重度子痫前期患者脐静脉血清中VEGF及sFlt-1的表达及其对内皮细胞损伤的影响

Expression of Vascular Endothelial Growth Factor and Soluble fms-like Tyrosine Kinase Receptor 1 in Umbilical Vein Serum of Patients with Severe Preeclampsia and Their Effects on Injury of Endothelial Cells

目的探讨重度子痫前期患者脐静脉血清中血管内皮生长因子(vascular endothelial growth factor,VEGF)和可溶性血管内皮生长因子受体1(soluble f ms-like tyrosine kinase receptor 1,sFlt-1)表达的特点,及其对内皮细胞损伤的影响。方法采用ELISA试剂盒定量检测10例正常妊娠及10例重度子痫前期患者脐静脉血清中sFlt-1及VEGF的蛋白表达水平。分别将两组血清在体外干预人脐静脉内皮细胞株(EVC-304)生长,利用:①荧光标记的牛血清白蛋白检测内皮细胞的单层屏障功能;②MTT法检测内皮细胞的增殖能力;③硝酸还原酶法检测内皮细胞的一氧化氮合成能力;以评估两组血清对内皮细胞功能的影响。结果①与正常妊娠组相比,重度子痫前期组患者脐静脉血清中sFlt-1蛋白水平明显升高;而游离VEGF蛋白水平明显降低,两者呈负相关。②与正常妊娠组相比,重度子痫前期组脐静脉血清可使内皮细胞功能明显受损,包括:(1)通过单层内皮细胞的牛血清白蛋白浓度升高,即内皮细胞的单层屏障功能受损;(2)内皮细胞增殖能力明显被抑制;(3)培养液中NO浓度明显降低。③内皮细胞功能损伤程度与重度子痫前期组脐静脉血清中sFlt-1/VEGF水平成正相关。结论子痫前期患者血清中sFlt-1和VEGF表达失衡,与子痫前期内皮细胞损伤密切相关,可能是参与子痫前期发生发展的重要机制之一。

Objective To investigate the expression of vascular endothelial growth factor（VEGF）and soluble fms-like tyrosine kinase receptor 1（sFlt-1）in serum obtained from umbilical vein of patients with severe preeclampsia,and their effects on the injury of endothelial cells.Methods The levels of sFlt-1 and VEGF proteins in umbilical vein serum from 10 cases of severe preeclampsia and 10 cases of normotensive pregnancy were determined by using ELISA.The culture of human umbilical vein endothelial cell lines（EVC-304）was interfered with serum samples as described previously.The effect of umbilical vein serum on the function of endothelial cells was tested on the basis of following aspects：①Monolayer barrier function was evaluated by transferring fluorescently-labeled BSA across EVC-304 monolayer;②Cell proliferation was measured by using MTT assay;③The levels of secretory nitric oxide（NO）was assayed by nitrate reductase assay.Results ①The level of sFlt-1 protein in umbilical vein serum of patients with severe preeclampsia was significantly higher,whereas the level of VEGF protein was significantly lower than in normotensive pregnancy.There was obviously negative correlation between the level of sFlt-1 and VEGF in severe preeclampsia.②Compared to normotensive pregnancy,the umbilical vein serum of patients with severe preeclampsia could lead to the injury of endothelial cells,including：The increased transfer of fluorescence-labeled BSA across EVC-304 monolayer,indicating the damage of monolayer barrier function;The proliferation ability of EVC-304 was markedly decreased;The level of secretory NO was significantly reduced as compared with that in normotensive pregnancy group.③There was a positive correlation between the injury of endothelial cells and the level of sFlt-1/VEGF in umbilical vein serum of patients with severe preeclampsia.Conclusion The injury of endothelial cells is closely correlated with imbalance of sFlt-1 and VEGF levels in serum of patients with preeclampsia.