Aging Enables Ca²⁺ Overload and Apoptosis Induced by Amyloid-β Oligomers in Rat Hippocampal Neurons: Neuroprotection by Non-Steroidal Anti-Inflammatory Drugs and R-Flurbiprofen in Aging Neurons

Article type: Research Article

Authors: Calvo-Rodríguez, María^a | García-Durillo, Mónica^a | Villalobos, Carlos^{a; *} | Núñez, Lucía^{a; b}

Affiliations: [a] Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain | [b] Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Spain

Correspondence: [*] Correspondence to: Dr. Carlos Villalobos, Instituto de Biología y Genética Molecular (IBGM), c/Sanz y Forés 3, 47003 Valladolid, Spain. Tel.: +34 983 184821; Fax: +34 983 184800; E-mail: carlosv@ibgm.uva.es.

Abstract: The most important risk factor for Alzheimer’s disease (AD) is aging. Neurotoxicity in AD has been linked to dyshomeostasis of intracellular Ca2+ induced by small aggregates of the amyloid-β peptide 1-42 (Aβ42 oligomers). However, how aging influences susceptibility to neurotoxicity induced by Aβ42 oligomers is unknown. In this study, we used long-term cultures of rat hippocampal neurons, a model of neuronal in vitro aging, to investigate the contribution of aging to Ca2+ dishomeostasis and neuron cell death induced by Aβ42 oligomers. In addition, we tested whether non-steroidal anti-inflammatory drugs (NSAIDs) and R-flurbiprofen prevent apoptosis acting on subcellular Ca2+ in aged neurons. We found that Aβ42 oligomers have no effect on young hippocampal neurons cultured for 2 days in vitro (2 DIV). However, they promoted apoptosis modestly in mature neurons (8 DIV) and these effects increased dramatically after 13 DIV, when neurons display many hallmarks of in vivo aging. Consistently, cytosolic and mitochondrial Ca2+ responses induced by Aβ42 oligomers increased dramatically with culture age. At low concentrations, NSAIDs and the enantiomer R-flurbiprofen lacking anti-inflammatory activity prevent Ca2+ overload and neuron cell death induced by Aβ42 oligomers in aged neurons. However, at high concentrations R-flurbiprofen induces apoptosis. Thus, Aβ42 oligomers promote Ca2+ overload and neuron cell death only in aged rat hippocampal neurons. These effects are prevented by low concentrations of NSAIDs and R-flurbiprofen acting on mitochondrial Ca2+ overload.

Keywords: Aβ₄₂ oligomers, aging, Alzheimer’s disease, calcium, hippocampal neurons, mitochondria, non-steroidal anti-inflammatory drugs, NSAIDs, R-flurbiprofen

DOI: 10.3233/JAD-151189

Journal: Journal of Alzheimer's Disease, vol. 54, no. 1, pp. 207-221, 2016