In a recent work, our group showed the existence of two distinct mesenchymal stem cell (MSC) subsets within human umbilical cord blood. One less proliferative and short-living (SL-CBMSC), the other with higher growth rate and long-living (LL-CBMSC), and therefore better suited for regenerative medicine applications. We examined whether LL-CBMSC possess peculiar paracrine properties able to affect angiogenesis or inflammatory processes. It was shown for the first time that pro-angiogenic, proliferation-stimulating and tissue repairing factors were released at high level not only as soluble cytokines, but also as mRNA precursors embedded in membrane vesicles. The combination of this primary (proteic factors interacting with surface receptors) and delayed (mRNA transferred and translated via vesicle fusion and cargo release) interaction in endothelial target cells resulted in strong blood vessel induction with the development of capillary-like structures. In addition, LL-CBMSC dynamically modulated their release of pro-angiogenic and anti-inflammatory factors in an in vitro model of damage. In conclusion, LL-CBMSC synthesize and secrete multiple factors that may be attuned in response to the status of the target cell, a crucial requisite when paracrine mechanisms are needed at onset of tissue regeneration.

中文翻译：

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脐带血间充质干细胞的血管生成和抗炎特性：可溶性因子和细胞外囊泡，用于细胞再生。

在最近的工作中，我们的小组表明人脐带血中存在两个不同的间充质干细胞（MSC）亚群。一种增殖和短寿命（SL-CBMSC）少，另一种具有较高的生长率和长寿命（LL-CBMSC），因此更适合于再生医学应用。我们检查了LL-CBMSC是否具有能够影响血管生成或炎症过程的特殊旁分泌特性。首次表明促血管生成，增殖刺激和组织修复因子不仅作为可溶性细胞因子而且作为嵌入膜囊泡的mRNA前体高水平释放。内皮靶细胞中这种初级相互作用（蛋白因子与表面受体相互作用）和延迟相互作用（通过RNA融合和货物释放转移和翻译的mRNA）的结合导致了强烈的血管诱导，并形成了毛细血管样结构。另外，在体外损伤模型中，LL-CBMSC动态调节其促血管生成和抗炎因子的释放。总之，LL-CBMSC合成并分泌多种因子，这些因子可响应靶细胞的状态而调节，这是在组织再生开始时需要旁分泌机制时的关键条件。LL-CBMSC在体外损伤模型中动态调节其促血管生成因子和抗炎因子的释放。总之，LL-CBMSC合成并分泌多种因子，这些因子可响应靶细胞的状态而调节，这是在组织再生开始时需要旁分泌机制时的关键条件。LL-CBMSC在体外损伤模型中动态调节其促血管生成因子和抗炎因子的释放。总之，LL-CBMSC合成并分泌多种因子，这些因子可响应靶细胞的状态而调节，这是在组织再生开始时需要旁分泌机制时的关键条件。