Skeletal muscle contains multiple cell types that work together to maintain tissue homeostasis. Among these, satellite cells (SC) and fibroadipogenic progenitors cells (FAPs) are the two main stem cell pools. Studies of these cells using animal models have shown the importance of interactions between these cells in repair of healthy muscle, and degeneration of dystrophic muscle. Due to the unavailability of fresh patient muscle biopsies, similar analysis of interactions between human FAPs and SCs is limited especially among the muscular dystrophy patients. To address this issue here we describe a method that allows the use of frozen human skeletal muscle biopsies to simultaneously isolate and grow SCs and FAPs from healthy or dystrophic patients. We show that while the purified SCs differentiate into mature myotubes, purified FAPs can differentiate into adipocytes or fibroblasts demonstrating their multipotency. We find that these FAPs can be immortalized and the immortalized FAPs (iFAPs) retain their multipotency. These approaches open the door for carrying out personalized analysis of patient FAPs and interactions with the SCs that lead to muscle loss.

中文翻译：

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从冷冻肌肉活检组织中分离人纤维脂肪生成祖细胞和卫星细胞

骨骼肌包含多种细胞类型，它们协同工作以维持组织稳态。其中，卫星细胞 (SC) 和成纤维祖细胞 (FAP) 是两个主要的干细胞库。使用动物模型对这些细胞进行的研究表明，这些细胞之间的相互作用在健康肌肉修复和营养不良肌肉退化中的重要性。由于无法获得新鲜的患者肌肉活检，对人类 FAP 和 SCs 之间相互作用的类似分析受到限制，尤其是在肌营养不良患者中。为了解决这个问题，我们描述了一种方法，该方法允许使用冷冻的人类骨骼肌活检，同时从健康或营养不良的患者中分离和培养 SCs 和 FAP。我们表明，虽然纯化的 SCs 分化为成熟的肌管，纯化的 FAP 可以分化为脂肪细胞或成纤维细胞，证明它们的多能性。我们发现这些 FAP 可以永生化，永生化的 FAP (iFAP) 保留其多能性。这些方法为对患者 FAP 进行个性化分析以及与导致肌肉损失的 SCs 的交互打开了大门。