电烧伤大鼠血清诱导单核细胞分泌VEGF对单核-内皮细胞黏附作用的影响

目的:观察电烧伤大鼠血清诱导的单核细胞分泌血管内皮生长因子(VEGF)的水平,探讨其对单核细胞与血管内皮细胞黏附作用的影响。方法:制做电烧伤大鼠模型,制备电烧伤大鼠血清,同时制备正常大鼠血清作为对照。采用夹心ELISA法检测正常大鼠血清和电烧伤大鼠血清中VEGF及其可溶性受体s Flt-1含量。按照随机数字表法将人单核细胞株THP-1细胞分为正常血清组和电烧伤血清组,ELISA法检测2组细胞上清液中VEGF和s Flt-1含量。按照随机数字表法将人单核细胞株THP-1细胞分为正常血清组、烧伤血清组、正常血清+阻断剂组和烧伤血清+阻断剂组。取培养3 h、6 h的THP-1细胞,加入单层血管内皮细胞株EA.hy926细胞,行单核-内皮细胞黏附检测。结果:大鼠电烧伤后血清VEGF水平较正常大鼠显著增加,s Flt-1水平较正常大鼠明显减少。电烧伤血清诱导THP-1细胞分泌VEGF,s Flt-1水平随之减少。电烧伤血清可促进单核细胞与内皮细胞的黏附作用,s Flt-1可抑制电烧伤血清诱导的单核细胞与内皮细胞的黏附作用。结论:电烧伤大鼠血清诱导单核细胞分泌VEGF,从而促进单核-内皮细胞黏附。阻断VEGF的生物学效应,可有效抑制单核-内皮细胞的黏附。

Effect of monocyte-secreted VEGF induced by electrical burn serum on monocyte-endothelial cell adhesion

AIM: To observe the level of vascular endothelial growth factor (VEGF) secreted by monocytes cultured with electrical burn serum, and to explore the effect of VEGF on monocyte-endothelial cell adhesion.METHODS: The electrical burn serum of the rat was prepared. The normal serum from the rats without treating electric current was also collected for control. The contents of VEGF and its soluble receptor sFlt-1 in electrical burn group were determined by double-antibody sandwich ELISA. THP-1 cells were randomly divided into normal serum group and electrical burn serum group. The contents of VEGF and sFlt-1 in the culture supernatants were measured by double-antibody sandwich ELISA. THP-1 cells were also randomly divided into another 4 groups:normal serum group, electrical burn serum group, normal serum+inhibitor group and electrical burn serum+inhibitor group. THP-1 cells, which were incubated with the serum for 3 h and 6 h, were labeled with calcein-AM and then were added into the well with monolayer of endothelial cell line EA.hy926 to detect monocyte-endothelial cell adhesion.RESULTS: The levels of serum VEGF of the rats with electrical burns were significantly increased, the levels of serum sFlt-1 were significantly decreased as compared with the controls. The levels of VEGF secreted by THP-1 cells cultured with electrical burn serum were significantly increased, the levels of sFlt-1 were decreased correspondingly. Electrical burn serum enhanced monocyte-endothelial cell adhesion, sFlt-1 inhibited the adhesion between monocytes and endothelial cells.CONCLUSION: The monocytes exposed to the electrical burn serum secrete VEGF, which enhance the adhesion between monocytes and endothelial cells. Blockage of VEGF activity may effectively inhibit monocyte-endothelial cell adhesion.