葡萄糖和肿瘤坏死因子-α对内皮细胞中早期生长反应基因-1表达的影响

Expression of early growth response gene-1 in endothelial cells induced by TNF-α and glucose

目的探讨葡萄糖和肿瘤坏死因子-α对内皮细胞中早期生长反应基因-1表达的影响。方法利用人脐静脉内皮细胞体外培养,予以25mmol/L葡萄糖和/或10ng/ml肿瘤坏死因子-α与内皮细胞共同孵育,运用蛋白免疫印迹方法检测细胞中早期生长反应基因-1蛋白的表达,运用酶联免疫吸附法检测纤溶酶原激活抑制物-1的表达。结果葡萄糖和肿瘤坏死因子-α均可增加早期生长反应基因-1的表达,两种因素共同作用产生协同作用。而且,葡萄糖和肿瘤坏死因子-α也可促进纤溶酶原激活抑制物-1的表达。细胞外调节蛋白激酶1/2的抑制剂(PD98059)可下调肿瘤坏死因子-α所诱导的早期生长反应基因-1、纤溶酶原激活抑制物-1的表达,而对葡萄糖所诱导的早期生长反应基因-1的表达无明显影响。结论肿瘤坏死因子-α可能通过细胞外调节蛋白激酶1/2路径促进早期生长反应基因-1和纤溶酶原激活抑制物-1表达。肿瘤坏死因子-α和葡萄糖可能通过不同的信号通路调节早期生长反应基因-1、纤溶酶原激活抑制物-1表达,在肥胖、糖尿病等代谢紊乱所致的血管并发症的发生中起到重要的作用。

Objective To investigate the expression of early growth response gene-1 （Egr-1） induced by glucose and tumor necrosis factor-α（TNF-α） in endothelial cells. Methods Human umbilical vein endothelial cells were cultured and incubated with 25mmol/L glucose and/or 10ng/ml TNF-α. The expression of Egr-1 protein was quantified by Western blotting, and plasminogen activator inhibitor-1 （PAI-1） levels were measured by enzyme linked immuno-sorbent assay （ELISA）. Results Both glucose and TNF-α in- creased Egr-1 expression, while simultaneous exposure to the two factors exerted an additive effect. Furthermore, PAI-1 was also upregulated in the presence of TNF-α and glucose. Extracellular regulated protein kinasesl/2 （ERK1/2） inhibitor, PD98059, downregulated TNF-α-induced Egr-1 and PAI-1 expression, but had no effect on glucose-induced Egr-1 expression. Conclusion TNF-α induces Egr-1 protein expression and PAI-1 levels through the ERK1/2 pathway. Differential regulation of Egr-1 expression by TNF-α and glucose in endothelial cells may be an important consideration in the mechanisms linking these factors to the development of vascular dysfunction in metabolic disorders such as obesity and diabetes.