格格党

手机浏览器扫描二维码访问

Chapter 7 Cellular therapy（第1页）

Chapter7Cellulartherapy

banner"

>

Mostdiseaseshavecellulariybetraplebiochemicalimbalabecorrectedbydrugs.Thecellsreturntoanear-normalstateafeelsbetter.Someplexdiseasesstartwithgepreventaparticularproteinbeingexpressedetheproteinstrusuchawaythatitsfunisalteredoriive.Evenwiththedbalaernalrepairorcellsuiegenegesesd，whehefualcellprocesses，theyhaveadevastatiohorfuncreasedgrowthcausedbygeotheslipperyslopeofcerwherethese‘outoftrol’cellsfurthergetheirgeiddeveloptheabilityforlimitlessdivisionand，insomecases，gaiytoiissues.Ireatingsuchdiseasesrequiresthattheerrantcellsareremoved，corrected，oreveerreplayotherdiseasesarelylifethreateningbutotbecorrectedbydrugtreatmeheirplexbioature.Theidealsolutiothediseaseatitsrthefaultycells.Thisprocessiscalledcellulartherapyandbedividediforms.Themostfamiliaristhetransplantationofmaturefunalcells，asinabloodtransfusion，andstemcellsasiransplaillawaitastandardtherapyfortheintroduodifiedhumanorareplacearequiredsubstance，susulin-produgcellsfordiabetics.

MaheSwissphysidalchemistPhilippusAureolusParacelsusasthefirstpersoheceptofcelltherapyinhisbrossenWuSurgeryBook’）publishedin1536ie:‘thehearthealstheheart，luheluhespleen;likecureslike’.Thisremarkhistheorythateatihyanimalanswouldrebuildaalizetheparticularageingorfaultyaritionistdoethanoneofamoderherapist.Aslongagoas1667，Jean-BaptisteDenis，wintheroyallaboratoryofLouisXIV，attemptedtotransfusebloodfromaentallyillpatiere-bloodtransfusiono1912hysistriedtotreatsufferingfromuivethyroidlahyroid1931，aSwissPaulhe‘fatherofcelltherapy’byatwheroduethyroidtissueintoarapidlydeteripatienteriencedseveredamagetlandsdurihepatientredlivedforafurther30years.Niehansbeownedforhiscellulartreatments，andhispatientsincludedmembersofvariousRoyalfamilies，PopePiusXII，politidfamousfilmstars.Hisnameaments，especiallyskiyprocesses，liveonatthePaulNiehansidedinSwitzerlandbyhisdaughter.The20thturyislitteredwithstoriesofso-calledcellulartherapies.JohnBrinkley，knowglanddoctor’，reportedlydid16，000operationsiedmenwithtissuefromthetesticlesofyounggoats，assertingthatthisprocedurewaseffectiveagainstimpotendcouldditifromasanity.Hislicewasrevokedonthegroundsofimmoralityandunprofessionalduct.JamesWilsoheuseofboviissuecells.Heclaimedthatsuchcellularpreparatioh‘havetheabilitytomigratetoanytissueinneedofrepairahesite，takeoeristicsofthehealthycellitassociateswith’.Otherattemptsalongsimilarlinesdredsofdeathsbyvioleionstobacterialorviraliionsingtwomenwhodiedofgasgangrenefollowiioalsheepcells.Other，eveionableembryoransplanttherapieswerepioneeredbyNiehansinSwitzerland.Inthe1970s，hisstudentWolframKuhupaMexico，wheretherewereions，usingembryonicbluesharkcellspurchasedofflocalfishermenandwithadubiousnumberoflivecells，to‘treat’patientsforawiderangeofdiseases.Asaresultofthis‘quadthebadpressitreceived，itisherewasahighdegreeofscepticismaboutcell-basedtherapiesasroachedthe21sttury.

Transplantationofbloodcells

Bloodtransfusionusinganimalbloodstartedihturybutwasunsuccessfulbecauseofbloodgroupinpatibilityaions.SuchwasthedeathtollthattransfusionwasbahroughoutEuropeforover150years.Arouurhtury，KarlLandsteinerdisanbloodgroups（A，B，AB，O），forwhichhereceivedtheNobelPrizein1930.Mixingbloodfromindividualswithinpatiblegroupsleadstobloodglutination.Landsteinerdiscoveredthatthisprocesswasduetoanimmunologicalreabetweendissimilarbloodgroups.Theclassifiofbloodgroupsisbasedonthepresenceorabsenheritedantigens，ingproteins，carbohydrates，andlipids，onthesurfaceoftheredbloodcells.Ifinpatiblebloodisiibodiesi’sbloodplasmaattaewredbloodddestroythemiioncalledhaeminrenalfailureandcirculatoryshock.Bloodtransfusionisnowaroutineprodmostblooddonatioioheirpoheseincluderedbloodcells，platelets，whitebloodcells，plasma，andvariousproteinssutibodiesandgfactors（seeChapter5）.Seleposallowforspeeios，auseofaunitofblood.Forexample，plateletshelprestoretheblood’sgabilitywheopeoplewithtoofewplatelets（thromboia），aleadingtosevereandspontaneousbleedingandwhiesasideeffeotherapy.Whilethetransfusionofwhitecellsisrarefiions，ithasbeeherapywhenthecellshavebeeiipulatedtoeliti-tumourcellactivity.

Inthe1970s，EdwardDonnallThomasdemobonemarrowfusedintravenouslyrepopulatethebonemarrorodualbloodcells，workforwhichhereceivedtheNobelPrizein1990.Theactivetheserepopulatiiobloodstemcells.Cytsrequiredforcertreatmeroyalldividingdtlydonotdisatebetweentumourdbloodstemcells.Replagthepatient’sstemcellsfollowiherapyreplehebonemarrowcellpopulationaheresumptionofnormalbloodcellproduarrolantationhasbeenusedinawiderangeofcertherapiesingleukaemiaandlymphomatorepairbecausedbychemotherapy.Boransplantshavealsobeensuctreatingiaandotherdiseaseswherestemcellsaredamagedorabsent.

Autologousbloodstemcelltherapyusesthepatient’sownstemcells，whichareremovedaotreatmeagesofautologoustransplaheyarerelativelyfreeofiionandthereuionismorerapidaologoustransplaalossibleandsoothersourcellsareneeded.Allogeneisplantsihydoissuesmustbeaclosetissuematchtothoseofthepatiehedoive）isgeothepatiehematchofspecificcell-surfas，calledthehistopatibilityplex.EvenasingleDNAbasepairdiffereinginagedaminoaeofthefivehistopatibilityproteiinamismatgboraresareabletosequeheDNAofallfivehistopatibilitygeopatibility.Owilymatchedstemcellsbutueddonorsneedasmanymatismatcreasestheriskofgraftrejeraftversushostdisease.Graftrejeothebodyrejeelantedcellswhilegraftversushostdiseaseothenewcellsrejectthebody.Botheffectsresultinanimmunologicalreathatbefatal.

&reatments，bonemarrowwastakenfreboypicallythepelvis，throughareachesthetreoftheboeiqueisreferredtoasabonemarrowharvestandisperformedundergehesiawithalltherequirementsofhospitalizingthedonor.Nowadaysstembesourgblood.Thismethodedfromahatgstemcreaseddramaticallyfollowiionsofablrowthfarowthfadtheirstemcellsarecollectedbyameicalseparator，afterwhichtheredcellsarereturhedonor.

Itisalsopossibletoisolateusefulamountsofbloodstemniotidtheumbilicalcord.Cordbloodhasahightrationofstemcells，butonlyenoughforbloodstemsplantsinyoung.Usingbinationsofgrowthfactors，itispossibletoamplifytheemtheumbilicalcordallowingpossibleuseinadulttransplants.Umbilicalstemerallyproducelowlevelsofgraftversushostdisease.Steofone’sownumbilicellsforpossiblefutureuseinadultlifehasdevelopedintoanexpandiissuestepanies.

aherapy

Intheearly1960s，mouseembryoniaeshavingstemcellcharacteristicswerederivedfromateratoa.Thiscertissueismadeupofgermcellsthatarederivedfromtheovarydiredirectlyduetobirthdefectsresultingfrembryodevelopmehesecellswashinderedbyproblemsofgeioability.TheisolationofESesfromnormalembryos（seeChapter6）overcamethesedefedbegananewareaofresearch，explthepossibilitiesofisolatingandmanipulatinghumanembryoniccellsforpossibleuseasstemcelltreatmentsinadults.

MouseEScellshavebeeehegeiehesegeiiceareextremelyuseful，astheyactasamodeltostudythefunsofindividualgenesiohumans.Transgenicmicearecreatedbytransferringagene（forexampleahumaedgeoculturedEScells.Alternatively，individualgenesockedout’byintrodugafeenadrugresistaeuhesegenemanipulatiooriouslyi，ahetreatedeedtobegrownindselectedfeheselectedcellsarethenmijetotheinnercellmassofanormalembryobeforeimplantatioerusofafostermothermouse.Thehaveacopyoftheintroduepreseheirpairedes（i.e.theyareheterozygous）aherbredtogainhomozygousstrainsinwhiewgene（orkgene）hasaates，sotheeffectarentiheahegeneisexpressedinaparticulartissueorcelltypewilldependonitsgenomiehatusuallybedirectedattheEScelllevelbycarefulmolecularsele.Therearenowthousandseraihaspeealterationandtheyhavegreatlyenhanderstandingofmanyplexbiologicalprocesses.Wheheoverexpressionehemajorcauseofadisease，transgeniimalsactasamodelfordevelopingnewdrugsorpharmaceutiterventiohesegeiipulationsintrodugesthatresultiuses，esbe‘resdgrownincultureforusefulresearch.

ThereareanumberofpossiblesouranEScells:（i）cadaverfoetaltissue，（ii）embryafterireatments，（iii）embryosmadesolelyforresearchpurposesusingIVF，and（iv）embryosmadeusiraoeggs（theteiqueusedtocreateDollythesheep）.AllhumanEScellsourcesraiseethidreligiousquestions.trybytry，pulationusuallyrefiectsthepredomihidreligiousviews，withmanytriespletelyprohibitingallworkonembrystrictregulations，whilesomehavefew，ifaiosofhumaemcellresearchbelievethatahumanlifebeginsassoonasaneggisfertilized.Thedestrubryoisdeemedmorallyasmurder.TheyalsuethatESologiesareafirststeptoreproduing，whidamentallyviolatesahesanctityoflife.Propuethatiuralreproduaeilizedbutfailtoimplaerus.Afertilizedegg，whileitmaybeinghumabesideredahumailithasbeensuccessfullyimplantedinawomahemethodsrequiredforIVFroutiemorehumahanarehecourseofafertilitytreatment，leavingexcessembryosthatareoftensimplydisditismorallypermissibletousesuchembryosforpotentiallylife-savingbiomedicalresearch.ESesfromearly1990sexperimentshavebeeeduseinicaltreatments.

Oneexampleofusireathumaniheapprovalin2009forthefirstphaseoficaltrialsfortransplantationofhumahebrainandspinalcodeorcells），derivedinculturefromhumaopatientswithinjuredspinalcords.ThefirstpatieedinOctober2010byHaeamattheUyofia，IrvineandspohebiotepanyGerosinratshadpreviouslyshownthattherehadbeehereentinanimalswithspinaljuriesafteraseveransplantationofhumahadbeeooligodendroeageihisnewongoingstudytotreatparaplegicswilllastforatleastfiveyears.Whileitisthistreatmentwillpletelycuretheinjury，itishopedthatitwillshowsuffitrepairoftheobeworthwhile.ThisisapistudypromisingabrightfuturefortheuseofEScellsfspinalinjuries.

&hical，religious，andpolitistraintsofisolatingembryoniantherapyhasdriventheresearchdream，ayofindugorde-differentiatingadultbryo-likepluripotecouldbeusediherapy.In2006，ShinyaYamanakaproduducedpluripotentousefibroblastcellsbyftheexpressioneroviruses（aDNAvirusfamilythatissequehehostDoiheexpressioifiedasimportantformaintaiheadultfibroblastcells.Earlyattemptsdidallysuccessfulastheexpressionofsenesceraftertransplantationintothemouseembryo.Thisproblemwasoverein2008byusienes.Uroviruses，thisvirusdoesnotisowhehoste.SeveralgroupsmirroredthesemouseexperimentsinadulthumahefollDingandcolleaguesfounditossibletoatitopluripotehoutoionbutusimentwithtwosmallchemithesizedproteins.Themanipulationofanindividual’sadultcellstoproduic-likecellscapabletheiransandtissuesisprediajoricaltreatmeure.

&ialofusiorepairdiseasedanddamagedanswithouttheriskaionorothersideeffeendpointthatisdrivingmuchresearch.Stemcelltherapiesexistbut，sofar，oalmedicaltreatments.Themainareasressareiingofdmuscledamage，diabetes，liver，Parkinson’sdisease，andHuntingdon’sdisease.

Cardiovasculardisease—inghypertension，aryheartdisease，stroke，aiveheartfailure—isthemajorcauseofdeathinmanytriesaroundtheworld.Whendeprivedofoxygen，cardiacmusclecells（yocytes）dieandthistriggerstheformationofscartissue，theoverloadofbloodfloressure，agofviablecardiaccellsleadifailureah.Usi，andpigmodels，varioustypesofstemgembryonidothelial，andnaturallyheartstemcellshavebeensheedamagedhearttissues.Afewstudiesinhumans，usuallyundergery，haveshownthatstemtroduceddirectlytotheheartortrahebloodcirhavegivenimproveddiionofne>

Musculardystrophyisagroupofgeicdisordersicausesthemusclestoweakenwithtimeauallyleadstoprematuredeath.Theiscausedbytheproteindystrophinwhiaiyofmusgmouseanddogmodels，stemcellscalledmesoangioblasts（programmedtodiffereomusclecells）withacorrecteddystrophingeransplanted.Normaldystrophinlevelsahwereregainedinfouroutofsixdogs，suggestiherapymaybethewayaheadfortreatmentofthisgeicdisease.

In2008，EScellsweretodevelopingintoimmaturebetacellscapableinsulin，whichwereabletoreversediabetesihesameyear，adulthumanskincells，firstiopluripotentcells，rogrammedtoprodu.Amoreexgaspectwasthatthesecellssesulioglucose（astheydonormallyihinthepaisonlyamatteroftimebeforetransplantationofinsulin-produgcellswillreplaeedforalifetimespeinginsulininpeoplesufferingfromtype1diabetes.Similarprogresshasbeeuringliveristemmigliverregeionadistinctpossibility.

ThegraduallossofdnerveareasofthebraisinParkinson’sdisease.Earlycellulartreatmeraalbraintissue.Afewindividualsshorovementandprovidedageneralproofofprifromthetioustissuesource，theseicaltrialsdidhighlightseveralissuesingtheneedfequantitiesofpuredthatthefoetaltransplaedthemselvesbytransmissionofParkinson’sdisease.In2008，induitorstemcellswerecreatedfromskinfibroblastsofmidthenfurtherdiffereoneuronalprecursorcellswhich（follolantatioedintbrain.Thisapproachhasbeeendedinananimalmodelwhichmimison’sdiseasebykillingoffthenormaldcellswithatoxin.Transplantationofiemcellsgaveamarkedimprovemeoedanimals.ThemajeisnowtouandhowParkinson’sdiseasedevelopsaemcellmodelstodeveltreatments.

Huntington’sdiseaseisaivediseasethatischaracterizedbythedeathofhebrainthatproduitterchemical（gammaaminobutyricaicaltreatmentusingstemcellsfton’shasmirroredthatofParkinsoaltissueastemcellsgraftedibrainincreasebrainactivity，ingmions.Stemcellsmayhe‘magicbullet’forthisdiseasebutajorpartofitseffeagement.

Mesenchymalstemcells，foundinthebonemarrow，ducartilage，boendonas，mus，fat，aheyareeasytoisolatefromsmallquantitiesofbonemarrowandarereadilygrowsransplantatioocksareviableandcouldbeusedfor‘offtheshelf’therapies.Theyarealsofoualpulp，thesofttissueih.Wisdomteethareaparticularlyrichsourdthisopeingpossibilityofvisitiforastemsplant.Embryonichymalstemcellshavebeentrahejawbomieofthese‘trewintofullyfunalhardteethcapabletopaiooth-derivedstembepersuadedtehremaianIndianbiotepaheworld’sfirstdentalstemk.