缺氧预处理提高骨髓基质细胞促进血管新生能力

目的 研究缺氧对骨髓基质细胞(bone marrow stromal cells，BMSCs)表达血管内皮细胞生长因子(vascular endothelial growth factor，VEGF)及促进血管新生能力的影响。方法 将BMSCs置于缺氧环境下培养24h后，研究其VEGF表达的变化。将急性心肌梗死大鼠随机分为3组。未处理组在梗死后4w移植未经缺氧处理的BMSCs；缺氧组将经缺氧预处理的BMSCs注射到心肌梗死区；对照组仅注射无血清的培养液。在梗死后6w取各组标本观察梗死区及周围VEGF的表达和血管新生状况。结果 体外培养的BMSCs经缺氧预处理后VEGF的表达明显增加。缺氧组和未处理组梗死区及周围VEGF的表达和毛细血管密度较对照组明显增加。缺氧组VEGF的表达和毛细血管密度又较未处理组明显增加。结论 体外缺氧可诱导BMSCs高表达VEGF。BMSCs移植后促进梗死区及周围VEGF的表达，对血管新生有积极作用。移植前缺氧预处理使BMSCs促进缺血心肌组织表达更多的VEGF从而提高其促进血管新生作用。

Angiogenic potency of bone marrow stromal cells improved by ex vivo hypoxia prestimulation

Objective To study the effect of hypoxia-prestimulation on vascular endothelial growth factor (VEGF) expression of bone marrow stromal cells (BMSCs) and angiogenic potency.Methods BMSCs were cultured under hypoxia condition for 24 hours to explore the expression of VEGF. The rats with acute myocardial infarction were divided into 3 groups at random. In normoxia group, unstimulated BMSCs were implanted into the infarction region at 2 weeks after infarction. The rats in hypoxia group were implanted with hypoxia prestimulated BMSCs, the rats in control group received only DMEM injection. VEGF expression and angiogenic were observed in infarction regions at 6 weeks after infarction.Results VEGF expression of BMSCs cultured ex vivo after hypoxia prestimulation significantly increased. The capillary density and VEGF expression in hypoxia group were higher than those of normoxia group.Conclusions The expression of VEGF in BMSCs could be highly induced by ex vivo hypoxia stimulation. BMSCs implantation promoted the angiogenesis after myocardial infarction via increasing VEGF expression. Angiogenic potency of BMSCs was improved by ex vivo hypoxia prestimulation via higher VEGF expression.