Correction of eIF2-dependent defects in brain protein synthesis, synaptic plasticity, and memory in mouse models of Alzheimer's disease

Neuronal protein synthesis is essential for long-term memory consolidation. Conversely, dysregulation of protein synthesis has been implicated in a number of neurodegenerative disorders, including Alzheimers disease (AD). Several types of cellular stress trigger the activation of protein kinases that converge on the phosphorylation of eukaryotic translation initiation factor 2 (eIF2-P). This leads to attenuation of cap-dependent mRNA translation, a component of the integrated stress response (ISR). We show that AD brains exhibit increased eIF2-P and reduced eIF2B, key components of the eIF2 translation initiation complex. We further demonstrate that attenuating the ISR with the small molecule compound ISRIB (ISR Inhibitor) rescues hippocampal protein synthesis and corrects impaired synaptic plasticity and memory in mouse models of AD. Our findings suggest that attenuating eIF2-P-mediated translational inhibition may comprise an effective approach to alleviate cognitive decline in AD.