Differences in the neurotoxicity profile induced by ATP and ATPgammaS in cultured cerebellar granule neurons.
Extracellular ATP and P2 receptors may play a crucial role in the neurodegeneration of the CNS. Here, we investigated in neuronal cerebellar granule cultures the biological effect of the quite stable P2 receptor agonist ATPgammaS and compare it to the cytotoxic action of ATP. Time-course experiments showed that 500 microM ATPgammaS causes 50-100% cell death in 15-24 h. As proved by pharmacological means, ATPgammaS toxicity apparently involves neither indirect activation of NMDA receptors, nor ectonucleotidase activities, nor nucleoside transport and intracellular purine metabolism. Moreover, ATPgammaS induces detrimental effects without modifying the expression of several P2X and P2Y receptor proteins. Cell death instead occurs after extracellular release of the cytosolic enzyme lactic dehydrogenase and inhibition of the overall activity of the intracellular dehydrogenases. Moreover, ATPgammaS causes transient outflow of cytochrome c from mitochondria (maximal 2.5-fold stimulation in 4 h), it raises the intracellular reactive oxygen species (about four-fold in 1 h) and cAMP levels (about 40% in 15 min-4 h). Among several P2 receptor antagonists, only pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid 4-sodium promotes 80-100% neuroprotection.
Amadio
Susanna
S
Santa Lucia Foundation/CERC, Rome, Italy
D'Ambrosi
Nadia
N
Trincavelli
Maria Letizia
ML
Tuscano
Daniela
D
Sancesario
Giuseppe
G
Bernadi
Giorgio
G
Martini
Claudia
C
Volonté
Cinzia
C
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000633:toxicity*; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D058910:Purinergic P2 Receptor Agonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013778:Tetrazolium Salts; D013844:Thiazoles
D009419:Nerve Tissue Proteins; D058910:Purinergic P2 Receptor Agonists; D017382:Reactive Oxygen Species; D016194:Receptors, N-Methyl-D-Aspartate; D013778:Tetrazolium Salts; D013844:Thiazoles; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; C022571:adenosine 5'-O-(3-thiotriphosphate); D011732:Pyridoxal Phosphate; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D000262:Adenylyl Cyclases; C022616:thiazolyl blue