HIV-1 Vpr Induces Adipose Dysfunction in Vivo Through Recipr(2)

27November2013

Vol5Issue213213ra164

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HIV-1 Vpr Induces Adipose Dysfunction in Vivo Through Reciprocal Effects on PPAR/GR Co-Regulation

Wehypothesizedthatvirion-freeVpr,withtheabilitytotransduceadiposeandhepaticcells,persistsinthecirculationofHIVpatientsaf-tertreatmentwith“viral-suppressive”ARTandissufficienttoproducetheHIV-associatedmetabolicphenotypethroughPPARgco-repression,GRcoactivation,andcellcyclearrestinadiposeandhepatictissues.WetestedthesehypothesesbymeasuringVprinthecirculationofHIV-infectedpatientsonARTandspecifyingVpr-mediatedpatho-genicmechanismsintwomousemodels:transgenic(expressingVprinadiposetissuesandliver)andpharmacologic(designedtomeasuretheeffectsofcirculatingVpr).

A

1000

*

Serum Vpr (pg/ml)

100

10

1

RESULTS

VprcirculatesinthebloodofART-treatedHIVpatientswithundetectableVL

WemeasuredVprbyimmunoaffinitycapillaryelectrophoresis(ICE)inmaskedserumsamplesfromHIV-negativepersons(n=20)andthreeHIV-infectedgroups:(i)ART-naïve(n=25),(ii)onnucleosidereversetranscriptaseinhibitors(NRTIs)only(n=61),and(iii)oncombinationART(cART,n=70),ofwhom25hadundetectableVL.Ninety-sixpercentoftheHIVpatients(88%onARTwithunde-tectableVL)haddetectable(true-positive)serumVpr(Fig.1A).ThesedataindicatethatVprproducedbyHIV-1persistinginreservoirscanbereleasedintothecirculation.SerumVprrangesoverlappedintheHIV-positivegroups;themedianvaluewaslowerinthecARTgroupthaninthetreatment-naïvegroup.TherewasnocorrelationbetweenVprlevelandVLamonguntreatedorNRTI-onlypatients.VprwasidentifiedinadiposetissuesandliverobtainedatautopsyoftwoHIV-infected,butnotofthreeHIV-uninfected,persons(tableS1).Vprexpressedinadiposetissuesandlivercirculatesinthebloodoftransgenicmice(Vpr-Tg)

VprmRNAwasdetectedinadiposetissueandliverofVpr-Tgmice,whichexpressVprunderthecontrolofthephosphoenolpyruvatecarboxykinase(PEPCK)promoter(Fig.1B).ExpressionofVprwasweakerinliverthaninadiposetissue,likelybecauseofVpr’sabilitytoblunttheexpres-sionofPEPCK(seebelow).ICEdemonstratedVprintheseraofVpr-Tgmice[194±7pg/ml(mean±SE)],showingthatVprproducedintissuesisreleasedintothebloodstream(Fig.1C).Togeneratethepharmacologicmodel,wedefinedthepharmacokineticsofsyntheticVpr(sVpr)inwild-typemiceusingintraperitonealinjections.Theserumhalf-lifeofsVprwasshort(6to12hours,fig.S1);hence,achronicsubcutaneous(Alzet)infusionmethod(deliveringsVprfor14days)wasadopted.MeanserumVprconcentrationinthesesVpr-treatedmicewas755±16pg/mlafter14days(Fig.1C).

Whole-bodylipolysisisincreasedinVpr-TgandsVpr-treatedmice

AcceleratedlipolysisisacardinalmetabolicdefectinHIVpatients(17–19).Lipidkineticstudiesusingsteady-stateinfusionsofisotopesofglycerolandpalmitate(17)revealedthatfastingtotalandnetlipolysiswereincreasedinVpr-Tgmiceofoneline(Fig.2A)(butnotofanotherline;tableS2)andinsVpr-treatedmice(Fig.2B).TheseVpr-TgandsVpr-treatedmicehadhigherfastingrespiratoryexchangeratios(RERs)thantheirrespectivecontrolsundertheconditionsoftheinfusionstudies,indicatingbluntedfatoxidation(Fig.2,CandD)for4hoursearlyinthefastingperiod.However,longercalorimetry

0.1

HIV – HIV + HIV + HIV + HIV +

no ART NRTI cART cART with undetectable VL

N (20) (25) (61) (70) (25)

B

WT

Vpr

+

WT

Vpr

+

LiverFat

C

1000800

6004002000

WT

Vpr-Tg

Alzet-H20

Alzet-Vpr

Fig.1.VprinHIVpatientsandmousemodels.(A)Box-and-whiskerplotsofserumVprconcentrationsinHIV-negativepersonsandfourHIV-infectedgroups:ART-naïve,onNRTIonly,oncART,andoncARTwithunde-tectableVL.MedianVprconcentrationsinpatients:ART-naïve=7.0pg/ml;NRTIonly=32.0pg/ml;cART=3.9pg/ml;cARTwithundetectableVL=4.2pg/ml.Whiskersindicateminimumandmaximumofalldata.Dashedlineindicatescutoffbetweenfalse-andtrue-positivevalues.False-positiverate=3%ART-naïveHIV,0%HIVonNRTI,6%HIVoncART,and4%HIVoncARTwithundetectableVL.(B)VprmRNAinliverofVpr-Tg(n=5)com-paredtowild-type(WT)littermates(n=5)andinPGFofVpr-Tg(n=8)comparedtoWT(n=5);“+”indicatespositivecontrolDNA.(C)VprproteininseraofVpr-TgandsVpr-treatedmice.Horizontallinesindicatemeanvalues.*P=0.001forART-naïvecomparedtocART-treatedHIVpatients.

underconditionsofchronicfeedingwithregular(n=11wildtype;n=10Vpr-Tg)orhigh-fat(n=11wildtype;n=12Vpr-Tg)diet,withthemicepermittedtomovefreely,showednogroupdifferencesinfatoxidationaveragedover24hours(tableS3).

27November2013

Vol5Issue213213ra164

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Serum Vpr (pg/ml)

HIV-1 Vpr Induces Adipose Dysfunction in Vivo Through Reciprocal Effects on PPAR/GR Co-Regulation

A

Ra FFA (mmol/kg/h)

**

Ra FFA (mmol/kg/h)

**

**

**

*

25

20

00

FRaFAt FFAn

FRaFAt FFAn

RER

RER

WTVpr-Tg

E

Ra

Ra

4.5

F

WTVpr-Tg

Fat weight (% of body wt)

4.5

Vehicl

Fat weight (% of body wt)

esVpr

VehiclesVpr

**

50

WTVpr-Tg

B

40

VehiclesVpr

C

0.760.750.740.730.720.710.70

WTVpr-Tg

D

0.770.760.750.740.730.720.710.70

VehiclesVpr

3.0

*

**

3.0

*

1.5

*

*

1.5

*

*

0.0

IF

PGF

RPF

TotalWAT

BAT

0.0

IF

PGF

RPF

TotalWAT

BAT

Fig.2.AlteredfastinglipidkineticsandfatmassinVpr-TgandsVpr-treatedmice.(AandB)Acceleratedfastingtotalandnetlipolysisin(A)Vpr-Tg(n=6pergroup;P=0.007and0.005)and(B)sVpr-treated(n=7)comparedtowater(vehicle)–treated(n=4)mice(P=0.01and0.006).RaFFAt,totalfreefattyacidplasmaentryrate(totallipolysis);RaFFAn,netfreefattyaci …… 此处隐藏：5656字，全部文档内容请下载后查看。喜欢就下载吧 ……