简介：AIMToinvestigatetheroleofthecomplement5a(C5a)/C5areceptor(C5aR)pathwayinthepathogenesisofacuteliverfailure(ALF)inamousemodel.METHODSBALB/cmicewererandomlyassignedtodifferentgroups,andintraperitonealinjectionsoflipopolysaccharide(LPS)/D-galactosamine(D-GalN)(600mg/kgand10μg/kg)wereusedtoinduceALF.TheKaplanMeiermethodwasusedforsurvivalanalysis.Serumalanineaminotransferase(ALT)levels,atdifferenttimepointswithina1-wkperiod,weredetectedwithabiochemistryanalyzer.Pathologicalexaminationoflivertissuewasperformed36hafterALFinduction.Serumcomplement5(C5),C5a,tumornecrosisfactor-α(TNF-α),interleukin(IL)-1β,IL-6,high-mobilitygroupproteinB1(HMGB1)andsphingosine-1-phosphatelevelsweredetectedbyenzyme-linkedimmunosorbantassay.Hepaticmorphologicalchangesat36hafterALFinductionwereassessedbyhematoxylinandeosinstaining.ExpressionofC5aR,sphingosinekinase1(SphK1),p38-MAPKandp-p38-MAPKinlivertissue,peripheralbloodmononuclearcells(PBMCs)andperitonealexudativemacrophages(PEMs)ofmiceorRAW264.7cellswasanalyzedbywesternblotting.C5aRmRNAlevelsweredetectedbyquantitativereal-timePCR.RESULTSActivationofC5andup-regulationofC5aRwereobservedinlivertissueandPBMCsofmicewithALF.BlockadeofC5aRwithaC5aRantagonist(C5aRaC5aRa)significantlyreducedthelevelsofserumALT,inflammatorycytokines(TNF-α,IL-1βandIL-6)andHMGB1,aswellasthelivertissuedamage,butincreasedthesurvivalrates(P<0.01forall).BlockadeofC5aRdecreasedSphK1expressioninbothlivertissueandPBMCssignificantlyat0.5hafterALFinduction.C5aRapretreatmentsignificantlydownregulatedthephosphorylationofp38-MAPKinlivertissuesofALFmiceandC5astimulatedPEMsorRAW264.7cells.Moreover,inhibitionofp38-MAPKactivitywithSB203580reducedSphK1proteinproductionsignificantlyinPEMsafterC5astimulation.CONCLUSIONTheC5a/C5aRpath

简介：AIM:Toelucidatethemechanism(s)bywhichS-adenosyl-L-methionine(SAM)decreaseshepatitisCvirus(HCV)expression.METHODS:WeexaminedtheeffectsofSAMonviralexpressionusinganHCVsubgenomicrepliconcellculturesystem.Huh7HCV-repliconcellsweretreatedwith1mmol/LSAMfordifferenttimes(24-72h),thentotalRNAandproteinswereisolated.cDNAwassynthesizedandrealtime-PCRwasachievedtoquantifyHCV-RNA,superoxidedismutase1and2(SOD-1,SOD-2)catalase,thioredoxin1,methionineadenosyltransferase1Aand2A(MAT1A,MAT2A)expression,andGAPDHandRPS18asendogenousgenes.Expressionofcellularandviralproteinwasevaluatedbywestern-blotanalysisusingantibodiesvsHCV-NS5A,SOD-1,SOD-2,catalase,thioredoxin-1,MAT1A,MAT2A,GAPDHandactin.TotalglutathionelevelsweremeasuredatdifferenttimesbyEllman’srecyclingmethod(0-24h).Reactiveoxidativespecies(ROS)levelswerequantifiedbythedichlorofluoresceinassay(0-48h);Pyrrolidindithiocarbamate(PDTC)wastestedasanantioxidantcontrolandH2O2asapositiveoxidantagent.RESULTS:SAMexpositiondecreasedHCV-RNAlevels50%-70%comparedtonon-treatedcontrols(24-72h).SAMinducedasynergicantiviraleffectwithstandardIFNtreatmentbutitwasindependentofIFNsignaling.Inaddition,1mmol/LSAMexpositiondidnotmodifyviralRNAstability,butitneedscellulartranslationmachineryinordertodecreaseHCVexpression.TotalglutathionelevelsincreaseduponSAMtreatmentinHCV-repliconcells.Transcriptionalantioxidantenzymeexpression(SOD-1,SOD-2andthioredoxin-1)wasincreasedatdifferenttimesbutinterestingly,therewasnosignificantchangeinROSlevelsuponSAMtreatment,contrarytowhatwasdetectedwithPDTCtreatment,whereanaverage40%reductionwasobservedinexposedcells.TherewasaturnoverfromMAT1A/MAT2A,sinceMAT1Aexpressionwasincreased(2.5fold-timesat48h)andMAT2Awasdiminished(from24h)uponSAMtreatmentatboththetranscriptionalandtranslationall