Rafael Calais Gaspar, PhD, MSc
Postdoctoral AssociateAbout
Research
Publications
2025
Notch1 Signalling Is Downregulated by Aerobic Exercise, Leading to Improvement of Hepatic Metabolism in Obese Mice
Gaspar R, Macêdo A, Nakandakari S, Muñoz V, Abud G, Vieira R, de Sousa Neto I, Pavan I, da Silva L, Simabuco F, da Silva A, Salgado W, Marchini J, Nonino C, Cintra D, Ropelle E, Pajvani U, de Freitas E, Pauli J. Notch1 Signalling Is Downregulated by Aerobic Exercise, Leading to Improvement of Hepatic Metabolism in Obese Mice. Liver International 2025, 45: e70068. PMID: 40078075, DOI: 10.1111/liv.70068.Peer-Reviewed Original ResearchConceptsNotch1 signalingAerobic exerciseRegulation of hepatic glucoseObese miceImpact of aerobic exerciseEffects of Notch1 signalingAerobic exercise trainingMTORC1 pathway activationNotch1 pathwayObese individualsTissue of obese miceCross-sectional studyNotch1 mRNA levelsMitochondrial respirationExercise trainingLivers of obese individualsTreadmill runningGluconeogenic enzymesHepG2 cell lineLipid accumulationTraining groupHepatic glucoseHepatic metabolismNotch1 proteinPathway activationTime-restricted feeding reduces inflammatory markers and downregulates JAG1 and NICD protein levels in the liver of aged mice
Macêdo A, de Sousa Neto I, Antonio G, Gaspar R, de Lima R, Dias L, Vieira R, Muñoz V, Brunelli D, da Silva A, Cintra D, Ropelle E, Pauli J. Time-restricted feeding reduces inflammatory markers and downregulates JAG1 and NICD protein levels in the liver of aged mice. Nutrition 2025, 133: 112691. PMID: 39983606, DOI: 10.1016/j.nut.2025.112691.Peer-Reviewed Original ResearchConceptsRNA-seq datasetsNotch1 intracellular domainMitochondrial respirationTime-restricted feedingAged miceInflammatory markersAd libitum dietIntracellular domainHepatic mitochondrial respirationATP productionLiver mitochondrial respirationCellular longevityLiver of aged miceLibitum dietDisease Activity ScoreCompared to adult animalsNotch1 signalingProtein contentTime-restricted feeding protocolsUpregulation of Notch1Investigated metabolic parametersProtein levelsNotch1Adult miceCollagen fibersDeterminants of increased muscle insulin sensitivity of exercise-trained versus sedentary normal weight and overweight individuals
Pesta D, Anadol-Schmitz E, Sarabhai T, Kamp Y, Gancheva S, Trinks N, Zaharia O, Mastrototaro L, Lyu K, Habets I, Kamp-Bruls Y, Dewidar B, Weiss J, Schrauwen-Hinderling V, Zhang D, Gaspar R, Strassburger K, Kupriyanova Y, Al-Hasani H, Szendroedi J, Schrauwen P, Phielix E, Shulman G, Roden M. Determinants of increased muscle insulin sensitivity of exercise-trained versus sedentary normal weight and overweight individuals. Science Advances 2025, 11: eadr8849. PMID: 39742483, PMCID: PMC11691647, DOI: 10.1126/sciadv.adr8849.Peer-Reviewed Original ResearchConceptsOverweight-to-obeseNormal weightEndurance-trained humansMuscle mitochondrial contentAthlete's paradoxTrained athletesExercise-trainedOverweight individualsAthletesObesity subtypesObservational studyIntramyocellular triglyceride accumulationInsulin sensitivityHigher insulin sensitivityMitochondrial contentIncreased insulin sensitivityMuscleFemale individualsIndividualsInsulin resistanceObesityMitochondrial partitioningIncreased calpainNPKC activityProtein kinase C
2024
SGLT2 inhibition alters substrate utilization and mitochondrial redox in healthy and failing rat hearts
Goedeke L, Ma Y, Gaspar R, Nasiri A, Lee J, Zhang D, Galsgaard K, Hu X, Zhang J, Guerrera N, Li X, LaMoia T, Hubbard B, Haedersdal S, Wu X, Stack J, Dufour S, Butrico G, Kahn M, Perry R, Cline G, Young L, Shulman G. SGLT2 inhibition alters substrate utilization and mitochondrial redox in healthy and failing rat hearts. Journal Of Clinical Investigation 2024, 134: e176708. PMID: 39680452, PMCID: PMC11645152, DOI: 10.1172/jci176708.Peer-Reviewed Original ResearchConceptsSodium-glucose cotransporter type 2Heart failureKetone oxidationGas chromatography-mass spectrometryFatty acid oxidationLeft ventricular ejection fractionReduced myocardial oxidative stressVentricular ejection fractionKetone supplementationWeeks of treatmentMyocardial oxidative stressDecreased pyruvate oxidationInduce heart failurePlasma glucose levelsIn vivo effectsSGLT2i treatmentEjection fractionAssociated with improvementsAwake ratsSGLT2 inhibitionCardioprotective benefitsLiquid chromatography-tandem mass spectrometryPlasma ketonesRates of ketonizationChromatography-tandem mass spectrometryCeramide synthesis inhibitors prevent lipid-induced insulin resistance through the DAG-PKCε-insulin receptorT1150 phosphorylation pathway
Xu W, Zhang D, Ma Y, Gaspar R, Kahn M, Nasiri A, Murray S, Samuel V, Shulman G. Ceramide synthesis inhibitors prevent lipid-induced insulin resistance through the DAG-PKCε-insulin receptorT1150 phosphorylation pathway. Cell Reports 2024, 43: 114746. PMID: 39302831, DOI: 10.1016/j.celrep.2024.114746.Peer-Reviewed Original ResearchLipid-induced hepatic insulin resistanceHepatic insulin resistancePhosphorylation pathwayAntisense oligonucleotidesCeramide synthesis inhibitorsLipid-induced insulin resistanceMyriocin treatmentCeramide synthesisDihydroceramide desaturaseInsulin resistanceHepatic ceramideMyriocinCeramideCeramide contentInsulin-sensitizing effectsPhosphorylationHepatic insulin sensitivityPathwaySynthetic pathwayDES1Glucose productionSynthesis inhibitorDGAT2DesaturaseInhibitionEffect of Weight Loss on Skeletal Muscle Bioactive Lipids in People With Obesity and Type 2 Diabetes.
Petersen M, Yoshino M, Smith G, Gaspar R, Kahn M, Samovski D, Shulman G, Klein S. Effect of Weight Loss on Skeletal Muscle Bioactive Lipids in People With Obesity and Type 2 Diabetes. Diabetes 2024, 73: 2055-2064. PMID: 39264820, PMCID: PMC11579410, DOI: 10.2337/db24-0083.Peer-Reviewed Original ResearchMuscle insulin sensitivitySkeletal muscle insulin sensitivityType 2 diabetesEffects of weight lossInsulin sensitivityWeight lossWeight loss-induced improvementWhole-body insulin sensitivityObesityGlucose tracer infusionAssociated with changesHyperinsulinemic-euglycemic clamp procedureCeramide contentSn-1,2-DAGMuscleSmall molecule inhibition of glycogen synthase I reduces muscle glycogen content and improves biomarkers in a mouse model of Pompe disease
Gaspar R, Sakuma I, Nasiri A, Hubbard B, LaMoia T, Leitner B, Tep S, Xi Y, Green E, Ullman J, Petersen K, Shulman G. Small molecule inhibition of glycogen synthase I reduces muscle glycogen content and improves biomarkers in a mouse model of Pompe disease. AJP Endocrinology And Metabolism 2024, 327: e524-e532. PMID: 39171753, PMCID: PMC11482269, DOI: 10.1152/ajpendo.00175.2024.Peer-Reviewed Original ResearchGAA-KO miceMouse model of Pompe diseaseModel of Pompe diseasePompe diseaseMetabolic dysregulationRegular chowMouse modelSmall molecule inhibitionInsulin sensitivityReduced spontaneous activityGroups of male miceEnzyme acid alpha-glucosidaseProgressive muscle weaknessImprove metabolic dysregulationSynthase IWhole-body insulin sensitivityAcid alpha-glucosidaseImproved glucose toleranceIncreased AMPK phosphorylationWT miceAbnormal accumulation of glycogenGlycogen storage disorderMale miceSpontaneous activityImproved biomarkers1571-P: CIDEB and CGI-58 Regulate Liver Lipid Droplet Size with Cholesterol Content, Linking to Inflammation and Fibrosis in Metabolic Dysfunction–Associated Steatohepatitis
SAKUMA I, GASPAR R, NASIRI A, KAHN M, ZHENG J, GUERRA M, YIMLAMAI D, MURRAY S, PERELIS M, BARNES W, VATNER D, PETERSEN K, SAMUEL V, SHULMAN G. 1571-P: CIDEB and CGI-58 Regulate Liver Lipid Droplet Size with Cholesterol Content, Linking to Inflammation and Fibrosis in Metabolic Dysfunction–Associated Steatohepatitis. Diabetes 2024, 73 DOI: 10.2337/db24-1571-p.Peer-Reviewed Original ResearchLipid droplet sizeCGI-58Choline-deficient l-amino acid-defined high-fat dietGlycerol-3-phosphate acyltransferaseAntisense oligonucleotidesComparative gene identification-58Glycerol-3-phosphateLoss of function mutationsLipid droplet morphologyExpression of CGI-58Liver inflammationCidebCholesterol contentFunction mutationsL-amino acid-defined high-fat dietComplications of type 2 diabetesMolecular mechanismsDevelopment of liver inflammationMacrophage crown-like structuresType 2 diabetesHigh-fat dietCrown-like structuresASO treatmentGPAMKnockdown292-OR: Coenzyme A Synthase Knockdown Alleviates Metabolic Dysfunction–Associated Steatohepatitis via Decreasing Cholesterol in Liver Lipid Droplets
SAKUMA I, GASPAR R, NASIRI A, KAHN M, GUERRA M, YIMLAMAI D, MURRAY S, PERELIS M, BARNES W, VATNER D, PETERSEN K, SAMUEL V, SHULMAN G. 292-OR: Coenzyme A Synthase Knockdown Alleviates Metabolic Dysfunction–Associated Steatohepatitis via Decreasing Cholesterol in Liver Lipid Droplets. Diabetes 2024, 73 DOI: 10.2337/db24-292-or.Peer-Reviewed Original ResearchCholine-deficient l-amino acid-defined high-fat dietAccumulation of cholesterolMRNA expressionPlasma ALTL-amino acid-defined high-fat dietProtective effectLiver lipid dropletsType 2 diabetesPotential therapeutic approachHigh-fat dietDecreased plasma ALTFibrosis markersFree cholesterol accumulationLipid dropletsLiver inflammationDay 1Macrophage markersHepatic inflammationMouse modelMarker expressionTherapeutic approachesDay 2Day 3Day 7Fibrosis1577-P: CIDEB Knockdown Promotes Increased Hepatic Mitochondrial Fat Oxidation and Reverses Hepatic Steatosis and Hepatic Insulin Resistance by the PKCε-Insulin Receptor Kinase Pathway
ZHENG J, NASIRI A, GASPAR R, HUBBARD B, SAKUMA I, MA X, MURRAY S, PERELIS M, BARNES W, SAMUEL V, PETERSEN K, SHULMAN G. 1577-P: CIDEB Knockdown Promotes Increased Hepatic Mitochondrial Fat Oxidation and Reverses Hepatic Steatosis and Hepatic Insulin Resistance by the PKCε-Insulin Receptor Kinase Pathway. Diabetes 2024, 73 DOI: 10.2337/db24-1577-p.Peer-Reviewed Original ResearchReceptor kinase pathwaysMitochondrial fat oxidationHepatic insulin resistanceKinase pathwayExpression of cidebAmeliorated HFD-induced hepatic steatosisHFD-induced hepatic steatosisHFD-induced insulin resistanceSteatotic liver diseasePathogenesis of type 2 diabetesHepatic steatosisCidebHyperinsulinemic-euglycemic clamp studiesHepatic triglyceride accumulationInsulin resistanceReverse hepatic steatosisTriglyceride accumulationHepatic insulin sensitivityInsulin sensitivityPathwayHepatic expressionHigh-fatWhole-body insulin sensitivityLiver diseaseTranslocation
News
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- September 14, 2023
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- April 04, 2023
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- September 17, 2020
Discoveries & Impact (September 2020)
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