2022
Humanized Dsp ACM Mouse Model Displays Stress-Induced Cardiac Electrical and Structural Phenotypes
Stevens TL, Manring HR, Wallace MJ, Argall A, Dew T, Papaioannou P, Antwi-Boasiako S, Xu X, Campbell SG, Akar FG, Borzok MA, Hund TJ, Mohler PJ, Koenig SN, El Refaey M. Humanized Dsp ACM Mouse Model Displays Stress-Induced Cardiac Electrical and Structural Phenotypes. Cells 2022, 11: 3049. PMID: 36231013, PMCID: PMC9562631, DOI: 10.3390/cells11193049.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsArrhythmias, CardiacArrhythmogenic Right Ventricular DysplasiaDesmoplakinsDisease Models, AnimalHeartHumansMicePhenotypeConceptsArrhythmogenic cardiomyopathyMouse modelStructural phenotypesFibro-fatty infiltrationFirst mouse modelHeart failureChamber dilationVentricular arrhythmiasPressure overloadArrhythmic eventsCardiac performanceCardiac stressSudden deathCardiovascular stressInherited disorderG variantConnexin 43MiceDesmosomal genesReduced expressionExternal stressorsACM familyDisease developmentMurine equivalentIncomplete penetrance
2021
Right predominant electrical remodeling in a pure model of pulmonary hypertension promotes reentrant arrhythmias
Strauss B, Bisserier M, Obus E, Katz MG, Fargnoli A, Cacheux M, Akar JG, Hummel JP, Hadri L, Sassi Y, Akar FG. Right predominant electrical remodeling in a pure model of pulmonary hypertension promotes reentrant arrhythmias. Heart Rhythm 2021, 19: 113-124. PMID: 34563688, PMCID: PMC8742785, DOI: 10.1016/j.hrthm.2021.09.021.Peer-Reviewed Original ResearchConceptsPulmonary arterial hypertensionVT/VFExtrapulmonary toxicityPN ratsVentricular tachycardia/fibrillationCardiac magnetic resonance imagingRight ventricular hypertrophySprague-Dawley ratsMultiple reentrant circuitsConnexin 43 expressionMagnetic resonance imagingConnexin 43 phosphorylationRV activationArterial hypertensionMonocrotaline modelVentricular hypertrophyLeft pneumonectomyElectrical remodelingMyocardial fibrosisConduction slowingSevere formAP durationArrhythmic vulnerabilityReentrant circuitAP alternansArrhythmia Mechanism and Dynamics in a Humanized Mouse Model of Inherited Cardiomyopathy Caused by Phospholamban R14del Mutation
Raad N, Bittihn P, Cacheux M, Jeong D, Ilkan Z, Ceholski D, Kohlbrenner E, Zhang L, Cai CL, Kranias EG, Hajjar RJ, Stillitano F, Akar FG. Arrhythmia Mechanism and Dynamics in a Humanized Mouse Model of Inherited Cardiomyopathy Caused by Phospholamban R14del Mutation. Circulation 2021, 144: 441-454. PMID: 34024116, PMCID: PMC8456417, DOI: 10.1161/circulationaha.119.043502.Peer-Reviewed Original ResearchConceptsHuman PLNRapid pacingInterventricular activation delayHumanized mouse modelAction potential prolongationLocal conduction blockSteep repolarization gradientsArrhythmogenic featuresMacroreentrant circuitHemodynamic changesElectric remodelingElectrophysiological remodelingRight ventricleVentricular tachycardiaPotential prolongationSudden deathConduction blockMouse modelAdult knockArrhythmia susceptibilityAdrenergic stimulationStructural remodelingArrhythmogenic phenotypeArrhythmia mechanismsRegulatory protein phospholamban
2019
Renewal Theory as a Universal Quantitative Framework to Characterize Phase Singularity Regeneration in Mammalian Cardiac Fibrillation
Dharmaprani D, Schopp M, Kuklik P, Chapman D, Lahiri A, Dykes L, Xiong F, Aguilar M, Strauss B, Mitchell L, Pope K, Meyer C, Willems S, Akar FG, Nattel S, McGavigan AD, Ganesan AN. Renewal Theory as a Universal Quantitative Framework to Characterize Phase Singularity Regeneration in Mammalian Cardiac Fibrillation. Circulation Arrhythmia And Electrophysiology 2019, 12: e007569. PMID: 31813270, DOI: 10.1161/circep.119.007569.Peer-Reviewed Original ResearchMeSH KeywordsAction PotentialsAnimalsAtrial FibrillationBiological EvolutionComputer SimulationDisease Models, AnimalHeart Conduction SystemHeart RateHumansModels, CardiovascularMulticenter Studies as TopicObservational Studies as TopicRatsReproducibility of ResultsSheep, DomesticStochastic ProcessesTime FactorsVentricular FibrillationConceptsPoisson renewal processRenewal theoryRenewal processPhase singularityMaximum entropy theoryExponential probability distribution functionProbability distribution functionFormation/destructionConstant rate parametersEntropy theoryInterevent timesDistribution functionExponential distributionRotational eventsCardiomyocyte-Specific STIM1 (Stromal Interaction Molecule 1) Depletion in the Adult Heart Promotes the Development of Arrhythmogenic Discordant Alternans
Cacheux M, Strauss B, Raad N, Ilkan Z, Hu J, Benard L, Feske S, Hulot JS, Akar FG. Cardiomyocyte-Specific STIM1 (Stromal Interaction Molecule 1) Depletion in the Adult Heart Promotes the Development of Arrhythmogenic Discordant Alternans. Circulation Arrhythmia And Electrophysiology 2019, 12: e007382-e007382. PMID: 31726860, PMCID: PMC6867678, DOI: 10.1161/circep.119.007382.Peer-Reviewed Original ResearchConceptsVT/VFAPD alternansStore-operated CaVentricular tachycardia/ventricular fibrillationOptical action potential mappingAdult heartVT/Adult murine modelDiscordant alternansConduction velocity slowingSarcoplasmic reticulum CaArrhythmogenic discordant alternansInitial beatsEarly mortalityFlox/Poor survivalVentricular fibrillationDiscordant APD alternansMurine modelCardiac hypertrophyConduction velocityLittermate controlsAdult miceRapid pacingElectrophysiological substrate
2018
Intra-tracheal gene delivery of aerosolized SERCA2a to the lung suppresses ventricular arrhythmias in a model of pulmonary arterial hypertension
Strauss B, Sassi Y, Bueno-Beti C, Ilkan Z, Raad N, Cacheux M, Bisserier M, Turnbull IC, Kohlbrenner E, Hajjar RJ, Hadri L, Akar FG. Intra-tracheal gene delivery of aerosolized SERCA2a to the lung suppresses ventricular arrhythmias in a model of pulmonary arterial hypertension. Journal Of Molecular And Cellular Cardiology 2018, 127: 20-30. PMID: 30502350, PMCID: PMC6561115, DOI: 10.1016/j.yjmcc.2018.11.017.Peer-Reviewed Original ResearchMeSH KeywordsAction PotentialsAerosolsAnimalsArrhythmias, CardiacConnexin 43Disease Models, AnimalGene Transfer TechniquesGenetic TherapyHeart Conduction SystemHumansMalePotassium ChannelsPulmonary Arterial HypertensionRats, Sprague-DawleyRNA, MessengerSarcoplasmic Reticulum Calcium-Transporting ATPasesTracheaConceptsPulmonary arterial hypertensionSudden cardiac deathVentricular tachyarrhythmiasCTRL heartsExpression of Cx43Conduction velocityArterial hypertensionHeart rateAP durationAdvanced pulmonary arterial hypertensionIncidence of VTOptical action potential mappingPacing-induced ventricular tachyarrhythmiasRisk of VTAEP substrateElectro-mechanical dysfunctionImpaired chronotropic responseMinimal conduction velocitiesRight ventricular failureSustained ventricular tachyarrhythmiasAPD heterogeneityPulmonary vascular remodelingRapid heart rateAge-matched ratsIntra-tracheal deliveryPrimary Effect of SERCA2a Gene Transfer on Conduction Reserve in Chronic Myocardial Infarction
Motloch LJ, Cacheux M, Ishikawa K, Xie C, Hu J, Aguero J, Fish KM, Hajjar RJ, Akar FG. Primary Effect of SERCA2a Gene Transfer on Conduction Reserve in Chronic Myocardial Infarction. Journal Of The American Heart Association 2018, 7: e009598. PMID: 30371209, PMCID: PMC6222964, DOI: 10.1161/jaha.118.009598.Peer-Reviewed Original ResearchConceptsMyocardial infarctionVentricular tachycardiaSERCA 2aVirus serotype 1Heart failureOptical action potential mappingPacing-induced ventricular tachycardiaIschemic heart failureNonischemic heart failureSerotype 1SERCA2a gene transferChronic myocardial infarctionExpression of Cx43Contractile reserveVelocity reserveHemodynamic functionDobutamine stressAnterior MIElectrophysiological effectsQRS durationConduction reserveConduction velocityNaive pigsAnimal modelsElectrophysiological substrate
2017
Protein Phosphatase Inhibitor-1 Gene Therapy in a Swine Model of Nonischemic Heart Failure
Watanabe S, Ishikawa K, Fish K, Oh JG, Motloch LJ, Kohlbrenner E, Lee P, Xie C, Lee A, Liang L, Kho C, Leonardson L, McIntyre M, Wilson S, Samulski RJ, Kranias EG, Weber T, Akar FG, Hajjar RJ. Protein Phosphatase Inhibitor-1 Gene Therapy in a Swine Model of Nonischemic Heart Failure. Journal Of The American College Of Cardiology 2017, 70: 1744-1756. PMID: 28958332, PMCID: PMC5807083, DOI: 10.1016/j.jacc.2017.08.013.Peer-Reviewed Original ResearchConceptsNonischemic heart failureHeart failureEjection fractionIntracoronary deliveryTherapeutic efficacyLeft ventricular end-diastolic pressureDp/dt maximumLeft ventricular ejection fractionVentricular end-diastolic pressureVolume overload heart failureAdverse electrical remodelingIschemic heart failureVentricular ejection fractionVentricular volume indexAtrial ejection fractionEnd-diastolic pressureSevere mitral regurgitationCellular immune responsesCalcium transient amplitudeLarge animal modelGene therapyActive inhibitor-1Improved contractilityInhibitor-1 geneCardiac dysfunction
2015
The Classically Cardioprotective Agent Diazoxide Elicits Arrhythmias in Type 2 Diabetes Mellitus
Xie C, Hu J, Motloch LJ, Karam BS, Akar FG. The Classically Cardioprotective Agent Diazoxide Elicits Arrhythmias in Type 2 Diabetes Mellitus. Journal Of The American College Of Cardiology 2015, 66: 1144-1156. PMID: 26337994, PMCID: PMC4560843, DOI: 10.1016/j.jacc.2015.06.1329.Peer-Reviewed Original ResearchConceptsAction potential durationVentricular tachyarrhythmiasT2DM heartsIschemia-induced ventricular tachyarrhythmiasOptical action potential mappingType 2 diabetes mellitusAdenosine triphosphate-sensitive potassium channelsMitochondrial adenosine triphosphate-sensitive potassium channelsTriphosphate-sensitive potassium channelsLow-dose diazoxideFree fatty acid levelsIncidence of arrhythmiasNormal Sprague-Dawley ratsSprague-Dawley ratsOnset of arrhythmiasMessenger ribonucleic acid expressionFatty acid levelsRibonucleic acid expressionAPD adaptationElicit arrhythmiasUntreated T2DMIschemic eventsDiabetes mellitusDiabetic patientsIschemic challenge
2014
Cardiac I-1c Overexpression With Reengineered AAV Improves Cardiac Function in Swine Ischemic Heart Failure
Ishikawa K, Fish KM, Tilemann L, Rapti K, Aguero J, Santos-Gallego CG, Lee A, Karakikes I, Xie C, Akar FG, Shimada YJ, Gwathmey JK, Asokan A, McPhee S, Samulski J, Samulski RJ, Sigg DC, Weber T, Kranias EG, Hajjar RJ. Cardiac I-1c Overexpression With Reengineered AAV Improves Cardiac Function in Swine Ischemic Heart Failure. Molecular Therapy 2014, 22: 2038-2045. PMID: 25023328, PMCID: PMC4429688, DOI: 10.1038/mt.2014.127.Peer-Reviewed Original ResearchConceptsIschemic heart failureHigh-dose groupHeart failureCardiac functionLarge anterior myocardial infarctionLeft ventricular ejection fractionPreload recruitable stroke workChronic heart failureAdvanced heart failureLow-dose groupVentricular ejection fractionAnterior myocardial infarctionActive inhibitor-1Ejection fractionIntracoronary injectionSaline groupContractility indexMyocardial infarctionPressure-volume analysisStroke volumeStroke workCardiac performanceHemodynamic parametersCardiovascular systemCardiac gene therapyEffect of bortezomib on the efficacy of AAV9.SERCA2a treatment to preserve cardiac function in a rat pressure-overload model of heart failure
Chaanine A, Nonnenmacher M, Kohlbrenner E, Jin D, Kovacic J, Akar F, Hajjar R, Weber T. Effect of bortezomib on the efficacy of AAV9.SERCA2a treatment to preserve cardiac function in a rat pressure-overload model of heart failure. Gene Therapy 2014, 21: 379-386. PMID: 24572786, PMCID: PMC3976435, DOI: 10.1038/gt.2014.7.Peer-Reviewed Original ResearchConceptsHeart failureCardiac functionRodent heart failure modelsRat cardiomyocytesHeart failure modelPressure overload modelEffect of bortezomibProteasome inhibitor bortezomibNeonatal rat cardiomyocytesAdult rat cardiomyocytesWestern blot analysisSERCA2a proteinPressure-volume analysisSERCA2a levelsBortezomib treatmentConcurrent treatmentSERCA2a mRNAInhibitor bortezomibBortezomibHeart samplesHuman SERCA2aSerotype 1Proteasome inhibitorsAAV serotypes 1Proteasome inhibition
2010
Altered Spatiotemporal Dynamics of the Mitochondrial Membrane Potential in the Hypertrophied Heart
Jin H, Nass RD, Joudrey PJ, Lyon AR, Chemaly ER, Rapti K, Akar FG. Altered Spatiotemporal Dynamics of the Mitochondrial Membrane Potential in the Hypertrophied Heart. Biophysical Journal 2010, 98: 2063-2071. PMID: 20483313, PMCID: PMC2872265, DOI: 10.1016/j.bpj.2010.01.045.Peer-Reviewed Original ResearchUltrastructure and Regulation of Lateralized Connexin43 in the Failing Heart
Hesketh GG, Shah MH, Halperin VL, Cooke CA, Akar FG, Yen TE, Kass DA, Machamer CE, Van Eyk JE, Tomaselli GF. Ultrastructure and Regulation of Lateralized Connexin43 in the Failing Heart. Circulation Research 2010, 106: 1153-1163. PMID: 20167932, PMCID: PMC2896878, DOI: 10.1161/circresaha.108.182147.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAutophagyConnexin 43Disease Models, AnimalDogsGap JunctionsHeart FailureHeart VentriclesHeLa CellsHumansMembrane MicrodomainsMicroscopy, ConfocalMicroscopy, Electron, TransmissionMicrotubule-Associated ProteinsMyocardiumPhosphorylationRatsRats, Sprague-DawleyRecombinant Fusion ProteinsTransfectionConceptsGFP-LC3Gap junctionsLateral membranesDistinct phosphorylated formsGap junction turnoverGap junction internalizationForm of LC3Internalized gap junctionsGap junction proteinJunction turnoverSubcellular locationBiochemical regulationCellular pathwaysMultilamellar membrane structuresEndogenous Cx43Phosphorylated formNeonatal rat ventricular myocytesHeLa cellsIntracellular Cx43Membrane structureJunction proteinsCx43ProteinPotential therapeutic implicationsConnexin43
2008
Key pathways associated with heart failure development revealed by gene networks correlated with cardiac remodeling
Gao Z, Barth AS, DiSilvestre D, Akar FG, Tian Y, Tanskanen A, Kass DA, Winslow RL, Tomaselli GF. Key pathways associated with heart failure development revealed by gene networks correlated with cardiac remodeling. Physiological Genomics 2008, 35: 222-230. PMID: 18780759, PMCID: PMC2585017, DOI: 10.1152/physiolgenomics.00100.2007.Peer-Reviewed Original Research
2007
Dynamic changes in conduction velocity and gap junction properties during development of pacing-induced heart failure
Akar FG, Nass RD, Hahn S, Cingolani E, Shah M, Hesketh GG, DiSilvestre D, Tunin RS, Kass DA, Tomaselli GF. Dynamic changes in conduction velocity and gap junction properties during development of pacing-induced heart failure. AJP Heart And Circulatory Physiology 2007, 293: h1223-h1230. PMID: 17434978, DOI: 10.1152/ajpheart.00079.2007.Peer-Reviewed Original ResearchMeSH KeywordsAction PotentialsAnimalsCardiac Pacing, ArtificialConnexin 43Disease Models, AnimalDogsDown-RegulationGap JunctionsHeart Conduction SystemHeart FailureMalePhosphorylationProtein IsoformsTachycardia, VentricularTime FactorsVentricular Function, LeftVentricular PressureVentricular RemodelingConceptsEnd-stage heart failureHeart failureConduction velocityMechanical dysfunctionCV slowingPacing-induced heart failureDevelopment of HFOnset of HFMechanical functionCx43 isoformConduction abnormalitiesCx43 lateralizationAdvanced stageBaseline levelsMyocardial preparationsPhosphorylation of Cx43High-resolution optical mappingSustained downregulationMarked increaseDephosphorylated Cx43LVEDPGap junction propertiesConduction changesDysfunctionTime course
2006
Bioartificial Sinus Node Constructed via In Vivo Gene Transfer of an Engineered Pacemaker HCN Channel Reduces the Dependence on Electronic Pacemaker in a Sick-Sinus Syndrome Model
Tse HF, Xue T, Lau CP, Siu CW, Wang K, Zhang QY, Tomaselli GF, Akar FG, Li RA. Bioartificial Sinus Node Constructed via In Vivo Gene Transfer of an Engineered Pacemaker HCN Channel Reduces the Dependence on Electronic Pacemaker in a Sick-Sinus Syndrome Model. Circulation 2006, 114: 1000-1011. PMID: 16923751, DOI: 10.1161/circulationaha.106.615385.Peer-Reviewed Original ResearchAnimalsArrhythmias, CardiacBioartificial OrgansCyclic Nucleotide-Gated Cation ChannelsDisease Models, AnimalElectrophysiologyGene Transfer TechniquesGuinea PigsHeart RateHyperpolarization-Activated Cyclic Nucleotide-Gated ChannelsIon ChannelsMicePacemaker, ArtificialPotassium ChannelsSick Sinus SyndromeSinoatrial NodeSwineSwine, Miniature
2005
Molecular mechanisms underlying K+ current downregulation in canine tachycardia-induced heart failure
Akar FG, Wu RC, Juang GJ, Tian Y, Burysek M, DiSilvestre D, Xiong W, Armoundas AA, Tomaselli GF. Molecular mechanisms underlying K+ current downregulation in canine tachycardia-induced heart failure. AJP Heart And Circulatory Physiology 2005, 288: h2887-h2896. PMID: 15681701, DOI: 10.1152/ajpheart.00320.2004.Peer-Reviewed Original Research
2002
Unique Topographical Distribution of M Cells Underlies Reentrant Mechanism of Torsade de Pointes in the Long-QT Syndrome
Akar FG, Yan GX, Antzelevitch C, Rosenbaum DS. Unique Topographical Distribution of M Cells Underlies Reentrant Mechanism of Torsade de Pointes in the Long-QT Syndrome. Circulation 2002, 105: 1247-1253. PMID: 11889021, DOI: 10.1161/hc1002.105231.Peer-Reviewed Original ResearchConceptsLong QT syndromeSpecific ion channel mutationsCongenital long QT syndromeM cellsQT interval prolongationIon channel mutationsInterval prolongationReentrant mechanismTdP arrhythmiasConduction blockCanine wedge preparationReentrant circuitTransmural dispersionLeft ventricleAction potentialsTransmural wallIntact myocardiumTopographical distributionChannel mutationsWedge preparationsMidmyocardial cellsRepolarizationLQT2Cellular basisElectrical instability