中文摘要：

血管的发生和发育不仅对胚胎形成中各器官的发育分化十分重要,并且对成体的创伤修复和生殖功能也具有重要意义.血管内皮细胞是形成心血管封闭管道系统的形态基础,体外多种细胞可经诱导分化产生出内皮祖/内皮细胞（endothelialprogenitor/endothelial cells,EPCs/ECs）,但是存在一些不足.鉴于人类胚胎干细胞（human embryonic stem cells,hESCs）诱导分化的全能性和长期增殖能力,为EPCs/ECs提供了新的来源.现有文献报道,hESCs诱导分化为EPCs/ECs的比例较低,为了提高该诱导分化效率,我们使用分阶段的二维诱导方法,首先将细胞接种在超纯层纤连蛋白（Matrigel）上,之后通过在不同阶段添加不同的因子,最终获得CD31＋KDR＋细胞的比例可以达到16%.进一步内皮诱导分化的结果显示,获得的EPCs/ECs的比例可以达到约32%,这些细胞具有在Matrigel上形成血管样结构的能力,可结合植物凝集素.实时定量PCR的结果显示,诱导分化所得的细胞表达众多内皮相关基因,并且免疫荧光的结果也表明部分细胞表达内皮细胞特异性表面标志CD31.

英文摘要：

Vasculogenesis and angiogenesis are fundamental processes for the formation and restoration of circulatory system, which plays important role in embryonic organ development, adult wound healing and reproduction. Vascular endothelial cells are the foundation of cardiovascular systems. Although it has been proved that several kinds of stem cells could be induced to generate endothelial cells ex vivo, there are still some shortages in these cell sources. Depending on the multipotency and infinitive reproductive capability, human embryonic stem cells （hESCs） become the new sources. However, the efficiency for deriving endothelial progenitor/ endothelial cells （EPCs/ECs） from hESCs is low. To increase endothelial induction efficiency, we used a two-stage induction protocol. By the treatment of different cytokine cocktails at different stages and the using of Matrigel matrix, we obtained about 16% CD3 I＋KDR＋ cells from hESCs. The following endothelial induction stage with EGM2 medium showed approximate 32% subgroup of EPCs/ECs. The derived cells had the capability for tube-like structure formation on Matrigel and the ability to cohere with fluorescein griffonia （bandeiraea） simplicifolia lectin II. Q-PCR indicated that the induced cells express endothelial specific genes. Immunofluorescence detection indicated the expression of endothelial specific marker-CD31. Taken together, we have successfully derived EPCs/ECs from human embryonic stem cells with a modified method.