Aspirin inhibits tumor necrosis factor-α-stimulated fractalkine expression in human umbilical vein endothelial cells

Background Fractalkine is an important chemokine mediating local monocyte accumulation and inflammatoryreactions in the vascular wall.Aspirin inhibits inflammatory cytokine expression closely related to atherosclerosis throughthe way independent of platelet and cyclooxygenase (COX).There has been no report about the effect of aspirin onfractalkine expression.We aimed to determine the fractalkine expression in human umbilical vein endothelial cell(HUVEC) stimulated by tumor necrosis factor (TNF)-a and the effect of aspirin intervention.Methods Six of 8 HUVEC groups received either different concentrations of aspirin (0.02,0.2,1.0,5.0 mmol/L) or 40μmol/L pyrrolidinecarbodithioc acid (PDTC) or 0.5 μmol/L NS-398.The other two groups were negative control andpositive control (TNF-α-stimulated).After being incubated for 24 hours,cells of the 8 groups except the negative controlone were stimulated with TNF-α(4 ng/ml) for another 24 hours.After that,the cells were collected for RNA isolation andprotein extraction.Results Both mRNA and protein expressions of fractalkine in HUVEC were upregulated by 4 ng/ml TNF-a stimulation.Aspirin inhibited fractalkine expression in a dose-dependent manner at mRNA and protein levels.Nuclear factor-kappa Binhibitor,PDTC,effectively decreased the fractalkine expression.Fractalkine expression was not influenced by COX-2selective inhibitor NS-398.COX-1 protein expression was not changed by either TNF-a stimulation or aspirin,PDTC,NS-398 intervention.Both mRNA and protein expression of COX-2 in HUVEC were upregulated by 4 ng/ml TNF-αstimulation.Aspirin decreased COX-2 expression in a dose-dependent manner at mRNA and protein levels.Conclusions TNF-a-stimulated fractalkine expression is suppressed by aspirin in a dose-dependent manner throughthe nuclear factor-kappa B p65 pathway.