Identification of hamster inducible nitric oxide synthase (iNOS) promoter sequences that influence basal and inducible iNOS expression

Journal of Leukocyte Biology: An Official Publication of the Reticuloendothelial Society

关键词: C/EBP‐;    β;    transcriptional regulation;    NF‐;    IL‐;    6;    NOS2;   

DOI  :  10.1189/jlb.1010568

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

IFN‐γ/LPS‐activatedhamster(Mesocricetusauratus)macrophagesexpresssignificantlylessiNOS(NOS2)thanactivatedmousemacrophages,whichcontributestothehamsterˈssusceptibilitytointracellularpathogens.WedeterminedamechanismresponsiblefordifferencesiniNOSpromoteractivityinhamstersandmice.TheHtPP(1.2kb)showedlowbasalandinduciblepromoteractivitywhencomparedwiththemouse,andsequenceswithina100‐bpregion(−233to−133)ofthemouseandhamsterpromotersinfluencedthisactivity.Moreover,withinthis100bp,weidentifiedasmallerregion(44bp)inthemousepromoter,whichrecoveredbasalpromoteractivitywhenswappedintothehamsterpromoter.Themousehomolog(100‐bpregion)containedacis‐elementforNF‐IL‐6(−153/−142),whichwasabsentinthehamstercounterpart.EMSAandsupershiftassaysrevealedthatthehamstersequencedidnotsupportthebindingofNF‐IL‐6.IntroductionofafunctionalNF‐IL‐6bindingsequenceintothehamsterpromoteroritsalterationinthemousepromoterrevealedthecriticalimportanceofthistranscriptionfactorforfulliNOSpromoteractivity.Furthermore,thebindingofNF‐IL‐6totheiNOSpromoter(−153/−142)invivowasincreasedinmousecellsbutwasreducedinhamstercellsafterIFN‐γ/LPSstimulation.DifferencesintheactivityoftheiNOSpromoterswereevidentinmouseandhamstercells,sotheywerenotmerelyaresultofspecies‐specificdifferencesintranscriptionfactors.Thus,wehaveidentifieduniqueDNAsequencesandacriticaltranscriptionfactor,NF‐IL‐6,whichcontributetotheoverallbasalandinducibleexpressionofhamsteriNOS...

【 授权许可】

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