InordertoinvestigatewhetherlipoxinA4(LXA4)hasanantagonisticeffectonlipopolysaccharide(LPS)-inducedsynthesisofinterleukin(IL)-1β,IL-6andIL-8inratpulmonarymicrovascularendothelialcells(PMVEC),andtoexplorethemolecularmechanismsofsignalpathwayinLXA4actions,culturedPMVECweretreatedwithLPS,withorwithoutpreincubationwithLXA4.ProteinsofIL-1β,IL-6andIL-8insupernatantwereanalyzedbyenzyme-linkedimmunosorbentassay(ELISA).ExpressionsofmRNAofIL-1β,IL-6andIL-8weredeterminedbyRT-PCR.Expressionsofphosphorylationofphosphoinositide3-kinase(PI3-K)andmyeloiddifferentiationfactor88(MyD88)wereanalyzedbyWesternblot.ActivitiesofDNA-bindingofnuclearfactor-kappaB(NF-κB)andactivatorprotein-1(AP-1)weremeasuredbyelectrophoreticmobilityshiftassay(EMSA).TheresultsshowedthatLPSinducedproductionofIL-1β,IL-6andIL-8inratPMVECviaMyD88/PI3-K/NF-κBandAP-1pathway-dependentsignaltransduction.LPS-stimulatedexpressionofPI3-K,activitiesofNFκBandAP-1,secretionofproteinandexpressionofmRNAofIL-1β,IL-6andIL-8butnotMyD88expressioninPMVECwereinhibitedbyLXA4inadose-dependentmanner.Inconclusion,LXA4inhibitssynthesisofIL-1β,IL-6andIL-8bydown-regulationofPI3-K/NF-κBandAP-1signalpathwayinPMVEC.
