目的研究血管内皮生长因子C(VEGF-C)、基质细胞衍生因子-1(SDF-1)、单核细胞趋化蛋白-1(MCP-1)和粒细胞集落刺激因子(G-CSF)对CD34^+/CD133^+/VEGFR-3^+淋巴管内皮祖细胞(LEPCs)的趋化和动员作用。方法用Percoll非连续密度梯度离心法分离狗外周血单个核细胞,再用流式细胞术分选VEGFR-3^+LEPCs,激光扫描共焦显微镜下观察细胞特征性标志物CD34和CD133的表达。通过跨膜迁移实验观察VEGF-C、SDF-1、MCP-1和G-CSF对LEPCs的趋化作用,并用扫描电镜观察迁移细胞的形态特征。在大鼠皮下分别注射VEGF-C、SDF-1、MCP-1和G-CSF,用流式细胞术检测外周血单个核细胞中LEPCs数目,同时用全自动血样分析仪计数白细胞。结果与对照组相比,VEGF-C、SDF-1、MCP-1和G-CSF组跨膜迁移细胞的百分率增大,用VEGFR-3和CXCR-4阻断抗体处理后VEGF-C和SDF-1的趋化迁移作用明显降低。注射VEGF-C、SDF-1、MCP-1和G-CSF后,大鼠外周血中LEPCs的数量明显增多。未见白细胞显著增多。结论VEGF-C、SDF-1、MCP-1和G-CSF对LEPCs有趋化迁移和动员作用,VEGF-C/VEGFR-3和SDF-1/CXCR-4信号途径在LEPCs趋化迁移方面起着重要调控作用。
Objective To investigate the effects of VEGF-C, SDF-1, MCP-1 and G-CSF on migration and mobilization of CD34^+/CD133^+/VEGFR-3^+ lymphatic endothelial progenitor cells (LEPCs). Methods Mononuclear cells were isolated from canine peripheral blood by non-continuous density centrifugation with Pereoll solution. VEGFR-3^+ cells were sorted with now cytometxy. Expression of specific marks CD34 and CD133 on VEGFR-3^+ cells were observed under a confocal laser scanning microscope. The effects of VEGF-C, SDF-1, MCP-1 and G-CSF on chemotatic migration of LEPCs were examined by transmigration assay. The morphological characteristics of the transmigrated cells were observed under scanning electron microscope. VEGF-C, SDF-1, MCP-1 and G-CSF were administrated to rats by subcutaneous injection. The number of LEPCs in peripheral blood was analyzed with flow cytometry and white blood cells were counted with blood cell analyzer. Results The percentage of the migrated cells through the membrane was greater in the VEGF-C, SDF-1, MCP-1 and G-CSF groups than that in the control group. After the cells were treated with blocking antibodies of VEGFR-3 and CXCR-4, the percentage of the migrated cells decreased obviously. After the injections of VEGF-C, SDF-1, MCP-1 and G-CSF, LEPCs in peripheral blood of rats increased obviously, while significant increase of white blood cells was observed. Conclusion VEGF-C, SDF-1, MCP-1 and G-CSF play a role in the chemotatic migration and mobilization of LEPCs. The signaling pathways of VEGF-C/VEGFR-3 and SDF-1/CXCR-4 have important regulating effects on the chemotatic migration and mobilization of LEPCs.