Pulmonary Development and Disease in Down Syndrome : a ...
Transcript of Pulmonary Development and Disease in Down Syndrome : a ...
PulmonaryDevelopmentandDiseaseinDownSyndrome:aScien7ficJourneyfromthe
BedtoBenchSite
Csaba Galambos MD, PhD Department of Pathology and Laboratory Medicine & Pediatric Heart Lung Center,
Children’s Hospital Colorado & University of Colorado School of Medicine
Diagnos7cPediatricPathology(Lung)
BenchResearchonLungDevelopment&
Disease
PediatricPulmonaryVascularBiology&Pathology
-4montholdmalewithtrisomy21-bornat364/7weeksgesta7onalage-birthweightof3080grams-deliveredbyCesareansec7ontoa34yearoldG2P1mother-mul7plerespiratoryproblemssincebirthincludingpulmonaryhypertension,chronicrespiratoryfailure,andtracheobronchomalaciarequiringassistedven7la7on-Nocardiacorotherorgananomalies-AVeralonghospitalcoursewithoutimprovementinhiscardiorespiratorystatus,hisfamilydecidedtowithdrawlifesupportandanautopsypermitwasgranted
Casestudy
20x
PAPA
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BrDEFECTIVEVASCULARREMODELING
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Control Downsyndrome
DIMINISHEDALVEOLARIZATION
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IMPAIREDMICROVASCULARGROWTH
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Histopathology
Respiratory:severechroniclungdisease,pulmonaryhypoplasiaandpulmonaryhypertensionrelatedtoDownsyndrome
CauseofDeath
Babies with DS succumb to respiratory disease without any co-morbid condition
v DSassociatedwithincreasedriskfordevelopingrespiratorydisordersincludingseverepulmonaryhypertension(PHT)andpersistentpulmonaryhypertensionofthenewborn(PPHN)
v PrevalencestudyatSieCenterforDownSyndrome(ongoing):-1,252childrenwithDS,27.6%(n=346)withPHT-PPHNincidence:9.9%(vs0.1ingeneralpopulaJon)
v ChildrenwithDSandco-morbidi7es,suchascongenitalheartdiseaseorobstruc7vesleepapnea,aremoresuscep7blefordevelopingacceleratedPHTthanchildrenwithoutDS
v OneoftheleadingcausesofdeathinpeoplewithDSisrespiratoryrelated
Thegene7candmolecularmechanismsresponsibleforpulmonaryhypoplasiaandPHTinDSareunknown
PulmonarydiseaseandDownsyndrome
Downsyndromeassociatedlungdisordersareunderstudied
ChallengesofDownsyndromeresearch
v manygenes(300+):onegenedysfunc5on-onepathway-onediseasephenotypeparadigmdoesnotapply
v genesareoverexpressed
v ~80clinicalphenotypesinvariouscombina7ons
GENETICPATHWAYSANDCONFOUNDINGFACTORSLEADTOVARIABLEDSPHENOTYPES
80clinicalphenotypesofDS
1.5foldoverexpressionoftrisomicgenes
(“dosagesensi5vegenes”)
celltype&7meofdevelopmentstage
1
upand/ordownregula7onofdisomicgenes(“modifiablegenes”viatranscrip5onalregula5on)
2
confoundingfactors(hypoxemia)
3
3
3
BronchopulmonaryDysplasia
2x
40x
20x
PAPA
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40x
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An7-angiogenicDisorder Control
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Downsyndrome
AreDS-relatedlunghypoplasiaandPHTan5-angiogenicdisorders?
JudahFolkman,MDSurgeon-Scien7st
Founderofangiogenesisresearch
v Pa7entswithDShaveadecreasedincidenceofpro-angiogenesisrelateddiseasesincludingsolidtumors,atherosclerosis,diabe7cre7nopathy,andvascularanomalies
v Genesforpotentan7-angiogenicfactorsarepresentonthetriplicatedchromosome21andoverexpressedinpa7entswithDSandinDSanimalmodels
Endosta7n(ES),B-amyloidpep7de(BAP)andCalcineurinRegulator-1(RCAN-1/DSCR-1)
v AllprominentendogenousanJ-angiogenicfactors
v AlllocatedonChromosome21andallindividualswithDShaveanextracopy
v PaJentswithDShaveincreasedserumand/orJssuelevels
v TheyspecificallyinhibittheproliferaJonandmigraJonofvascularendothelialcells
v TheysuppressVEGF-VEGFR2inducedsignalingcausingmarkedangiogenesisinhibiJon
ItisunknownwhetherES/BAP/RCAN1-relatedan7angiogenicmechanismscontribute
toabnormallungdevelopmentandPHTinDS
OVERRIDINGHYPOTHESIS
Overexpressionofchromosome21-relatedan7-angiogenicfactorsplayacri7calroleinthe
developmentoflunghypoplasiaandpulmonaryhypertensionininfantsand
childrenwithDownsyndrome
Specificstudyques7ons
1. DolungsinpeoplewithDSshowimpairedalveolarandvasculargrowth/remodeling?
2. DolungsofafetuswithDownsyndromeoverexpressES,BAP,RCAN-1andotheran7-angiogenicgenes(disomic)andshowvasculargrowthimpairment?
3. Areangiogenicfunc7onsofendothelialcellsandprogenitorsisolatedfromindividualswithDSimpaired?
Studyques7on-1
DolungsinpeoplewithDSshowimpairedalveolarandvasculargrowth/remodeling?
Study1-Design
Retrospective Autopsy Review Children 0-8 years
With DS or typical with CHD Excluded disorders of lung development
Study Population Patients with DS (n=13) Typical patients age and CHD matched controls
(n=4) Clinical data obtained from autopsy reports Routine H&E lung histology reviewed Serial sectioning and 3D image reconstruction to
clarify microvascular anatomy
Study1-Results
Study1-Summary
Infants and Children with DS who died of severe cardiopulmonary disease have: Histologic evidence of abnormal lung development
Alveolar simplification Histologic evidence of abnormal pulmonary vascular development
Prominent arterial hypertensive remodeling Prominent bronchial vessels Persistence of double capillary network Prominent intrapulmonary anastomotic vessels
Findings present in those with DS with and without CHD are more prevalent than typical patients who were age and CHD matched controls Study 1 supports angiogenic hypothesis
DBushetal.JPeds2017
Studyques7on-2
DolungsofafetuswithDSoverexpressES,BAP,RCAN-1andotheran7-angiogenicgenes
(disomic)andshowvasculargrowthimpairment?
Study2-DesignHuman fetal lung tissue* from
Down syndrome (n=4) Typical controls (n=4)
Individual qPCR (mRNA) and Western Blot Analysis (Protein)
Endostatin B-Amyloid Protein (BAP) Regulator of Calcineurin-1 (DSCR1)
Angiogenesis-associated mRNA microarray (84 angiogenic
genes) IHC evaluation for impaired angiogenesis:
Vessel Density (CD31) Vessel Thickness (SMA)
*U.Maryland,Bal:more/NICHDBrain&TissueBankforDevelopmentalDisorders
Study2-ResultsmRNA mRNA
Study2-Results
(EndostaJn)
(TumstaJn)
(TissueMetalloproteinaseinhibitor3)
Study 2 - Results
Study2-SummaryAnti-angiogenic factors are over-expressed in the lungs of fetuses with DS Chromosome 21-related Genes (trisomic) and Proteins
ENDOSTATIN BAP RCAN1/DSCR1
Non Chromosome 21-related Genes (disomic) TIMP3 COL4A3
Early abnormal vascular growth in the lungs of fetuses with DS Reduced vessel density Increased vessel wall thickness
Study 2 supports angiogenic hypothesis
CGalambosetal.PLOS-12016
Areangiogenicfunc7onsofendothelialcellsandprogenitorsisolatedfromindividualswithDS
impaired?
Studyques7on-3
Study3-Results(ongoing)Endothelialcells(HUVEC)andprecursors(endothelialcolonyformingcells)
isolatedfromindividualswithDSshowimpairedangiogenicfunc7ons
Dr.CBaker,PHLC
DiseasespecificDSmousemodels• tofurthertestourangiogenichypothesis• studyspecificmolecularmechanisms• exploreavarietyofinterven7ons/treatmentop7ons
www.down-syndrome.org/research-practice
MousemodelsofDownsyndromeNocharacteriza7on/researchoflungdisordershasbeendone
inanyofDSmousemodels• Mouse orthologues of human Chr21 on 3 separate mouse chromosomes
• Mmu 10 – ENDOSTATIN (37 genes) • Mmu 16 – DSCR1/RCAN1 & BAP* (102 genes) • Mmu 17 – NO ANTIANGIOGENIC GENE (17 genes)
Guptaetal,MammGenome,2016
Summary• Lungdisease(PHT/PPHN)isasignificant
contributortomorbidityandmortalityofinfantsandchildrenwithDS
• DSLunghistologyischaracterizedbyvascularandalveolargrowthabnormali7es
• LungdiseaseinDSisunderstudied• LungpathologyofDSisdrivenbyan7-
angiogenicmechanisms• Earlyinterven7onwithangiogenic
s7mulatorsorblockersofan7-angiogenicpathwaysmaypreventlungdiseaseinthosewithDS
• AngiogenicbiomarkerswillhelppredictlungdiseaseinthosewithDS
Summary
MembersofDept.ofPathologyDrs.AnnThorandMarkLovell
MembersofPediatricHeartLungCenterAngelaMinic,DougBush,GregorySeedorf,BlairDodson,ChrisBakerDr.SteveAbman—Scien7ficDirector
FundsFounda7onJérômeLejeuneforDownSyndrome Children’sHospitalColoradoResearchIns7tuteTheLindaCrnicIns7tuteforDownSyndromeChallengeGrantJaydendeLucaFounda7on(Dr.DunbarIvy)forPulmonaryHypertensionDean’sBridgeFund,UniversityofColoradoDenver
Collabora7onDr.CharlesHoefferLabatUniversityofColoradoBoulderTheLindaCrnicIns7tuteforDownSyndrome-Drs.FranHickey,JoaquinEspinosaUniv.Maryland,Bal7more/NICHDBrain&TissueBankforDevelopmentalDisorders
“DownSyndromeTakesTheBreathAway”“PeoplewithDSaregiA.Bystudyingtheirbiologycanhelpthemandtherestofmankind.”
----DrTomBlumenthal,FormerExecuJveDirectorofLCIforDS
Self-Advocates,Families,&ResearchercelebrateWorldDownSyndromeDayintheCOCapitoltogetherwithGovernorJohnW.Hickenlooper(3/22/17)