title: Calcium signaling in insulin action on striated muscle.
abstract: Striated muscles (skeletal and cardiac) are major physiological targets of insulin and this hormone triggers complex signaling pathways regulating cell growth and energy metabolism. Insulin increases glucose uptake into muscle cells by stimulating glucose transporter (GLUT4) translocation from intracellular compartments to the cell surface. The canonical insulin-triggered signaling cascade controlling this process is constituted by well-mapped tyrosine, lipid and serine/threonine phosphorylation reactions. In parallel to these signals, recent findings reveal insulin-dependent Ca(2+) mobilization in skeletal muscle cells and cardiomyocytes. Specifically, insulin activates the sarco-endoplasmic reticulum (SER) channels that release Ca(2+) into the cytosol i.e., the Ryanodine Receptor (RyR) and the inositol 1,4,5-triphosphate receptor (IP3R). In skeletal muscle cells, a rapid, insulin-triggered Ca(2+) release occurs through RyR, that is brought about upon S-glutathionylation of cysteine residues in the channel by reactive oxygen species (ROS) produced by the early activation of the NADPH oxidase (NOX2). In cardiomyocytes insulin induces a fast and transient increase in cytoplasmic [Ca(2+)]i trough L-type Ca(2+) channels activation. In both cell types, a relatively slower Ca(2+) release also occurs through IP3R activation, and is required for GLUT4 translocation and glucose uptake. The insulin-dependent Ca(2+) released from IP3R of skeletal muscle also promotes mitochondrial Ca(2+) uptake. We review here these actions of insulin on intracellular Ca(2+) channel activation and their impact on GLUT4 traffic in muscle cells, as well as other implications of insulin-dependent Ca(2+) release from the SER.
authors.affiliation: Center for Molecular Studies of the Cell (CEMC), Faculty of Medicine, Chile; Advanced Center for Chronic Disease (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Chile; Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago 8380492, Chile. Electronic address: acontreras@med.uchile.cl.
authors.forename: A
authors.initials: A
authors.lastname: Contreras-Ferrat
authors.affiliation: Center for Molecular Studies of the Cell (CEMC), Faculty of Medicine, Chile; Advanced Center for Chronic Disease (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Chile.
authors.forename: S
authors.initials: S
authors.lastname: Lavandero
authors.affiliation: Center for Molecular Studies of the Cell (CEMC), Faculty of Medicine, Chile.
authors.forename: E
authors.initials: E
authors.lastname: Jaimovich
authors.affiliation: The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.
authors.forename: A
authors.initials: A
authors.lastname: Klip
mesh_terms: D020013:Calcium Signaling / Q000235:genetics*; D003920:Diabetes Mellitus / Q000378:metabolism* / Q000503:physiopathology; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism
chemical_list: D051275:Glucose Transporter Type 4; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007328:Insulin; D017382:Reactive Oxygen Species; D019837:Ryanodine Receptor Calcium Release Channel; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases
keywords: Ca(2+); Cardiomyocytes; GLUT4; IP(3)R; Insulin; Mitochondria; Myotubes; NOX2; RyR