Abstract—

Extracellular vesicles (EVs) and, particularly, exosomes are becoming a promising material for “cell-free therapy” of many pathologic conditions. In the recent years therapeutic effects of mesenchymal stromal cells (MSCs) have been attributed to their secretory factors, including EVs. In this study we aim to investigate how EVs produced by MSCs of different tissue origin can influence myogenesis and fibrosis–the main processes that accompany skeletal muscle regeneration. Bone marrow, adipose tissue, intact muscle, and injured muscle-derived rat MSCs were obtained and cultured according to standard protocols. EVs were obtained by ultracentrifugation from the MSC-conditioned medium of cell passages 2 and 3. The effects of EVs were estimated on the in vitro models of myogenesis and fibrosis. Samples of isolated EVs contained nano-sized vesicles that carried some exosomal markers. Promyogenic microRNA were found in EVs from bone marrow and muscle MSCs. We found that MSC-derived EVs from all sources significantly increased the number of newly formed myotubes in myoblast culture in vitro and also reduced the number and size of fibrotic nodules in muscle fibroblast culture in vitro. Our results suggest that MSC-derived EVs indeed possess antifibrotic and promyogenic potentials. However, the role of microRNA in these processes is yet to be determined, and the effect of EVs on skeletal muscle regeneration is yet to be tested in vivo.

中文翻译：

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间充质基质细胞衍生的细胞外囊泡：其特征和对体外纤维化和肌发生的影响。

摘要—

细胞外囊泡（EV），尤其是外泌体正成为许多病理状况的“无细胞疗法”的有前途的材料。近年来，间充质基质细胞（MSC）的治疗作用已归因于它们的分泌因子，包括EV。在这项研究中，我们旨在研究不同组织来源的MSC产生的电动汽车如何影响肌发生和纤维化-伴随骨骼肌再生的主要过程。根据标准方案获得并培养了骨髓，脂肪组织，完整的肌肉和受伤的肌肉来源的大鼠MSC。通过从细胞第2代和第3代的MSC条件培养基中超速离心获得EV。评估了EV的作用于肌发生和纤维化的体外模型。分离出的电动汽车样本包含带有某些外泌体标记物的纳米大小的囊泡。在来自骨髓和肌肉MSC的电动汽车中发现了早生性microRNA。我们发现，来自所有来源的MSC来源的EV显着增加了体外成肌细胞培养中新形成的肌管的数量，还减少了体外成肌细胞培养中纤维化结节的数量和大小。我们的结果表明，MSC衍生的电动汽车确实具有抗纤维化和早生的潜力。然而，microRNA在这些过程中的作用尚待确定，EV对骨骼肌再生的作用尚待体内测试。我们发现，来自所有来源的MSC来源的电动汽车显着增加了体外成肌细胞培养中新形成的肌管的数量，并且还减少了体外成肌细胞培养中纤维化结节的数量和大小。我们的结果表明，MSC衍生的电动汽车确实具有抗纤维化和早生的潜力。然而，microRNA在这些过程中的作用尚待确定，EV对骨骼肌再生的作用尚待体内测试。我们发现，来自所有来源的MSC来源的EV显着增加了体外成肌细胞培养中新形成的肌管的数量，还减少了体外成肌细胞培养中纤维化结节的数量和大小。我们的结果表明，MSC衍生的电动汽车确实具有抗纤维化和早生的潜力。然而，microRNA在这些过程中的作用尚待确定，EV对骨骼肌再生的作用尚待体内测试。