简介:Withinthenervoussystem,regenerationislimited,andthisisduetothesmallamountofneuralstemcells,theinhibitoryoriginofthestemcellnicheandoftentothedevelopmentofascarwhichconstitutesamechanicalbarrierfortheregeneration.Regardingtheseaspects,manyeffortshavebeendoneintheresearchofacellcomponentthatcombinedwithscaffoldsandgrowthfactorscouldbesuitablefornervousregenerationinregenerativemedicineapproaches.Autologousmesenchymalstemcellsrepresentnowadaystheidealcandidateforthisaim,thanktotheirmultipotencyandtotheiramountinsideadulttissues.However,issuesintheirharvesting,throughtheuseofinvasivetechniques,andproblemsinvolvedintheirageing,requiretheresearchofnewautologoussources.Tothispurpose,therecentdiscoveryofastemcellscomponentinteeth,andwhichderivefromneuralcrestcells,hascametothelightthepossibilityofusingdentalstemcellsinnervoussystemregeneration.Inthiswork,inordertogiveguidelinesontheuseofdentalstemcellsforneuralregeneration,webrieflyintroducetheconceptsofregenerationandregenerativemedicine,wethenfocustheattentiononodontogenesis,whichinvolvestheformationandthepresenceofastemcomponentindifferentpartsofteeth,andfinallywedescribesomeexperimentalapproacheswhichareexploitingdentalstemcellsforneuralstudies.
简介:Cancertreatmentfailure,drugresistance,ormetastaticrecurrencearethoughttobecausedmainlybytheexistenceofaverysmallnumberofcancerstemcells(CSCs).Thecharacteristicsofthissubgroupofcellsincludeself-renewal,tumorigenesis,multipledifferentiationandhighinvasiveness,metastasis,anddrugresistancepotential.ManystudieshavedemonstratedthatCSCsplayimportantrolesintumorgrowth,spreadandmetastaticrelapseaftertreatment,andarecloselyrelatedtotheprognosisofpatients.Fromatherapeuticviewpoint,deepinsightsintotheCSCsbiology,developmentofspecifictherapeuticstrategiesfortargetingCSCs,andcharacterizationoftheirmicroenvironmentcouldbeanidealwaytocombatcancer.
简介:ExogenoussubstancePaccelerateswoundhealingindiabetes,butthemechanismremainspoorlyunderstood.Here,weestablishedaratmodelbyintraperitoneallyinjectingstreptozotocin.Fourwounds(1.8cmdiameter)weredrilledusingaself-madepunchontotheback,bilateraltothevertebralcolumn,andthentreatedusingamnioticmembranewithepidermalstemcellsand/orsubstanceParoundandinthemiddleofthewounds.Withthecombinedtreatmentthewound-healingratewas100%at14days.Withprolongedtime,typeIcollagencontentgraduallyincreased,yettypeIIIcollagencontentgraduallydiminished.Abundantproteingeneproduct9.5-andsubstanceP-immunoreactivenervefibersregenerated.Partialnervefiberendingsextendedtotheepidermis.ThetherapeuticeffectsofcombinedsubstancePandepidermalstemcellswerebetterthanwithamnioticmembraneandeitherfactoralone.OurresultssuggestthatthecombinationofsubstancePandepidermalstemcellseffectivelycontributestonerveregenerationandwoundhealingindiabeticrats.
简介:Theextracellularmatrix,whichincludescollagens,laminin,orfibronectin,playsanimportantroleinperipheralnerveregeneration.Recently,aSchwanncell-derivedextracellularmatrixwithclassicalbiomaterialwasusedtomimictheneuralniche.However,extensiveclinicaluseofSchwanncellsremainslimitedbecauseofthelimitedorigin,lossofanautologousnerve,andextendedinvitroculturetimes.Inthepresentstudy,humanumbilicalcord-derivedmesenchymalstemcells(hUCMSCs),whichareeasilyaccessibleandmoreproliferativethanSchwanncells,wereusedtoprepareanextracellularmatrix.WeidentifiedthemorphologyandfunctionofhUCMSCsandinvestigatedtheireffectonperipheralnerveregeneration.Comparedwithanon-coateddishtissueculture,thehUCMSC-derivedextracellularmatrixenhancedSchwanncellproliferation,upregulatedgeneandproteinexpressionlevelsofbrain-derivedneurotrophicfactor,glialcell-derivedneurotrophicfactor,andvascularendothelialgrowthfactorinSchwanncells,andenhancedneuriteoutgrowthfromdorsalrootganglionneurons.ThesefindingssuggestthatthehUCMSC-derivedextracellularmatrixpromotesperipheralnerverepairandcanbeusedasabasisfortherationaldesignofengineeredneuralniches.
简介:Acutemyeloidleukemia(AML)ischaracterizedbytheaccumulationofcirculatingimmatureblaststhatexhibituncontrolledgrowth,lacktheabilitytoundergonormaldifferentiation,andhavedecreasedsensitivitytoapoptosis.Accumulatingevidenceshowsthebonemarrow(BM)nicheiscriticaltothemaintenanceandretentionofhematopoieticstemcells(HSC),includingleukemiastemcells(LSC),andanincreasingnumberofstudieshavedemonstratedthatcrosstalkbetweenLSCandthestromalcellsassociatedwiththisnichegreatlyinfluencesleukemiainitiation,progression,andresponsetotherapy.Undeniably,stromalcellsintheBMnicheprovideasanctuaryinwhichLSCcanacquireadrug-resistantphenotypeandtherebyevadechemotherapyinduceddeath.YinandYang,theancientChinesephilosophicalconcept,vividlyportraystheintricateanddynamicinteractionsbetweenLSCandtheBMniche.Infact,LSC-inducedmicroenvironmentalreprogrammingcontributessignificantlytoleukemogenesis.Thus,identifyingthecriticalsignalingpathwaysinvolvedintheseinteractionswillcontributetotargetoptimizationandcombinatorialdrugtreatmentstrategiestoovercomeacquireddrugresistanceandpreventrelapsefollowingtherapy.Inthisreview,wedescribesomeofthecriticalsignalingpathwaysmediatingBMniche-LSCinteraction,includingSDF1/CXCL12,Wnt/β-catenin,VCAM/VLA-4/NF-κB,CD44,andhypoxiaasanewly-recognizedphysicaldeterminantofresistance,andoutlinetherapeuticstrategiesforovercomingtheseresistancefactors.
简介:〔摘要〕活动区是幼儿园课程实施的一种有效途径,是教育教学实践的一种极好的形式。活动区环境的创设、材料的投放、教师的观察指导以及活动后的讲评是一个有机的整体,它们之间相互联系、相互补充,但归结起来应围绕着一个中心,即以促进幼儿发展为中心。如果说,良好的活动区环境、丰富适宜的活动材料是活动区开展活动的基础,那么孩子与各种材料之间、与教师、同伴间的互动过程则是教师要观察的内容,本文主要对活动区活动与幼儿发展进行分析探讨。
简介:Excessivenoise,ototoxicdrugs,infections,autoimmunediseases,andagingcancauselossofspiralganglionneurons,leadingtopermanentsensorineuralhearinglossinmammals.Stemcellshavebeenconfirmedtobeabletodifferentiateintospiralganglionneurons.Littlehasbeenreportedonadiposetissue-derivedstemcells(ADSCs)forrepairofinjuredspiralganglionneurons.Inthisstudy,wehypothesizedthattransplantationofneuralinduced-humanADSCs(NI-hADSCs)canrepairtheinjuredspiralganglionneuronsinguineapigswithneomycin-inducedsensorineuralhearingloss.NI-hADSCswereinducedwithculturemediumcontainingbasicfibroblastgrowthfactorandforskolinandtheninjectedtotheinjuredcochleae.GuineapigsthatreceivedinjectionofHanks’balancedsaltsolutionintothecochleaewereusedascontrols.Hematoxylin-eosinstainingshowedthatat8weeksaftercelltransplantation,thenumberofsurvivingspiralganglionneuronsinthecelltransplantationgroupwassignificantlyincreasedthanthatinthecontrolgroup.Alsoat8weeksaftercelltransplantation,immunohistochemicalstainingshowedthatagreaternumberofNI-hADSCsinthespiralganglionsweredetectedinthecelltransplantationgroupthaninthecontrolgroup,andtheseNI-hADSCsexpressedneuronalmarkersneurofilamentproteinandmicrotubule-associatedprotein2.Within8weeksaftercelltransplantation,theguineapigsinthecelltransplantationgrouphadagraduallydecreasedauditorybrainstemresponsethreshold,whilethoseinthecontrolgrouphadalmostnoresponseto80dBofclicksorpuretoneburst.ThesefindingssuggestthatalargeamountofNI-hADSCsmigratedtothespiralganglions,survivedforaperiodoftime,repairedtheinjuredspiralganglioncells,andtherebycontributedtotherecoveryofsensorineuralhearinglossinguineapigs.