【摘要】 目的探讨循环早期内皮祖细胞(early-EPC)与外向生长内皮细胞(OEC)的生物学差别以及在血管新生中的作用。方法分离单个核细胞于体外培养early-EPC和OEC,并通过流式细胞仪测定CD14、CD34、CD45、CD105、CD133、血管内皮生长因子2型受体(VEGFR2)、血管性血友病因子(vWF)的表达情况。应用激光共聚焦鉴定细胞吞噬及结合的能力,并分别测定两种细胞的增殖能力、黏附功能、成血管能力以及分泌一氧化氮及血管内皮生长因子(VEGF)。其次,将18只日本大耳白兔随机分为early-EPC组(n=6)、OEC组(n=6)及对照组(n=6)。在3组动物制造出急性心肌缺血模型后,分别向心肌内移植early-EPC、OEC及培养液。4周后测定移植细胞的分布情况及血管密度,并分析心功能的变化。结果 early-EPC显示为CD14、CD45阳性,而OEC不表达CD14、CD45。两种细胞均表达内皮标志CD105、VEGFR2及vWF;均可以吞噬乙酰化低密度脂蛋白(ac-LDL)并结合荆豆凝集素1(UEA-1)。OEC增殖力、成血管能力较early-EPC明显增强,但两种细胞黏附能力及分泌VEGF、一氧化氮的能力无差别。early-EPC移植不能增加血管密度及改善心功能,而OEC可以整合入血管、促进血管新生并改善心功能。结论 early-EPC不具备祖细胞的特征。OEC具有祖细胞的特征,能促进缺血心肌的血管新生,是适合的移植种子细胞。更多还原

【Abstract】 Objective To investigate the biological difference between early endothelial progenitor cell (EPC) and outgrowth endothelial cell (OEC). Methods Two types of cells,early EPC and OEC were cultured and isolated from peripheral blood mononuclear cells. CD14,CD34,CD45,CD105,CD133,vascular endothelial growth factor receptor 2(VEGFR-2) and von willebrand-factor(vWF) were determined by flow cytometry. Both early EPC and OEC were assayed by confocal laser scanning microscopy,in term of their capacities for tube formation,cell proliferation,adhesion,production of nitric oxygen (NO) and vascular endothelial growth factor (VEGF). Eighteen Rabbits were randomly categorized into early EPC,OEC and control group (n=6). Cells were characterized by uptaking acetylated low density lipoprotein (ac-LDL) and binding ulexeuropaeusagglutinin-1(UEA-1). Four week after transplantation of both cells,exogenous early EPC and OEC were analyzed for therapeutic efficacy in acute myocardial ischemia model of rabbits. Moreover,Left ventricular function was assessed by using echocardiography. Capillary density and expression of VEGF were evaluated as well. Results Early-EPC revealed CD14 and CD45 positive,while OEC showed CD14,CD45 negative. Both Early EPC and OEC expressed endothelial cell antigen,CD105,VEGFR2 and vWF,acetylated-LDL and combined UEA-1. As revealed in observation,OEC demonstrated rather stronger capacities for proliferation and tube formation than early EPC. Apparently there were no significant difference in cell adhesion,VEGF and NO secretion between the two types of cells. Thus,it can be further inferred that intramyocardial transplantation of OEC,rather than early EPC,could increase capillary density,enhance EF value,and elevate mRNA expression of VEGF. Conclusion Early EPC had no characteristic of progenitor cell. Ex vivo expanded OEC could induce therapeutical vasculogenesis in ischemic myocardium.更多还原