This study delves into possible mechanisms underlying the stimulating influence of UC-MSCs transplantation on functional and structural recovery of ischemic skeletal muscles. Limb ischemia was created in Sprague-Dawley rats by excision of femoral and popliteal arteries. Allogeneic rat PKH26-labeled UC-MSCs were administered by direct intramuscular injection. Animals of experimental group responded to the transplantation by improvement in their locomotor function as assessed by the rotarod performance test on day 9 and 29 after transplantation. Histomorphometric analysis showed that relative area of the lesions in the experimental group was significantly smaller than in the control group at all time points during the observation. Calculated densities of microcirculation vessels within the lesions were significantly higher in the experimental group than in the control group on day 10 after transplantation. Only a part of the transplanted allogeneic UC-MSCs survived within the ischemic muscle tissue, and a considerable portion of these surviving cells were found alongside the VEGF-producing preserved muscle fibers. The PKH26 label was not found within the walls of capillaries or larger blood vessels. The administration of allogeneic UC-MSCs significantly increased the proportion of M2 macrophages, exhibiting proangiogenic and anti-inflammatory properties, for at least 10 days following the transplantation.

中文翻译：

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脐带来源的间充质基质/干细胞可在大鼠模型中增强手术诱导的骨骼肌缺血的恢复。

这项研究探讨了潜在的机制潜在的UC-MSCs移植对缺血性骨骼肌的功能和结构恢复的刺激作用。通过切除股动脉和pop动脉，在Sprague-Dawley大鼠中产生肢体缺血。通过直接肌内注射施用同种异体大鼠PKH26标记的UC-MSC。实验组的动物通过移植后第9天和第29天的轮转能力测试评估其运动功能的改善对移植作出反应。组织形态计量学分析显示，在观察期间的所有时间点，实验组的病变相对面积均显着小于对照组。移植后第10天，实验组病变内微循环血管的计算密度显着高于对照组。移植的同种异体UC-MSC中只有一部分在缺血性肌肉组织中存活，并且发现这些存活细胞中有相当一部分与产生VEGF的保留肌纤维并存。在毛细血管壁或较大的血管壁中未发现PKH26标签。在移植后至少10天，异体UC-MSC的使用显着增加了M2巨噬细胞的比例，表现出促血管生成和抗炎特性。这些存活细胞中有相当一部分是在产生VEGF的保存的肌肉纤维旁发现的。在毛细血管壁或较大的血管壁中未发现PKH26标签。在移植后至少10天，异基因UC-MSC的使用显着增加了M2巨噬细胞的比例，表现出促血管生成和抗炎特性。这些存活细胞中有相当一部分是在产生VEGF的保存的肌肉纤维旁发现的。在毛细血管壁或较大的血管壁中未发现PKH26标签。在移植后至少10天，异基因UC-MSC的使用显着增加了M2巨噬细胞的比例，表现出促血管生成和抗炎特性。