2021
Short-term overnutrition induces white adipose tissue insulin resistance through sn-1,2-diacylglycerol – PKCε – insulin receptorT1160 phosphorylation
Lyu K, Zhang D, Song J, Li X, Perry RJ, Samuel VT, Shulman GI. Short-term overnutrition induces white adipose tissue insulin resistance through sn-1,2-diacylglycerol – PKCε – insulin receptorT1160 phosphorylation. JCI Insight 2021, 6: e139946. PMID: 33411692, PMCID: PMC7934919, DOI: 10.1172/jci.insight.139946.Peer-Reviewed Original ResearchConceptsInsulin resistanceInsulin actionAdipose tissue insulin resistanceTissue insulin resistanceWT control miceHyperinsulinemic-euglycemic clampShort-term HFDTissue insulin actionAdipose tissue insulin actionDiet-fed ratsPotential therapeutic targetHFD feedingControl miceInsulin sensitivityTherapeutic targetLipolysis suppressionImpairs insulinHFDPKCε activationGlucose uptakeΕ activationMiceDiacylglycerol accumulationRecent evidenceProtein kinase C
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
2018
PKCε contributes to lipid-induced insulin resistance through cross talk with p70S6K and through previously unknown regulators of insulin signaling
Gassaway BM, Petersen MC, Surovtseva YV, Barber KW, Sheetz JB, Aerni HR, Merkel JS, Samuel VT, Shulman GI, Rinehart J. PKCε contributes to lipid-induced insulin resistance through cross talk with p70S6K and through previously unknown regulators of insulin signaling. Proceedings Of The National Academy Of Sciences Of The United States Of America 2018, 115: e8996-e9005. PMID: 30181290, PMCID: PMC6156646, DOI: 10.1073/pnas.1804379115.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAnimals, Genetically ModifiedDiabetes Mellitus, Type 2Diet, High-FatDisease Models, AnimalGene Knockdown TechniquesHumansInsulinInsulin Receptor Substrate ProteinsInsulin ResistanceLipid MetabolismLiverPhosphorylationProtein Kinase C-epsilonProteomicsRatsReceptor, InsulinRibosomal Protein S6Ribosomal Protein S6 Kinases, 70-kDaRNA, Small InterferingSignal TransductionConceptsHigh-fat diet-induced hepatic insulin resistanceDiet-induced hepatic insulin resistanceLipid-induced insulin resistanceProtein phosphorylationSiRNA-based screenProtein kinase C εSet of proteinsCross talkHepatic insulin resistanceQuantitative phosphoproteomicsMotif analysisUnknown regulatorKinase assaysPhosphoproteomic dataCanonical insulinP70S6KInsulin receptorImpact of lipidSystem-level approachPKCεDiacylglycerolPhosphorylationKey mediatorNew therapeutic approachesInsulin resistance
2016
Insulin receptor Thr1160 phosphorylation mediates lipid-induced hepatic insulin resistance
Petersen MC, Madiraju AK, Gassaway BM, Marcel M, Nasiri AR, Butrico G, Marcucci MJ, Zhang D, Abulizi A, Zhang XM, Philbrick W, Hubbard SR, Jurczak MJ, Samuel VT, Rinehart J, Shulman GI. Insulin receptor Thr1160 phosphorylation mediates lipid-induced hepatic insulin resistance. Journal Of Clinical Investigation 2016, 126: 4361-4371. PMID: 27760050, PMCID: PMC5096902, DOI: 10.1172/jci86013.Peer-Reviewed Original ResearchConceptsInsulin receptorKinase activityHigh-fat diet-induced hepatic insulin resistanceKinase activation loopNonalcoholic fatty liver diseaseLipid-induced hepatic insulin resistanceProtein kinase CHepatic insulin resistanceDiet-induced hepatic insulin resistanceDiacylglycerol-mediated activationActivation loopPKCε inhibitionAlanine mutationsInsulin resistanceMolecular mechanismsKinase CCritical pathophysiological rolePathogenesis of T2DMechanistic linkMutantsGlycogen synthesisConsequent inhibitionPhosphorylationActive configurationPKCε
2015
Insulin-independent regulation of hepatic triglyceride synthesis by fatty acids
Vatner DF, Majumdar SK, Kumashiro N, Petersen MC, Rahimi Y, Gattu AK, Bears M, Camporez JP, Cline GW, Jurczak MJ, Samuel VT, Shulman GI. Insulin-independent regulation of hepatic triglyceride synthesis by fatty acids. Proceedings Of The National Academy Of Sciences Of The United States Of America 2015, 112: 1143-1148. PMID: 25564660, PMCID: PMC4313795, DOI: 10.1073/pnas.1423952112.Peer-Reviewed Original Research
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