低氧对人脐带间充质干细胞活性和内皮分化能力的影响及VEGF的干预作用(英文)

Role of hypoxia in viability and endothelial differentiation potential of UC-MSCs and VEGF interference

目的:探讨低氧对人脐带间充质干细胞(hUC-MSCs)的活性及向内皮细胞分化能力的影响,并进一步探索外源性VEGF对低氧损伤的保护作用。方法:在体外对hUC-MSCs进行分离培养。对hUC-MSCs的形态学和表型特征进行分析。在添加/不添加50 ng/mL VEGF的情况下,对hUC-MSCs分别进行不同时间的低氧诱导后,对细胞凋亡率、ROS生成及细胞增殖能力进行检测,并对hUC-MSCs的内皮分化能力进行评估。结果:低氧诱导早期(6,12 h),hUC-MSCs的凋亡及ROS生成显著增加,增殖能力显著下降;晚期(24,72 h),细胞的增殖及凋亡水平与对照组间无明显差异;高浓度(50 ng/mL)外源性VEGF抑制低氧诱导早期出现的凋亡增加及增殖下降;外源性VEGF存在的情况下,低氧诱导14 d,hUC-MSCs表达早期内皮细胞表型,并能获得部分内皮细胞功能。结论:低氧早期造成hUC-MSCs急性损伤,晚期通过逐步适应恢复细胞活性并保持了其分化潜能。VEGF能够保护急性缺氧对细胞的损伤,并能诱导其向内皮样细胞分化。

Objective： To investigate the effect of hypoxia on cell viability and the endothelial differentiation potential in human umbilical cord derived mesenchymal stem cells （UC-MSCs）, and to assess the in vitro protective role of VEGF under low oxygen tension. Methods： MSCs were isolated from human umbilical cords and cultured in vitro. The morphological and phenotypic characterizations of human UC-MSCs were analyzed, The hypoxia induction was performed with or without the presence of 50 ng/mL of VEGF for different lengths of time. The cell proliferation, apoptosis, and reactive oxygen species （ROS） generation were assessed. Meanwhile, the endothelial differentiation potential of the UC-MSCs was measured. Results： An increased apoptosis and ROS generation but reduced proliferation rate were observed at early stages （6, 12 h） after transferring the UC-MSCs from the atmospheric condition to the hypoxia condition. However, the UC-MSCs presented equal proliferation and apoptosis levels under hypoxic condition as compared with those under the atmospheric condition at the later stages （24, 72 h）. A high concentration of exogenous VEGF （50 ng/mL） attenuated the increased apoptosis and inhibited the proliferation of UC-MSCs, induced by a short-term hypoxia treatment. After 14 days of exogenous VEGF induction under the an early endothelial phenotype consisting of a mature functions. hypoxia condition, the UC-MSCs acquired endothelial molecule and some endothelial Conclusion： UC-MSCs progressively adapt to hypoxia in a step-by-step manner and maintain differentiation potential under hypoxia condition. VEGF can protect the UC-MSCs from cell damage and induce a differentiation of UC-MSCs toward endothelial lineage under hypoxic conditions.