活体动物基因表达的分子影像学研究方法

活体动物基因表达的分子影像学研究方法徐宇虹August2008,Hangzhou基因表达的时空特征常规的mRNA的检测

蛋白产物的检测-->断裂的时间信息,缺失的空间信息分子影像学方法!什么是分子影像Molecularimaging--- Imaging“molecularevents”/”biological processes”ina“systems”setting无创-->连续多次观查-->时间序列信息影像-->空间信息ImagingmodalitiesCT3Dobjectsetof2Dprojections

PrincipleofelectrontomographyTheprincipleoftomographicreconstruction:CollectmultipleprojectionsOfa3-DobjectContrastMechanismNonionicmonomerFromR.Older,:internettutorialIodinatedContrastCompoundsCompound[Iodine]mg/mLmOsm/kgIonicmonomerupto4001400-2100Ionicdimer320600Nonionicmonoupto350600-800Nonionicdimer320290HighResolutionSpiralCTVisualizingvertebralforamenaBudingeretal.,LBNLandNCSAMRIContrastMechanismGadolinium-BasedContrastParamagneticagentDecreasesT1relaxationtimesToxicinfreestateGadodiamide(Omniscan)FenanoparticlescontrastingagentsThesusceptibilityeffectofirongiveshighcontrastthatisobservableonT2-weightedinMRIUSPIOaredexran-coatedironoxidenanoparticlesthatareinternalizedintomononuclearphagocyticcellsLymphocyteswithoutcontrastingagentLymphocyteswithcontrastingagentUSreal-timeimaging;relativelyshortandefficientimagingprotocols,comparedwithMRIornuclearimaging;noninvasiveness(intheabsenceofcontrast)tominimizepatientdiscomfort;lowoperatingcosts;largeinstalledequipmentbase;andcomplementarytherapeuticandimagingapplications.UltrasoundContrastAgentsIMAGENT:perflexane(stablegas)lipidmicrospheresDonotgivetopatientswithcardiacshunts14%reportedAE(compareto11%withsaline):headache,nauseamostcommonOPTISON:humanalbuminmicrosphereswithoctafluoropropaneContraindicatedifhypersensitivitytobloodproducts17%reportedAE:headache,nausea,flushing,dizzinessPETContrastMechanismOpticalcontrastmechanism

For‘Transparent’AnimalsOnlyBiologyAnatomyMetabolismReceptorbindingGeneexpressionCelltraffickingCelldeathModalityX-rayCTSPECTPETMRIBioluminescenceFluorescenceMajordiseasesCardiovasculardiseaseCancerDepressionArthritisAlzheimer’sDiseaseParkinson’sdiseaseMolecularimaging

(geneexpressionimaging)Whatismolecularresolution?Imaginggeneexpressionproduct-ProteinImagingreportergeneexpressionHaubnerRetal.,CancerRes.61:1781,2001.Smith-Jones,etal.NatureBiotechnology22,701-706(2004)ImagingreportergeneTracerTrappingMethodsEnzymesasreportergenesEnzymesasreportergenesPhosphorylationHSV1-TKtrapsradiolabeledacyclovir(nucleotide-5’-monophosphatescannotcrossplasmamembrane)DeaminationCytosinedeaminatetrapsradiolabeled5-fluorocytosineX=O,Y=OH,Z=HX=CH,Y=OH,Z=HX=O,Y=OH,Z=FX=CH,Y=OH,Z=FX=O,Y=F,Z=H<GCV><PCV><FGCV><FPCV><FHBG>HSV-TKsubstratesYaghoubiS,etal.“Humanpharmaco-kineticanddosimetrystudiesof[18F]FHBG:AreporterprobeforimagingHSV1-tkreportergeneexpression”JNuclMed2001.PETImagingofAd-CMV-HSV1-tkTransgeneExpressioninLiverCancerPatients

PenuelasI,etal.Gastroenterology2005MRIOtherenzymaticsystemsGalactopyronosecapb-galactosidaseMeadeetal.,CaltechFireflySeapansyBioluminescenceLuciferin/coelenterazineLuciferaseoxidationproductOtherenzymaticsystemsTracerTrappingMethodsLigandreporterprobesTracerTrappingMethodsLigandreporterprobesTracerTrappingMethodsLigandreporterprobesLigandreporterprobesystems-ReportergeneexpressionleadstodopamineD2receptorproduction.Trapsdopamineantagonistspiperone.-Expressionoftransferrinreceptorstrapsion-oxidenanoparticlesbondedtotransferrin.MRIreportergeneTfRGambhiretal.,UCLAFluorescentproteinsGFPRFPApplicationsofgeneimaging1.EmbryonicStemCelllabelingImagingstemcellsurvival,proliferationandmigrationinvivo2.ImagingtherapeuticgenedeliveryThymidinekinaseservesasaPETreportergenewhen[18F]-FHBGisusedinpico-nanomolarconcentration.Thymidinekinaseservesassuicidegenewhenganciclovirisadministeredinmilligramdosages.VEGFtherapeuticgene

HSVTKimaginggeneRatsinjectedwith1x1010pfuAd-CMV-VEGF121-CMV-HSV1-sr39tkduringtheperi-infarctperiod.Invivoperfusion/metabolismdefectsconfirmedbyhistology.HSV1-sr39tkreportergeneconfirmedbythymidinekinaseantibodystain.At2months,VEGFtreatedanimalsshowsignificantincreasesincapillaries(CD31stain;747±104vs.450±101/mm2)andsmallbloodvessels(α-SMAstain;8.1±0.8vs.5.1±1.2/mm2).3