Aspirin binds to PPARa to stimulate hippocampal plasticity and protect memory

Despite its long history, until now, no receptor has been identified for aspirin, one of the most widely used medicines worldwide. Here we report that peroxisome proliferator-activated receptor alpha (PPAR alpha), a nuclear hormone receptor involved in fatty acid metabolism, serves as a receptor of aspirin. Detailed proteomic analyses including cheminformatics, thermal shift assays, and TR-FRET revealed that aspirin, but not other structural homologs, acts as a PPAR alpha ligand through direct binding at the Tyr314 residue of the PPAR alpha ligand-binding domain. On binding to PPAR alpha, aspirin stimulated hippocampal plasticity via transcriptional activation of cAMP response element-binding protein (CREB). Finally, hippocampus-dependent behavioral analyses, calcium influx assays in hippocampal slices and quantification of dendritic spines demonstrated that low-dose aspirin treatment improved hippocampal plasticity and memory in FAD5X mice, but not in FAD5X/Ppara-null mice. These findings highlight a property of aspirin: stimulating hippocampal plasticity via direct interaction with PPAR alpha.