Altered calcium homeostasis and mitochondrial dysfunction in cortical synaptic compartments of presenilin-1 mutant mice
Begley, J.G.; Duan, W.; Chan, S.; Duff, K.; Mattson, M.P.
Journal of Neurochemistry 72(3): 1030-1039
1999
ISSN/ISBN: 0022-3042 PMID: 10037474 DOI: 10.1046/j.1471-4159.1999.0721030.x
Accession: 010148072
Alzheimer's disease is characterized by amyloid beta-peptide deposition, synapse loss, and neuronal death, which are correlated with cognitive impairments. Mutations in the presenilin-1 gene on chromosome 14 are causally linked to many cases of early-onset inherited Alzheimer's disease. We report that synaptosomes prepared from transgenic mice harboring presenilin-1 mutations exhibit enhanced elevations of cytoplasmic calcium levels following exposure to depolarizing agents, amyloid beta-peptide, and a mitochondrial toxin compared with synaptosomes from nontransgenic mice and mice overexpressing wild-type presenilin-1. Mitochondrial dysfunction and caspase activation following exposures to amyloid beta-peptide and metabolic insults were exacerbated in synaptosomes from presenilin-1 mutant mice. Agents that buffer cytoplasmic calcium or that prevent calcium release from the endoplasmic reticulum protected synaptosomes against the adverse effect of presenilin-1 mutations on mitochondrial function. Abnormal synaptic calcium homeostasis and mitochondrial dysfunction may contribute to the pathogenic mechanism of presenilin-1 mutations.