Glucose transport activation in human hematopoietic cells M07e is modulated by cytosolic calcium and calmodulin.
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.
Maraldi
Tullia
T
Department of Biochemistry G. Moruzzi, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy.
Rugolo
Michela
M
Fiorentini
Diana
D
Landi
Laura
L
Hakim
Gabriele
G
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
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