糖皮质激素及NAC对腺病毒E1A蛋白上调IL-8及ICAM-1的抑制作用

目的探讨腺病毒E1A蛋白在致炎因素TNF-α作用下对人肺腺癌细胞(A549)炎症因子IL-8和ICAM-1表达的影响以及地塞米松(DXM)和N-乙酰半胱氨酸(NAC)的干预作用。方法构建稳定表达E1A蛋白的A549细胞系(E1A+组)及对照质粒转染细胞系(E1A-组)。用TNF-α刺激、DXM以及NAC干预细胞,用ELISA检测炎症因子IL-8蛋白的表达,流式细胞术检测ICAM-1的表达。结果E1A+组在10μg.L-1的TNF-α作用前后细胞IL-8蛋白浓度分别为(48.49±0.27)ng.L-1和(22 841.75±12.92)ng.L-1,明显高于E1A-组作用前的(1.67±0.07)ng.L-1和作用后的(3 576.04±3.20)ng.L-1,两组相比差异有统计学意义(P<0.01)。与TNF-α单独作用组相比,DXM和NAC预作用细胞可明显降低TNF-α诱导下IL-8的高表达,差异有统计学意义(P<0.01)。E1A+组在10μg.L-1的TNF-α作用前后细胞ICAM-1蛋白浓度(荧光强度)分别为17.12±3.32和35.12±3.19,均高于E1A-组作用前0.59±0.09和作用后29.72±3.32,两组相比差异有统计学意义(P<0.01)。与TNF-α单独作用组相比,DXM和NAC预作用细胞可明显降低TNF-α诱导的ICAM-1的表达,差异有统计学意义(P<0.01)。结论 E1A蛋白能够增加TNF-α诱导下的IL-8和ICAM-1蛋白的表达。DXM和NAC能够明显拮抗TNF-α诱导下的IL-8和ICAM-1的蛋白表达,具有较强的抗炎作用。腺病毒E1A蛋白对NAC及DXM的抗炎作用无明显拮抗作用。

Dexamethasone and N-acetyl-L-cysteine inhibits adenoviral E1A-triggered expression of IL-8 and ICAM-1 in A549 Cells

Aim To explore the influence of adenovirus ElA on IL-8 and ICAM-1 expression induced by TNF-α in A549,and the effect of NAC and dexamethasone upon the effect of E1A protein upregulated overexpression of IL-8 and ICAM-1 induced by in cell stably expression E1A protein.Methods Eukaryotic expression vector plasmid containing whole E1A gene was transfected into A549 cells.Expression of IL-8 and ICAM-1 in response to TNF-α,dexamethasone and NAC was compared between adenovirus E1A positive clones,control clones by ELISA and flow cytometry.Results The level of IL-8 increased from(1.67±0.07)ng·L-1 to(3 576.04±3.20)ng·L-1 in E1A negative cells and(48.49±0.27)ng·L-1 to(22 841.75±12.92)ng·L-1 in E1A positive cells with 10 μg·L-1 TNF-α treatment.The concentration of IL-8 protein was obviously increased in E1A positive cells with or without TNF-α treatment.The effect of NAC and DXM abolishing the overexpression of IL-8 induced by TNF-α showed no difference in both E1A positive and E1A negative cells.The concentration of ICAM-1 increased from 0.59±0.09 to 29.72±3.32 in E1A negative cells and 17.12±3.32 to 35.12±3.19 in E1A positive cells with 10 μg·L-1 TNF-α treatment.The concentration of ICAM-1 was obviously increased in E1A positive cells with or without TNF-α treatment.Treatment with DXM or NAC clearly decreased TNF-α-induced ICAM-1 secretion in both E1A positive and E1A negative cells.Conclusions These results indicate that E1A upregulates ICAM-1 and IL-8 expression induced by TNF-α in human lung adenocarcinoma cell line.DXM and NAC abolish the overexpression of IL-8 induced by TNF-α.Expression of adenoviral E1A has no effect on DXM and NAC induced anti-inflammatory effect.