Targeting the FOXO4-p53 axis by retro-inverso peptide senolytic agents: a pharmacological strategy to mitigate brain aging and cognitive decline.

Cellular senescence, driven by the interaction between FOXO4 and p53, is increasingly recognized as a crucial mechanism in brain aging and the development of neurodegenerative disorders. The senolytic peptide FOXO4-DRI, which has been thoughtfully designed, selectively disrupts the FOXO4-p53 complex, inducing apoptosis in senescent cells while preserving healthy tissue. In aged mammalian models, administering FOXO4-DRI decreases the accumulation of senescent cells, restores cerebral blood flow and the integrity of the blood-brain barrier (BBB), reverses hippocampal atrophy, and enhances cognitive function. Furthermore, in models of Alzheimer's disease (AD) and tauopathy, this intervention eliminates amyloid-β and pathological tau, leading to improved memory performance. Preliminary human studies involving FOXO4-axis modulators, such as high-dose fisetin, show a reduction in the senescence-associated secretory phenotype (SASP) and enhancements in cognitive and physical measures among older adults. These findings collectively identify the FOXO4-p53 axis as a potential pharmacological target in brain aging and highlight senolytic therapy as a promising strategy for altering diseases to postpone or reverse age-related cognitive decline. This review consolidates recent findings indicating that FOXO4-dependent senescence significantly contributes to neuroinflammation, synaptic dysfunction, and impaired neurogenesis in the aging brain.