Neuronal loss of NCLX-dependent mitochondrial calcium efflux mediates age-associated cognitive decline
Pooja Jadiya, H Cohen, Devin W. Kolmetzky, Ashlesha Kadam, Dhanendra Tomar, John W. Elrod
Abstract
Mitochondrial calcium overload contributes to neurodegenerative disease development and progression. We recently reported that loss of the mitochondrial sodium/calcium exchanger (NCLX), the primary mechanism of m Ca 2+ efflux, promotes m Ca 2+ overload, metabolic derangement, redox stress, and cognitive decline in models of Alzheimer's disease (AD). However, whether disrupted m Ca 2+ signaling contributes to neuronal pathology and cognitive decline independent of pre-existing amyloid or tau pathology remains unknown. Here, we generated mice with neuronal deletion of the mitochondrial sodium/calcium exchanger (NCLX, Slc8b1 gene), and evaluated age-associated changes in cognitive function and neuropathology. Neuronal loss of NCLX resulted in an age-dependent decline in spatial and cued recall memory, moderate amyloid deposition, mild tau pathology, synaptic remodeling, and indications of cell death. These results demonstrate that loss of NCLX-dependent m Ca 2+ efflux alone is sufficient to induce an Alzheimer's disease-like pathology and highlights the promise of therapies targeting m Ca 2+ exchange.