title: Glucose transport activation in human hematopoietic cells M07e is modulated by cytosolic calcium and calmodulin.
abstract: The aim of this work was to investigate the role of cytosolic calcium and calmodulin-dependent systems in the activation of glucose uptake in the human megakaryocytic cell line M07e. Glucose uptake was significantly raised by elevation of cytosolic Ca(2+) concentration ([Ca(2+)](c)) with thapsigargin, this effect being additive to the activation induced by cytokines (SCF, GM-CSF and TPO) and hydrogen peroxide. Intracellular Ca(2+) chelation by BAPTA decreased basal and activated glucose uptake in a dose-dependent manner. BAPTA reduced the GLUT1 translocation induced by SCF and H(2)O(2), suggesting a major role for Ca(2+) in GLUT1 intracellular trafficking. In the absence of extracellular Ca(2+), 2-aminoethoxydiphenyl-borate (2-APB) abolished the activation of glucose uptake induced by cytokines and H(2)O(2) suggesting an involvement in GLUT1 regulation in responses related to InsP(3)-induced Ca(2+) release. Under our experimental conditions, all the stimuli inducing glucose uptake activation failed to increase [Ca(2+)](c) suggesting that cytosolic Ca(2+) plays a permissive role in the regulation of GLUT1. The calmodulin antagonist W-7 and the inhibitor of Ca(2+)-calmodulin dependent protein kinase II (CAMK II) KN-62 removed the glucose transport activation by all the tested stimuli. These results suggest that in M07e cells calmodulin and CAMKII are involved in GLUT1 stimulation by cytokines and ROS.
authors.affiliation: Department of Biochemistry G. Moruzzi, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy.
authors.forename: Tullia
authors.initials: T
authors.lastname: Maraldi
authors.forename: Michela
authors.initials: M
authors.lastname: Rugolo
authors.forename: Diana
authors.initials: D
authors.lastname: Fiorentini
authors.forename: Laura
authors.initials: L
authors.lastname: Landi
authors.forename: Gabriele
authors.initials: G
authors.lastname: Hakim
mesh_terms: D000818:Animals; D001896:Boron Compounds / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism*; D002460:Cell Line; D002614:Chelating Agents / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry*; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D051272:Glucose Transporter Type 1 / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008533:Megakaryocytes / Q000166:cytology / Q000502:physiology*; D009543:Nifedipine / Q000378:metabolism; D016877:Oxidants / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D019284:Thapsigargin / Q000378:metabolism
chemical_list: D001896:Boron Compounds; D002121:Calcium Channel Blockers; D002147:Calmodulin; D002614:Chelating Agents; D016207:Cytokines; D004791:Enzyme Inhibitors; D051272:Glucose Transporter Type 1; D016877:Oxidants; D020033:Protein Isoforms; D017382:Reactive Oxygen Species; C495677:SLC2A1 protein, human; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D019284:Thapsigargin; D006861:Hydrogen Peroxide; C109986:2-aminoethoxydiphenyl borate; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D009543:Nifedipine; D005947:Glucose; D002118:Calcium