U937泡沫细胞中血管内皮生长因子的表达及药物的抑制作用

目的研究U937泡沫细胞中血管内皮生长因子(VEGF)表达以及丹酚酸B和银杏叶提取物对其的抑制作用。方法U937细胞与80 mg·L^-1氧化型低密度脂蛋白(OX-LDL)孵育48 h,建立U937泡沫细胞模型。用基础酶联免疫吸附试验(ELISA)检测各组培养基中VEGF蛋白分泌含量,用免疫组织化学法检测VEGF蛋白表达,用原位杂交法检测VEGF mRNA水平。给予不同浓度丹酚酸B和银杏叶提取物,观察VEGF表达的变化。结果培养的U937泡沫细胞培养液中VEGF含量和细胞中VEGF表达均明显高于U937正常细胞。丹酚酸B和银杏叶提取物加入后阳性反应明显减弱。结论泡沫细胞中VEGF呈高表达、含量明显增加,而丹酚酸B和银杏叶提取物可明显降低其含量。

EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH FACTOR IN U937 FOAM CELLS AND THE INHIBITORY EFFECT OF DRUGS

AIM: To study the expression of vascular endothelial growth factor (VEGF) in U937 foam cells and the inhibitory effect of salvianolic acid B and Ginkgo biloba extract in vitro. METHODS: U937 cells were incubated with 80 mg.L-1 oxidized low density lipoprotein (OX-LDL) for 48 h and a macrophage-derived foam cell model was established. The VEGF concentration in the media was determined by ELISA; the VEGF protein expression in cells was measured with immunohistochemistry; the VEGF mRNA level in cells was measured by in situ hybridization; the positive ratio detected by a morphometrical analysis system was used as the amount of the VEGF protein expression and the mRNA level. RESULTS: After U937 cells were incubated with OX-LDL, VEGF expression level increased greatly both in the cells and in the media. Salvianolic acid B and Ginkgo biloba extract were shown to remarkably inhibit the increase of VEGF. After treated with 10 micrograms/L-1 salvianolic acid B and Ginkgo biloba extract, the VEGF protein concentration in the media and positive ratio in the cells decreased compared with foam cells. After treated with 10 micrograms.L-1 salvianolic acid B and 100 micrograms.L-1 Ginkgo biloba extract, the VEGF mRNA level decreased measured by in situ hybridization. CONCLUSION: A high VEGF expression level was determined in U937 foam cells. Salvianolic acid B and Ginkgo biloba extract were found to inhibit VEGF expression significantly in U937 foam cells in vitro.