Muscle stem cells: New ALS growth factor therapy and disease model

 描述(申请人提供)：肌萎缩侧索硬化症(ALS)是一种进行性疾病，导致运动神经元退化、肌肉萎缩，最终死于呼吸衰竭。本项目的主要目标是确定从诱导多能干细胞(IPSCs)中新建立的人骨骼肌祖细胞/干细胞(HSMPC)是否可以用于体外细胞治疗(基于干细胞的生长因子输送)，并作为研究ALS的体外模型。指导这一提议的基本假设是，IPSC来源的hSMPC有效地分化为新的骨骼肌细胞，并有助于肌肉再生。这种能力赋予了IPSC来源的hSMPC传递体外生长因子的能力，并在体外模拟ALS的各个方面。我们的假设是基于我们已发表的工作和新的初步数据，证明了从IPSC生产hSMPC的可行性。我们将制备基因修饰的hSMPC来运送已知的在ALS啮齿动物模型中具有神经保护作用的关键生长因子，包括胶质细胞系衍生神经营养因子(GDNF)和血管内皮生长因子(VEGF)。在建立细胞后，我们将把它们移植到四肢肌肉中，以便为ALS大鼠输送生长因子(目标1)。我们期望整合的祖细胞能够有效地将生长因子输送到靶肌肉(包括它们的神经肌肉连接)，从而保护运动神经元/肌肉连接、运动神经元存活和肢体功能。由于ALS最常见的死亡原因是呼吸衰竭，我们将进一步检验基于横隔膜hSMPC的生长因子传递延长ALS大鼠运动神经元存活，从而保护呼吸运动功能的假设(目标2)。最后，我们将从家族性肌萎缩侧索硬化症患者捐赠者的IPSCs中创建新的hSMPC系。通过分析它们的细胞特性，并将其与运动神经元共同培养，我们将通过在体外模拟ALS来扩大hSMPC的用途，进一步了解肌源性营养因子的作用(目标3)。这些目标将为基于细胞和生长因子的体外治疗的潜力提供非常新颖的见解，并将建立一个新的疾病模型，以促进我们对肌肉和神经肌肉连接在这种致命的神经退行性疾病中的相对贡献的理解。IPSC来源的hSMPC可用于开发针对患者的、基于细胞的ALS治疗方法，并提供新型的人类疾病体外模型。该项目的结果有望加快ALS患者临床前研究的进展。鉴于肌萎缩侧索硬化症的灾难性后果，缺乏有效的治疗方法，以及社会的负担，及时回答这里提出的问题是当务之急。

 DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a progressive disease causing motor neuron degeneration, muscular atrophy and, ultimately, death by respiratory failure. Our major goal in this project is to determine if newly established human skeletal muscle progenitor/stem cells (hSMPCs) derived from induced pluripotent stem cells (iPSCs) can be used for ex vivo cell therapy (stem cell-based growth factor delivery), and as an in vitro model to study ALS. The fundamental hypothesis guiding this proposal is that iPSC-derived hSMPCs efficiently differentiate into new skeletal muscle cells and contribute to muscle regeneration. This capacity confers the capacity for iPSC-derived hSMPCs to deliver ex vivo growth factors, and to model aspects of ALS in vitro. Our hypothesis is based on our published works and new preliminary data demonstrating the feasibility of producing hSMPCs from iPSCs. We will prepare genetically modified hSMPCs to deliver key growth factors known to be neuroprotective in ALS rodent models, including glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF). After establishing the cells, we will transplant them into the limb muscles to deliver growth factors in ALS rats (Aim 1). We expect integrated progenitors to effectively deliver growth factors to target muscles (including their neuromuscular junctions), thereby preserving motor neuron/muscle attachments, motor neuron survival and limb function. Since the most common cause of death in ALS is respiratory failure, we will further test the hypothesis that diaphragm hSMPC-based growth factor delivery prolongs motor neuron survival, thereby preserving respiratory motor function in ALS rats (Aim 2). Finally, we will create new hSMPC lines from iPSCs derived from familial ALS patient donors. By analyzing their cellular characteristics and co-culturing these cells with motor neurons, we will extend the utility of hSMPCs by simulating ALS in vitro, furthering our understanding of the roles played by muscle derived trophic factors (Aim 3). These aims will provide highly novel insights concerning the potential of ex vivo cell and growth factor-based treatments, and will establish a new disease model to advance our understanding of the relative contributions from muscles and neuromuscular connections in this fatal neurodegenerative disease. iPSC- derived hSMPCs can be used to develop patient-specific, cell-based ALS treatments, and provide novel in vitro models of human disease. The results of this project are expected to accelerate progress towards pre-clinical studies in ALS patients. Given the devastating outcome in ALS, the lack of effective treatments, and the burden on society, it is imperative that the questions posed here be answered in a timely manner.