2024
Quantitative Assessment of Mitochondrial Morphology and Electrophysiological Function in the Diabetic Heart
Cacheux M, Rudokas M, Tieu A, Rizk J, Hummel M, Akar F. Quantitative Assessment of Mitochondrial Morphology and Electrophysiological Function in the Diabetic Heart. Methods In Molecular Biology 2024, 2803: 75-86. PMID: 38676886, DOI: 10.1007/978-1-0716-3846-0_6.Peer-Reviewed Original ResearchConceptsMitochondrial shapeMitochondrial networkMitochondrial architectureSubcellular localizationMitochondrial morphologyDiabetic heartOxidative phosphorylationATP synthesisAction potentialsSarcolemmal ion channelsExcitation-contraction couplingFission eventsOptical action potentialsExcitation-contractionCardiac myocytesElectrophysiological properties
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 ResearchConceptsArrhythmogenic 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 penetranceAtrial AMP-activated protein kinase is critical for prevention of dysregulation of electrical excitability and atrial fibrillation
Su KN, Ma Y, Cacheux M, Ilkan Z, Raad N, Muller GK, Wu X, Guerrera N, Thorn SL, Sinusas AJ, Foretz M, Viollet B, Akar JG, Akar FG, Young LH. Atrial AMP-activated protein kinase is critical for prevention of dysregulation of electrical excitability and atrial fibrillation. JCI Insight 2022, 7: e141213. PMID: 35451373, PMCID: PMC9089788, DOI: 10.1172/jci.insight.141213.Peer-Reviewed Original ResearchConceptsTranscription factorsKey transcription factorMaster metabolic regulatorIon channel subunitsGap junction proteinTranscriptional reprogrammingAMPK deletionProtein kinaseBiological functionsTranscriptional downregulationMetabolic regulatorChannel subunitsIon channelsAMPK expressionMetabolic stressAtrial fibrillationAMPKJunction proteinsElectrical excitabilityHomeostatic roleStructural remodelingConnexinsAtrial ion channelsRemodelingDownregulationA novel exosome-based therapy for post-MI arrhythmias
Cacheux M, Akar FG. A novel exosome-based therapy for post-MI arrhythmias. European Heart Journal 2022, 43: 2157-2159. PMID: 35325140, DOI: 10.1093/eurheartj/ehac155.Peer-Reviewed Original ResearchGene editing reverses arrhythmia susceptibility in humanized PLN-R14del mice: modelling a European cardiomyopathy with global impact
Dave J, Raad N, Mittal N, Zhang L, Fargnoli A, Oh JG, Savoia ME, Hansen J, Fava M, Yin X, Theofilatos K, Ceholski D, Kohlbrenner E, Jeong D, Wills L, Nonnenmacher M, Haghighi K, Costa KD, Turnbull IC, Mayr M, Cai CL, Kranias EG, Akar FG, Hajjar RJ, Stillitano F. Gene editing reverses arrhythmia susceptibility in humanized PLN-R14del mice: modelling a European cardiomyopathy with global impact. Cardiovascular Research 2022, 118: 3140-3150. PMID: 35191471, PMCID: PMC9732517, DOI: 10.1093/cvr/cvac021.Peer-Reviewed Original ResearchConceptsAdeno-associated virus 9Ventricular tachycardiaCardiac functionStroke volumeHigh arrhythmia burdenSustained ventricular tachycardiaSudden cardiac deathCardiac magnetic resonancePre-symptomatic carriersYoung adult miceWeeks of ageDroplet digital polymerase chain reactionArrhythmia burdenVulnerable myocardiumCardiac deathEjection fractionPreclinical evidenceMalignant arrhythmiasVentricular dilationHumanized miceWT miceCardiac outputPolymerase chain reactionPLN-R14DelAdult mice
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 substrateAcute Left Ventricular Unloading Reduces Atrial Stretch and Inhibits Atrial Arrhythmias
Ishikawa K, Watanabe S, Lee P, Akar FG, Lee A, Bikou O, Fish K, Kho C, Hajjar RJ. Acute Left Ventricular Unloading Reduces Atrial Stretch and Inhibits Atrial Arrhythmias. Journal Of The American College Of Cardiology 2018, 72: 738-750. PMID: 30092950, PMCID: PMC6160394, DOI: 10.1016/j.jacc.2018.05.059.Peer-Reviewed Original ResearchConceptsLV end-diastolic pressureEnd-diastolic pressureLV unloadingMyocardial infarctionSubacute myocardial infarctionPressure-volume loopsLA pressureAortic regurgitationRyanodine receptor phosphorylationLA tissuesLV loadingReduced LV ejection fractionAtrial arrhythmia inducibilityLV assist deviceLV ejection fractionMean LA pressureLeft ventricular performancePressure-volume catheterMaximum LA volumeLV loading conditionsReceptor phosphorylationMedian 55NOX2 levelsArrhythmia inducibilityAtrial stretchOptical Action Potential Mapping in Acute Models of Ischemia–Reperfusion Injury: Probing the Arrhythmogenic Role of the Mitochondrial Translocator Protein
Ilkan Z, Strauss B, Campana C, Akar FG. Optical Action Potential Mapping in Acute Models of Ischemia–Reperfusion Injury: Probing the Arrhythmogenic Role of the Mitochondrial Translocator Protein. Methods In Molecular Biology 2018, 1816: 133-143. PMID: 29987816, DOI: 10.1007/978-1-4939-8597-5_10.Peer-Reviewed Original ResearchConceptsOptical action potential mappingIschemia-reperfusion injuryTranslocator proteinPost-ischemic arrhythmiasIonotropic propertiesPostischemic arrhythmiasR injuryHypertensive ratsAcute modelArrhythmogenic roleElectrophysiological substrateElectrophysiological propertiesArrhythmia mechanismsPharmacological inhibitionIntact heartInjuryTSPO ligandsMitochondrial translocator proteinArrhythmiasTSPO geneHeartPatientsRatsQuantitative assessmentIncidence
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 dysfunctionOxidative stress and inflammation as central mediators of atrial fibrillation in obesity and diabetes
Karam BS, Chavez-Moreno A, Koh W, Akar JG, Akar FG. Oxidative stress and inflammation as central mediators of atrial fibrillation in obesity and diabetes. Cardiovascular Diabetology 2017, 16: 120. PMID: 28962617, PMCID: PMC5622555, DOI: 10.1186/s12933-017-0604-9.Peer-Reviewed Original ResearchConceptsAtrial fibrillationOxidative stressCommon sustained cardiac arrhythmiaMaintenance of AFSustained cardiac arrhythmiaDiabetic heartElectrical remodelingRisk factorsAtrial excitabilityTherapeutic strategiesCardiac arrhythmiasInflammationCentral mediatorObesityDiabetesFibrillationMechanistic linkMellitusArrhythmiasExcitability
2016
Reducing mitochondrial bound hexokinase II mediates transition from non-injurious into injurious ischemia/reperfusion of the intact heart
Nederlof R, Gürel-Gurevin E, Eerbeek O, Xie C, Deijs GS, Konkel M, Hu J, Weber NC, Schumacher CA, Baartscheer A, Mik EG, Hollmann MW, Akar FG, Zuurbier CJ. Reducing mitochondrial bound hexokinase II mediates transition from non-injurious into injurious ischemia/reperfusion of the intact heart. Journal Of Physiology And Biochemistry 2016, 73: 323-333. PMID: 28258543, PMCID: PMC5534207, DOI: 10.1007/s13105-017-0555-3.Peer-Reviewed Original ResearchConceptsIschemia/reperfusionR injuryCardiac energeticsRecovery of functionHexokinase IISignificant LDH releasePossible underlying mechanismsIschemic insultCardiac recoveryControl heartsMtHKIIReperfusionIschemiaDHE fluorescenceRat heartR intervalLDH releasePeptide treatmentIntact heartInjuryUnderlying mechanismHeartMVO2NecrosisTreatment
2015
LKB1 deletion causes early changes in atrial channel expression and electrophysiology prior to atrial fibrillation
Kim GE, Ross JL, Xie C, Su KN, Zaha VG, Wu X, Palmeri M, Ashraf M, Akar JG, Russell KS, Akar FG, Young LH. LKB1 deletion causes early changes in atrial channel expression and electrophysiology prior to atrial fibrillation. Cardiovascular Research 2015, 108: 197-208. PMID: 26378152, PMCID: PMC4571838, DOI: 10.1093/cvr/cvv212.Peer-Reviewed Original ResearchConceptsLiver kinase B1Protein kinaseLKB1 deletionMetabolic regulator AMPAtrial fibrillationChannel expressionMHC-CreElectrophysiological functionKnockout mouse modelRelated kinasesLKB1 pathwayGene expressionPerpetuation of AFKinase B1Neonatal atrial myocytesΑMHC-CreKinasePostnatal day 1Patch-clamp recordingsAtrial growthWeeks of ageDeletionSodium current densityAction potential generationSpecific roleThe 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 challengeGene therapy to restore electrophysiological function in heart failure
Motloch LJ, Akar FG. Gene therapy to restore electrophysiological function in heart failure. Expert Opinion On Biological Therapy 2015, 15: 803-817. PMID: 25865107, PMCID: PMC5547747, DOI: 10.1517/14712598.2015.1036734.Peer-Reviewed Original ResearchConceptsHeart failureHF patientsMajor public health epidemicPro-arrhythmic activitySafe therapeutic optionSudden cardiac deathCause of morbidityGene therapyPublic health epidemicAbnormal excitabilityCardiac deathTherapeutic optionsTherapeutic effectMyocardial conductionHeart rateLethal arrhythmiasGene therapy approachesElectrophysiological functionUnmet needArrhythmogenic disordersGene-based approachesCalcium cyclingHealth epidemicCardiac gene therapyConduction system
2014
A formidable “TASK”: Tipping the balance in favor of rhythm control for the management of atrial fibrillation
Akar FG. A formidable “TASK”: Tipping the balance in favor of rhythm control for the management of atrial fibrillation. Heart Rhythm 2014, 11: 1806-1807. PMID: 25041966, DOI: 10.1016/j.hrthm.2014.07.018.Commentaries, Editorials and Letters