学科分类
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11 个结果
  • 简介:TheundecapeptidesubstanceP(SP)wasshowntobeintimatelyinvolvedinboththestructuralandfunctionalaspectsoftheanteriorpituitary.Yet,inadditiontoitsinfluencesonhormonalsecretion,SPmaywellpossessmoreactionsinthismastergland.ThepresentstudywasfthereforeaimedtoinvestigatetheeffectofSPontheproliferationofratanteriorpituitarycellsinprimaryculture,ItwasfoundthatSPcoulddose-dependentlyincreasetheincorporationoftritiatedthymidine(3H-TdR)intoculturedanteriorpituitarycells.OthermammaliantachykininssuchasneurokininAandneurokininBhadsimilareffectbuttovaryingdegrees.TheequipotentanalogueofSP,Norleucine^11-SP(Nle^11-SP),alsoactedlikewise.withitsactionantagonizablebyspantide,aSPreceptorblocker.TofurthercharacterizethenatureofcellsresponsivetothechallengeofSP,immunocytochemicalstainingagainstS-100proteinandsomeadenohypophysealhormoneswasperformedaloneorplusautoradiography.TheresultsshowedthatthepercentageofS-100proteinimmunorectivecellswasapparentlyelevatedbytheaddtionofNle^11-Spfor48h,whichindicatesapreferentialproliferationoffolliculo-stellatecellsundertheregime.ThiswasconfirmedbyincreasesinimmunocytochemicalorautoradiographicallabellingindicesofanteriorpituitarySubstancePandanteriorpituitarycellproliferation.Cellstreatedsimilarly.Takentogether,TheseresultsrevealthatthetrophicactionofSPobservedpreviouslyinothertissuesisalsopresentatleastinculturedratanteriorpituitarycells.withrespondingcellsbeingpredominantlyfolliculo-stellatecellsastypifiedbyS-100proteinimmunoreactivity.Therefore,anintra-pituitarytrophicactionofSPinvivocouldbeanticipated.

  • 标签: P物质 大鼠 垂体前叶细胞 体外增殖 促进作用
  • 简介:cAMPmediatedsignalingmayplayasuppressiveroleinimmuneresponse.WepreviouslyfoundthatthecAMP-elevators(CTxand8-Br-cAMP)inhibitedIL-12,IL-la,IL-6geneexpression,butincreasedthetranscriptionallevelsofIL-10andIL-1RainLPS-treatedmurineperitonealmacrophages.ThepresentstudyexaminedapossiblemolecularmechanisminvolvedincAMPelevators-inducedinhibitionofIL-12p40expressioninresponsetoLPS.OurdatademonstratedthatcAMPelevatorsdownregulatedIL-12p40mRNAexpressionandIL-12pT0productioninmurineperitonealmacrophages.SubsequentstudiesrevealedthatcAMP-elevatorsblockedphosphorylationofp38MAPK,butdidnotaffecttheactivityofNF-κBbindingtoIL-12promoter(-136/-112).ThisisthefirstreportthatcAMPelevatorsinhibitLPS-inducedIL-12productionbyamechanismthatisassociated,atleastinpart,withp38-dependentinhibitionbycAMPsignalingpathways.

  • 标签: 巨噬细胞 腹膜 鼠科动物 蛋白磷酸化 CAMP
  • 简介:TherearetwopossibleoutcomeswhenDNAdamageoccursinnormalmammaliancells:eitherinductionofcell-cyclecheckpointwhichinhibitstheprogressofthecellcyclesaswellasactivatesDNArepairpathways,oractivationofapoptosistoeliminatedamagedcells.Thep53tumour-suppressorgeneplaysakeyroleinselectingthesepathways.Inourpresentworks,thehumangastriccancercelllineAGSwastreatedwithtripchlorolide,apotentantitumorcompoundpurifiedfromaChineseherbTripterygiumWilfordiiHook.Singlecellgelelectrophoresis(Cometassay)showedthatthetreatmentoftripchlorolideresultedinDNAdamageinAGScells.ThedamagedAGScellswentthroughapoptosis,whichwastime-anddose-dependent.

  • 标签: 胃癌细胞 P53 激活 雷公藤提取物 诱导 细胞凋亡
  • 简介:Recentstudiesindicatethatcell-cyclecheckpointsaretightlycorrelatedwiththeregulationofapoptosis,inwhichp53playsanimportantrole.OurpresentworksshowthattheexpressionofE6/E7oncogenesofhumanpapillomavirusinHeLacellsisinhibitedinthepresenceofanti-tumorreagenttripchlorolide(TC),whichresultsintheup-regulationofp53inHeLacells.Interestingly,underthesameTC-treatment,thecellsattheearlyS-phasearemoresusceptibletoapoptosisthanthoseatthemiddleS-phasealthoughp53proteinisstabilizedtothesamelevelinbothsituations.Significantdifferenceisexhibitedbetweenthetwospecifiedexpressionprofiles.Furtheranalysisdemonstratesthatanti-apoptoticgenesurvivinisup-regulatedbyp53intheTC-treatedmiddle-Scells,whereasitisdown-regulatedbyp53intheTC-treatedearly-Scells.Takentogether,thepresentstudyindicatesthatthedifferentialp53-regulatedexpressionofsurvivinatdifferentstagesofthecellcycleresultsindifferentcellularoutputsunderthesameapoptosis-inducer.

  • 标签: 细胞循环 P53基因 细胞凋亡 TC SURVIVIN 基因表达
  • 简介:Changesinthedistributionof1P1-antigeninthedevelopingchickretinahavebeenexaminedbyindriectimmunofluorescencestainingtechniqueusingthenovelmonoclonalantibody(MAb)1P1.Expressionofthe1P1antigenwasfoundtoberegulatedinradialaswellasintangentialdimensionoftheretina,beingpreferentiallyorexclusivelylocatedintheinnerandouterplexiformlayersoftheneuralretinadependingonthestagesofdevelopment,Withtheonsetoftheformationoftheinnerplexiformlayer1P1antigenbecomesexpressedintheretina.Withprogressingdifferentiationoftheinnerplexiformlayer1P1immunofluorescencerevealed2subbandsatE9and6subandsatE18,Atpostnatalstages(afterP3)immunoreactivitywasreducedinaninside-outsidesequenceleadingtothecompleteabsenceofthe1P1antigeninadulthood.1P1antigenexpressionintheouterplexiformlayerwasalsosubjecttodevelopmentalregulation.Thespation-temporalpatternof1P1antigenexpressionwascorrelatedwiththetimecourseofhistologicaldifferentationofchickretina,namelythesynapserichplexiformlayers.Whetherthe1P1antigenwasfunctionallyinvolvedindendriteextensionandsynapseformationwasdiscussed.

  • 标签: 鸡胚 视网膜发育 网织层 IP1抗原 表达 时空分布
  • 简介:WereportedinthismanuscriptthatTGF-β1inducesapoptosisinAML12murinehepatocytes,whichisassociatedwiththeactivationofp38MAPKsignalingpathway.SB202190,aspecificinhibitorofp38MAPK,stronglyinhibitedtheTGF-β1-inducedapoptosisandPAI-1promoteractivity.TreatmentofcellswithTGF-β1activatesp38.Furthermore,over-expressionofdominantnegativemutantp38alsoreducedtheTGF-β1-inducedapoptosis.Thedataindicatethattheactivationofp38isinvolvedinTGF-β1-mediatedgeneexpressionandapoptosis.

  • 标签: 转化生长因子Β 细胞凋亡 P38 肝细胞 信号传导
  • 简介:Thec-erbB-2proto-oncogeneencodesa185kDaproteinp185,whichbelongstoepidermalgrowthfactorreceptorfamily.Amplificationofthisgenehasbeenshowntocorrelatewithpoorclinicalprognosisforcertaincancerpatients.ThemonoclonalantibodyA21whichdirectedagainstp185specificallyinhibitsproliferationoftumorcellsoverexpressingp185,henceallowsittobeacandidatefortargetedtherapy.InordertoovercomeseveraldrawbacksofmurineMAb,wecloneditsVHandVLgenesandconstructedthesingle-chainFv(scFv)throughapeptidelinker.TherecombinantscFvA21wasexpressedinEscherichiacoliandpurifiedbytheaffinitycolumn.SubsequentlyitwascharacterizedbyELISA,Westernblot,cellimmunohistochemistryandFACS.Alltheseassaysshowedthebindingactivitytoextracellulardomain(ECD)ofp185.BasedonthosepropertiesofscFvA21,wefurtherconstructedthescFv-Fcfusionmoleculewithahomodimerformandtherecombinantproductwasexpressedinmammaliancells.Inaseriesofsubsequentanalysisthisfusionproteinshowedidenticalantigenbindingsiteandactivitywiththeparentantibody.Theseanti-p185engineeredantibodieshavepromisedtobefurthermodifiedasatumortargetingdrugs,withaviewofapplicationinthediagnosisandtreatmentofhumanbreastcancer.

  • 标签: p185^c-erbB-2 肿瘤表面抗原 重组抗体片段 基因表达 特性
  • 简介:Amurinemacrophage-likecelllineJ774,acquired,inresponsetoLPS,anabilitytokilltumornecrosisfactor(TNF)-insensitivetargetP815mastocytomacellswhereasanothercellline,P388D1didnot,LPStriggeredsignalingmechanismsbetweenthetwocelllineswerecomparedwithanaimtoinquireaboutthepossiblenatureoftheabove-mentioneddifference,TheresultswhowedthattwocelllinesrespondtoLPS-treatmentbyparallelactivationofbothphospholipasesCandA2(PLCandPLA2)toapproximatelythesameextent.ThemaximumresponseoftothenzymesofJ774cellswasnotedwithin10minthetreatmentwhereasthatofP388D1cellsrequiredmorethan20min,TheotherpropertiesofLPS-responsiveenzymesstudiedweresimilarbetweentwocelllines,includingActivationofPLCandPLA2andPKCinmacrophagesbyLPS.Ca2+augmentationofenzymeactivation,participationofguaninenucleotidebinding(G)proteinsintheinitialactivationpreocesses,andinhibitionofenzymeactivationbythepriortreatmentofcellswithcholeraorpertussistoxinsetc.Moreover,LPS-triggeredactivationofPLCandPLA2wasfoundtobefollowedbytheincreaseofPKCactivitiesinbothcelllines.Inspiteofthesesimilarities.J774cellspossessedbothbasicandacidicformsofPKCactivities,whileP388D1cellsownedonlyPKCofbasicform,Nevertheless,thequestionwhyJ774cellsbutnotP388D1cells,canacquirethetumoricidalactivity,aganistP815,cellsfollowingLPStreatmentrematinstobeanswered.

  • 标签: 鼠巨噬细胞细胞系 磷脂酶A2 磷脂酶C 蛋白激酶C LPS诱导激活
  • 简介:Amurinemacrophage-likecellline,J774,acquried,inresponsetoLPS,anabilitytokilltumornecrosisfactor(TNF)-insensitivetargetP815mastocytomacells,whereasanothercellline,P388D1,didnot.LPS-triggeredsignalingmechanismsbetweenthetwocelllineswerecomparedwithanaimtoinquireaboutthepossiblenatureoftheabove-mentioneddifference.TheresultsshowedthattwocelllinesrespondtoLPS-treatmentbyparallelactivationofbothphospholipasesCandA2(PLCandPLA2)toapproximatelythesameextent.ThemaximumresponseofbothenzymesofJ774cellswasnotedwithin10minofthetreatment,whereasthatofP388D1cellsrequiredmorethan20min.TheotherpropertiesofLPS-responsiveenzymesstudiedweresimilarbetweentwocelllines,ineludingActivationofPLCandPLA2andPKCinmacrophagesbyLPSCa2+augmentationofenzymeactivation,participationofguaninenucleotidebinding(G)proteinsintheinitialactivationprocesses,andinhibitionofenzymeactivationbythepriortreatmentofcellswithcholeraorpartussistoxinsetc.Moreover,LPS-triggeredactivationofPLCandPLA2wasfoundtobefollowedbytheincreaseofPKCactivitiesinbothcelllines.Inspiteofthesesimilarities,J774cellspossessedbothbasicandacidicformsofPKCactivities,whileP388D1cellsownedonlyPKCofbasicform.Nevertheless,thequestionwhyJ774cells,butnotP388D1cells,canacquirethetumoricidalactiyity,aganistP815cellsfollowingLPS-treatmentremainstobeanswered.

  • 标签: MURINE macrophagss LPS-induced activation PLO PLA2
  • 简介:OverexpressionandactivationofHER-2/neu(alsoknownasc-erbB-2),aproto-oncogene,wasfoundinabout30%ofhumanbreastcancers,promotingcancergrowthandmakingcancercellsresistanttochemo-andradio-therapy.Wild-typep53iscrucialinregulatingcellgrowthandapoptosisandisfoundtobemutatedordeletedin60-70%ofhumancancers.Andsomecancerswithawild-typep53donothavenormalp53function,suggestingthatitisimplicatedinacomplexprocessregulatedbymanyfactors.Inthepresentstudy,weshowedthattheoverexpressionofHER-2/neucoulddecreasetheamountofwild-typep53proteinviaactivatingPI3Kpathway,aswellasinducingMDM2nucleartranslocationinMCF7humanbreastcancercells.BlockageofPI3KpathwaywithitsspecificinhibitorLY294002causedG1-Sphasearrest,decreasedcellgrowthrateandincreasedchemo-andradio-therapeuticsensitivityinMCF7cellsexpressingwild-typep53.However,itdidnotincreasethesensitivitytoadriamycininMDA-MB-453breastcancercellscontainingmutantp53.OurstudyindicatesthatblockingPI3KpathwayactivationmediatedbyHER-2/neuoverexpressionmaybeusefulinthetreatmentofbreasttumorswithHER-2/neuoverexpressionandwild-typep53.

  • 标签: p53蛋白 乳腺癌 细胞增殖 HER-2/NEU PI3K路径 基因表达