Magnitude Improvement of Molecular Signaling Imagin(RMI)

分子信号成像（RMI）的大幅改进

• 批准号: 6965087
• 负责人: HOWARD J HALPERN
• 金额: $ 31.72万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6965087
• 关键词: Adenoviridae; athymic mouse; bioimaging /biomedical imaging; biological signal transduction; cell line; collagenase; electron spin resonance spectroscopy; hypoxia inducible factor 1; laboratory rabbit; laboratory rat; molecular /cellular imaging; technology /technique development; transfection /expression vector

DESCRIPTION (provided by applicant): The recent definition of cellular signaling pathways has provided new insight into the means by which multi-cellular organisms coordinate a transcriptional response to environmental change. Imaging cellular signaling in mammals will provide insight into the factors that modulate these signals in vivo. Electron Paramagnetic Resonance (EPR) imaging has provided novel, high resolution oxygen images in mice. Molecular imaging with optical detection has limited depth sensitivity making measurements in larger animals difficult. Other techniques suffer from various limitations. We propose here to explore low frequency EPR imaging, with sensitivity deep in tissues, to detect, as an example of cellular signaling, the induction of hypoxia peptide signal molecules. Unique features of EPR images including low signal background, high spatial resolution (1 mm or less) in small mammals, the promise of scaling to larger animals and sensitivity deep in animal tissues distinguish this technique and encourage its exploration. Hypoxia Inducible Factor (HIF) proteins play a major role in controlling and coordinating the response of cells and organisms to hypoxia. The work will involve the construction of an EPR spin probe, to be injected into the animal, which is silent until it encounters a proteinase (MMP2). It will also involve the engineering of an MMP2 gene construct just upstream of the HIF1alpha binding protein promoter into a viral vector. The viral vector will then be used to 1) infect cells in tumors or 2) surrounding normal tissues. Tumor or tissue hypoxia will stimulate production of HIF-1alpha binding protein which will stimulate the production of MMP2 which will activate the silent spin probe. EPR oxygen images will then be obtained to correlate the levels of hypoxia at which hypoxic cell signaling is triggered in the tumors of a living animal. This will provide a measure of the in vivo threshold for hypoxic signaling. Such a technology promises order of magnitude improvements of resolution and sensitivity

描述（由申请人提供）：细胞信号传导途径的最新定义为多细胞生物体协调对环境变化的转录反应提供了新的见解。对哺乳动物的细胞信号进行成像将有助于深入了解体内调节这些信号的因素。电子顺磁共振（EPR）成像提供了新的，高分辨率的小鼠氧气图像。具有光学检测的分子成像具有有限的深度灵敏度，使得在较大动物中的测量变得困难。其他技术受到各种限制。我们建议在这里探索低频EPR成像，在组织深处的灵敏度，检测，作为细胞信号传导的一个例子，缺氧肽信号分子的诱导。EPR图像的独特功能，包括低信号背景，小哺乳动物的高空间分辨率（1 mm或更小），缩放到较大动物的前景和动物组织深处的灵敏度，区分这种技术，并鼓励其探索。缺氧诱导因子（HIF）蛋白在控制和协调细胞和生物体对缺氧的反应中起主要作用。这项工作将涉及EPR自旋探针的构建，将其注射到动物体内，直到遇到蛋白酶（MMP 2）才沉默。它还将涉及将位于HIF 1 α结合蛋白启动子上游的MMP 2基因构建体工程改造到病毒载体中。然后，病毒载体将用于1）感染肿瘤中的细胞或2）周围的正常组织。肿瘤或组织缺氧将刺激HIF-1 α结合蛋白的产生，HIF-1 α结合蛋白将刺激MMP 2的产生，MMP 2将激活沉默的自旋探针。 然后将获得EPR氧图像，以关联在活体动物的肿瘤中触发缺氧细胞信号传导的缺氧水平。这将提供缺氧信号传导的体内阈值的量度。这样的技术保证了分辨率和灵敏度的数量级改进