title: Glutamate-induced toxicity in hippocampal slices involves apoptotic features and p38 MAPK signaling.
abstract: Glutamate excitotoxicity may culminate with neuronal and glial cell death. Glutamate induces apoptosis in vivo and in cell cultures. However, glutamate-induced apoptosis and the signaling pathways related to glutamate-induced cell death in acute hippocampal slices remain elusive. Hippocampal slices exposed to 1 or 10 mM glutamate for 1 h and evaluated after 6 h, showed reduced cell viability, without altering membrane permeability. This action of glutamate was accompanied by cytochrome c release, caspase-3 activation and DNA fragmentation. Glutamate at low concentration (10 microM) induced caspase-3 activation and DNA fragmentation, but it did not cause cytochrome c release and, it did not alter the viability of slices. Glutamate-induced impairment of hippocampal cell viability was completely blocked by MK-801 (non-competitive antagonist of NMDA receptors) and GAMS (antagonist of KA/AMPA glutamate receptors). Regarding intracellular signaling pathways, glutamate-induced cell death was not altered by a MEK1 inhibitor, PD98059. However, the p38 MAPK inhibitor, SB203580, prevented glutamate-induced cell damage. In the present study we have shown that glutamate induces apoptosis in hippocampal slices and it causes an impairment of cell viability that was dependent of ionotropic and metabotropic receptors activation and, may involve the activation of p38 MAPK pathway.
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Trindade, 88040-900 Florianopolis, SC, Brazil.
authors.forename: Simone
authors.initials: S
authors.lastname: Molz
authors.forename: Helena
authors.initials: H
authors.lastname: Decker
authors.forename: Tharine
authors.initials: T
authors.lastname: Dal-Cim
authors.forename: Carla
authors.initials: C
authors.lastname: Cremonez
authors.forename: Fabiano M
authors.initials: FM
authors.lastname: Cordova
authors.forename: Rodrigo B
authors.initials: RB
authors.lastname: Leal
authors.forename: Carla I
authors.initials: CI
authors.lastname: Tasca
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004789:Enzyme Activation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000633:toxicity*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D066298:In Vitro Techniques; D008297:Male; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D018691:Excitatory Amino Acid Antagonists; D047428:Protein Kinase Inhibitors; D018698:Glutamic Acid; D016291:Dizocilpine Maleate; D045304:Cytochromes c; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3