title: Modulation by cADPr of Ca2+ mobilization and oxidative response in dimethylsulfoxide- or retinoic acid-differentiated HL-60 cells.
abstract: In human phagocytic cells, reactive oxygen species (ROS) generation in response to N-formyl-L-Methionyl-L-Leucyl-L-Phenylalanine (fMLF) is largely dependent on cytosolic free calcium concentration ([Ca2+]i). Cyclic ADP-ribose (cADPr) is able to regulate Ca2+ release from intracellular stores through the ryanodine receptor but its potential role in biological responses has so far not been determined. In this study, we examined whether extracellular and intracellular cADPr is required in fMLF-induced [Ca2+]i rise and consequently in the oxidative response in human neutrophil-like HL-60 cells differentiated with dimethylsulfoxide or all-trans-retinoic acid (ATRA). We establish that extracellular cADPr cannot elicit [Ca2+]i elevation. Furthermore, we demonstrate that 8-Br-cADPr, a functional antagonist of cADPr, inhibits Ca2+ entry into HL-60 cells differentiated with ATRA and stimulated with fMLF (95+/-4 and 148+/-5 nM respectively, n=3). Finally, we show that this partial inhibition of Ca2+ mobilization is unrelated to ROS production (10.0+/-0.3 vs. 9.6+/-0.5 A.U., n=3). In conclusion, we showed that cADPr can control fMLF-induced Ca2+ influx but is unable to regulate a Ca2+-dependent biological response, i.e. H2O2 production.
authors.affiliation: Laboratoire de Biologie et Physiologie Intégrée. Faculté des Sciences, de la Technologie et de la Communication. Université du Luxembourg, Luxembourg.
authors.forename: S
authors.initials: S
authors.lastname: Bréchard
authors.forename: A
authors.initials: A
authors.lastname: Brunello
authors.forename: J-L
authors.initials: JL
authors.lastname: Bueb
authors.forename: E J
authors.initials: EJ
authors.lastname: Tschirhart
mesh_terms: D020013:Calcium Signaling / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D036563:Cyclic ADP-Ribose / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010455:Peptides / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D010455:Peptides; D036563:Cyclic ADP-Ribose; D014212:Tretinoin; D019284:Thapsigargin; D006861:Hydrogen Peroxide; D004121:Dimethyl Sulfoxide