Noninvasive monitoring and tracking of muscle stem cells

描述(由申请人提供)： 这项建议的总体目标是开发高分辨率成像方法，以非侵入性评估骨骼和心肌肌病基于细胞的治疗方法。目前分析细胞疗法的方法在很大程度上局限于动物模型的侵入性测量。在这项建议中，重点是发展非侵入性磁共振(MR)分析，以监测干细胞在体内的迁移、活性和在细胞输送到心肌和骨骼肌后的植入。这项技术的一个直接应用是监测细胞疗法，以减轻肌肉营养不良的破坏性影响。 为了实现体内单细胞的敏感性，干细胞将磁性标记的超顺磁性氧化铁(SPIO)复合体。SPIO标记的细胞将在肌肉注射后的营养不良动物模型(MDX)中进行监测(目标1)。在AIM 2中，将开发31P光谱和成像方法来跟踪营养不良骨骼肌中肌源性干细胞(MDSC)的分化和整合。MDSCs将被改造成有条件地表达一种独特的肌肉特异性MR标记基因(精氨酸激酶)。在目标3中，将确定MR检测细胞通过循环系统归巢到肌肉损伤和再生的偏远局部位置的能力。为了最大限度地促进细胞迁移，我们将利用定向内源性(急性损伤诱导)和外源性(SDF-1的病毒传递)干细胞趋化因子的表达。最后，在目标4中，我们将确定MR监测营养不良小鼠心脏细胞移植治疗的能力。我们预计，这些非侵入性方法将为以细胞为基础的治疗肌营养不良症以及其他涉及骨骼或心脏肌肉疾病的疾病的临床前研究提供必要的反馈。

DESCRIPTION (provided by applicant): The overall objective of this proposal is to develop high resolution imaging methods to noninvasively evaluate cell based therapies in skeletal- and cardiac myopathies. Current methods for the analysis of cell based therapies are largely restricted to invasive measurements in animal models. In this proposal, emphasis is placed on the development of noninvasive magnetic resonance (MR) assays to monitor in vivo stem cell migration, viability, and engraftment following cell delivery to cardiac and skeletal muscle. An immediate application of this technology is the monitoring of cell therapies to mitigate the devastating effects of muscular dystrophy. In order to achieve in vivo single cell sensitivity, stem cells will be magnetically labeled supraparamagnetic iron oxide (SPIO) complexes. SPIO labeled cells will be monitored in dystrophic animal model (mdx) following intramuscular injection (Aim 1). In Aim 2, 31p-spectroscopic and imaging methods will be developed to track the differentiation and integration of muscle derived stem cells (MDSC) in dystrophic skeletal muscle. MDSCs will be engineered to conditionally express a unique muscle specific MR marker gene (arginine kinase). In Aim 3, the ability of MR to detect cell homing through the circulatory system into remote, local sites of muscle damage and regeneration will be determined. In order to maximize cell migration, we will utilize targeted endogenous (induced by acute injury) and exogenous (viral delivery of SDF-1) expression of stem cell chemotactic factors. Finally, in Aim 4 we will determine the ability of MR to monitor cell transplantation therapy in the dystrophic mouse heart. We anticipate that these noninvasive methods will provide essential feedback for pre-clinical studies targeting cell-based therapy in muscular dystrophy, as well as in other diseases involving skeletal- or cardiac myopathies.