Mapping Functional Heterogeneity in Tissue

绘制组织中的功能异质性

• 批准号: 10018055
• 负责人: MICHAEL GAMCSIK
• 金额: $ 18.25万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-15 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10018055
• 关键词: 4T1; Address; Affect; Back; Biochemical Pathway; Biological Assay; Biopsy Specimen; Carbon; Chronic; Clinical; Data; Dependence; Detection; Diagnosis; Diagnostic; Disease; Freezing; Functional Imaging; Genomics; Genotype; Glutathione; Glycine; Harvest; Heterogeneity; Hypoxia; Image; Information Systems; Infusion procedures; Isotope Labeling; Isotopes; Kinetics; Label; Link; Liver; Liver neoplasms; Location; Magnetic Resonance Imaging; Mammary Neoplasms; Mammary gland; Maps; Mass Spectrum Analysis; Measures; Medical; Metabolic; Metabolism; Methods; Microtomy; Molecular; Molecular Profiling; Monitor; Mus; Oxidation-Reduction; Pathway interactions; Patients; Perfusion; Phenotype; Pimonidazole; Positron-Emission Tomography; Prevention; Proteins; Public Health; Reporting; Resolution; Sampling; Serine; Spatial Distribution; Specific qualifier value; Spectrum Analysis; Structure; Systems Biology; Techniques; Testing; Time; Tissue Harvesting; Tissue Sample; Tissues; Tumor Tissue; Urea; Work; base; clinical diagnostics; clinical examination; diagnostic assay; experimental study; genetic signature; imaging modality; improved; isotope incorporation; metabolic rate; precision medicine; prognostic; stable isotope; tool; tumor

ABSTRACT Abstract: Mass spectrometry imaging (MSI) provides unprecedented detail of molecular distributions across ex vivo tissue samples. Although MSI has the capability to map molecules ranging from large proteins to small metabolites, these data only describe the tissue status at a single time point and lack any information on how these molecules interact to provide metabolic function. Typical functional studies derive kinetic data from administration of isotope-labeled substrates and monitoring label transit in tissue samples harvested over a specified time-course. Isotope kinetics tracked by MSI, however, have some unique requirements to in order to perform a similar functional study and exploit the full power of the technique to provide location-specific metabolite flux. This proposal will develop an MSI-based method to track isotope metabolic activity through the use of a timed infusion of isotopologues of glycine to measure the rate of glutathione and serine metabolic flux within each 50 x 50 x 10 m image voxel. This timed infusion allows a voxel-by-voxel determinations of metabolic rates, i.e. functional images that are not possible by other methods. In addition, since metabolic flux and pathway selection is influenced both by tissue perfusion and oxygenation, we also will develop MSI-based methods to measure tissue perfusion and hypoxia in the same samples. Isotopologues of pimonidazole will be used to map regions of both chronic and cycling hypoxia that can be tied directly to glutathione metabolic activity. To demonstrate the feasibility of these techniques in different tissue types, we will map functional heterogeneity across mouse liver and mammary 4T1 tumors. As the MSI method uses frozen thin-sections, histochemical data from adjacent sections can be used to tie traditional tissue markers to metabolic function. The methods described herein will be demonstrated on the glutathione and serine pathways but can be used to study functional heterogeneity in any tissue and any metabolic network with proper selection of substrates.

抽象的 摘要：质谱成像（MSI）提供了前所未有的分子分布细节。 体内组织样本。尽管 MSI 能够绘制从大蛋白质到小蛋白质的分子图谱 代谢物，这些数据仅描述单个时间点的组织状态，并且缺乏关于如何代谢的任何信息 这些分子相互作用以提供代谢功能。典型的功能研究从以下来源获得动力学数据 管理同位素标记的底物并监测在一段时间内收获的组织样本中的标记转运 指定的时间进程。然而，MSI 跟踪的同位素动力学有一些独特的要求，以便 进行类似的功能研究并充分利用该技术的力量来提供特定于位置的 代谢通量。该提案将开发一种基于 MSI 的方法，通过 使用甘氨酸同位素体的定时输注来测量谷胱甘肽和丝氨酸代谢通量的速率 在每个 50 x 50 x 10 μm 图像体素内。这种定时输注允许逐个体素地测定代谢 率，即其他方法无法实现的功能图像。此外，由于代谢通量和途径 选择受到组织灌注和氧合的影响，我们还将开发基于 MSI 的方法 测量同一样本中的组织灌注和缺氧。哌莫硝唑的同位素体将用于绘制图谱 慢性缺氧和循环缺氧区域可能与谷胱甘肽代谢活动直接相关。到 证明这些技术在不同组织类型中的可行性，我们将绘制功能异质性图 跨越小鼠肝脏和乳腺 4T1 肿瘤。由于 MSI 方法使用冷冻薄片，因此组织化学数据 来自相邻切片的数据可用于将传统组织标记物与代谢功能联系起来。所描述的方法 本文将在谷胱甘肽和丝氨酸途径上进行演示，但可用于研究功能 通过适当选择底物，任何组织和任何代谢网络中的异质性。