title: Secretion of ATP from Schwann cells in response to uridine triphosphate.
abstract: The mechanisms by which uridine triphosphate (UTP) stimulates ATP release from Schwann cells cultured from the sciatic nerve were investigated using online bioluminescence techniques. UTP, a P2Y(2) and P2Y(4) receptor agonist, stimulated ATP release from Schwann cells in a dose-dependent manner with an ED(50) of 0.24 microm. UTP-stimulated ATP release occurs through P2Y(2) receptors as it was blocked by suramin which inhibits P2Y(2) but not P2Y(4) receptors. Furthermore, positive immunostaining of P2Y(2) receptors on Schwann cells was revealed and GTP, an equipotent agonist with UTP at rat P2Y(4) receptors, did not significantly stimulate ATP release. UTP-stimulated ATP release involved second messenger pathways as it was attenuated by the phospholipase C inhibitor U73122, the protein kinase C inhibitor chelerytherine chloride, the IP(3) formation inhibitor lithium chloride, the cell membrane-permeable Ca(2+) chelator BAPTA-AM and the endoplasmic reticulum Ca(2+)-dependent ATPase inhibitor thapsigargin. Evidence that ATP may be stored in vesicles that must be transported to the cell membrane for exocytosis was found as release was significantly reduced by the Golgi-complex inhibitor brefeldin A, microtubule disruption with nocodazole, F-actin disruption with cytochalasin D and the specific exocytosis inhibitor botulinum toxin A. ATP release from Schwann cells also involves anion transport as it was significantly reduced by cystic fibrosis transmembrane conductance regulator inhibitor glibencamide and anion transporter inhibitor furosemide. We suggest that UTP-stimulated ATP release is mediated by activation of P2Y(2) receptors that initiate an IP(3)-Ca(2+) cascade and protein kinase C which promote exocytosis of ATP from vesicles as well as anion transport of ATP across the cell membrane.
authors.affiliation: The Neurobiology Laboratory, Department of Physiology & Institute for Biomedical Research, University of Sydney, NSW, 2006 Australia.
authors.forename: Guo Jun
authors.initials: GJ
authors.lastname: Liu
authors.forename: Eryn L
authors.initials: EL
authors.lastname: Werry
authors.forename: Max R
authors.initials: MR
authors.lastname: Bennett
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000470:Alkaloids; D000818:Animals; D000831:Animals, Newborn; D053119:Benzophenanthridines; D001905:Botulinum Toxins / Q000494:pharmacology; D019274:Botulinum Toxins, Type A; D020126:Brefeldin A / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D015638:Cytochalasin D / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004963:Estrenes / Q000494:pharmacology; D005665:Furosemide / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D006034:Glycyrrhetinic Acid / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007150:Immunohistochemistry / Q000379:methods; D007546:Isoquinolines / Q000494:pharmacology; D018613:Microscopy, Confocal / Q000379:methods; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010617:Phenanthridines / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058473:Receptors, Purinergic P2Y2; D012583:Schwann Cells / Q000187:drug effects* / Q000378:metabolism; D012584:Sciatic Nerve / Q000166:cytology; D013449:Sulfonamides / Q000494:pharmacology; D013498:Suramin / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D013997:Time Factors; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D014544:Uridine Triphosphate / Q000494:pharmacology*
chemical_list: D000470:Alkaloids; D053119:Benzophenanthridines; D004963:Estrenes; D007546:Isoquinolines; D019384:Nucleic Acid Synthesis Inhibitors; C546387:P2ry2 protein, rat; D010617:Phenanthridines; D011500:Protein Synthesis Inhibitors; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D011760:Pyrrolidinones; D018048:Receptors, Purinergic P2; D058473:Receptors, Purinergic P2Y2; D013449:Sulfonamides; C096323:rimabotulinumtoxinB; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D020126:Brefeldin A; D015638:Cytochalasin D; D015240:Phorbol 12,13-Dibutyrate; D011732:Pyridoxal Phosphate; D013498:Suramin; D019284:Thapsigargin; D005665:Furosemide; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; C016299:chelerythrine; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D010738:Type C Phospholipases; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; D006034:Glycyrrhetinic Acid; D005905:Glyburide; D002118:Calcium; D014544:Uridine Triphosphate