Circadian regulation of RPE functions

RPE 功能的昼夜节律调节

• 批准号: 9980411
• 负责人: Gianluca Tosini
• 金额: $ 49.42万
• 依托单位: MOREHOUSE SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9980411
• 关键词: 11 cis Retinal; Affect; Afferent Neurons; Aging; Blood-Retinal Barrier; Cells; Choroid; Circadian Rhythms; Cues; Cyclic AMP; DRD2 gene; Data; Development; Dopamine; Environment; Environmental Risk Factor; Event; Excision; Eye; Firefly Luciferases; Gene Targeting; Genes; Genetic Predisposition to Disease; Genetic Transcription; Goals; Health; In Vitro; Knock-in Mouse; Knowledge; Life Style; Light; Lipofuscin; Location; Luciferases; Mediating; Messenger RNA; Modeling; Modernization; Molecular; Monitor; Mus; Natural regeneration; Neural Retina; Neuromodulator; Nutrient; Organ; Pathology; Periodicity; Phagocytes; Phagocytosis; Phase; Photoreceptors; Physiological Processes; Physiology; Play; Preparation; Process; Receptor Signaling; Regulation; Reporter; Reporting; Research Proposals; Retina; Retinal Diseases; Role; Signal Transduction; Structure of retinal pigment epithelium; Testing; Time; Tissues; Transgenic Mice; age related; circadian; circadian pacemaker; circadian regulation; experimental study; improved; mouse model; receptor; rod outer segment disc; tool; transcriptome; visual cycle

The retinal pigment epithelium (RPE) is involved in many processes necessary to maintain photoreceptor function and health. The RPE is also involved in the regulation of the photoreceptor outer segment turnover (disk shedding and phagocytosis) a process that has been shown to be under circadian control. We have recently developed an RPE-choroid preparation in which we can monitor, in real-time, the circadian clock using the PER2::LUC knock-in mouse, a transgenic mouse model where the PER2 oscillation is faithfully reported via a firefly luciferase. This model is unique in that it reflects both transcription and post-translational events, providing a powerful tool to investigate circadian clock function in a specific tissue and/or cell. Using this new preparation we have demonstrated that the mouse RPE contains a circadian clock that is entrained by the neuromodulator dopamine (DA). In the present proposal (Specific Aim 1) we will test the hypothesis that DA, via D2-like receptors located in the RPE, entrains the circadian clock in the RPE, thus synchronizing the daily burst in phagocytosis of rod outer segment disks. Then we will identify the molecular mechanisms by which DA synchronizes the circadian clock in the RPE. In Specific Aim 2 we will test the prediction that removal of D2R signaling will affect the daily rhythm of phagocytosis thus leading to lipofuscin accumulation and reduced photoreceptor viability during aging. Finally, in Specific Aim 3 we will define the roles of RPE and inner retinal clocks in the regulation of the daily rhythm in RPE phagocytic activity. To reach this goal we will disrupt circadian clocks selectively in RPE and neural retina and assess the consequences on the daily rhythm of phagocytosis. The experiments described in this research proposal will determine the role that DA and its associated receptors play in the regulation of the circadian rhythms in the RPE and the role of retinal/RPE circadian clocks in the regulation of the daily rhythm of RPE phagocytic activity.

视网膜色素上皮细胞（RPE）参与许多必要的过程， 维持感光细胞的功能和健康。RPE还参与监管 光感受器外节翻转（圆盘脱落和吞噬作用）是一个过程， 已经被证明是受昼夜节律控制的。我们最近开发了一种 RPE-脉络膜准备，我们可以实时监测，生物钟使用 PER 2：：LUC敲入小鼠，一种转基因小鼠模型，其中PER 2振荡 是通过萤火虫荧光素酶如实报道的。这个模型的独特之处在于它反映了 转录和翻译后事件，提供了一个强大的工具，研究 生物钟在特定组织和/或细胞中的功能。使用这种新制剂， 已经证明，小鼠RPE包含一个昼夜节律钟， 神经调节剂多巴胺（DA）。在本提案（具体目标1）中，我们将测试 假设DA通过位于RPE中的D2样受体， 时钟的RPE，从而同步每天爆发吞噬杆外 段磁盘。然后，我们将确定DA的分子机制， 在视网膜色素上皮细胞中调节生物钟。在具体目标2中，我们将测试预测 D2 R信号的去除将影响吞噬作用的每日节律，从而导致 脂褐素积累和老化过程中感光细胞活力降低。最后在 具体目标3我们将定义RPE和内部视网膜时钟在调节 RPE吞噬细胞活性的日节律。为了达到这一目标，我们将扰乱昼夜节律， 在RPE和神经视网膜中选择性地时钟，并评估对日常生活的影响。 吞噬节律本研究提案中描述的实验将 确定DA及其相关受体在调节多巴胺受体中的作用。 视网膜色素上皮的昼夜节律和视网膜/视网膜色素上皮昼夜节律钟在视网膜色素上皮中的作用 调节RPE吞噬活性的日节律。