Rafael Calais Gaspar, PhD, MSc
Postdoctoral AssociateAbout
Research
Publications
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 diseaseTranslocationRho-Kinase Is Differentially Expressed in the Adipose Tissue of Rodent and Human in Response to Aging, Sex, and Acute Exercise
Muñoz V, Vieira R, Katashima C, Gaspar R, Lino M, dos Santos Trombeta J, Duft R, Macêdo A, da Silva A, Ropelle E, de Moura L, Cintra D, Chacon-Mikahil M, Cavaglieri C, Pauli J. Rho-Kinase Is Differentially Expressed in the Adipose Tissue of Rodent and Human in Response to Aging, Sex, and Acute Exercise. The Journals Of Gerontology Series A 2024, 79: glae001. PMID: 38197701, DOI: 10.1093/gerona/glae001.Peer-Reviewed Original ResearchWhite adipose tissueAcute physical exerciseBrown adipose tissueAdipose tissueFemale rodentsInflammatory markersPhysical exerciseROCK activityInguinal white adipose tissueHuman white adipose tissueHigh-fat dietRho-kinasePossible therapeutic targetAcute exerciseAdipokine productionImpaired thermogenesisEndocrine functionMetabolism improvementTherapeutic targetAdipose depotsHuman preadipocytesROCK2 expressionMetabolic stressPreadipocyte differentiationCell senescence
2023
Lysophosphatidic acid triggers inflammation in the liver and white adipose tissue in rat models of 1-acyl-sn-glycerol-3-phosphate acyltransferase 2 deficiency and overnutrition
Sakuma I, Gaspar R, Luukkonen P, Kahn M, Zhang D, Zhang X, Murray S, Golla J, Vatner D, Samuel V, Petersen K, Shulman G. Lysophosphatidic acid triggers inflammation in the liver and white adipose tissue in rat models of 1-acyl-sn-glycerol-3-phosphate acyltransferase 2 deficiency and overnutrition. Proceedings Of The National Academy Of Sciences Of The United States Of America 2023, 120: e2312666120. PMID: 38127985, PMCID: PMC10756285, DOI: 10.1073/pnas.2312666120.Peer-Reviewed Original ResearchTime-restricted feeding combined with resistance exercise prevents obesity and improves lipid metabolism in the liver of mice fed a high-fat diet
Damasceno de Lima R, Fudoli Lins Vieira R, Rosetto Muñoz V, Chaix A, Azevedo Macedo A, Calheiros Antunes G, Felonato M, Rosseto Braga R, Castelo Branco Ramos Nakandakari S, Calais Gaspar R, Ramos da Silva A, Esper Cintra D, Pereira de Moura L, Mekary R, Rochete Ropelle E, Pauli J. Time-restricted feeding combined with resistance exercise prevents obesity and improves lipid metabolism in the liver of mice fed a high-fat diet. AJP Endocrinology And Metabolism 2023, 325: e513-e528. PMID: 37755454, DOI: 10.1152/ajpendo.00129.2023.Peer-Reviewed Original ResearchConceptsNonalcoholic fatty liver diseaseResistance exercise trainingTime-restricted feedingFatty liver diseaseHigh-fat dietLiver diseaseExercise trainingWeight gainGlycemic homeostasisMetabolic disordersEffects of TRFCommon liver diseaseDiet-induced obesityMajor risk factorEnergy expenditureFatty acid oxidation genesLiver of miceAccumulation of fatBody weight gainRespiratory exchange rateAccumulation of lipidsLower mRNA expressionRT groupPrevents obesityRisk factors
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Discoveries & Impact (September 2020)