Identifying the role of the ocular immune response in age-related sleep disturbances

项目摘要 睡眠是进化过程中的一种保守功能，对保持健康和延长寿命至关重要。 随着年龄的增长，睡眠质量会下降，这往往发生在疾病发生之前，也与疾病的发病有关。 然而，导致睡眠衰老的机制尚不清楚。在人类和果蝇身上， 黑腹果蝇是一种内源性生物钟，它设定了24小时的睡眠和活动节奏 受从眼睛接收到的光输入的影响。然而，随着年龄的增长，视力会下降， 抑制昼夜节律。伴随这种下降而来的是免疫系统的慢性激活。一个 免疫反应的中央调节因子是转录因子核因子-κ-B(NF-KappaB)，它在 苍蝇和哺乳动物都协调对细菌病原体和损伤信号的反应。使用 利用生物信息学的方法，我们在果蝇中发现了受NF-κB调控的基因表达上调 在光感受器细胞中随年龄增长。考虑到这一观察结果，我们测试了改变以下情况的假设 发生在眼睛随着年龄的增长而引发睡眠衰老。我们发现，抑制NF-κB同源物，在 光感受器细胞随着年龄的增长维持总睡眠时间和睡眠巩固，这表明 眼睛的免疫反应会导致睡眠衰老。此外，我们已经确认，住房飞来 持续的黑暗抑制了苍蝇头部核因子-κB调控基因的表达，表明核因子-κB 活动受光的调节。这项提案建立在这些初步调查结果的基础上，具有两个具体目标。在目标1中， 我们将确定眼睛中受核因子-κB调控的基因，这些基因会导致睡眠衰老。要完成 为此，我们编制了一份在光感受器中表达显著变化的基因清单 年纪大了，而且失去了味觉。我们将抑制光感受器中的每一个候选基因并识别 其功能丧失的睡眠表型与调味效果相似的基因。在目标2中，我们将坚定地确立 光和光转导信号级联是否促进光感受器中的NF-κB活性。为 为此，我们将使用现有的基于荧光素酶的NF-κB遗传报告，我们可以在 感光细胞。利用果蝇可用的强大遗传工具，我们将能够测试 参与光转导信号级联的基因会影响NF-κB荧光素酶报告活性，从而使我们 为了查明光调节核因子-κB的机制，这项工作最终将揭示这一机制 通过眼睛老化影响睡眠衰老，并将识别保守的基因靶点可能是 在哺乳动物中进行调节，以随年龄保持睡眠质量。

Project Summary Sleep is a conserved function across evolution that is critical for maintaining health and promoting longevity. With age, there are declines in sleep quality that often precede, and are associated with, the onset of disease. However, the mechanisms responsible for sleep senescence are unclear. In both humans and the fruit fly, Drosophila melanogaster, endogenous circadian clocks that set 24h rhythms in sleep and activity are influenced by light input received from the eye. However, with age, there are declines in vision and a dampening of circadian rhythms. Concomitant with this decline, is a chronic activation of the immune system. A central regulator of the immune response is the transcription factor Nuclear Factor Kappa-B (NF-κB), which in both flies and mammals coordinates the response to bacterial pathogens and damage signals. Using a bioinformatics approach in Drosophila, we identified that genes regulated by NF-κB show elevated expression in the photoreceptor cells with age. With this observation in mind, we tested the hypothesis that changes that occur in the eye with age drive sleep senescence. We found that inhibiting the NF-κB homolog, relish, in the photoreceptor cells maintains total sleep time and sleep consolidation with age, suggesting that increases in the ocular immune response drives sleep senescence. Furthermore, we have identified that housing flies in constant darkness suppresses the expression of NF-κB-regulated genes in the fly head, indicating that NF-κB activity is regulated by light. This proposal builds on these preliminary findings with two specific aims. In Aim#1, we will identify genes that are regulated by NF-κB in the eye and that drive sleep senescence. To accomplish this, we have compiled a list of genes whose expression is significantly changed in the photoreceptors with age, and with loss of relish. We will inhibit each of these candidate genes in the photoreceptors and identify genes whose loss-of-function sleep phenotype mimics the effect of relish. In Aim #2, we will firmly establish whether light and the phototransduction signaling cascade promotes NF-κB activity in the photoreceptors. For this, we will use an existing luciferase-based genetic reporter for NF-κB that we can express in the photoreceptor cells. Using the powerful genetic tools available to Drosophila, we will be able to test whether genes involved in the phototransduction signaling cascade affect NF-κB luciferase reporter activity, allowing us to pinpoint the mechanism through which light regulates NF-κB. Ultimately, this work will reveal the mechanism through which eye aging affects sleep senescence, and will identify conserved genetic targets that may be modulated in mammals for preserving sleep quality with age.