Multipotent mesenchymal stromal cells (MSCs) are potentially therapeutic for muscle disease because they can accumulate at the sites of injury and act as immunosuppressants. MSCs are attractive candidates for cell-based strategies that target diseases with chronic inflammation, such as Duchenne muscular disease (DMD). We focused on the anti-inflammatory properties of IL-10 and hypothesized that IL-10 could increase the typically low survival of MSCs by exerting a paracrine effect after transplantation. We developed a continuous IL-10 expression system of MSCs using an adeno-associated virus (AAV) vector. To investigate the potential benefits of IL-10 expressing AAV vector-transduced MSCs (IL-10-MSCs), we examined the cell survival rates in the skeletal muscles after intramuscular injection into mice and dogs. Systemic treatment with IL-10-MSCs derived from dental pulp (DPSCs) was comprehensively analyzed using the canine X-linked muscular dystrophy model in Japan (CXMDJ), which has a severe phenotype similar to that of DMD patients. In vivo bioluminescence imaging analysis revealed higher retention of IL-10-MSCs injected into the hindlimb muscle of mice. In the muscles of dogs, myofiber-like tissue was formed after the stable engraftment of IL-10-MSCs. Repeated systemic administration of IL-10-DPSCs into the CXMDJ model resulted in long-term engraftment of cells and slightly increased the serum levels of IL-10. IL-10-hDPSCs showed significantly reduced expression of pro-inflammatory MCP-1 and upregulation of stromal-derived factor-1 (SDF-1). MRI and histopathology of the hDPSC-treated CXMDJ indicated the regulation of inflammation in the muscles, but not myogenic differentiation from treated cells. hDPSC-treated CXMDJ showed improved running capability and recovery in tetanic force with concomitant increase in physical activity. Serum creatine kinase levels, which increased immediately after exercise, were suppressed in IL-10-hDPSC-treated CXMDJ. In case of local injection, IL-10-MSCs could maintain the long-term engraftment status and facilitate associated tissue repair. In case of repeated systemic administration, IL-10-MSCs facilitated the long-term retention of the cells in the skeletal muscle and also protected muscles from physical damage-induced injury, which improved muscle dysfunction in DMD. We can conclude that the local and systemic administration of IL-10-producing MSCs offers potential benefits for DMD therapy through the beneficial paracrine effects of IL-10 involving SDF-1.

中文翻译：

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表达IL-10的多能间充质基质细胞对肌肉营养不良的细胞存活率和治疗益处

多能间充质基质细胞（MSCs）对肌肉疾病具有潜在的治疗作用，因为它们可以在损伤部位积聚并充当免疫抑制剂。MSC是针对以慢性炎症疾病为基础的细胞策略的有吸引力的候选者，例如杜兴氏肌肉疾病（DMD）。我们专注于IL-10的抗炎特性，并假设IL-10可以通过在移植后发挥旁分泌作用来增加MSCs通常较低的存活率。我们开发了使用腺相关病毒（AAV）载体的MSC的连续IL-10表达系统。为了调查表达IL-10的AAV载体转导的MSC（IL-10-MSC）的潜在益处，我们检查了小鼠和狗肌肉注射后骨骼肌中的细胞存活率。使用日本犬X连锁肌营养不良模型（CXMDJ），综合分析了源自牙髓（DPSC）的IL-10-MSC的全身治疗，该模型具有与DMD患者相似的严重表型。体内生物发光成像分析显示，注入小鼠后肢肌肉的IL-10-MSC保留更高。在狗的肌肉中，稳定植入IL-10-MSC后形成了肌纤维样组织。将IL-10-DPSCs全身性重复给药到CXMDJ模型中会导致细胞长期植入，并稍微增加IL-10的血清水平。IL-10-hDPSCs显示促炎性MCP-1的表达显着降低和基质衍生因子1（SDF-1）的上调。经hDPSC处理的CXMDJ的MRI和组织病理学表明肌肉中炎症的调节，但不能从处理过的细胞中生肌分化。hDPSC处理的CXMDJ表现出更好的跑步能力和强直力量的恢复，同时伴随着体育锻炼的增加。运动后立即增加的血清肌酸激酶水平在IL-10-hDPSC治疗的CXMDJ中被抑制。在局部注射的情况下，IL-10-MSC可以维持长期的植入状态并促进相关的组织修复。在重复全身性给药的情况下，IL-10-MSCs促进了细胞在骨骼肌中的长期保留，并保护了肌肉免受物理损伤引起的损伤，从而改善了DMD中的肌肉功能障碍。我们可以得出结论，通过IL-10涉及SDF-1的有益旁分泌作用，局部和全身给药产生IL-10的MSCs为DMD治疗提供了潜在的好处。