Circadian Rhythm In Cone Photoreceptors: Cellular Mechanisms

视锥细胞感光器的昼夜节律：细胞机制

• 批准号: 7384427
• 负责人: GLADYS Y KO
• 金额: $ 27.81万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7384427
• 关键词: 1-Phosphatidylinositol 3-Kinase; Actins; Age related macular degeneration; Blindness; Calcium Channel; Cell membrane; Cellular biology; Cessation of life; Circadian Rhythms; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyclic GMP; Cytoskeleton; DNA Sequence Rearrangement; Data; Defect; Development; Disease; Disruption; Event; Future; Gated Ion Channel; Genes; Goals; Human; Image; Institutes; Knowledge; L-Type Calcium Channels; Lead; MEKs; Macular degeneration; Mediating; Medical; Mitogen-Activated Protein Kinases; Molecular; Mutation; Neurons; Night Blindness; Output; Pathogenesis; Pathway interactions; Periodicity; Phase; Phosphatidylinositide 3-Kinase Inhibitor; Phosphatidylinositols; Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide; Phosphotransferases; Photoreceptors; Physiology; Play; Polymerase Chain Reaction; Proteins; Regulation; Research; Retina; Retinal Cone; Retinal Degeneration; Retinal Diseases; Reverse Transcriptase Polymerase Chain Reaction; Role; Signal Pathway; Signal Transduction; Somatostatin; Stream; Techniques; Time; Transfection; United States; Vision; Visual impairment; Western Blotting; Work; base; calmodulin-dependent protein kinase II; circadian pacemaker; day; immunocytochemistry; inhibitor/antagonist; intracellular protein transport; neurotransmission; neurotransmitter release; novel; patch clamp; prevent; protein expression; protein transport

DESCRIPTION (provided by applicant): Macular degeneration is a major cause of visual impairment in the United States and is associated with the death of cone photoreceptors. The pathogenesis and the cellular events responsible for the distortion of central vision in macular degeneration are not understood. Circadian oscillators in retina photoreceptors are known to play important roles in regulating photoreceptor function and physiology, and disruption of these circadian oscillators leads to the death of photoreceptors and could contribute to the pathogenesis of macular degeneration. The objective of the proposed research is to elucidate the signaling pathways from the circadian oscillators leading to the regulation of L-type voltage-dependent calcium channels (VDCCs) in cone photoreceptors, since the L-type VDCCs are essential in regulating neurotransmitter release in the retina. For example, mutation of the L-type VDCC a1f subunit gene causes incomplete congenital stationary night blindness in humans, with a defect in neurotransmission between photoreceptors and second-order neurons. An integrative approach with multiple techniques including electrophysiological patch-clamp recordings, Western immunoblotting, immunocytochemistry with confocal imaging, quantitative real-time RT- PCR and gene transfection, will be used in this application to achieve the following four specific aims: Specific Aim 1. Characterize the circadian rhythmicity of VDCCs in chick cone photoreceptors. The circadian rhythmicity of L-type VDCCs at multiple time points throughout the entire circadian day will be characterized in detail. Specific Aim 2. Identify the cellular signaling pathways underlying the circadian regulation of VDCCs. The roles of PKA, MAP kinase, CaMKII and PI3 kinase as output pathways leading to the circadian regulation of VDCCs will be determined. Specific Aim 3. Elucidate the roles of actin cytoskeleton rearrangement and protein trafficking on circadian regulation of VDCCs. Specific Aim 4. Define the cellular mechanisms of the phase-dependent modulation of VDCCs by somatostatin. While somatostatin serves as a VDCC inhibitor in other neurons, it shows both phase-dependent enhancement and inhibition of L-type VDCCs in cones. This project will be among the very first studies to define the circadian regulation of L-type VDCCs and their molecular mechanisms in retina photoreceptors. Understanding the molecular signaling of circadian regulation of retina function may ultimately provide knowledge for developing new strategies to treat retinal diseases, especially age-related macular degeneration, and preventing blindness in the future, which are the long-term goals of the PI.

描述（由申请人提供）：黄斑变性是美国视觉障碍的主要原因，与锥形感受器的死亡有关。尚不清楚导致黄斑变性中中央视力扭曲的发病机理和细胞事件。已知视网膜光感受器中的昼夜节律振荡器在调节光感受器功能和生理学中起重要作用，这些昼夜节律振荡器的破坏会导致光感受器的死亡，并可能有助于黄斑退化的发病机理。拟议的研究的目的是阐明从圆锥体光感受器调节L型电压依赖性钙通道（VDCC）的昼夜节律振荡器的信号传导途径，因为L型VDCCS在调节Retina的神经递质释放中至关重要。例如，L型VDCC A1F亚基基因的突变会导致人类的先天性固定夜间失明，并且在光感受器和二阶神经元之间存在神经传递缺陷。 An integrative approach with multiple techniques including electrophysiological patch-clamp recordings, Western immunoblotting, immunocytochemistry with confocal imaging, quantitative real-time RT- PCR and gene transfection, will be used in this application to achieve the following four specific aims: Specific Aim 1. Characterize the circadian rhythmicity of VDCCs in chick cone photoreceptors. L-Type VDCC在整个昼夜节日的多个时间点上的昼夜节律将详细介绍。具体目标2。确定VDCC昼夜调节的基础的细胞信号通路。将确定PKA，MAP激酶，CAMKII和PI3激酶作为导致VDCC昼夜调节的输出途径的作用。具体目的3。阐明肌动蛋白细胞骨架重排和蛋白质运输对VDCC的昼夜节律调节的作用。特定目的4。定义生长抑素对VDCC相位依赖性调制的细胞机制。虽然生长抑素在其他神经元中充当VDCC抑制剂，但它既显示出锥体中L型VDCC的相位依赖性增强和抑制作用。该项目将是定义L型VDCC的昼夜节律调节及其分子机制的最早研究之一。了解视网膜功能的昼夜节律调节的分子信号传导最终可以为制定新的策略来治疗视网膜疾病，尤其是与年龄相关的黄斑变性，并预防未来的失明，这是PI的长期目标。