Tissue Imaging Using Desorption Electrospray Ionization Mass Spectrometry

使用解吸电喷雾电离质谱进行组织成像

• 批准号: 7641837
• 负责人: Robert Graham Cooks
• 金额: $ 20.7万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7641837
• 关键词: Animals; Biological Markers; Brain; Characteristics; Charge; Chemicals; Complex; Computer-Assisted Image Analysis; Data; Degenerative Disorder; Detection; Development; Diagnosis; Disease; Environment; Future; Image; Imagery; In Situ; In Vitro; Label; Lesion; Lipids; Location; Maps; Mass Spectrum Analysis; Measurement; Measures; Methods; Molecular; Multiple Sclerosis; Mus; Myelin Sheath; Nature; Nerve; Nerve Degeneration; Nerve Sheaths; Nervous system structure; Optical Methods; Phospholipids; Positioning Attribute; Process; Protocols documentation; Raman Spectrum Analysis; Rattus; Reagent; Resolution; Sampling; Solvents; Spatial Distribution; Specificity; Spectrometry, Mass, Electrospray Ionization; Spinal Cord; Spottings; Techniques; Testing; Tissues; Work; biological systems; chemical reaction; computerized data processing; disease characteristic; functional group; imaging modality; improved; in vivo; interest; ionization; ionization technique; molecular recognition; outcome forecast; public health relevance; relating to nervous system; research study; tandem mass spectrometry; technology development; tumor

DESCRIPTION (provided by applicant): We propose to investigate the distribution of lipids in and near spinal cord tissue using direct examination of untreated tissue sections. The aim is to map the distribution of lipids characteristic of the myelin sheath in healthy mice and in animals with neural degenerative disease. It is expected that differences in less polar lipid distributions will occur and might be characteristic of disease state, but the spatial distribution in and near the nerves and the exact nature of the compounds that will be observed is unknown, since previous measurements have either been made with spectroscopic methods with limited molecular recognition capabilities (e.g. CARS) or with severely limited spatial resolution (e.g. extraction followed by LC-ESI-MS). One aim of the study is to identify lesions through changes in chemical composition and to correlate structural and chemical changes associated with lesions. This will be achieved by a combination of existing optical methods, especially coherent anti-Stokes raman spectroscopy (CARS) with new ambient mass spectrometry methods. The experiments will require the development of a high resolution (ca 10 micron) imaging capability for desorption electrospray ionization mass spectrometry (DESI-MS). DESI-MS is an ambient ionization method that allows rapid and direct chemical analysis of tissue sections with no prior sample treatment. In order to detect lipids with high sensitivity in the tissue matrix, capabilities for reactive DESI will need to be developed; this method involving in situ localized derivatization of the lipid using a charge-labeled reagent which is carried to the spot being interrogated by the spray solvent. Tandem mass spectrometry will be used to further improve the specificity of detection of the lipids of interest. The large amounts of molecular information obtained during MS/MS chemical imaging require comprehensive analysis using advanced data processing methods and new techniques for data representation and visualization, data searching and image comparisons will be implemented. In preliminary work at lower spatial resolution, DESI-MS has been demonstrated to allow differentiation of tumor and non-tumor sections of tissue through spatial distributions of polar lipids, especially phospholipids. Although this technique has many potential applications involving in-vitro and in-vivo chemical analysis for biological systems, in this R21 application, we concentrate on technology development aimed at providing the spatial and chemical information needed t characterize neural degeneration and specifically demyelin. PUBLIC HEALTH RELEVANCE: It is proposed to develop new imaging methods which can be used to identify lipids and other chemicals that might serve as biomarkers to follow the fundamental processes occurring in the course of neural diseases like multiple sclerosis (MS). Specific information on the chemical changes in the nerve sheath will be sought in order to allow future diagnosis and prognosis of neural diseases.

描述(由申请人提供)：我们建议通过直接检查未经处理的组织切片来调查脂质在脊髓组织及其附近的分布。其目的是绘制出具有髓鞘特征的脂质在健康小鼠和患有神经退行性疾病的动物中的分布。预计较低极性的脂质分布会出现差异，可能是疾病状态的特征，但神经内和神经附近的空间分布以及将观察到的化合物的确切性质尚不清楚，因为以前的测量要么是使用分子识别能力有限的光谱方法(例如CARS)，要么是空间分辨率严重受限(例如，提取后再进行LC-ESI-MS)。这项研究的目的之一是通过化学成分的变化来识别病变，并将与病变相关的结构和化学变化联系起来。这将通过将现有的光学方法，特别是相干反斯托克斯拉曼光谱(CARS)和新的环境质谱学方法相结合来实现。这些实验将需要开发高分辨率(约10微米)的解吸电喷雾电离质谱仪(DESI-MS)成像能力。DESI-MS是一种环境电离方法，允许对组织切片进行快速和直接的化学分析，而无需事先进行样品处理。为了检测组织基质中高灵敏度的脂类，需要开发反应DESI的能力；这种方法包括使用电荷标记试剂对脂类进行原位局部衍生化，该试剂被带到喷雾溶剂询问的地点。串联质谱仪将被用来进一步提高检测目标脂类的特异性。在MS/MS化学成像过程中获得的大量分子信息需要使用先进的数据处理方法和新的数据表示和可视化技术进行综合分析，并将实现数据搜索和图像比较。在较低空间分辨率的初步工作中，DESI-MS已被证明可以通过极性脂类，特别是磷脂的空间分布来区分肿瘤和非肿瘤组织切片。尽管这项技术有许多潜在的应用，包括生物系统的体外和体内化学分析，但在R21的应用中，我们专注于技术开发，旨在提供表征神经变性和特定脱髓鞘蛋白所需的空间和化学信息。公共卫生相关性：建议开发新的成像方法，可用于识别可能用作生物标记物的脂质和其他化学物质，以跟踪多发性硬化症(MS)等神经疾病病程中发生的基本过程。将寻求关于神经鞘中化学变化的具体信息，以便将来能够诊断和预测神经疾病。