Microvesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells Stimulated by Hypoxia Promote Angiogenesis Both In Vitro and In Vivo
Microvesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells Stimulated by Hypoxia Promote Angiogenesis Both In Vitro and In Vivo
复制标题
缺氧刺激的人脐带间充质干细胞来源的微泡在体外和体内促进血管生成
DOI：
10.1089/scd.2012.0095
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发表时间：
2012-12-01
影响因子：
4
通讯作者：
Guo, Zi-Kuan
中科院分区：
文献类型：
--
作者：
Zhang, Hong-Chao;Liu, Xin-Bin;Guo, Zi-Kuan
尽管间充质干细胞(MSCs)已被越来越多地用于治疗各种疾病，但其潜在的机制仍不清楚。本研究用低氧刺激人脐带(UC)来源的MSCs，用超速离心法收集培养上清液中的膜微囊(MVS)，在电子显微镜下观察，并用流式细胞仪技术鉴定其来源。结果表明，在低氧刺激下，MSCs释放出大量直径约为100 nm的微血管。MVS的表型与亲本MSCs相似，但大多数MVs的血小板衍生生长因子受体均为阴性。DiI标记实验表明，MSC-MVS在加入培养液后8h内即可内化到人UC内皮细胞。羧基荧光素琥珀酰亚胺酯标记技术和四甲基偶氮唑盐试验表明，MSC-MVS对UC-ECs的增殖有促进作用，且呈剂量依赖性。此外，MVS可促进UC-ECs在Matrigel基质中形成毛细血管网络。在大鼠后肢缺血模型中，激光多普勒成像分析显示，与对照组(P<；0.0001)相比，骨髓间充质干细胞和骨髓间充质干细胞-血管内皮细胞均能显著改善血流恢复。这些数据表明，MV的释放是MSC通过促进血管生成而有效治疗的主要机制之一。
Although mesenchymal stem cells (MSCs) have been increasingly trialed to treat a variety of diseases, the underlying mechanisms remain still elusive. In this study, human umbilical cord (UC)-derived MSCs were stimulated by hypoxia, and the membrane microvesicles (MVs) in the supernatants were collected by ultracentrifugation, observed under an electron microscope, and the origin was identified with the flow cytometric technique. The results showed that upon hypoxic stimulus, MSCs released a large quantity of MVs of similar to 100nm in diameter. The MVs were phenotypically similar to the parent MSCs, except that the majority of them were negative for the receptor of platelet-derived growth factor. DiI-labeling assay revealed that MSC-MVs could be internalized into human UC endothelial cells (UC-ECs) within 8 h after they were added into the culture medium. Carboxyfluorescein succinimidyl ester-labeling technique and MTT test showed that MSC-MVs promoted the proliferation of UC-ECs in a dose-dependent manner. Further, MVs could enhance in vitro capillary network formation of UC-ECs in a Matrigel matrix. In a rat hindlimb ischemia model, both MSCs and MSC-MVs were shown to improve significantly the blood flow recovery compared with the control medium (P < 0.0001), as assessed by laser Doppler imaging analysis. These data indicate that MV releasing is one of the major mechanisms underlying the effectiveness of MSC therapy by promoting angiogenesis.