目的:研究来自口腔颌面部的脱落乳牙牙髓干细胞(stem cells from human exfoliated deciduous teeth, SHED)、牙髓干细胞(dental pulp stem cells, DPSC)和颌骨骨髓间充质干细胞(bone marrow mesenchymal stem cell, BMSC)的增殖能力及成血管内皮细胞分化潜能,为血管组织工程再生种子细胞的选择提供依据。方法:取临床乳牙和恒牙牙髓组织及颌骨组织并采用酶消化法分离培养相应的间充质干细胞,流式细胞技术检测间充质干细胞相关表面抗原的表达。采用CCK-8 (cell counting kit-8)法检测细胞的增殖能力。通过Matrigel三维培养技术诱导间充质干细胞成血管内皮细胞分化,并通过管腔计数及real-time PCR技术比较3种间充质干细胞的成血管内皮细胞分化能力。采用鸡胚绒毛尿囊膜(chick embryo chorioallantoic membrane, CAM)技术观察3种不同间充质干细胞新生血管能力。结果:3种干细胞均阳性表达CD73、CD90、CD105、CD146,阴性表达 CD34、CD45,符合间充质干细胞表面标记物的表达规律。SHED和DPSC的CD146表达率多于BMSC,CCK-8法检测显示SHED的增殖能力最强。诱导后的3种细胞均可在Matrigel基质胶上形成管腔样结构,诱导后SHED和BMSC形成的血管总长度大于DPSC,SHED形成的管腔数多于BMSC和DPSC。real-time PCR 结果显示几种成血管相关的细胞因子在不同细胞间表达存在差别。诱导后SHED的CD31、VEGFR2、vWF表达显著高于另外两种细胞。BMSC的VEGFR1表达量高于其他组,SHED高于DPSC。VEGF的表达在4组之间差异无统计学意义。3种细胞在CAM上计数新生血管数目显示较空白对照组差异无统计学意义,SHED组血管总长度较空白对照和BMSC大。结论:SHED、DPSC及 BMSC均能向成血管内皮细胞方向诱导分化且在Matrigel培养基上形成血管和管腔,SHED具有更强的分化和形成管腔的能力,同时SHED较BMSC及DPSC具有更强的增殖能力。

Objective: To compare the proliferation and capacity of differentiation to vascular endothelial cells and angiogenesis induction among stem cells from human exfoliated deciduous teeth (SHED), dental pulp stem cells (DPSC) and human bone marrow mesenchymal stem cells (BMSC) from orofacial bone. Methods: SHED and DPSC were isolated from pulp tissue of the patients. BMSC were isolated from orthognathic or alveolar surgical sites. The surface markers of the cells were detected by flowcytometry. Cell counting kit-8 (CCK-8) assays were conducted to detect the proliferation ability of the cells. The cells were induced into endothelial cells with conditional medium and then the induced cells were cultured in Matrigel medium. The expression of angiogenesis-related genes such as platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 1 (VEGFR1), vascular endothelial growth factor receptor 2 (VEGFR2) and von Willebrand Factor (vWF) were quantified by real-time PCR. The cells were cultured in chick embryo chorioallantoic membrane (CAM) and the vessels were counted after 5 days. Results: The cell surface markers CD73, CD90, CD105 and CD146 of all the stem cells were positive, CD34 and CD45 were negative. The CD146 positive rate of SHED and DPSC was higher than that of BMSC. SHED had a higher proliferation rate than DPSC and BMSC. After angiogenic induction for 14 d, 3 kinds of cells emanated pseudopodia formed grid structure long vasculature in Matrigel media. The total length of tube formation of induced BMSC (7 759.7 μm) and SHED (7 734.3 μm) was higher than DPSC (5 541.0 μm). The meshes number of induced SHED (70.7) was higher than DPSC (60) and BMSC (53.7) in Matrigel medium. The expression of CD31, VEGFR2 and vWF genes of SHED were higher than those of BMSC and DPSC. VEGFR1 gene expression of BMSC was higher than that of the other groups, and SHED was higher than DPSC. The expression of VEGF showed no difference among the cells. No deference was showed between the effect of the stem cells and negative control on new formed vessels in CAM. The total length of vessels of SHED (30.4 mm) was higher than that of the negative control (20.9 mm) and BMSC (28.0 mm). Conclusion: SHED, DPSC and BMSC can differentiate into vascular endothelial cells. SHED showed a stronger angiogenesis differentiation and proliferation potential compared with DPSC and BMSC.