Expression of long-lasting synaptic plasticity and long-term memory requires protein synthesis, which can be repressed by phosphorylation of eukaryotic initiation factor 2 α-subunit (eIF2α). Elevated phosphorylation of eIF2α has been observed in the brains of Alzheimer's disease patients and Alzheimer's disease model mice. Therefore, we tested whether suppressing eIF2α kinases could alleviate synaptic plasticity and memory deficits in Alzheimer's disease model mice. Genetic deletion of eIF2α kinase PERK prevented enhanced phosphorylation of eIF2α and deficits in protein synthesis, synaptic plasticity and spatial memory in mice that express familial Alzheimer's disease–related mutations in APP and PSEN1. Similarly, deletion of another eIF2α kinase, GCN2, prevented impairments of synaptic plasticity and defects in spatial memory exhibited by the Alzheimer's disease model mice. Our findings implicate aberrant eIF2α phosphorylation as a previously unidentified molecular mechanism underlying Alzheimer's disease–related synaptic pathophysioloy and memory dysfunction and suggest that PERK and GCN2 are potential therapeutic targets for treatment of individuals with Alzheimer's disease.
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We thank the late Dr. Mark A. Smith (Case Western Reserve University) for providing postmortem Alzheimer's disease brain samples, R.C. Wek (Indiana University School of Medicine) for providing the ATF4 antibody, C.A. Hoeffer for help with the design of the mouse breeding, H. Bowling and M.V. Chao (New York University School of Medicine) for providing primary cultured neurons, E. Santini for advice on the statistical analyses for the mouse behavioral tests, Y. Chen for technical help, M. Dorsey for keeping colonies of transgenic mice, and all members of the Klann laboratory for comments on the manuscript. This work was supported by US National Institutes of Health grants NS034007 and NS047834, and Alzheimer's Association Investigator grant to E.K.
The authors declare no competing financial interests.
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Ma, T., Trinh, M., Wexler, A. et al. Suppression of eIF2α kinases alleviates Alzheimer's disease–related plasticity and memory deficits. Nat Neurosci 16, 1299–1305 (2013) doi:10.1038/nn.3486
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