title: Overexpression of vesicle-associated membrane protein (VAMP) 3, but not VAMP2, protects glucose transporter (GLUT) 4 protein translocation in an in vitro model of cardiac insulin resistance.
abstract: Cardiac glucose utilization is regulated by reversible translocation of the glucose transporter GLUT4 from intracellular stores to the plasma membrane. During the onset of diet-induced insulin resistance, elevated lipid levels in the circulation interfere with insulin-stimulated GLUT4 translocation, leading to impaired glucose utilization. Recently, we identified vesicle-associated membrane protein (VAMP) 2 and 3 to be required for insulin- and contraction-stimulated GLUT4 translocation, respectively, in cardiomyocytes. Here, we investigated whether overexpression of VAMP2 and/or VAMP3 could protect insulin-stimulated GLUT4 translocation under conditions of insulin resistance. HL-1 atrial cardiomyocytes transiently overexpressing either VAMP2 or VAMP3 were cultured for 16 h with elevated concentrations of palmitate and insulin. Upon subsequent acute stimulation with insulin, we measured GLUT4 translocation, plasmalemmal presence of the fatty acid transporter CD36, and myocellular lipid accumulation. Overexpression of VAMP3, but not VAMP2, completely prevented lipid-induced inhibition of insulin-stimulated GLUT4 translocation. Furthermore, the plasmalemmal presence of CD36 and intracellular lipid levels remained normal in cells overexpressing VAMP3. However, insulin signaling was not retained, indicating an effect of VAMP3 overexpression downstream of PKB/Akt. Furthermore, we revealed that endogenous VAMP3 is bound by the contraction-activated protein kinase D (PKD), and contraction and VAMP3 overexpression protect insulin-stimulated GLUT4 translocation via a common mechanism. These observations indicate that PKD activates GLUT4 translocation via a VAMP3-dependent trafficking step, which pathway might be valuable to rescue constrained glucose utilization in the insulin-resistant heart.
authors.affiliation: Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, P. O. Box 616, 6200 MD Maastricht, The Netherlands. robert.schwenk@dife.de
authors.forename: Robert W
authors.initials: RW
authors.lastname: Schwenk
authors.forename: Yeliz
authors.initials: Y
authors.lastname: Angin
authors.forename: Laura K M
authors.initials: LK
authors.lastname: Steinbusch
authors.forename: Ellen
authors.initials: E
authors.lastname: Dirkx
authors.forename: Nicole
authors.initials: N
authors.lastname: Hoebers
authors.forename: Will A
authors.initials: WA
authors.lastname: Coumans
authors.forename: Arend
authors.initials: A
authors.lastname: Bonen
authors.forename: Jos L V
authors.initials: JL
authors.lastname: Broers
authors.forename: Guillaume J J M
authors.initials: GJ
authors.lastname: van Eys
authors.forename: Jan F C
authors.initials: JF
authors.lastname: Glatz
authors.forename: Joost J F P
authors.initials: JJ
authors.lastname: Luiken
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism; D002460:Cell Line; D004041:Dietary Fats / Q000494:pharmacology; D015870:Gene Expression; D051275:Glucose Transporter Type 4 / Q000378:metabolism*; D006331:Heart Diseases / Q000378:metabolism / Q000473:pathology; D007328:Insulin / Q000494:pharmacology / Q000502:physiology; D007333:Insulin Resistance; D050356:Lipid Metabolism; D008297:Male; D051379:Mice; D009200:Myocardial Contraction; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology / Q000502:physiology; D010168:Palmitates / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D021381:Protein Transport; D051381:Rats; D011917:Rats, Inbred Lew; D015398:Signal Transduction; D050988:Vesicle-Associated Membrane Protein 2 / Q000235:genetics / Q000378:metabolism*; D051040:Vesicle-Associated Membrane Protein 3 / Q000235:genetics / Q000378:metabolism*
chemical_list: D018955:CD36 Antigens; D004041:Dietary Fats; D051275:Glucose Transporter Type 4; D007328:Insulin; D010168:Palmitates; C495693:Slc2a4 protein, mouse; D050988:Vesicle-Associated Membrane Protein 2; D051040:Vesicle-Associated Membrane Protein 3; C494808:vesicle-associated membrane protein 2, mouse; C494953:vesicle-associated membrane protein 3, mouse; C089212:protein kinase D; D011493:Protein Kinase C