The exocytotic signaling pathway induced by nerve growth factor in the presence of lyso-phosphatidylserine in rat peritoneal mast cells involves a type D phospholipase.
Nerve growth factor (NGF) has been previously shown to induce exocytosis in rat peritoneal mast cells (RPMCs) in the presence of lyso-phosphatidylserine (lysoPS) by interacting with high-affinity NGF receptors of the TrkA-type. In RPMCs, type D phosphatidylcholine-selective phospholipases (PLDs) have been postulated to be involved in some exocytotic signaling pathways induced by different agonists. The aim of the present study was to assess a putative functional role of PLD for NGF/lysoPS-induced exocytosis in RPMCs. In 1-[14C]palmitoyl-2-lyso-3-phosphatidylcholine-labelled RPMCs, NGF/lysoPS stimulated the formation of diacylglycerol (DAG) and, in the presence of ethanol (1% [v/v]), phosphatidylethanol (PEtOH). These data indicate PLD-activation by NGF/lysoPS in RPMCs. Preincubation of RPMCs for 2 min with ethanol, an inhibitor of PLD-derived DAG-formation, dose-dependently (IC(50): 0.6% [v/v]) and agonist-selectively inhibited the NGF/lysoPS induced release of [3H]serotonin ([3H]5-HT) in [3H]5-HT-loaded RPMCs, confirming the functional importance of PLD-action. Exocytosis and PEtOH-production was potently inhibited by the broad-spectrum serine/threonine kinase inhibitor staurosporine and activated by the protein kinase C(PKC)-activator PMA (phorbol-12-myristate-13-acetate) suggesting a role for PKC as mediator for NGF/lysoPS-induced activation of PLD.
Seebeck
J
J
Institute of Pharmacology, Christian-Albrechts-Universität (CAU) Kiel, Hospitalstr. 4, D-24105, Kiel, Germany. jseebeck@pharmakologie.uni-kiel.de
Westenberger
K
K
Elgeti
T
T
Ziegler
A
A
Schütze
S
S
D000818:Animals; D004075:Diglycerides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects*; D036341:Intercellular Signaling Peptides and Proteins; D008246:Lysophospholipids / Q000494:pharmacology*; D008407:Mast Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D020932:Nerve Growth Factor / Q000494:pharmacology*; D010455:Peptides; D010537:Peritoneum / Q000166:cytology / Q000187:drug effects; D010703:Phorbol Esters / Q000494:pharmacology; D010739:Phospholipase D / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013997:Time Factors; D014862:Wasp Venoms / Q000494:pharmacology
D004075:Diglycerides; D004791:Enzyme Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D008246:Lysophospholipids; D010455:Peptides; D010703:Phorbol Esters; D014862:Wasp Venoms; C025059:lysophosphatidylserine; C119222:phorbol-12-myristate; D012701:Serotonin; D000431:Ethanol; C037500:mastoparan; D020932:Nerve Growth Factor; D011493:Protein Kinase C; D010739:Phospholipase D