The Role Of Adenoviral E1A Protein In Glucocorticoid Modulates Anti-inflammatory Effects

Objective:The aim of this study is to explore the influence of adenovirus ElA on IL-8andICAM-1expression induced by TNF-α in A549,and the effect of dexamethasone upon theeffect of E1A protein upregulated overexpression of IL-8and ICAM-1induced by TNF-α andfurther verify the relationship between latern Adenoviral infection and COPD.To highlight thefurther therapy of COPD.Method:Eukaryotic expression vector plasmid containing wholeE1A gene was transfected into A549cells. Expression of IL-8and ICAM-1in response toTNF-α stimulation were measured by ELISA and Flow Cytometry in E1A positive clones andE1A negative clones.To illustrate the role of glucocorticoids on the inflammation mediatorexpression in response to TNF-α in human alveolar epithelial cells and the effects ofadenovriral E1A protein upon this anti-inflammtion effect of glucocorticoids.E1A-positiveclones and E1A negative clones were treatment with TNF-α or glucocorticoid.The expressionof GR,HDAC1,HDAC2and NF-κB were measured with western blot and the activity ofhistone deacetylase （HDAC） was measured with colorimetric HDAC activity assaykit.Results:Cells stably expressing E1A protein were identified by RT-PCR,238bp and375bpfragments were only observed in E1A positive clones.For western blot andimmunocytochemistry,the specific banding and stain were observed only in E1A positiveclones.The level of IL-8were increased from（1.67±0.07）ng·L^-1to（3576.04±3.20）ng·L^-1inE1A negative cells and from （48.49±0.27）ng·L^-1to （22841.75±12.92）ng·L^-1in E1A positivecells with10μg·L^-1TNF-α treatment.The concentration of IL-8protein was obviouslyincreased in E1A positive cells with or without TNF-α treatment.The effect of DXM abolishedthe overexpression of IL-8induced by TNF-α show no difference in both E1A positive and E1A negative cells.The concentration of ICAM-1were increased from0.59±0.09to29.72±3.32in E1A negative cells and17.12±3.32to35.12±3.19in E1A positive cells with10μg·L^-1TNF-α treatment.The concentration of ICAM-1was obviously increased in E1Apositive cells with or without TNF-α treatment.Treatment with DXM clearly decreasedTNF-α-induced ICAM-1secretion in both E1A positive and E1A negativecells.Glucocorticoids increased the expression of HDAC1and HDAC2both in E1A-positiveand negative clones.Glucocorticoids may blunt the expression of HDAC1and HDAC2triggered by TNF-α. Glucocorticoids may blunt the activation of transcription factors NF-κBtriggered by TNF-α and glucocorticoids have no effect on activation of GR.Conclusion:Theseresults indicate that E1A upregulated IL-8and ICAM-1expression induced by TNF-α inhuman lung adenocarcinoma cell line.DXM abolished the overexpression of IL-8and ICAM-1induced by TNF-α. Expression of adenoviral E1A had no effect on DXM inducedanti-inflammatory effect.