Circadian Rhythm in Cone Photoreceptors: Cellular Mechanisms

视锥细胞感光器的昼夜节律：细胞机制

基本信息

批准号：
8368458
负责人：
GLADYS Y KO
金额：
$ 36.23万
依托单位：
TEXAS A&M AGRILIFE RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-04-01 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8368458
关键词：
Adenylate Cyclase Affect Age related macular degeneration Apoptosis Architecture Biochemical Bioinformatics Biological Assay Blindness Ca(2+)-Transporting ATPase Calcium Calcium Channel Cell Survival Cell membrane Cells Cessation of life Circadian Rhythms Complex Data Degenerative Disorder Disease Electrophysiology (science)Electroretinography Elements Event Extracellular Protein Future Gene Expression Genes Glycogen Synthase Kinase 3 Goals Health Homeostasis Impairment Ion Channel Knowledge Lead Light Link Macular degeneration Membrane Metabolism MicroRNAs Microscopy Mission Molecular Mutation National Eye Institute Outcome Outcome Study Pathway interactions Patients Photoreceptors Photosensitivity Physiological Physiology Prevention Process Proto-Oncogene Proteins c-akt Public Health Regulation Research Resolution Retina Retinal Retinal Cone Retinal Degeneration Retinal Photoreceptors Role Signal Pathway Signal Transduction Sirolimus Time United States National Institutes of Health Vision Work XLRS1 protein cell growth macula neurotransmitter release novel prevent voltage

项目摘要

DESCRIPTION (provided by applicant): Understanding the mechanisms that maintain photoreceptor health and survival is critical, since there is no treatment to reverse photoreceptor death associated with ocular diseases such as Macular Degeneration (MD), the leading cause of vision impairment and blindness. This devastating disease is often specifically associated with the death of cone photoreceptors, which are highly concentrated in the macula. The circadian time-keeping mechanism in photoreceptors is known to regulate its function and physiology, and disruption of photoreceptor circadian rhythms leads to photoreceptor death. However, it is still not completely understood how photoreceptor circadian rhythms are regulated, and why photoreceptors are more sensitive to light damage at night. Hence, there is a critical need to understand the cellular mechanisms responsible for cone photoreceptor circadian rhythms, which will uncover key elements leading to the prevention of photoreceptor death and MD. The central hypothesis of this proposal is that protein kinase B (Akt)-related signaling is the major pathway that regulates the circadian rhythm of photoreceptor L-VGCCs, and intense light stimulation at night causes drastic changes of Akt- dependent signaling and L-VGCCs that subsequently triggers photoreceptor apoptosis. Photoreceptor L-VGCCs are essential in gating neurotransmitter release, and the calcium (Ca2+) influx through L-VGCCs triggers subsequent Ca2+- dependent events and affects intracellular Ca2+ homeostasis. Imbalanced intracellular Ca2+ homeostasis is known to trigger cell apoptosis. Hence, precise regulation of L-VGCCs is critical for photoreceptor survival and health. The long-term goals of this research are to understand the molecular mechanisms responsible for the photoreceptor circadian rhythm, and how this rhythm impacts its survival and health. The objectives of this project are to elucidate how microRNAs (miRNAs) integrate into Akt signaling to regulate the circadian rhythm of photoreceptor L-VGCCs and to reveal the functional significance of L-VGCC circadian rhythms especially in intracellular Ca2+ homeostasis. Combinations of bioinformatics analysis, electrophysiology, molecular / biochemical assays, and advanced high resolution microscopy will be used to investigate the following specific aims. Aim 1. Elucidate how miRNAs regulate the circadian rhythms of photoreceptor L-VGCCs. Aim 2. Investigate how bright light at night causes photoreceptor apoptosis more severely than during the day. Aim 3. Determine how the dynamic trio - L-VGCC, retinoschisin (rs1), and plasma membrane Ca2+-ATPase (PMCA1) - promote membrane retention of L-VGCCs and Ca2+ homeostasis. There are physical interactions between L-VGCCs, retinoschisin, and PMCA1, but the functions of these interactions are not clear. The outcomes of these studies will reveal new mechanisms on miRNAs and integrated Akt-related signaling in the regulation of ion channels and circadian rhythms, and how circadian regulation of photoreceptor L- VGCCs contribute to Ca2+ homeostasis, cell survival, and photosensitivity. Understanding the novel functions of miRNAs and integrated signaling pathways will ultimately provide new knowledge for preventing blindness caused by photoreceptor death. PUBLIC HEALTH RELEVANCE: The outcome of the proposed research will reveal new mechanisms that are critical in maintaining retinal photoreceptor health and survival. The proposed research is relevant to public health because understanding the cellular mechanisms of circadian regulation in retinal photoreceptors will ultimately provide knowledge for developing new strategies to treat ocular diseases and especially for preventing blindness caused by macular degeneration, since disruption of circadian rhythms in the retina causes photoreceptor death that could lead to macular degeneration. Therefore, the research proposed in this application is pertinent to part of the mission of the National Eye Institute at NIH in garnering fundamental knowledge that will help promote the prevention and treatment of ocular diseases.

描述（由申请人提供）：了解保持光感受器健康和生存的机制至关重要，因为没有治疗方法可以逆转光感受器与眼部疾病（例如黄斑变性（MD））相关的死亡，这是视力障碍和失明的主要原因。这种毁灭性疾病通常与高度集中在黄斑中的锥形光感受器的死亡特别有关。已知光感受器中的昼夜节时间保存机制可调节其功能和生理学，并且受感受器昼夜节律的破坏会导致光感受器死亡。但是，仍然尚不完全了解如何调节光感受器昼夜节律，以及为什么光感受器对夜间轻损伤更敏感。因此，迫切需要了解导致锥体光感受器昼夜节律的细胞机制，这将发现导致预防光感受器死亡和MD的关键要素。 The central hypothesis of this proposal is that protein kinase B (Akt)-related signaling is the major pathway that regulates the circadian rhythm of photoreceptor L-VGCCs, and intense light stimulation at night causes drastic changes of Akt- dependent signaling and L-VGCCs that subsequently triggers photoreceptor apoptosis.光感受器L-VGCC在门控神经递质释放中至关重要，并且通过L-VGCCS钙（Ca2+）涌入钙（CA2+）涌入随后发生的Ca2+ - 依赖性事件并影响细胞内CA2+稳态。已知细胞内Ca2+稳态不平衡会引发细胞凋亡。因此，L-VGCC的精确调节对于感光器的存活和健康至关重要。这项研究的长期目标是了解导致光感受器昼夜节律的分子机制，以及这种节奏如何影响其生存和健康。该项目的目标是阐明microRNA（miRNA）如何整合到AKT信号传导中，以调节光感受器L-VGCC的昼夜节律，并揭示L-VGCC昼夜节律的功能意义，尤其是在细胞内CA2+稳态中。生物信息学分析，电生理学，分子 /生化测定和先进的高分辨率显微镜的组合将用于研究以下特定目的。目标1。阐明miRNA如何调节光感受器L-VGCC的昼夜节律。 AIM 2。研究夜间的明亮光多于白天更严重地引起光感受器的细胞凋亡。 AIM 3。确定动态三重奏-L-VGCC，视网膜感染素（RS1）和质膜CA2+ -ATPase（PMCA1）如何促进L-VGCCS和Ca2+稳态的膜保留。 L-VGCC，视网膜气概和PMCA1之间存在物理相互作用，但是这些相互作用的功能尚不清楚。这些研究的结果将揭示有关miRNA的新机制，并在离子通道和昼夜节律调节中综合与AKT相关的信号传导，以及光感受器L-vGCC的昼夜节律调节如何有助于Ca2+ CA2+稳态，细胞存活和照相水平。了解miRNA的新功能和综合信号通路最终将提供新知识，以预防受感光者死亡引起的失明。公共卫生相关性：拟议研究的结果将揭示新的机制，这些机制对于维持视网膜感受器健康和生存至关重要。拟议的研究与公共卫生有关，因为了解视网膜感受器中昼夜节律调节的细胞机制最终将提供知识，以制定新的策略来治疗眼部疾病，尤其是预防因黄斑变性引起的失明，因为视网膜中昼夜节律的破坏会导致光感受器死亡导致光感受器死亡，从而导致麦克拉尔·马西尔（Macuartar）导致麦克拉尔（Macuartar）。因此，本申请中提出的研究与NIH国家眼科研究所的一部分有关，以获得基本知识，这将有助于促进预防和治疗眼部疾病。