Innovative Approaches to Treat Duchenne Muscular Dystrophy Using iPSC-Derived Muscle Progenitors

 描述（由申请人提供）：杜氏肌营养不良症（DMD）是一种由肌营养不良蛋白缺乏引起的致死性肌肉萎缩性疾病，最终导致肌细胞凋亡和肌肉收缩力受损。诱导多能干细胞（iPSC）提供了纠正DMD基因缺陷的潜力，并在不引起免疫激活的情况下为移植创造健康的细胞。然而，这需要工程化iPSC以促进归巢和植入到患病肌肉组织中而不促进肿瘤发生。我们的长期目标是优化iPSC分化为肌源性祖细胞（MPC），这些细胞被定向归巢到肌肉组织中并移植，而不经历无限制的生长。我们的中心假设是，精确的MPC基因工程，加上通过预处理或外泌体递送对宿主肌肉生态位的靶向修饰，将通过SDF-CXCR 4轴促进供体iPSC衍生的MPC的归巢和植入，以安全有效地治疗DMD。其基本原理是开发从DMD患者中产生大量功能性MPC的方法，这些MPC无肿瘤，可以有效地定位于肌肉损伤部位并促进修复。我们计划通过追求以下三个具体目标来测试我们的中心假设并实现本申请的目标。在目的1中，我们将检验iPSC衍生的祖细胞对于营养不良肌肉的再生是有效且安全的假设。在目标2中，我们将使用基于CRISPR-on的基因组平台测试来自DMD小鼠的iPSC衍生的肌源性前体中CXCR 4的活化改善DMD小鼠中供体细胞的植入的假设。在目标3中，我们将检验以下假设：通过缺血预处理或iPSC-外泌体介导的SDF-1α蛋白递送优化肌肉中的再生微环境，增强供体MPC的归巢和/或存活，以增强肌肉修复。这些实验有可能证明iPSC衍生的祖细胞的移植，加上优化宿主肌肉微环境的方法，将更有效地改善营养不良病理学并改善DMD患者的生活质量。

 DESCRIPTION (provided by applicant): Duchenne Muscular Dystrophy (DMD) is a lethal muscle wasting disease caused by the lack of dystrophin, which eventually leads to apoptosis of muscle cells and impaired muscle contractility. Induced pluripotent stem cells (iPSC) offer the potential to correct the DMD gene defect and create healthy cells for transplantation without causing immune activation. However, this requires engineering iPSCs to facilitate homing and engraftment into diseased muscle tissue without promoting tumorigenesis. Our long-term goal is to optimize the differentiation of iPSC into myogenic progenitor cells (MPC) that are directed to home into muscle tissue and engraft without undergoing unrestrained growth. Our central hypothesis is that precise MPC genetic engineering, coupled with targeted modification of the host muscle niche by preconditioning or exosome delivery, will boost homing and engraftment of donor iPSC-derived MPC via the SDF-CXCR4 axis to safely and effectively treat DMD. The rationale is to develop methodology to produce large quantities of functional MPC from patients with DMD that are tumor free and can effectively home to sites of muscle injury and facilitate repair. We plan to test our central hypothesis and accomplish the objectives of this application by pursuing the following three specific aims. In Aim 1, we will test the hypothesis that iPSC-derived progenitor cells are effective and safe for regeneration of dystrophic muscle. In Aim 2, we will test the hypothesis that activation of CXCR4 in iPSC-derived myogenic precursors from DMD mice using a CRISPR-on based genomic platform improves engraftment of donor cells in DMD mice. In Aim 3, we will test the hypothesis that optimizing the regenerative microenvironment in muscle by ischemic preconditioning or iPSC-exosome-mediated delivery of SDF-1α protein enhances the homing and/or survival of donor MPC to augment muscle repair. These experiments have the potential to demonstrate that transplantation of iPSC-derived progenitors, coupled with methods to optimize the host muscle microenvironment, will more effectively ameliorate dystrophic pathology and improve the quality of life for patients with DMD.