Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator o...Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells （ECs） is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs. Methods Bovine retinal ECs （BRECs） were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF （100 ng/ml） and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase （eNOS） were detected using Western blotting. Griess reaction was used to detect nitric oxide （NO）. Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C （PKC） altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase （PI3K） or reactive oxygen species （ROS） significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased. Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.展开更多
基金This study was supported in part by grants from the National Natural Science Foundation of China （No. 30571994, No. 30570713 and No. 30630032）.
文摘Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells （ECs） is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs. Methods Bovine retinal ECs （BRECs） were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF （100 ng/ml） and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase （eNOS） were detected using Western blotting. Griess reaction was used to detect nitric oxide （NO）. Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C （PKC） altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase （PI3K） or reactive oxygen species （ROS） significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased. Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.
文摘目的:观察大鼠多发性脑梗死后脑组织内皮细胞表达细胞间粘附分子-1(ICAM-1)蛋白和一氧化氮合酶(NOS)阳性神经元表达的时程变化。方法:48只健康雄性SD大鼠制成多发性脑梗死模型,梗死后分别于1 h到14 d不同时间点处死并取脑,应用免疫组织化学法和NADPH-d组化法标记脑组织切片ICAM-1蛋白和NOS阳性神经元,设对照组和正常组,各6只大鼠。结果:多发性脑梗死后2 h ICAM-1蛋白表达达到高峰,NOS阳性神经元表达也同样达到高峰。结论:ICAM-1和NOS神经元参与大鼠多发性脑梗死的脑损伤。
