King's College London

Research portal

Calpain cleavage and inactivation of the sodium calcium exchanger-3 occur downstream of Aβ in Alzheimer's disease

Research output: Contribution to journalArticlepeer-review

Original languageEnglish
Pages (from-to)49-59
Number of pages11
JournalAGING CELL
Volume13
Issue number1
Early online date6 Aug 2013
DOIs
Accepted/In press28 Jul 2013
E-pub ahead of print6 Aug 2013
PublishedFeb 2014

Documents

King's Authors

Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by pathological deposits of β-amyloid (Aβ) in senile plaques, intracellular neurofibrillary tangles (NFTs) comprising hyperphosphorylated aggregated tau, synaptic dysfunction and neuronal death. Substantial evidence indicates that disrupted neuronal calcium homeostasis is an early event in AD that could mediate synaptic dysfunction and neuronal toxicity. Sodium calcium exchangers (NCXs) play important roles in regulating intracellular calcium and accumulating data suggests that reduced NCX function, following aberrant proteolytic cleavage of these exchangers, may contribute to neurodegeneration. Here we show that elevated calpain, but not caspase-3, activity is a prominent feature of AD brain. In addition, we observe increased calpain-mediated cleavage of NCX3, but not a related family member NCX1, in AD brain relative to unaffected tissue and that from other neurodegenerative conditions. Moreover, the extent of NCX3 proteolysis correlated significantly with amounts of Aβ1-42. We also show that exposure of primary cortical neurons to oligomeric Aβ1-42 results in calpain-dependent cleavage of NCX3 and we demonstrate that loss of NCX3 function is associated with Aβ toxicity. Our findings suggest that Aβ mediates calpain cleavage of NCX3 in AD brain, and therefore that reduced NCX3 activity could contribute to the sustained increases in intraneuronal calcium concentrations that are associated with synaptic and neuronal dysfunction in AD.

Download statistics

No data available

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454