Cooperation in signal transduction of extracellular guanosine 5' triphosphate and nerve growth factor in neuronal differentiation of PC12 cells.
Guanosine 5' triphosphate (GTP), acting synergistically with the nerve growth factor (NGF), enhances the proportion of neurite-bearing cells in cultures of PC12 rat pheochromocytoma cells. We studied the transduction mechanisms activated by GTP in PC12 cells and found that addition of GTP (100 microM) increased intracellular calcium concentration ([Ca(2+)](i)) in cells that were between 60 and 70% confluent. Addition of GTP also enhanced activation of NGF-induced extracellular regulated kinases (ERKs) and induced Ca(2+) mobilization. This mobilization, due to the activation of voltage-sensitive and ryanodine-sensitive calcium channels, as well as pertussis toxin-sensitive purinoceptors, modulates Ca(2+)-activated K(+) channels not involved in activation of ERKs. The results presented here indicate that GTP-triggered [Ca(2+)](i) increase may be a key event in GTP signal transduction, which can modulate activity of ERKs. The physiological importance of the GTP effect lies in its capacity to interact with the NGF-activated pathway to enhance neurite outgrowth from PC12 cells.
Dipartimento di Scienze del Farmaco, Centro di Scienze dell'Invecchiamento, Ce.S.I., Università degli Studi "G. d'Annunzio," Nuovo Polo Didattico pal. B, Via dei Vestini 29, 66013 Chieti-Pescara, Italy.
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Guarnieri
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Fanò
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Rathbone
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Mariggiò
D000818:Animals; D001463:Barbiturates / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002452:Cell Count / Q000379:methods; D002454:Cell Differentiation / Q000502:physiology*; D002614:Chelating Agents / Q000494:pharmacology; D003022:Clotrimazole / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004533:Egtazic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005110:Extracellular Space / Q000187:drug effects*; D005455:Fluorescent Antibody Technique / Q000379:methods; D005456:Fluorescent Dyes / Q000378:metabolism; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006131:Growth Inhibitors / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000502:physiology*; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D007555:Isoxazoles / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D018613:Microscopy, Confocal / Q000379:methods; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020932:Nerve Growth Factor / Q000502:physiology*; D016501:Neurites / Q000187:drug effects / Q000502:physiology; D009543:Nifedipine / Q000494:pharmacology; D016716:PC12 Cells / Q000166:cytology*; D037342:Pertussis Toxin / Q000494:pharmacology; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction / Q000502:physiology*; D013498:Suramin / Q000031:analogs & derivatives* / Q000494:pharmacology; D013997:Time Factors; D014227:Triazines / Q000494:pharmacology
D001463:Barbiturates; D002121:Calcium Channel Blockers; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D006131:Growth Inhibitors; D007476:Ionophores; D007555:Isoxazoles; C105374:NF023; D014227:Triazines; C052795:bis(1,3-dibutylbarbiturate)trimethine oxonol; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D004533:Egtazic Acid; D015759:Ionomycin; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; C012842:Cibacron Blue F 3GA; D011732:Pyridoxal Phosphate; D013498:Suramin; D005707:Gallic Acid; D006160:Guanosine Triphosphate; D020932:Nerve Growth Factor; D037342:Pertussis Toxin; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D003022:Clotrimazole; D009543:Nifedipine; D002118:Calcium