人脐血CD133+血管内皮祖细胞的培养、鉴定与分化研究

目的探讨从人脐血中分离、体外培养CD133^＋血管内皮祖细胞（EPCs）的方法及其生长特性和鉴定。方法采用密度梯度离心法结合MACS分选法提取人脐血中CD133^＋细胞,进行流式细胞仪检测纯度,予EBM-2培养液接种培养,观察其生长特性;利用Dil-LDL及FITC-Lectin摄取实验、细胞免疫组织化学等进行鉴定。结果经流式细胞仪检测CD133^＋细胞平均占单核细胞的（1．13±0．10）％,磁珠分选所得CD133^＋细胞平均纯度为（91．45±1．04）％;CD133^＋细胞贴壁生长,可分化为梭形血管内皮细胞及形成集落;CD133^＋细胞培养过程中Dil-LDL及FITC-Lectin摄取阳性,双染阳性率为（95．83±1．72）％;CD133^＋细胞培养1周后经免疫组织化学检测CD34、Ⅷ因子阳性率分别为（95．83±2．23）％和（95．92±1．43）％,与人脐静脉内皮细胞比较差异无统计学意义;CD133^＋细胞体外培养4d、1周可形成小血管结构。结论免疫磁珠分选法可获取较高纯度CD133^＋血管内皮祖细胞,在生长因子作用下诱导其分化为成熟血管内皮细胞。

Study on culture, identification and differentiation of CD133+ endothelial progenitor cells from human umbilical cord blood

OBJECTIVE: To study the isolation, culture and identification of CD133+ endothelial progenitor cells (EPCs) from human umbilical cord blood in vitro. METHODS: EPC separation was performed with density gradient centrifugation and MACS separation. Purity of EPCs was determined by flow cytometry. EPC was cultured with EBM-2 to study the cultivate features of EPC. Uptake test of Dil-LDL and FITC-Lectin and immunohistochemistry were performed. RESULTS: According to flow cytometry, (1.13 +/- 0.10)% of mono-nuclear cells were CD133+ and the purities of CD133+ EPCs were (91.45 +/- 1.04)% on average. CD133+ EPCs became adherent, spindle-shaped and formed cluster during culture. Uptake test of Dil-LDL and FITC-Lectin were positive. (95.83 +/- 1.72)% of CD133+ cells were found positive in both uptake tests. The positive rates of immunostaining of cell markers CD34 and factor VIII were (95.83 +/- 2.23)% and (95.92 +/- 1.43)% after cultured for one week, which showed no significant differences between CD133+ EPCs and human umbilical vein endothelial cells. Capillary structures were formed by CD133+ EPCs after cultured for 4 and 7 d in vitro. CONCLUSIONS: High purity of CD133+ EPCs can be obtained by MACS separation. CD133+ EPCs can differentiate into mature endothelial cells with the effects of stimulating factors.