QUANTITATIVE IMAGING OF ZINC METABOLISM IN THE BRAIN

大脑中锌代谢的定量成像

• 批准号: 6625455
• 负责人: RICHARD Blair THOMPSON
• 金额: $ 28.8万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-17 至 2004-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6625455
• 关键词: bioimaging /biomedical imaging; brain imaging /visualization /scanning; brain metabolism; chemical binding; fluorescence spectrometry; intracellular transport; metal metabolism; microdialysis; sulfonamides; technology /technique development; tissue /cell culture; zinc

Zinc is a metal ion with many functions in the body, including roles in DNA recognition, recognition, enzymatic catalysis, and neural function. Among these, the role(s) of zinc in the brain are the least well understood, yet evidence is mounting that zinc plays a role in nerve cell death following stroke, Alzheimer's disease, epilepsy, and other forms of brain damage. The major goal of this proposal is to develop a group of optical probes for studying zinc in neural tissue by fluorescence microscopy employing our fluorescence-based biosensor technology. The fluorescence-based sensing technology utilizes the high selectivity and affinity of human apo-carbonic anhydrase for zinc; upon binding Zn(II), a covalent or noncovalent label on the protein exhibits changes in fluorescence intensity, wavelength, lifetime, and/or anisotropy. Fluorescence anisotropy microscopy offers significant advantages over wavelength-ratiometric and lifetime-based microscopies. The demonstrated advantages of this approach compared to other fluorescence probes for zinc are thousand-fold better sensitivity (down to picomolar zinc); insensitivity to Mg(II) at 50 mM, Ca at 10 mM, and most other metals; excitation at visible wavelengths, and high efficiency. Specific aims include quantitative imaging of zinc release from mossy fiber boutons in the hippocampus, imaging intracellular free zinc levels and fluxes in cultured cells, observing zinc release in vivo with a microdialysis technique, and developing probes for multiphoton-excitation microscopy.

锌是一种金属离子，具有许多功能，包括在DNA识别，识别，酶促催化和神经功能中的作用。其中，锌在大脑中的作用是最了解的，但有证据表明锌在中风后，阿尔茨海默氏病，癫痫和其他形式的脑损伤中起作用在神经细胞死亡中起作用。该提案的主要目的是通过使用我们的基于荧光的生物传感器技术的荧光显微镜来开发一组光学探针，用于研究神经组织中的锌。基于荧光的传感技术利用了人apo-钙循环酶对锌的高选择性和亲和力。结合Zn（II）后，蛋白质上的共价或非共价标记表现出荧光强度，波长，寿命和/或各向异性的变化。荧光各向异性显微镜比波长比率和基于寿命的显微镜具有显着优势。与锌的其他荧光探针相比，这种方法的优势是千倍的敏感性（降至皮摩尔锌）。在50毫米时对Mg（II）不敏感，Ca为10 mm，大多数其他金属；可见波长的激发和高效率。具体目的包括在海马中从苔藓纤维胸子中释放锌的定量成像，成像培养细胞中的细胞内游离锌水平和通量，并通过微透析技术在体内观察锌释放，并为多光子激素显微镜的探针开发探针。