Spatial Analysis of Molecules in Tissue using MALDI-MS

描述(申请人提供)：拟议研究的目标是将高分辨率三维成像质谱学(IMS)技术发展到能够在实际时间范围内提供高分辨率图像的水平。高空间分辨率IMS(~10um)将与提供1微米矩阵晶体尺寸和高速激光(0.3 kHz)的组织制备方案一起使用，以有效和及时地提供多个连续切片的数据。它计划开发一种方案，允许以3D方式在组织体积中跟踪肽、蛋白质、脂类、药物和其他小分子。此外，计划完成以下工作所需的重大生物计算工作：处理数据维度和尺寸缩减、在单个2-D实验内和用于3-D重建的组织体积的连续切片之间的图像的相对定量的离子强度的归一化、具有解剖保真度的切片的配准以及在实际时间域中生成单个分子的3-D图像。这项技术将解决几个重要的生物学问题：1)评估小鼠大脑纹状体中纹状体的3-D分子分布和边界，与帕金森氏症、亨廷顿病和强迫症等神经精神障碍有关的亚结构；2)肿瘤和微环境中胶质瘤生长、进展和维持的分子事件的3-D图谱；3)与脑图谱中现有的3-D显微镜图像相关联的小鼠模型视神经中的3-D IMS数据的共同配准；用于PET成像的造影剂的配置和代谢的研究，磁共振扩散加权成像中分子方面的阐明，以及IMS获得的分子事件与磁共振弛豫数据的共同配准/关联。这项工作将把几种强大的成像方式结合在一起，并通过每种方式的独特属性，在理解整个组织动力学方面获得组合优势。在一个目标中，它计划将显微镜和IHC测量、MRI和IMS结合起来，作为一个单独的3D体积的一部分，可以使用标准的互联网工具轻松地进行查询。

DESCRIPTION (provided by applicant): The goal of the proposed studies is to develop high resolution 3-D Imaging Mass Spectrometry (IMS) technology to a level that it is capable of delivering high resolution images in a practical time frame. High spatial resolution IMS (~10 um) will be employed with tissue preparation protocols that provide 1 um matrix crystal sizes and high speed lasers (.3 kHz) to provide data on multiple serial sections in a efficacious and timely manner. It is planned to develop the protocols that would allow peptides, proteins, lipids and drugs and other small molecules to be tracked in a 3-D manner in a tissue volume. In addition, work is planned to accomplish the significant biocomputational effort needed to deal with data dimensionality and size reduction, normalization of ion intensities for the relative quantitation of images both within a single 2-D experiment and across serial sections of a tissue volume for 3-D reconstruction, registration of the sections with anatomic fidelity, and generation of a 3-D images of individual molecules in a practical time domain. Several important biological problems will be addressed with this technology; 1) assessment of the 3-D molecular distributions and boundaries of striosomes in the striatum of the mouse brain, substructures implicated in neuropsychiatric disorders such as Parkinsonism, Huntington's Disease, and obsessive-compulsive disorder, 2) 3-D mapping of molecular events in glioma growth, progression, and maintenance, both in the tumor and microenvironment, in the optic nerve of a mouse model with linkage to existing 3-D microscopy images in the brain atlas, 3) Co-registration of 3-D IMS data with other imaging modalities; studies of the disposition and metabolism of contrast agents used for PET imaging, the elucidation of molecular aspects in diffusion weighted imaging by MRI, and the co-registration/correlation of molecular events obtained by IMS with MR relaxation data. This work will bring together several powerful imaging modalities and, through the unique attributes of each, gain a combinatorial advantage in understanding whole tissue dynamics. In one aim, it is planned to combine microscopy and IHC measurements, MRI and IMS as part of a single 3-D volume that is easily interrogated using standard internet tools.