2020
Membrane-bound sn-1,2-diacylglycerols explain the dissociation of hepatic insulin resistance from hepatic steatosis in MTTP knockout mice
Abulizi A, Vatner DF, Ye Z, Wang Y, Camporez JP, Zhang D, Kahn M, Lyu K, Sirwi A, Cline GW, Hussain MM, Aspichueta P, Samuel VT, Shulman GI. Membrane-bound sn-1,2-diacylglycerols explain the dissociation of hepatic insulin resistance from hepatic steatosis in MTTP knockout mice. Journal Of Lipid Research 2020, 61: 1565-1576. PMID: 32907986, PMCID: PMC7707176, DOI: 10.1194/jlr.ra119000586.Peer-Reviewed Original ResearchConceptsHepatic insulin resistanceInsulin resistanceHepatic insulin sensitivityHepatic steatosisLipid-induced hepatic insulin resistancePKCε activationInsulin sensitivityKnockout miceNormal hepatic insulin sensitivityWild-type control miceHepatic ceramide contentHyperinsulinemic-euglycemic clampComprehensive metabolic phenotypingLipid dropletsHepatic DAG contentDAG contentGlucose intoleranceControl miceMTTP activityHepatic insulinAnimal modelsSteatosisAKT Ser/ThrMiceMetabolic phenotypingA 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 ResearchConceptsPlasma 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
Saturated and unsaturated fat induce hepatic insulin resistance independently of TLR-4 signaling and ceramide synthesis in vivo
Galbo T, Perry RJ, Jurczak MJ, Camporez J, Alves TC, Kahn M, Guigni BA, Serr J, Zhang D, Bhanot S, Samuel VT, Shulman GI. Saturated and unsaturated fat induce hepatic insulin resistance independently of TLR-4 signaling and ceramide synthesis in vivo. Proceedings Of The National Academy Of Sciences Of The United States Of America 2013, 110: 12780-12785. PMID: 23840067, PMCID: PMC3732992, DOI: 10.1073/pnas.1311176110.Peer-Reviewed Original ResearchConceptsHepatic insulin resistanceFat-induced hepatic insulin resistanceInsulin resistanceToll-like receptor 4 receptorTLR-4 knockout miceFat-induced insulin resistanceTLR-4 activationTLR-4 signalingType 2 diabetesImpairment of insulinInhibition of insulinCeramide synthesisActivation of PKCεTLR-4Hepatic steatosisHepatic accumulationKnockout miceIRS-2 signalingReceptor signalingCeramide accumulationAntisense oligonucleotideInsulinPrimary eventImpairmentFatty acidsRole of patatin‐like phospholipase domain‐containing 3 on lipid‐induced hepatic steatosis and insulin resistance in rats
Kumashiro N, Yoshimura T, Cantley JL, Majumdar SK, Guebre‐Egziabher F, Kursawe R, Vatner DF, Fat I, Kahn M, Erion DM, Zhang X, Zhang D, Manchem VP, Bhanot S, Gerhard GS, Petersen KF, Cline GW, Samuel VT, Shulman GI. Role of patatin‐like phospholipase domain‐containing 3 on lipid‐induced hepatic steatosis and insulin resistance in rats. Hepatology 2013, 57: 1763-1772. PMID: 23175050, PMCID: PMC3597437, DOI: 10.1002/hep.26170.Peer-Reviewed Original ResearchCGI-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 ResearchConceptsNonalcoholic 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