Objectives: 

Excitotoxicity is one of the most important mechanisms contributing to neuronal damage and cell death in neurodegenerative diseases and ischemic events. Excess of the excitatory neurotransmitter glutamate activates NMDA receptors that play an important role in excitotoxicity because of its high permeability to Ca2+. It has been suggested that the ensuing mitochondrial Ca2+ overload may contribute to neuronal cell death in excitotoxicity. We have reported previously that a series of non-steroidal anti-inflammatory drugs (NSAIDs) may inhibit mitochondrial Ca2+ overload and neuron cell death induced by amyloid β peptide oligomers. Here we studied directly whether NSAIDs may protect against NMDA acting on mitochondrial Ca2+ handling.

Materials: 

Hippocampal cells from neonatal rat pups were cultured for several periods and used for monitoring of cytosolic and mitochondrial Ca2+ by fluorescence and bioluminescence imaging, respectively. Cell death and apoptosis induced by NMDA were estimated by annexin V and propidium iodide staining in the presence and the absence of different NSAIDs.

Results: 

We found that NMDA induced a large increase in cytosolic and mitochondrial Ca2+ in hippocampal neurons and these effects increased with culture time. Moreover, NMDA induced cell death and this effect also increased with culture time. A series of NSAIDs inhibited cell death induced by NMDA. This effect was achieved also by a structural analogue lacking anti-inflammatory activity. Finally, NSAIDs inhibited mitochondrial Ca2+ uptake without affecting the rise in cytosolic Ca2+ induced by NMDA.

Conclusions: 

We conclude that NSAIDs may protect against excitotoxicity in hippocampal neurons. This effect is probably independent of anti-inflammatory activity but related to effects on mitochondrial Ca2+ handling.

This work was funded by DIGICYT (BFU2009-08967), Instituto de Salud Carlos III (Spain) and Junta de Castilla y León, Spain. MC holds a predoctoral fellowship from Junta de Castilla y León, Spain.