Imaging stem cell implants in neurodegenerative disease

神经退行性疾病中干细胞植入物的成像

• 批准号: 7060441
• 负责人: LORRAINE IACOVITTI
• 金额: $ 27.73万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7060441
• 关键词: Parkinson' s disease; aromatic L aminoacid decarboxylase; bioimaging /biomedical imaging; brain imaging /visualization /scanning; dopamine; dopamine transporter; genetically modified animals; immunocytochemistry; laboratory mouse; laboratory rat; longitudinal animal study; nerve stem cell; nervous system regeneration; neurons; positron emission tomography; reporter genes; single photon emission computed tomography; stem cell transplantation; technology /technique development

DESCRIPTION (provided by applicant): Despite considerable effort, there is still no reliable way to either prevent or rescue dopamine (DA) neurons from the progressive degeneration that occurs during aging or in Parkinson's Disease (PD). Since clinical diagnosis almost always occurs after the vast majority of DA neurons have been destroyed, researchers continue to work to develop ways in which to replace lost tissue with transplanted cells capable of dopaminergic function. Our goal is l to study purified populations of engineered stem, progenitor or fetal DA neurons after transplantation into the Parkinsonian rat. A major limitation of these approaches is the inability to monitor the progression, if any, of the grafted cells without highly invasive tissue biopsy, which invariably results in the death of the animal. The vast numbers of animals required for these studies could be reduced significantly (with the concomitant reduction in costs) if each animal could be studied non-invasively and repeatedly. In addition, measurements made of the DA neuronal regeneration in a rat model ex vivo are not translatable to humans. Molecular imaging, using PET and SPECT, of animal models of PD, and other neurodegenerative diseases, enables the study of the in vivo neurochemical basis of the disorder. In this proposal we aim to perform quantitative imaging of dopaminergic neurons in vivo in longitudinal studies of the same animals over an extended period of time after stem cell implantation. We aim to validate quantitative models of dopaminergic function in rats, using ultra-high resolution] PET and SPECT. [18F]DOPA imaging will be used with PET to monitor striatal dopa decarboxylase activity, while [99mTc]TRODAT-1 and SPECT will be used to measure dopamine transporter (DAT) availability directly. These will be validated against established post mortem methods, such as GFP reporter gene expression and immunocytochemistry. Longitudinal imaging studies of rats, following stem cell implantation, will enable the visualization of the regeneration of DA neurons over an extended period of time. Once the imaging techniques have been fully validated, they will be applied to a variety of stem cell implant models, and correlated with behavioral studies. This non-invasive approach will enable the best combination of cell types and growth factors to be established without sacrificing the animals. The ultimate goal of this study is to develop methods which will enable the monitoring in vivo of DA neuron replacement treatments in Parkinson's and other neurodegenerative diseases. This will provide vital information in the animal model of PD, allow us to longitudinally follow DA neuron regeneration, and, most importantly, will be translatable to clinical human studies using similar techniques.

描述（由申请人提供）： 尽管付出了相当大的努力，但仍然没有可靠的方法来预防或挽救多巴胺 (DA) 神经元在衰老过程中或帕金森病 (PD) 中发生的进行性退化。由于临床诊断几乎总是发生在绝大多数 DA 神经元被破坏之后，研究人员继续致力于开发用具有多巴胺能功能的移植细胞替代丢失的组织的方法。我们的目标是研究移植到帕金森病大鼠体内后纯化的工程干细胞、祖细胞或胎儿 DA 神经元群体。这些方法的一个主要限制是在没有高侵入性组织活检的情况下无法监测移植细胞的进展（如果有的话），这总是导致动物死亡。如果可以对每只动物进行非侵入性和重复性的研究，那么这些研究所需的大量动物就可以显着减少（同时降低成本）。此外，在离体大鼠模型中对 DA 神经元再生进行的测量不能转化为人类。使用 PET 和 SPECT 对 PD 和其他神经退行性疾病动物模型进行分子成像，可以研究该疾病的体内神经化学基础。在本提案中，我们的目标是在干细胞植入后的较长时间内对同一动物进行纵向研究，对体内多巴胺能神经元进行定量成像。我们的目标是使用超高分辨率 PET 和 SPECT 验证大鼠多巴胺能功能的定量模型。 [18F]DOPA 成像将与 PET 一起用于监测纹状体多巴脱羧酶活性，而 [99mTc]TRODAT-1 和 SPECT 将用于直接测量多巴胺转运蛋白 (DAT) 的可用性。这些将根据已建立的尸检方法进行验证，例如 GFP 报告基因表达和免疫细胞化学。干细胞植入后对大鼠进行的纵向成像研究将能够在较长时间内可视化 DA 神经元的再生。一旦成像技术得到充分验证，它们将应用于各种干细胞植入模型，并与行为研究相关联。这种非侵入性方法将能够在不牺牲动物的情况下建立细胞类型和生长因子的最佳组合。这项研究的最终目标是开发能够在体内监测帕金森病和其他神经退行性疾病的 DA 神经元替代治疗的方法。这将为 PD 动物模型提供重要信息，使我们能够纵向跟踪 DA 神经元再生，最重要的是，将可使用类似技术转化为临床人体研究。