氧应激在TNF-α诱导人内皮细胞PDGF-B链基因表达中的作用

Roles of oxygen stress on TNF-α-induced expression of platelet-derived growth factor-B chain gene in human endothelial cells

探讨氧应激在肿瘤坏死因子α(TNF α)诱导血管内皮细胞血小板衍生生长因子 B(PDGF B)链基因表达中的作用。培养的人脐静脉内皮细胞 (HUVECs)以TNF α处理或预先以小分子抗氧化剂N 已酰半胱氨酸 (NAC)处理 ,用ELISA和RT PCR法分别检测PDGF B的蛋白和mRNA表达 ,用氧化 还原敏感的荧光探针 2 ,7 Dichlorofluorescein(DCF)检测细胞内的氧化 还原水平。结果显示 ,TNF α(2 0 0U/mL)作用 2 4h后 ,HUVECs中PDGF B的蛋白含量和mRNA表达均明显增加 ,分别较对照组增加 5 0 %和 12 9% (P <0 0 5 ) ,但小分子抗氧化剂N 已酰半胱氨酸 (NAC ,2 0mmol/L)能明显阻断TNF α对PDGF B蛋白和mRNA表达的诱导作用。TNF α处理后 4hHUVEC的氧应激水平明显升高 ,至 2 4h时仍维持在较高水平 ,但可被NAC完全抑制。这些结果提示TNF α诱导血管内皮细胞PDGF

To investigate the roles of oxidative stress on tumor necrosis factor-α(TNF- α)-induced expression of PDGF-B chain gene in endothelial cells. Human umbilical vein endothelial cells (HUVECs) were collected and induced by TNF- α with or without pre-incubation with antioxidant N-acetylcysteine(NAC). The expressions of the PDGF-B chain gene at the protein and mRNA levels were measured by ELISA and RT-PCR methods. The oxidative stress was measured in the cells by 2,7-Dichlorofluorescein (DCF) staining,based on ROS-mediated conversion of DCF into fluoresent DCF. Both the protein content and mRNA expression level of the PDGF-B increased in the HUVECs (by 50% and 129%, respectively, P<0.05) after treated with TNF- α(200U/mL)for 24hr, but these inductions by TNF- α were blocked by NAC( 20mmol/L).Enhanced oxidative stress was found in the TNF- α-treated cells at 4h and 24h, and that was also inhibited by NAC. These results suggest that the oxidative stress may play a major role in the TNF- α-induced upregulation of PDGF-B gene.