2022
Distinct subcellular localisation of intramyocellular lipids and reduced PKCε/PKCθ activity preserve muscle insulin sensitivity in exercise-trained mice
Gaspar R, Lyu K, Hubbard B, Leitner B, Luukkonen P, Hirabara S, Sakuma I, Nasiri A, Zhang D, Kahn M, Cline G, Pauli J, Perry R, Petersen K, Shulman G. Distinct subcellular localisation of intramyocellular lipids and reduced PKCε/PKCθ activity preserve muscle insulin sensitivity in exercise-trained mice. Diabetologia 2022, 66: 567-578. PMID: 36456864, PMCID: PMC11194860, DOI: 10.1007/s00125-022-05838-8.Peer-Reviewed Original ResearchConceptsProtein kinase CsSubcellular compartmentsDistinct subcellular localisationMuscle insulin sensitivityMultiple subcellular compartmentsInsulin receptor kinaseNovel protein kinase CsActivation of PKCεSubcellular localisationPKCθ translocationReceptor kinasePlasma membraneSubcellular distributionTriacylglycerol contentCrucial pathwaysIntramuscular triacylglycerol contentRC miceDiacylglycerolConclusions/interpretationThese resultsPKCεPM compartmentPhosphorylationMuscle triacylglycerol contentSkeletal muscleRecent findings
2020
A Membrane-Bound Diacylglycerol Species Induces PKCϵ-Mediated Hepatic Insulin Resistance
Lyu K, Zhang Y, Zhang D, Kahn M, Ter Horst KW, Rodrigues MRS, Gaspar RC, Hirabara SM, Luukkonen PK, Lee S, Bhanot S, Rinehart J, Blume N, Rasch MG, Serlie MJ, Bogan JS, Cline GW, Samuel VT, Shulman GI. A Membrane-Bound Diacylglycerol Species Induces PKCϵ-Mediated Hepatic Insulin Resistance. Cell Metabolism 2020, 32: 654-664.e5. PMID: 32882164, PMCID: PMC7544641, DOI: 10.1016/j.cmet.2020.08.001.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsCell MembraneDiglyceridesHumansInsulin ResistanceLiverMalePhosphorylationProtein Kinase C-epsilonRatsRats, Sprague-DawleyReceptor, InsulinConceptsPlasma membraneEndoplasmic reticulumHigh-fat diet-induced hepatic insulin resistanceSubcellular fractionation methodInsulin receptor kinaseKey lipid speciesHepatic insulin resistanceDiet-induced hepatic insulin resistanceReceptor kinaseDiacylglycerol acyltransferase 2Molecular mechanismsAcute knockdownPhosphorylationLipid dropletsLipid speciesAcyltransferase 2KnockdownLiver-specific overexpressionDAG accumulationPKCϵDAG contentMembraneFractionation methodKinaseMitochondria
2013
Cellular Mechanisms by Which FGF21 Improves Insulin Sensitivity in Male Mice
Camporez JP, Jornayvaz FR, Petersen MC, Pesta D, Guigni BA, Serr J, Zhang D, Kahn M, Samuel VT, Jurczak MJ, Shulman GI. Cellular Mechanisms by Which FGF21 Improves Insulin Sensitivity in Male Mice. Endocrinology 2013, 154: 3099-3109. PMID: 23766126, PMCID: PMC3749479, DOI: 10.1210/en.2013-1191.Peer-Reviewed Original ResearchMeSH KeywordsAdipose Tissue, BrownAnimalsCells, CulturedDiet, High-FatDrug ImplantsEnergy MetabolismFibroblast Growth FactorsGlucose IntoleranceHumansInfusions, SubcutaneousInsulin ResistanceIsoenzymesLipectomyLipid MetabolismLiverMaleMiceMice, Inbred C57BLMuscle, SkeletalProtein Kinase CProtein Kinase C-epsilonProtein Kinase C-thetaRecombinant ProteinsConceptsType 2 diabetesInsulin resistanceRegular chowInsulin sensitivityInsulin actionNonalcoholic fatty liver diseaseFibroblast growth factor 21Fatty liver diseasePeripheral insulin sensitivityEffects of FGF21HFD-fed miceGrowth factor 21High-fat dietCellular mechanismsWild-type miceWhite adipose tissueMuscle insulin resistanceMuscle ceramide contentProtein kinase Cε activationFGF21 administrationLiver diseaseFactor 21Male miceNovel therapiesAdipose tissueCGI-58 knockdown sequesters diacylglycerols in lipid droplets/ER-preventing diacylglycerol-mediated hepatic insulin resistance
Cantley JL, Yoshimura T, Camporez JP, Zhang D, Jornayvaz FR, Kumashiro N, Guebre-Egziabher F, Jurczak MJ, Kahn M, Guigni BA, Serr J, Hankin J, Murphy RC, Cline GW, Bhanot S, Manchem VP, Brown JM, Samuel VT, Shulman GI. CGI-58 knockdown sequesters diacylglycerols in lipid droplets/ER-preventing diacylglycerol-mediated hepatic insulin resistance. Proceedings Of The National Academy Of Sciences Of The United States Of America 2013, 110: 1869-1874. PMID: 23302688, PMCID: PMC3562813, DOI: 10.1073/pnas.1219456110.Peer-Reviewed Original ResearchMeSH Keywords1-Acylglycerol-3-Phosphate O-AcyltransferaseAdipose Tissue, WhiteAnimalsCell MembraneDiet, High-FatDiglyceridesEndoplasmic ReticulumGene ExpressionGene Knockdown TechniquesHumansImmunoblottingInjections, IntraperitonealInsulin ResistanceLipidsLiverMaleMiceMice, Inbred C57BLOligonucleotides, AntisenseProtein Kinase C-epsilonProtein TransportReverse Transcriptase Polymerase Chain ReactionConceptsHepatic insulin resistanceInsulin resistanceHepatic steatosisCGI-58 knockdownHigh-fat fed miceHyperinsulinemic-euglycemic clamp studiesSevere hepatic steatosisCGI-58 expressionFat-fed miceLipid-induced hepatic insulin resistanceChanarin-Dorfman syndromeComparative gene identification-58Lipid droplet-associated proteinAdipose triglyceride lipaseDroplet-associated proteinAntisense oligonucleotide treatmentInsulin sensitivityASO treatmentClamp studiesLipotoxic conditionsKnockdown miceCGI-58PKCε activationMiceTriglyceride lipase
2011
Cellular mechanism of insulin resistance in nonalcoholic fatty liver disease
Kumashiro N, Erion DM, Zhang D, Kahn M, Beddow SA, Chu X, Still CD, Gerhard GS, Han X, Dziura J, Petersen KF, Samuel VT, Shulman GI. Cellular mechanism of insulin resistance in nonalcoholic fatty liver disease. Proceedings Of The National Academy Of Sciences Of The United States Of America 2011, 108: 16381-16385. PMID: 21930939, PMCID: PMC3182681, DOI: 10.1073/pnas.1113359108.Peer-Reviewed Original ResearchMeSH KeywordsAdultDiglyceridesEnzyme ActivationFatty LiverFemaleHumansInsulin ResistanceMaleMiddle AgedProtein Kinase C-epsilonConceptsNonalcoholic fatty liver diseaseFatty liver diseaseHepatic DAG contentInsulin resistanceHepatic insulin resistanceLiver diseaseHepatic steatosisCellular mechanismsHomeostatic model assessmentInsulin resistance indexMarkers of inflammationType 2 diabetesER stress markersLipid dropletsHepatic diacylglycerol contentEndoplasmic reticulum stressActivation of PKCεLiver biopsyNondiabetic individualsHepatocellular lipidsInsulin sensitivityCytoplasmic lipid dropletsDAG contentResistance indexAnimal models
2007
Inhibition of protein kinase Cε prevents hepatic insulin resistance in nonalcoholic fatty liver disease
Samuel VT, Liu ZX, Wang A, Beddow SA, Geisler JG, Kahn M, Zhang XM, Monia BP, Bhanot S, Shulman GI. Inhibition of protein kinase Cε prevents hepatic insulin resistance in nonalcoholic fatty liver disease. Journal Of Clinical Investigation 2007, 117: 739-745. PMID: 17318260, PMCID: PMC1797607, DOI: 10.1172/jci30400.Peer-Reviewed Original ResearchConceptsHepatic insulin resistanceNonalcoholic fatty liver diseaseFatty liver diseaseInsulin resistanceHigh-fat feedingLiver diseaseFat-induced hepatic insulin resistanceType 2 diabetes mellitusType 2 diabetesHepatic fat accumulationNovel therapeutic targetInsulin receptor kinase activityDiabetes mellitusHepatic steatosisFat accumulationRats resultsTherapeutic targetHepatic insulinReceptor kinase activityProtein kinase CεInsulin receptorCausal roleIsoforms of PKCAntisense oligonucleotideRats