VEGF受体flt-1和KDR在骨髓间充质干细胞中的表达及意义

Expressions of VEGF receptors flt-1 and KDR in bone marrow mesenchymal stem cells

目的:观察血管内皮生长因子(VEGF)受体flt1和KDR在成人骨髓间充质干细胞(MSCs)的表达情况,探讨MSCs分化为血管内皮细胞的可能性。方法:采用Percoll(1.073g·mL-1)分离液分离骨髓单个核细胞,体外培养MSCs,流式细胞术分析鉴定MSCs的纯度,在激光共聚焦扫描显微镜(LSCM)下观察flt1和KDR的表达,RTPCR检测VEGF作用下flt1及KDR表达改变情况。结果:经Percoll分离、体外培养扩增的MSCs,细胞纯度可达95%左右;flt1和KDR定位于MSCs的胞膜及胞浆;经VEGF处理的MSCs和flt1mRNA的表达较对照组增强,KDRmRNA的表达无明显改变。结论:培养的MSCs在体外稳定扩增,具有VEGF受体,传导VEGF的刺激,在适宜的环境和诱导因子的作用下,MSCs有望分化为血管内皮细胞。

Objective To investigate the expressions of vascular endothelial growth factor (VEGF) receptors flt-1 and KDR in human mesenchymal stem cells (MSCs). Methods MSCs were separated from bone marrow with Percoll reagent and expanded in culture medium. The surface antigens were detected, the labelled cells were analysed on a FACScan flow cytometer. The flt-1 and KDR expressions in MSCs were observed under laser scanning confocal microscope (LSCM). RT-PCR was used to detect the changes of flt-1 and KDR expressions treated with VEGF. Results Cultured MSCs were expanded as undifferentiated cells and the purity reached 95%. VEGF receptors flt-1 and KDR were positive in MSCs and the positive substance lied in cytoplasm and membrane of the cells. In MSCs treated with VEGF, the expression of flt-1 mRNA was increased, and the expression of KDR mRNA had not significant change, compared with control group. Conclusion MSCs can expand undifferentiatedly with VEGF receptors flt-1 and KDR and conduct stimulation of VEGF. In the conditions of proper enviroment and inducing factors, MSCs can be induced to differentiate into endothelial cells.