TNF-α对内皮细胞白介素-8基因表达的影响

Effects of TNF-α on IL-8 mRNA Expression in Endothelial Cells

IL - 8作为一种趋化细胞因子在炎症反应中具有重要作用 ,其在内皮细胞内的表达受多种细胞因子的调节。本文用 TNF-α孵育培养的人脐静脉内皮细胞不同时间后 ,用 RT- PCR法检测内皮细胞内 IL - 8m RNA的表达 ,并用免疫细胞化学染色法检测内皮细胞内 NF-κB的激活。结果发现 :(1)未用 TNF-α孵育的内皮细胞 IL - 8表达量很少 ,TNF-α孵育 1小时后 IL - 8表达明显增加 ,3 h进一步增加 ;6 h IL - 8表达降低 ,9h进一步降低至基础水平 ;(2 )未用 TND-α孵育的内皮细胞核 NF-κB p6 5免疫细胞化学染色呈阴性 ,NF-α孵育 1,3 h后 NF-κB p6 5免疫细胞化学染色呈阳性 ,6 h时后呈弱阳性 ,9h后呈阴性。提示 :TNF-α可诱导内皮细胞表达 IL - 8并可激活内皮细胞内 NF-κB,二者的时相过程基本一致。作者认为 TNF-α诱导 IL - 8在内皮细胞内表达可能与转录因子

As a kind of chemokine, IL 8 plays an important role in inflammatory reaction. Its expression in endothelial cells is regulated by a variety of cytokines. In this study, after incubating cultured human umbilical vein endothelial cells(HUVECs) with TNF α for different time, we employed RT PCR to assay IL 8 mRNA expression and immunocytochemical staining to detect NF κB activation in HUVECs. The results revealed:(1)IL 8 mRNA expressed little in untreated HUVECs; after HUVECs was pre incubated with TNF α for 1 hour, IL 8 mRNA expression increased greatly, and it increased further after pre incubated for 3 hours; howerver, when HUVECs was pre incubated with TNF α for 6 hours, IL 8 mRNA expression decreased, and it almost decreased to basal level when pre incubated for 9 hours; (2)the immunoreactivity of NF κB p65 in the nuclei of untreated HUVECs was negative; it became positive in the nuclei of HUVECs pre incubated with TNF α for 1 hour and 3 hours; it became weak positive in the nuclei of HUVECs pre incubated with TNF α for 6 hours, and after 9 hours, pre incubation, the immunoreactivity of NF κB p65 in the nuclei of HUVECs was negative. These results implied that TNF α was capable of inducing IL 8 gene expression and activation NF κB. and Their time courses were similar, thus suggesting that the induction of IL 8 gene expression by TNF α is probably due to the activation of NF κB.