Real-time tracking of single cells in live animals

实时追踪活体动物的单细胞

基本信息

批准号：
8930185
负责人：
Guillem Pratx
金额：
$ 24.09万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-19 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8930185
关键词：
Accounting Acute myocardial infarction Algorithms Animal Model Animals Behavior Biomedical Research Bone Marrow Cardiac Cardiovascular system Cause of Death Cell Therapy Cell Transplantation Cell Transplants Cells Clinical Clinical Research Computer Simulation Data Diabetes Mellitus Direct Costs Engraftment Ensure Facilities and Administrative Costs Fluorescence Goals Health Heart Heart Diseases Heart failure Home environment Homing Image Imaging Device Immune System Diseases Individual Injury Intervention Investigation Knowledge Label Life Malignant Neoplasms Measurement Medicine Methods Microscopy Mononuclear Mus Myocardial Infarction Operative Surgical Procedures Organism Outcome Patients Play Population Positron-Emission Tomography Protocols documentation Public Health Radioactivity Radiolabeled Research Research Personnel Research Project Grants Resolution Role Site Source Staging Stem cell transplant System Techniques Testing Time Tissues Transplantation United States Work base computer generated functional outcomes human disease image reconstruction imaging modality improved in vivo injured innovation insight instrumentation millimeter molecular imaging mouse model nervous system disorder novel pre-clinical prevent radiotracer reconstruction regenerative therapy simulation spatiotemporal tool trafficking

项目摘要

DESCRIPTION: Regenerative therapies based on stem cell transplantation hold great clinical promise, particularly for patients with damaged hearts and end-stage heart failure. Imaging plays an important role in these therapies by tracking the fate of the transplanted cells. However, existing imaging methods can only visualize where large groups of transplanted cells accumulate and not how single cells arrive there. The limited capabilities of these imaging tools prevent us from fully understanding the fate and dynamic behavior of single transplanted cells. Improving the efficiency and functional outcomes of cell-based therapies is a long-term goal of cardiovascular research. Our objective in this proposal is to develop a new imaging approach that can follow single transplanted cells in real time as they home to sites of cardiac injury. Our hypothesis is that, under certain conditions, micro positron emission tomography (microPET) can track single transplanted cells in live mice, with sub-millimeter spatial resolution and sub-second time resolution. These capabilities of microPET have not been explored yet because previous studies have exclusively relied on conventional reconstruction algorithms to track radiolabelled cells. By leveraging the knowledge that only a sparse set of cells contain radioactivity, it is possible to formulate an algorithm for reconstruction single cell trajectories from microPET measurements with much higher sensitivity and spatial resolution. The rationale for the proposed research is that tracking single cells in vivo at the whole-body level will allow for far more detailed insight into the dynamic behavior and fate of transplanted cells and their interaction with injured heart tissue than conventional bulk-tissue techniques. Our preliminary simulations indicate that a single cell labeled with 1-10 Bq can be tracked with microPET in vivo. We will test our hypothesis by pursuing the following two aims: (1) Expand trajectory reconstruction to track multiple single cells in parallel; and (2) Optimize cell labeling and track single cells in vivo. In the first aim, we will implement a new reconstruction algorithm that takes raw list-mode data from a small-animal PET scanner and reconstructs spatiotemporal trajectories for multiple single cells, in parallel. In the second aim, we will optimize radionuclie labeling of bone-marrow mononuclear cells to achieve 10 Bq/cell. We will then track the homing of these single cells to sites of cardiac injury in a mouse model of myocardial infarction. The reconstruction algorithm we plan to develop is innovative because, unlike previous algorithms, it accounts for the fact that radioactivity is only contained within the transplanted cells; thus it ues all available measurements in an optimal way. The proposed research project is significant because reconstructing the spatiotemporal trajectory of transplanted cells at the whole-body level would provide unprecedented information on the dynamics of cell trafficking in living organisms and could be applied to improve cell transplantation protocols for more efficient cell engraftment.

描述：基于干细胞移植的再生疗法具有巨大的临床承诺，特别是对于患有损坏的心脏和终末期心力衰竭的患者。成像通过跟踪移植细胞的命运在这些疗法中起重要作用。但是，现有的成像方法只能可视化大量移植细胞积聚而不是单个细胞如何到达那里的地方。这些成像工具的有限能力使我们无法完全了解单个移植细胞的命运和动态行为。提高基于细胞的疗法的效率和功能结果是心血管研究的长期目标。我们在此提案中的目标是开发一种新的成像方法，该方法可以实时跟随单个移植细胞，因为它们会回到心脏损伤部位。我们的假设是，在某些条件下，微孔识别发射断层扫描（MicroPET）可以跟踪活小鼠中的单个移植细胞，并具有亚毫米空间分辨率和亚秒时间分辨率。由于以前的研究仅依赖于传统的重建算法来跟踪放射性标记的细胞，因此尚未探索这些微型网络的这些能力。通过利用只有一组稀疏的单元格含放射性的知识，可以制定一种重建单细胞轨迹的算法从具有更高灵敏度和空间分辨率的微型网络测量值。拟议的研究的基本原理是，在整个身体水平上跟踪单个细胞在体内将使对移植细胞的动态行为和命运的详细见解及其与受伤的心脏组织的相互作用，而不是传统的体积组织。我们的初步模拟表明，可以用Micropet在体内跟踪标记为1-10 BQ的单个单元。我们将通过追求以下两个目标来检验我们的假设：（1）扩展轨迹重建以并联跟踪多个单个单元；（2）优化细胞标签和跟踪体内单细胞。在第一个目标中，我们将实施一种新的重建算法，该算法采用来自小动物的PET扫描仪的原始列表模式数据并重建了多个单个单元的时空轨迹。在第二个目标中，我们将优化骨ro的单核细胞的Radioniclie标记，以达到10 BQ/细胞。然后，我们将在心肌梗塞的小鼠模型中跟踪这些单个细胞的归巢到心脏损伤部位。我们计划开发的重建算法具有创新性，因为与以前的算法不同，它说明了放射性仅包含在移植细胞内的事实。因此，它以最佳的方式来实现所有可用的测量。拟议的研究项目具有重要意义，因为重建整个身体水平移植细胞的时空轨迹将提供有关生物体中细胞运输动力学的前所未有的信息，并可以应用于改善细胞移植方案以进行更有效的细胞植入。