人胎盘来源的间充质干细胞向血管内皮细胞分化潜能的研究

目的: 探讨人胎盘来源的间充质干细胞(placenta derived mesenchymal stem cells,PDMSCs)在体外分化为血管内皮细胞的潜能。方法: 利用组织块种植法体外分离培养PDMSCs,流式细胞术鉴定其表面抗原,应用含50 μg/L VEGF和10 μg/L bFGF的诱导分化液定向诱导PDMSCs向内皮细胞分化。免疫细胞化学检测分化过程中不同时点内皮特异性标志的表达变化。透射电镜和体外血管生成实验分别检测内皮特异性结构和内皮细胞功能。结果: PDMSCs表面抗原 CD105和CD166阳性,CD31、CD34和CD45阴性。诱导分化的内皮细胞形态呈鹅卵石样,早期内皮标志Flk-1/KDR在4 d表达最强;成熟的内皮标志CD31、vWF、CD144/VE-cadherin在内皮细胞分化过程中呈现时间依赖性表达(0 d、4 d、8 d和12 d)。透射电镜下可见内皮特异性结构:Weibel-Palade小体。细胞接种在细胞外基质凝胶中可形成毛细血管样结构。结论: 胎盘中可分离出大量PDMSCs,并且PDMSCs在体外可分化为具有功能特性的内皮细胞,因此胎盘组织可能成为血管组织工程和再生医学的理想种子细胞来源。

Differentiation potential of human placenta derived mesenchymal stem cells into vascular endothelial cells

AIM: To investigate the differentiation potential of human placenta derived mesenchymal stem cells (PDMSCs) into endothelial cells (ECs) in vitro. METHODS: PDMSCs were isolated from human placenta tissues, characterized by flow cytometry and induced to differentiate into endothelial cells with 50 μg/L VEGF and 10 μg/L bFGF. To detect the specific markers of ECs during the process of differentiation, the method of immunocytochemistry was performed. The specific structure and function of endothelial cells were observed by transmission electron microscopy and in vitro angiogenesis assay kit, respectively. RESULTS: CD105 and CD106 were positive in PDMSCs, while CD34,CD45 and CD31 were negative.The ECs differentiated from PDMSCs showed cobblestone-like morphology, and expressed early endothelial marker of Flk-1/KDR and mature endothelial markers of CD31, vWF and CD144/VE-cadherin in a time-dependent manner during the endothelial cell differentiation (0 day, 4 days, 8 days and 12 days). The endothelial specific structure, Weibel-palade body, was observed under transmission electron microscope. The inoculation of ECs on the extra cellular matrix gel formed capillary-like structures. CONCLUSION: Plentiful PDMSCs can be isolated from placenta, and differentiate into the cells with functional characteristics of ECs in vitro, indicating that the placenta tissues will become optimal source of seed cells for vascular engineering and regenerative medicine.