Mesenchymal stem cell-derived exosomes mitigate myocardial ischemia-reperfusion injury by inhibiting ferroptosis via the AMPK/FOXO3 signaling pathway.

Myocardial ischemia-reperfusion injury (MIRI) remains a critical challenge in the management of acute myocardial infarction due to its complex pathological mechanisms. Ferroptosis, a recently identified form of programmed cell death, is closely implicated in MIRI. Mesenchymal stem cell-derived exosomes (MSC-Exo), characterized by their unique biological properties and low immunogenicity, have emerged as promising therapeutic agents for suppressing ferroptosis. This study investigates the protective role and underlying molecular mechanisms of MSC-Exo in alleviating MIRI by inhibiting ferroptosis through activation of the AMPK/FOXO3 signaling pathway. MSC-Exo were isolated by ultracentrifugation, and their morphology and molecular marker expression were validated using transmission electron microscopy and Western blot analysis. Results showed that PKH26-labeled MSC-Exo were efficiently internalized by AC16 cardiomyocytes, confirming functional interaction with cardiac cells. In a hypoxia/reoxygenation (H/R) model, MSC-Exo pretreatment significantly reduced ferroptosis-associated markers, including reactive oxygen species (ROS), malondialdehyde (MDA), and acyl-CoA synthetase long-chain family member 4 (ACSL4), while upregulating antioxidant factors such as glutathione peroxidase 4 (GPX4) and glutathione (GSH). Experiments with the AMPK inhibitor Compound C further demonstrated that the anti-ferroptotic effects of MSC-Exo are mediated via the AMPK/FOXO3 signaling pathway. In vivo studies using a mouse model MIRI of coronary artery occlusion-reperfusion corroborated the cardioprotective effects of MSC-Exo, as evidenced by improved ST-segment elevation, reduced myocardial fibrosis, and decreased serum levels of cardiac biomarkers CK-MB and cardiac troponin I (cTnI). Collectively, these findings indicate that MSC-Exo exert significant cardioprotection by inhibiting ferroptosis through activation of the AMPK/FOXO3 pathway, offering a novel therapeutic strategy for MIRI management.