眠和 与集体饲养的兄弟姐妹相比，孤立果蝇的夜间睡眠时间更短。至 寻找可能对隔离引起的压力和睡眠抑制做出反应的遗传途径， 比较的RNAseq分析使用的果蝇的头部从组- 饲养果蝇，或来自长期与世隔绝的果蝇。在最受欢迎的 基因被认为是那些调节食欲的基因。这些映射到一个小的神经元回路，我们 将进一步表征以确定其在隔离诱导的应激反应中的可能作用 影响睡眠和饥饿。

Project Summary/Abstract Genetic screens in Drosophila have identified mutations that significantly reduce both night- time and daytime sleep. Genes affected by these mutations are expressed in the blood-brain- barrier-forming subperineurial glia of the fly and alter the morphological and biophysical properties of the barrier. We have discovered novel genetic interactions among some of these mutations: surprisingly, certain mutant combinations restore both sleep and blood-brain-barrier function. We propose further studies that could reveal molecular pathways connecting their gene products and clarify their contributions to sleep and barrier function. We discovered that in wild type Drosophila the blood-brain barrier opens and closes with a rhythm that requires a circadian clock. We have also found that barrier permeability is closely connected to sleep need: sleep deprivation opens the barrier, but rebound sleep closes it. What is being exchanged across the barrier in such a dynamic fashion? Nervous system function is protected by a steep concentration gradient of K+ separating the haemolymph and brain. In our proposed studies we will develop tools to quantify K+ flux across the blood brain barrier with high temporal resolution in living flies. Are episodes of sleep and wakefulness correlated with these ion exchanges? Do such measurements reveal features of wake/sleep behavior that are not evident using standard locomotor activity monitoring? Our studies have also shown that sleep mutants reduce lifespan, but in a fashion that can be reversed by time-controlled access to food. These effects require a circadian clock and we will determine which tissues are responsible for this response and whether lifespan restoration depends on sleep recovery. Chronic exposure to psychogenic stressors can have profound, long-lasting effects on both physical and mental health and is often accompanied by a profound loss of sleep. Chronic social isolation provides a means by which a psychogenic stressor can be easily applied for an extended period, and we observe significant reductions in total sleep, day-time sleep, and night-time sleep in isolated flies when compared to sleep in siblings that are group reared. To search for genetic pathways that might respond to isolation-induced stress and depress sleep, comparative RNAseq assays were performed using Drosophila heads collected from group- reared flies, or from flies stressed through chronic isolation. Among the most highly responding genes are those thought to regulate appetite. These map to a small neuronal circuit which we will further characterize to determine its possible role in isolation-induced stress responses affecting sleep and hunger.