Investigation of Zinc Neurochemistry by Fluorescent Sensing and MRI

通过荧光传感和 MRI 研究锌神经化学

• 批准号: 7583949
• 负责人: Stephen J. Lippard
• 金额: $ 29.6万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7583949
• 关键词: Acute; Adopted; Affinity; Age; Alzheimer' s Disease; Amines; Animals; Binding; Biochemical Reaction; Biological Monitoring; Brain; Brain region; Cells; Chemicals; Chemistry; Collaborations; Color; Confocal Microscopy; Contrast Media; Craniocerebral Trauma; Diagnosis; Drug Formulations; Electron Transport; Event; Fiber Optics; Figs - dietary; Fluorescein; Fluoresceins; Fluorescence; Functional Magnetic Resonance Imaging; Glutamates; Goals; Golgi Apparatus; Hippocampus (Brain); Housing; Image; Imaging Techniques; In Vitro; Investigation; Ions; Ischemia; Kinetics; Laboratories; Learning; Life; Ligands; Magnetic Resonance Imaging; Manganese; Measures; Memory; Metals; Microscopic; Mitochondria; Monitor; Nature; Nerve; Neuraxis; Neurodegenerative Disorders; Neurons; Nitrilotriacetic Acid; Organelles; Permeability; Physiological; Polymers; Porphyrins; Positioning Attribute; Process; Property; Psychological Techniques; Public Health; Reagent; Reporter; Reporting; Research; Research Personnel; Research Project Grants; Resolution; Rodent; Roentgen Rays; Role; Seizures; Simulate; Solid; Spatial Distribution; Spectrum Analysis; Structure; Study models; Testing; Thermodynamics; Time; Tissues; Toxic Encephalopathy; Toxic effect; Trauma; Upper arm; Vesicle; Water; Zinc; absorption; appendage; base; biological systems; brain tissue; cellular targeting; computer studies; controlled release; design; electronic structure; extracellular; fluorophore; in vivo; millisecond; monomer; nervous system disorder; neurochemistry; neurotransmission; photolysis; postsynaptic; presynaptic; prevent; programs; receptor; research study; response; restoration; salen; sensor; success; synchrotron radiation; theories; tool development; uptake

The long-term goal of this research is to track the time- and position-dependent flux of labile zinc in the central nervous system. Zinc stored in vesicles at presynaptic glutamatergic neurons in the hippocampus is released upon physiological stimulation to perform an undefined role in neurotransmission. Uncontrolled Zn2+ release in the brain is associated with damage following seizure, ischemia, and blunt head trauma. In order to study these neurochemical phenomena, zinc- responsive sensors will be prepared, characterized, and introduced into cells, including primary neuron cultures, and brain tissue to quantify Zn2+ stores, identify its targets, and track its mobilization under functional and pathological conditions. The design, synthesis, characterization, and utilization of the sensors constitute a major component of this research project. Eachsensor will have up to three modules. Minimally, there will be zinc-binding and zinc-reporting units. The binding module typically comprises multidentate ligands with variable Zn2+ affinity, selectivity for Zn2+ over competing ions in neuronal tissue, and fast, reversible coordination to monitor biological changes on the msec time scale. The zinc-reporting module will be a fluorophore, for use in wide- field and confocal microscopy, that responds to the bound ion. The reporters are mostly fluorescein and related constructs because of their brightness, photostability, and long excitation and emission wavelengths, but fluorescent jt-conjugated polymers will also be pursued. Sensors for monitoring zinc by magnetic resonance imaging (MRI) are proposed as well. Despite lower resolution, MRI has the advantage that it can be applied in live animals. Both zinc-responsive manganese(lll) porphyrin and salen constructs are introduced for this aspect of the proposal. Strategies are adopted for attaching an optional third module to localize a fluorescence- or MRI-based zinc sensor to specific cellular targets. In this manner, the sensors can be used to investigate Zn2+ dynamics at glutama- tergic receptors on postsynaptic neurons and at intracellular organelles following physiological or pathological stimulation. This project is relevant to public health, for it will provide information to test theories about the functions of Zn2+ in the brain as well as the means by which to evaluate the postulated association of uncontrolled zinc levels with neurodegenerative diseases, such as Alzheimer's, and with more acute toxic encephalopathies. The chemistry devised will also facilitate the development of tools to measure free zinc (pZn) in vivo and may assist in the formulation of strategies for diagnosing, treating, and preventing Zn2+-induced neurological.damage.

这项研究的长期目标是追踪不稳定锌的时间和位置依赖性通量。 中枢神经系统。锌储存在突触前谷氨酸能神经元的囊泡中 海马体在生理刺激下被释放，以执行不确定的作用 神经传递。大脑中不受控制的 Zn2+ 释放与以下损伤有关 癫痫发作、缺血和钝性头部创伤。为了研究这些神经化学现象，锌- 响应传感器将被制备、表征并引入到细胞中，包括初级细胞 神经元培养物和脑组织来量化 Zn2+ 储存、识别其目标并跟踪其 功能和病理条件下的动员。设计、合成、表征、 传感器的使用和使用构成了该研究项目的主要组成部分。每个传感器 最多将有三个模块。至少会有锌结合单元和锌报告单元。这 结合模块通常包含具有可变 Zn2+ 亲和力、选择性的多齿配体 Zn2+ 与神经元组织中的竞争离子进行快速、可逆协调以监测生物 毫秒时间尺度上的变化。锌报告模块将是一种荧光团，用于广泛的 场和共焦显微镜，对结合离子做出反应。记者们大多是荧光素 和相关结构，因为它们的亮度、光稳定性以及长激发和发射 波长，但荧光 jt 共轭聚合物也将被追求。监控传感器 还提出了通过磁共振成像（MRI）检测锌。尽管分辨率较低，MRI 其优点是可以应用于活体动物。锌响应型锰(III)卟啉 和 salen 结构是针对提案的这方面引入的。采取的策略是 连接可选的第三个模块，将基于荧光或 MRI 的锌传感器定位到特定的位置 细胞目标。通过这种方式，传感器可用于研究谷氨酰胺-的 Zn2+ 动力学。 突触后神经元和细胞内细胞器上的特能受体在生理或 病理刺激。该项目与公共卫生相关，因为它将提供测试信息 关于 Zn2+ 在大脑中的功能的理论以及评估 Zn2+ 的方法 假设不受控制的锌水平与神经退行性疾病有关，例如 阿尔茨海默病，以及更急性的中毒性脑病。所设计的化学也将促进 开发体内测量游离锌 (pZn) 的工具，并可能有助于制定 诊断、治疗和预防 Zn2+ 引起的神经损伤的策略。