Photic and Circadian Regulation of Retinal Melatonin

哺乳动物的视网膜含有调节视网膜功能多方面的生物钟 通过驱动基因表达的昼夜节律， 营业额和视觉敏感度。先前的研究表明褪黑激素通过g蛋白发挥作用- 褪黑素偶联受体（MTRs）在调节多种视网膜神经元的功能中起着关键作用。 昼夜节律和褪黑激素参与视网膜细胞活力的调节， 衰老在本申请中，我们将进一步调查地铁拆除对 视网膜通过使用褪黑激素熟练小鼠（C3 H-f +/+）小鼠，其中两种不同类型的g- 蛋白偶联的褪黑激素受体（MTRs）已被去除。这些新的动物模型 在我们的实验室开发提供了一个独特的和强大的工具，以调查 褪黑素和MTRs在视网膜中的作用。我们的初步数据表明褪黑激素的作用 在某些视网膜细胞内，可能通过褪黑激素受体1的形成来介导 和2个异聚体（MTRh）。本申请包括三个具体目的。在特定 目的1，我们将确定褪黑激素受体1型和褪黑激素受体2型是否形成 视网膜细胞中的异聚体。在具体目标2中，我们将研究褪黑激素的作用及其对 相关受体在褪黑激素椎间盘脱落日节律调节中的作用 熟练小鼠和褪黑激素受体敲除小鼠。最后，在具体目标3中， 确定外源性褪黑激素的施用是否增加视网膜的敏感性 通过激活MTRs来减轻光诱导的损伤，我们将分析 通过感光细胞和RPE细胞中的褪黑激素激活。在我们的研究中，我们将使用广泛的 一系列新的和技术先进的技术，如定量真实的时间Q-RT- PCR、生物发光共振能量转移（BRET）、激光捕获切割 显微镜和微阵列分析。 意义褪黑激素及其相关受体作用的特征可能 提供了新的和重要的见解褪黑激素的作用机制在眼睛和 在身体的其他部分更普遍。在我们的申请中提出的实验将 生成可能导致开发新的治疗工具来治疗或预防的数据 与褪黑激素系统功能障碍相关的疾病状态。

The mammalian retina contains circadian clocks that regulate multiple aspects of retinal function by driving circadian rhythms of gene expression, photoreceptor outer segment membrane turnover, and visual sensitivity. Previous work has shown that melatonin acting via g protein- coupled melatonin receptors (MTRs) plays a key role in the regulation of a wide variety of retinal circadian rhythms and melatonin is involved in the modulation of retinal cell viability during aging. In the present application we will further investigate the effect of MTR removal on the retina by using melatonin proficient mice (C3H-f+/+) mouse in which the two different types of g- protein coupled melatonin receptors (MTRs) have been removed. These new animal models developed in our laboratory provides a unique and powerful tool with which to investigate the role of melatonin and MTRs in the retina. Our preliminary data suggest that melatonin action within the some retinal cells is likely to be mediated via the formation of melatonin receptor 1 and 2 heteromers (MTRh). The present application comprises three specific aims. In specific aim 1, we will determine whether melatonin receptor type 1 and melatonin receptor type 2 form heteromers in retinal cells. In Specific aim 2, we will investigate the role of melatonin and its associated receptors in the regulation of the daily rhythms in disc shedding in melatonin proficient mice and melatonin receptor knock-out mice. Finally, in specific aim 3 we will determine whether administration of exogenous melatonin increase the sensitivity of the retina to light-induced damage via activation of MTRs and we will dissect the signaling pathways activate by melatonin in the photoreceptor and RPE cells. In our research, we will use a wide array of new and technologically advanced techniques, such as quantitative real time Q-RT- PCR, Bioluminescence Resonance Energy Transfert (BRET), laser capture dissecting microscopy, and microarray analysis. Significance. The characterization of the action of melatonin and its associated receptors may provide new and important insights on the mechanisms of action of melatonin in the eye and more in general in the rest of the body. The experiments proposed in our application will generate data that may lead to the development of new therapeutic tools to treat or prevent disease states associated with dysfunction of the melatonergic system.