Magnitude Improvement of Molecular Signaling Imaging (RMI)

分子信号成像 (RMI) 的巨大改进

• 批准号: 7478124
• 负责人: HOWARD J HALPERN
• 金额: $ 32.31万
• 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 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7478124
• 关键词: Adenovirus Vector; Animals; Arginine; Binding Proteins; Binding Sites; Biological; Cells; Collaborations; Dendrimers; Depth; Detection; Development; Electron Spin Resonance Spectroscopy; Endopeptidases; Engineering; Evaluation; Evolution; Facility Construction Funding Category; Frequencies; Gelatinase A; Genes; Genetic Transcription; Glycine; Goals; Growth; Heterogeneity; Human; Hypoxia; Hypoxia Inducible Factor; Hypoxia-Responsive Elements; Image; Injection of therapeutic agent; Leucine; Life; Link; MMP2 gene; Mammals; Measurement; Measures; Mediating; Medical; Modality; Molecular; Monitor; Mus; Normal tissue morphology; Numbers; Optics; Organism; Other Imaging Modalities; Oxygen; Peptide Hydrolases; Peptides; Personal Satisfaction; Physiology; Play; Process; Production; Proline; Proteins; Radiation; Research Personnel; Resolution; Risk; Role; Signal Induction; Signal Pathway; Signal Transduction; Signaling Molecule; System; Techniques; Technology; Testing; Tetracycline; Tetracyclines; Tissues; Translating; Valine; Viral Vector; Work; animal tissue; aspergillopepsin II; cellular imaging; computerized data processing; environmental change; image visualization; in vivo; insight; molecular imaging; monomer; novel; programs; promoter; response; size; tumor; 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的方式提供了新的见解。对哺乳动物细胞信号传导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) 成像为小鼠提供了新颖的高分辨率氧气图像。具有光学检测的分子成像的深度灵敏度有限，使得在较大动物中进行测量变得困难。其他技术也受到各种限制。我们在此建议探索低频 EPR 成像，在组织深处具有敏感性，以检测缺氧肽信号分子的诱导，作为细胞信号传导的一个例子。 EPR 图像的独特特征包括低信号背景、小型哺乳动物的高空间分辨率（1 毫米或更低）、放大到较大动物的前景以及动物组织深处的敏感性，这些特征使该技术与众不同并鼓励其探索。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发挥着重要作用。这项工作将涉及构建 EPR 自旋探针，将其注射到动物体内，该探针在遇到蛋白酶 (MMP2) 之前保持沉默。它还涉及将 HIF1α 结合蛋白启动子上游的 MMP2 基因构建体工程化到病毒载体中。然后病毒载体将用于 1) 感染肿瘤细胞或 2) 周围正常组织。肿瘤或组织缺氧会刺激 HIF-1α 结合蛋白的产生，从而刺激 MMP2 的产生，从而激活沉默的自旋探针。 然后获得 EPR 氧气图像，以关联活体动物肿瘤中触发缺氧细胞信号传导的缺氧水平。这将提供体内缺氧信号阈值的测量。这种技术有望提高分辨率和灵敏度的数量级