title: Susceptibility to excitotoxicity in aged hippocampal cultures and neuroprotection by non-steroidal anti-inflammatory drugs: role of mitochondrial calcium.
abstract: Brain damage after insult and cognitive decline are related to excitotoxicity and strongly influenced by aging, yet mechanisms of aging-dependent susceptibility to excitotoxicity are poorly known. Several non-steroidal anti-inflammatory drugs (NSAIDs) may prevent excitotoxicity and cognitive decline in the elderly by an unknown mechanism. Interestingly, after several weeks in vitro, hippocampal neurons display important hallmarks of neuronal aging in vivo. Accordingly, rat hippocampal neurons cultured for several weeks were used to investigate mechanisms of aging-related susceptibility to excitotoxicity and neuroprotection by NSAIDs. We found that NMDA increased cytosolic Ca(2+) concentration in young, mature and aged neurons but only promoted apoptosis in aged neurons. Resting Ca(2+) levels and responses to NMDA increased with time in culture which correlated with changes in expression of NMDA receptor subunits. In addition, NMDA promoted mitochondrial Ca(2+) uptake only in aged cultures. Consistently, specific inhibition of mitochondrial Ca(2+) uptake decreased apoptosis. Finally, we found that a series of NSAIDs depolarized mitochondria and inhibited mitochondrial Ca(2+) overload, thus preventing NMDA-induced apoptosis in aged cultures. We conclude that mitochondrial Ca(2+) uptake is critical for age-related susceptibility to excitotoxicity and neuroprotection by NSAIDs. Rat hippocampal neurons aged in culture were used to investigate mechanisms of age-related susceptibility to excitotoxicity and neuroprotection by non-steroidal anti-inflammatory drugs (NSAIDs). Old neurons display enhanced resting calcium and responses to NMDA along with increased expression of NMDA receptor subunits NR1 and NR2A altogether favoring mitochondrial calcium overload. NSAIDs protect neurons against excitotoxicity acting on mitochondrial calcium uptake. NMDA, N methyl d-aspartate.
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Valladolid, Valladolid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Calvo
authors.forename: Sara
authors.initials: S
authors.lastname: Sanz-Blasco
authors.forename: Erica
authors.initials: E
authors.lastname: Caballero
authors.forename: Carlos
authors.initials: C
authors.lastname: Villalobos
authors.forename: Lucía
authors.initials: L
authors.lastname: Núñez
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D008928:Mitochondria / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D016202:N-Methylaspartate / Q000633:toxicity; D018696:Neuroprotective Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D018690:Excitatory Amino Acid Agonists; D018696:Neuroprotective Agents; D016202:N-Methylaspartate; D002118:Calcium
keywords: NMDA; NSAIDs; aging; calcium; hippocampal neurons; mitochondria