Exosomal miR-451 Inhibits Ferroptosis by Targeting the PHD3/p53 Signaling Axis to Protect against Ischemic Stroke.
BACKGROUND Ischemic stroke causes irreversible neuronal injury. This study investigates whether exosomal miR-451 protects against stroke by inhibiting the PHD3/p53 pathway and attenuating ferroptosis in hippocampal neurons. METHODS An in vitro blood-brain barrier (BBB) model was established using co-cultured mouse hippocampal neurons (HT-22), astrocytes (C8-D1A), and brain microvascular endothelial cells (bEnd.3). Cerebral ischemia-reperfusion injury was mimicked by oxygen-glucose deprivation/reoxygenation (OGD/R). Barrier integrity was validated by fluorescein sodium permeability assay, 4-h liquid level difference assay, and immunofluorescence of tight junction protein ZO-1. Engineered exosomes loaded with miR-451 were characterized by nanoparticle size analysis and electron microscopy. Following exosome treatment, ferroptosis-related markers were assessed by qRT-PCR and immunofluorescence. A PHD3 overexpression plasmid was constructed to validate the involvement of the PHD3/p53 pathway, and bioinformatics analysis identified potential downstream targets of miR-451, including YTHDF2. RESULTS miR-451-loaded exosomes increased HT-22 viability and attenuated OGD/R-induced ferroptosis. Mechanistically, miR-451 downregulated PHD3 expression, reducing p53 levels. Bioinformatics analysis revealed a negative correlation between miR-451-targeted PHD3 and YTHDF2. YTHDF2 overexpression modulated ferroptosis markers, suggesting its regulatory role in ferroptosis. DISCUSSION These findings demonstrate that miR-451 confers neuroprotection via the PHD3/p53 axis to suppress ferroptosis, with YTHDF2 serving as an additional effector. The results underscore the therapeutic promise of exosome-delivered miR-451 for ischemic stroke treatment. CONCLUSION miR-451 protects against OGD/R-induced neuronal ferroptosis by targeting the PHD3/p53 axis, highlighting exosomal miR-451 as a potential therapeutic candidate for ischemic stroke.