Cardiac-derived extracellular vesicles carrying miR-4433b-3p accelerate cognitive decline and brain aging by suppressing TP53INP2-mediated neuronal autophagy in mice.

Brain aging is not an independent process, yet how systemic aging drives neural decline remains unclear. Here, we identified a circulating miR-4433b-3p, packaged within extracellular vesicles (EVs), as a trans-organ effector bridging cardiac aging with central nervous system (CNS) decline. Small RNA sequencing and human cohort validation revealed selective enrichment of miR-4433b-3p in aged plasma EVs (Op-EVs), correlating with blood biomarkers of brain aging. Source tracing in mice identified the aged heart as the major origin of miR-4433b-3p-laden EVs. Functionally, aged cardiac EVs (Oc-EVs) accumulated in the hippocampus, impaired memory and induced neuronal senescence. Mechanistically, miR-4433b-3p suppressed TP53INP2, a facilitator of autophagic flux, leading to disrupted autophagosome maturation. Restoring TP53INP2 or inhibiting miR-4433b-3p rescued neuronal autophagy and improved cognition. Collectively, these findings uncover a heart-brain axis by EV-mediated miRNA signaling, positioning cardiac EV-miR-4433b-3p as a circulating biomarker and potential therapeutic target for age-related cognitive decline.