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跟踪不稳定锌的时间和位置依赖性通量 中枢神经系统。在突触前谷氨酸能神经元中储存在囊泡中的锌 海马在生理刺激后释放出来，在 神经传递。大脑中不受控制的Zn2+释放与损害有关 癫痫发作，缺血和钝头创伤。为了研究这些神经化学现象，锌 - 响应式传感器将被准备，表征和引入细胞，包括主要的传感器 神经元培养物和脑组织以量化Zn2+存储，识别其目标并跟踪其目标 在功能和病理条件下动员。设计，合成，表征， 传感器的利用构成了该研究项目的主要组成部分。每个语音 最多有三个模块。最少，将有锌结合和锌报告的单元。这 绑定模块通常包含具有可变Zn2+亲和力的多齿配体，选择性 Zn2+在神经元组织中的竞争离子和快速，可逆协调以监测生物学 MSEC时间尺度的变化。锌报告的模块将是荧光团，用于广泛的 场和共聚焦显微镜，对结合离子有反应。记者主要是荧光素 以及相关的构造，因为它们的亮度，光稳定性以及较长的激发和发射 波长，但还将追求荧光JT偶联的聚合物。传感器进行监视 还提出了磁共振成像（MRI）的锌。尽管分辨率较低，但MRI具有 它可以应用于活动物的优势。两种锌响应锰（LLL）卟啉 并为提案的这一方面引入了Salen结构。采用策略 将可选的第三模块附加以将基于荧光或MRI的锌传感器定位到特定 细胞靶标。以这种方式，传感器可用于研究谷物的Zn2+动力学。 在生理学或生理学或细胞内细胞器上的染色受体 病理刺激。该项目与公共卫生有关，因为它将提供测试的信息 关于Zn2+在大脑中功能以及评估Zn2+功能的理论 假定不受控制的锌水平与神经退行性疾病的关联，例如 阿尔茨海默氏症，还有更多急性有毒脑病。设计的化学反应也将有助于 开发体内测量自由锌（PZN）的工具，并可能有助于制定 诊断，治疗和预防Zn2+诱导的神经系统的策略。