title: Cytoprotection against oxidative stress-induced damage of astrocytes by extracellular ATP via P2Y1 receptors.
abstract: Oxidative stress is the main cause of neuronal damage in traumatic brain injury, hypoxia/reperfusion injury, and neurodegenerative disorders. Although extracellular nucleosides, especially adenosine, are well known to protect against neuronal damage in such pathological conditions, the effects of these nucleosides or nucleotides on glial cell damage remain largely unknown. We report that ATP but not adenosine protects against the cell death of cultured astrocytes induced by hydrogen peroxide (H2O2). ATP ameliorated the H2O2-induced decrease in cell viability of astrocytes in an incubation time- and concentration-dependent fashion. Protection by ATP was inhibited by P2 receptor antagonists and was mimicked by P2Y1 receptor agonists but not by adenosine. The expressions of P2Y1 mRNAs and functional P2Y1 receptors in astrocytes were confirmed. Thus, ATP, acting on P2Y1 receptors in astrocytes, showed a protective action against H2O2. The astrocytic protection by the P2Y1 receptor agonist 2-methylthio-ADP was inhibited by an intracellular Ca2+ chelator and a blocker of phospholipase C, indicating the involvement of intracellular signals mediated by Gq/11-coupled P2Y1 receptors. The ATP-induced protection was inhibited by cycloheximide, a protein synthesis inhibitor, and it took more than 12 h for the onset of the protective action. In the DNA microarray analysis, ATP induced a dramatic upregulation of various oxidoreductase genes. Taken together, ATP acts on P2Y1 receptors coupled to Gq/11, resulting in the upregulation of oxidoreductase genes, leading to the protection of astrocytes against H2O2.
authors.affiliation: Division of Biosignaling, National Institute of Health Sciences, Setagaya, Tokyo, Japan.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Shinozaki
authors.forename: Schuichi
authors.initials: S
authors.lastname: Koizumi
authors.forename: Seiichi
authors.initials: S
authors.lastname: Ishida
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Sawada
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohno
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Inoue
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors; D009410:Nerve Degeneration / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D018696:Neuroprotective Agents / Q000378:metabolism / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010088:Oxidoreductases / Q000235:genetics; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D058472:Receptors, Purinergic P2Y1; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D018696:Neuroprotective Agents; D011500:Protein Synthesis Inhibitors; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D043802:GTP-Binding Protein alpha Subunits, Gq-G11