The use of cloned whole organisms in medical research

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Theuseof cloned wholeorganismsin medicalresearch

Cloningis one of themost moderntechnologies that havebeenfacedwith manycriticisms,but at the same time it has gained many supports. Cloning is aprocessthat is usedby scientiststo producecopiesof identicalDNA. Mostof thecritiquesareraisedby theanimalrightsactivists whoopposedto theuseof cloned wholeanimalmodelsin conductingmedicalresearch.Thepigsarethemostcommoncloned modelsthat areusedin thestudyof humandiseasesandphysiology.Thebiochemical resemblance,physiology,genetics,andphysiologyofthe pigandhumanbeingsare close,which make the pig clones appropriate for medical research (Henriksen2). Thisgivesscientistsan easyaccess becausetheonly thing they need todo is to trigger theexpressionof silentgenes in pigclones in orderto havethepig’smodelthat hascertaingeneticexpressionsthat are similarto human.Themodelscan then beinjectedwith drugsthat havebeendevelopedto treathumandiseasesbefore itis administeredto humanbeings.Themodelscan alsobe artificially inflictedwith a humandiseaseto allowtheresearchers studytheprogressof thatdiseaseanddevelopa proper treatment.

Theactsof inflictingthecloned animalwith humandiseasesandinjectingthem with pharmaceutical productsduring thedrugtrialsare themajorpointsof argument.Thisleadstothe question,is itethicalto deliberatelyinfectliveorganismsandinjectthem with chemicalsthat are intendedto benefithumanbeingsin casetheyare provento be successfulin treatingdiseases?Thispaperwill presentadiscussion arguing that&nbsptheuseof cloned animalmodelsin medicalresearchmeetstherequirementsofethicalstandards,inspiteoftheongoingcritiques.The paper will also focus on the discussion about handmadeCloning of pigsforexpressionof humanalpha 2 andbeta 1integrin formedicalresearch.

Handmadecloning technology

Purposeof thehandmadecloning technology

Medicalresearchers andotherscientificresearchers have a strong interestin conductingteststo assessthemechanismsof actionandefficiencyof thepharmaceutical productsthat theydevelop.However,itis generallyconsideredto be unethicalandillegalto conductthesetestson humanbeings.It comes down to the remainingalternative,which is to run test on animals like lab rats. Thispresentsa newformof challengebecauseanimalsdonot havea similargeneticcompositionas humanbeingsandneitherdotheysufferfrom thesamediseases.Thesechallengeshavenecessitatedtheuseof handmadecloning technology to developanimalmodelsthat expresscertainortargeted humangenes in orderto facilitatescientificresearch(Liu 2). Theprocessof developingclones formedicalresearchis explainedin thissectionusingan exampleof pigsthat expressalpha 2 andbeta 1integrin. Theideaof cloning a wholeanimalusingthehandmadeapproachisbasedon thenotionthatthenewpigscarrytheentiregenome of thedonorpig,so scientisttakesadvantageof theprocessto introducethetwo genes that foralpha 2 andbeta 1 integrins in orderto achievetheir researchobjectives.

Thehandmade cloning approach

Establishmentof theβ 1integrin expression

Thelab processbeginswith thegenerationof SB vectors wherethecassetteof eGFP expressisinsertedin a reverseorforwardorientation.Avector that is developedusingtheforwardorientationisusedin theconstructionof sometransposable vector that carryhITGB1 gene that is in turndrivenby CVM promoter (Staunstrup 2). Theexpressionof β 1integrin in cellsthat havenot beenexpressingitis achievedby transferringNIH3T3 fibroblast into thosecells.Themurine fibroblasts aretransferredwith pT2/CMV-hITGB1 orpT2/SV40-neo. TheSV40-neo combinedwith eitherpCMV-mSBorpCMV-SB100X expresses theinactiveformof mSBandhyperactive formof SB 100X transpose respectively.Thesuccessfulexpressionof β 1integrin is testedusingantibodiesthat recognizeβ 1integrin.

Developmentof blastocysts with transgene expression

Theseblastocysts are developedby substitutingtheCVM componentof pT2/CMV-hITGB11V40-neo with keratinoyte-specificinvolucrinpromoter, which increasestransposon size.Thelevel of expressionis elevatedby includingthefirstintron of a gene knownas involucrinin promoters downstream. Theintroductionof antibodythat is specificforβ1 integrin showsthestaining of endogenous β1 integrin andits distributionin cellsthat containT2/INV-hITGB1.SV40-neo (Staunstrup 3). Thedonorcellsforswinetransgenesis is producedby introducinga transgene cassettethat is drivenby INV in Göttingen fibroblasts. TheSB vector’s co-transfection withpCNV-SB100X increasestheinsertionrateby about12 times.

Transgenicstatusof thecloned pigs

Transgenicstatusof thecloned animals(pigsinthiscase)is testedusingPCR that isperformedon genome DNA that is derivedfrom fibroblasts. Thecopynumberof SB vector is determinedby performingthesouthernblotassay on a genome that isobtainedfrom thebloodof thecloned animals.

Figure1: Transgenic statusof thecloned pigs

Source:Staunstrup (5)

Figure1 A showthepiglets that havebeensuccessfullyclonedandhavethecapacityto expresshumanbeta 1integrin. PartB is thePRC resultsshowingtheexistenceofthe transgeniccassettein pigsthat havesuccessfullyexpressedbeta 1integrin, butitis not presentin thecontrolpiglets. PartC showstheresultsof thesouthernblotassay, which indicatesthatthecloned pigshavesomegeneticdistinctionsince theyaredrawnfrom differentdonors.

Producingtransgenic pigswith expresshumanalpha 2integrin

Transgenicpigsthat expressforalpha integrin aredevelopedfrom pT2/INV-hIGTA2.SV40-neo, which is a construct of theSB transposon (Staunstrup 7). Thisprocessresultsin theestablishmentof stableclones of HaCaT keratinocyte, which are in turnverifiedusingimmunostaining of theexpressionof alpha 2integrin. Theprocessof cloning foralpha 2integrin resultsin thedistributionof excess amountsof integrin allover thetransgenic cellswith someproteinsbeinglocalizedin theplasma membraneandthenucleus.Theprimaryfibroblasts should betransfectedwith pT2/INV-hITGA2.SV40-neo alongwithSB100X-encoding plasmid. Transfection with pCMV-SB100X reducestheriskof integratingSB100X gene (Staunstrup 7). Immunostaining andqRT-PCR are themajortechniquesusedto demonstratehITGA2’s expression.Althoughtheclones may be genetically identical,their respectivelevels of expressionof alpha integrin may varydepending on their epigenicprofiles.Flowcytometry is usedto assesstheexpressionof alpha 2integrin andK14, which howthe integrinattachesto theplasma membraneof keratinocyte.

Markersofthe skininflationthat areactivatedin cloned animalmodels

Thehandmadecloning techniqueresultsin successfulelevation(about 6-27 times)of expressionof IL-1 alpha. IL-1 alpha playsa vitalrolein paracrine andautoin inflammationresponsesthat are inflictedin psoriatic skin(Staunstrup 8). In addition,thecloned animalhas an elevatedlevel of nRNA that is responsibleforencoding of differentmarkersof skininflammation,which includechemokine, ligand 5, ligand 10, andIL-8. Thereleaseof thesemarkersis elevated2-19 timesin transgenic animalscomparedto thewild-typeanimalsthat areusedas controls.Moreover,cloning elevatesthelevels of cytokines IL-1 beta, tumornecrosis,andthe colony-stimulating(GM-CSF) factorsabout 2-5 times.Theelevationof markersthat are responsiblefortheinflammationof humanskinconfirmsthatthelaboratorycloning of animalsusingtheHandmade cloning approachhas successfullyproducedmodelsthat are susceptibleto similarskindiseasesthat affecthumanbeings.

Figure2: Expression of humanbeta 1integrin in cloned (transgenic) animals

Source:Staunstrup (8)

Figure2 A showdifferencesin levels of expressionof beta 1integrin in thewildanimal(C 1) usedas controlandcloned animals.Levels of humanintegrin can be assessedusingthe qRT-PCRtechniquethat is specificto humanbeta 1integrin. Figure2 B showstheimageof fluorescence microscopy of hITGB 1transgenic animalandfrozensectionsof cutaneous. Theimageshowsthatbasal cellstaining is presentin allsamples(includingthecontrolanimal),buttheexpressionof suprabasal is onlyevidentin samplesfromcloned animals.

Significanceof handmadecloning from thescientificpointof view

Theentireprocessof triggering theexpressionof humanbeta 1 andalpha 2integrins isaimedat developinganimalmodelsthat can be usedin thelaboratoryto studythehumanskininflammation.Thismeansthatthecloned organismsareartificially infectedwith a skininfectionwith theobjectiveof allowingthescientiststo comprehendthepathogenesis andprogressionof cutaneous inflammation(Staunstrup 16). Abetterunderstandingof thispathogenesis will helpthescientistsin improvethetherapiesthat are currently being used. Thismeansthatthecutaneous inflammationis a human-specific illness,butinsteadof studyingitin human,scientiststransferthediseaseto a cloned animalmodel.

Thesisargument

Casesfortheuseof cloned animalsformedicalresearch

Theissueof cloning wholeorganismsforthepurposesof conductingresearchon theefficacyof pharmaceutical productsandpathogenesis of varioushumandiseasesis controversial.However,there are three majorfactors(includingintrinsicbenefitsof thecloned modelsto humanlife,lackof moralrightson thepartof thecloned animalmodel,andtheviewthatanimalsarecreatedby humanbeingsas resourcesto improvehumanwellbeing) indicatingthattheuseof cloned animalmodelsin medicalresearchis ethicalandwithin themoralstandards.

Intrinsicbenefits

Theuseof cloned animalmodelsin medicalandresearchlaboratoriesisaimedat increasingthehumanunderstandingof variousdiseasesandfacilitatethediscoveryof theappropriatetypesof therapy.Theseare intrinsicbenefitsthat thesocietygetsfrom thecloning technology, andcannot be ignored.Thedefensefortheuseof cloned animalmodelsis based on theJeremy Bentham’s, a British Philosopher, statementthatan actioncan be consideredto be correctas longas itprovidessomeintrinsicbenefitsto thetargeted society(Miziara126).Although,Bentham advocates fortherespectof therightsof allbeings(humanandnon-human), thebenefitassociatedwith an actionis a priority.Currently, over 89 % of themedicalresearcher agreesthattheuseof cloned modelshas enhancedtheir efficiencyin research(Festing 526). Therefore,there is nodoubtthatthecloning technology isdoneforthegoodof humanwell-being,which makesitethical.

Clonedanimalmodelsas resourcesto addresshumanneeds

Clonedmodelsare createdby humanbeingswith someobjectivesin mind.Forexample,thecloning of pigswith theup-regulated expressionof integrins alpha 2 andbeta 1 is usefulin thedevelopmentof therapyforhumanskininflammation(Staunstrup 6). Itwould be difficultto achievesuchobjectivesin theabsenceof animalmodels.Theviewof animalmodelsas resourcesownedby humanbeingsandexistto satisfyhumanneedsisbasedon thenotionthat are superiorandhavecontrolover otherlivingthings.In addition,cloned animalmodelsare generatedartificially with alotofhumanefforts,which justifiestheir useto resolvethehealthissuesaffectinghumanbeings.

Lackof moralrights

Thecloned animalmodelshavenomoralrightsas comparedto humanbeings,andthisjustifiestheir usein laboratoryresearch.Carl Cohen advancedthisargumentby definingrightsas potentialclaimsorclaimsthat can be exercisedby one partyagainst theother(Nooobbbis 44). In thecaseof laboratoryresearch,thecloned animalmodelshavenocapacityto claimanyrightfrom researchers whodevelopedthem. However,Cohen arguesthat,althoughthecloned modelsdonot havethemoralrights,the humanbeinghavethemoralobligationsto protectanimalandavoidexploitingthem without validreasons.Theneedsto developeffectivetherapiesandenhancethehumanunderstandingof thepathologyof variousdiseasesare validreasonsthat rationalizetheuseof cloned models. Also, humanbeinghasa functional brainthat increasetheir reasoningcapacitycomparedto cloned animalmodels.Inmostcases,thecloned animalmodelsare usedduring their earlystagesof life,whentheya limitedabilityto knowwhatis happeningtothem.Therefore,itis moralandethicalforhumanbeingsto usecloned modelsin medicalresearchwith the objective of achieving some positive results.

Argumentsagainst theuseof cloned animalmodelsin medicalresearch

Therightsof allbeingsshould beconsideredequally

Theprincipleof equalconsiderationof interestof allbeingsholdsthatnon-human andhumanbeingshavecomparablerightsandinterestthat needsto beconsideredequally.Thisis especiallyimportantwhenconsideringtheavailablealternativesformedicalresearch.ThisconceptwasadvancedPeter Singer, whostatedthatbothnon-human andhumanbeingshavesimilarmoralrights,andthisforbidstheinflictionof painto them (Zimmerman 5). Thisprincipleimpliesthatifresearchers can useanimalsin laboratoryresearch,thenhumanbeingscan as wellbeusedin similarlaboratoryexperiments.Thereasonsusedto prohibitexperimentation on eitherof thesebeingsshould be equallyappliedto theother.However,thisdoesnot implythatbothnon-human andhumanbeingshaveequalrights.Cloning of animalmodelsis performedto trigger theexpressionof humangenes in thesemodels.Theobjectiveof thecloning formedicalresearchis to substitutehumanbeingsfortransgenic organisms.Therefore,Singer’s principlesholds that, if humanbeingsaresubstitutedforanimal models in order to study a disease affecting them,thennon-human beingsshould as wellbe substitutedfor human model when studying diseases that are specific to them.This is one of the ways of equal consideration of rights as well asinterest of all beings.

Equalcapacityto feelpain

Allbeings,bothnon-human andhuman,haveequalcapacityto feelpainwhensufferingisinflictedon them. Thisconceptwasadvancedby theanimalrightsactivist, Peter Singer, whoassertedthatnon-human andhumanenjoyandsufferequally(Steinbock 249). Thismeansthatnon-human andhumanbeingscan feelthepainwhentheyare deliberatelyinflictedwith theillness,injectedwith pharmaceutical products,ordissectedto learnmoreabout moreabout thepathologyof diseasesaswellas thefunctionality of thebodysystems.Thisprincipleis not based one’sreasoningorintelligence,buton sentience. Therefore,thedecisionto useanybeingin thelaboratoryresearchshould takeaccountof thenatureof an entitythat is beingconsidered.Althoughanimalsandhumanbeingshavedifferentrights,thefactthattheyhavethenervoussystemmakesthem equalin termsof feelings.Ifthisprincipleholds,cloned organismsshould not be usedin laboratoryexperiments.This is because inflicting them with human diseases and injectingthem with drugs whose mechanism of action is not known is unfair(under the principle of equal capacity to feel pain) and should beavoided at all costs.

Rebuttalarguments

Thereis an emerging argumentthatthecurrenttechnology allowstheuseof alternative methodsof conductingresearchon humanhealth,which givesscientistsan opportunityto reducetheuseof cloned animals.Forexample,theuseof viscoelastic andaerodynamic modelscan enablescientiststo explorethephysiologyofthelarynx,which is an ethicalpracticecomparedto dissectionof a cloned animalmodel(Miziara130).In addition,thesimulation forendoscopic surgerythat wasdevelopedby Brazilian ortorhinolaryngologistswhoopposetheuseof animalmodelssoughtto advocatefortheconsiderationof alternative methodsthat can substitutetheuseof animalmodels.Anothergroupof animalrightsactivists supporttheuseof culturecellsinsteadof cloning thewholeorganism.Forexample,researchers can growtumorsin cellculturesinsteadof relying on in vivo studyof cancer.Althoughthisargumentpresentsa viable solutionto reducetheuseof animalmodels,itdoesnot applyin allsituations.Foran instant,itmay not be possibleto testtheefficacyof drugsorprogressionof a diseaseon cellculturesandthisnecessitatestheuseof cloned wholeanimalmodels.

Conclusion

Althoughtheideaof usingcloned wholeanimalmodelsin medicalresearchhas facedalotofcriticisms,thecurrentpracticesmeettherequiredethicalstandards.Cloning of wholeorganismsisperformedforvariousreasons,butthemostcommononeis thestudyof humandiseasesandtheefficacyof drugsbefore theyare introducedto humanbeings.Thedeliberateinflictionof diseasesinto animalmodelshas attracteddebateswhereeachcampdefendstheethicalbackgroundof its reasoning.Thecampthat supportstheuseof cloned animalmodelsarguethatthepracticehas intrinsicbenefitsto themodernsociety,cloned modelsare propertiesof their developers whocan usethem to achievetheir researchobjectives,andcloned animalshavenomoralrightssince theyhavea limitedcapacityto reasonandclaimrightsagainst humanbeings.Theseargumentsdefendtheuseof cloned wholeorganismsin medicalresearch.However,there are somesupporters of animal rights movements&nbspwhobelievethatthecloned organismhavean equalcapacityto feelthesufferingsinflictedon them as wellas intereststhat should be givenan equalconsiderationto therightsof humanbeings.There is alsoan upcomingargumentthattheuseof animalmodelsis unnecessarysince there are othermodelsthat are based on the modern technology and can substitutetheuseof cloned animals. However,thisapproachdoesnot applyin allsituations.For example, the study of diseases progression and the efficacy ofdrugs require the use of animal models, preferably the cloned wholeanimals.

Workscited

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Liu,H., Li, Y., Liu, C., Bolund, L., Vajta, G., Dou, H., Yang, W., Luan,J., Wang, J., Yang, H., and Du, Y. “Development of transgenicminipigs with expression of antimorphic human cryptochrome 1”. PloSONE8.10 (2013): 1-12. Doi:10.1371/journal.pone.0076098

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