Noninvasive monitoring and tracking of muscle stem cells

描述（由申请人提供）： 本提案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肌和心肌病的细胞治疗。目前用于分析基于细胞的疗法的方法在很大程度上限于动物模型中的侵入性测量。在这项建议中，重点放在发展无创磁共振（MR）检测，以监测体内干细胞迁移，活力，并植入后的细胞输送到心脏和骨骼肌。这项技术的直接应用是监测细胞疗法，以减轻肌肉萎缩症的破坏性影响。 为了实现体内单细胞敏感性，干细胞将被磁性标记的超顺磁性氧化铁（SPIO）复合物。肌内注射后，将在营养不良动物模型（mdx）中监测SPIO标记的细胞（目的1）。目的2：发展31 p-光谱和成像技术来跟踪肌源性干细胞（MDSC）在营养不良骨骼肌中的分化和整合。MDSC将被工程化以有条件地表达独特的肌肉特异性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远程局部部位的能力。为了使细胞迁移最大化，我们将利用干细胞趋化因子的靶向内源性（由急性损伤诱导）和外源性（SDF-1的病毒递送）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中细胞移植治疗的能力。我们预计，这些非侵入性的方法将提供必要的反馈，为临床前研究针对基于细胞的治疗肌营养不良症，以及在其他疾病，涉及骨骼肌或心脏肌病。

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.