2024
Ceramide 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 inhibitorDGAT2DesaturaseInhibition
2023
1510-P: Lipid-Induced Renal Cortical Insulin Resistance Perturbs Gluconeogenic and Oxidative Metabolism via an sn-1,2-diacylglycerol-PKCe-Insulin Receptor Kinase Axis In Vivo
HUBBARD B, GASPAR R, ZHANG D, KAHN M, NASIRI A, SHULMAN G. 1510-P: Lipid-Induced Renal Cortical Insulin Resistance Perturbs Gluconeogenic and Oxidative Metabolism via an sn-1,2-diacylglycerol-PKCe-Insulin Receptor Kinase Axis In Vivo. Diabetes 2023, 72 DOI: 10.2337/db23-1510-p.Peer-Reviewed Original ResearchInsulin receptor kinasePyruvate carboxylaseHyperinsulinemic-euglycemic clampMitochondrial pyruvate oxidationInsulin resistanceOxidative metabolismMitochondrial pyruvate carboxylaseReceptor kinaseInhibitory phosphorylationAktS473 phosphorylationKinase axisChow fed miceImpairs insulinPyruvate oxidationKnockin micePhosphorylationKey targetFortress BiotechFed micePKCεDiacylglycerolRenal cortexHFDMetabolismBasal conditions
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
2021
335-OR: Lipid-Induced Insulin Resistance in the Renal Cortex Is Associated with Plasma Membrane Sn-1,2-diacylglycerol Accumulation and PKCe Translocation
HUBBARD B, GASPAR R, ZHANG D, KAHN M, NASIRI A, ZHANG X, CLINE G, SHULMAN G. 335-OR: Lipid-Induced Insulin Resistance in the Renal Cortex Is Associated with Plasma Membrane Sn-1,2-diacylglycerol Accumulation and PKCe Translocation. Diabetes 2021, 70 DOI: 10.2337/db21-335-or.Peer-Reviewed Original ResearchHigh-fat dietInsulin receptorInsulin resistanceLipid-Induced Insulin ResistanceRC miceProtein kinase CεRegular chowHFD miceRenal cortexCitrate synthase fluxHyperinsulinemic-euglycemic clamp conditionsAktS473 phosphorylationFatty acid fluxPyruvate oxidationPKCε translocationPyruvate dehydrogenase fluxPhosphorylationDiacylglycerol accumulationHFD feedingFat dietSpouse/partnerFold increaseSynthase fluxTranslocationIonis Pharmaceuticals
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 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