Magnitude Improvement of Molecular Signaling Imaging (RMI)

分子信号成像 (RMI) 的巨大改进

• 批准号: 7140393
• 负责人: HOWARD J HALPERN
• 金额: $ 32.07万
• 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/7140393
• 关键词: Adenoviridae; NIH Roadmap Initiative tag; 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）：细胞信号通路的最新定义为多细胞生物提供了对环境变化的转录响应的方式提供了新的见解。哺乳动物中的成像细胞信号传导将洞悉在体内调节这些信号的因素。电子顺磁共振（EPR）成像已在小鼠中提供了新颖的高分辨率氧图像。具有光学检测的分子成像具有有限的深度敏感性，因此在较大动物中的测量很困难。其他技术受到各种局限性。我们在这里提议探索低频EPR成像，并在组织中深处敏感性，以检测细胞信号传导的一个例子，即诱导缺氧肽信号分子的诱导。 EPR图像的独特特征，包括低信号背景，小型哺乳动物中的高空间分辨率（1 mm或更少），将缩放到大型动物的承诺以及动物组织深处的敏感性区分了这种技术并鼓励其探索。低氧诱导因子（HIF）蛋白在控制和协调细胞和生物对缺氧的反应方面起主要作用。这项工作将涉及将EPR旋转探针的构造，该探针被注射到动物中，直到它遇到蛋白酶（MMP2）。它还将涉及HIF1Alpha结合蛋白启动子上游的MMP2基因构建体的工程化，成为病毒载体。然后，病毒载体将用于1）感染肿瘤中的细胞或2）周围正常组织。肿瘤或组织缺氧将刺激HIF-1Alpha结合蛋白的产生，这将刺激MMP2的产生，这将激活无声的自旋探针。 然后将获得EPR氧图像，以将在活动物的肿瘤中触发低氧细胞信号传导的缺氧水平相关。这将提供低氧信号的体内阈值的度量。这样的技术有望改善分辨率和灵敏度的数量级