Mesenchymal stem cell-derived extracellular vesicles attenuate ferroptosis in aged hepatic ischemia/reperfusion injury by transferring miR-1275

With an aging global population, the proportion of aged donor livers in graft pools is steadily increasing. Compared to young livers, aged livers exhibit heightened susceptibility to hepatic ischemia/reperfusion injury (HIRI), which significantly limits their utilisation in liver transplantation (LT) and exacerbates organ shortages. Our previous study demonstrated that ferroptosis is a pivotal trigger for HIRI vulnerability in aged livers. However, effective clinical strategies for the inhibition of ferroptosis remain elusive. Utilizing an aged mouse HIRI model, primary hepatocytes, and human liver organoids, this study provides hitherto undocumented evidence that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) effectively alleviate HIRI in aged livers by inhibiting ferroptosis. Mechanistically, miR-1275, which was significantly enriched within MSC-EVs, was transferred to hepatocytes. Subsequently, miR-1275 downregulated the expression of SLC39A14, a crucial iron transporter that is upregulated in aged livers and plays a pivotal role in promoting ferroptosis. Furthermore, we found a negative correlation between SLC39A14 levels and prognosis of aged donor liver recipients using clinical LT samples. Silencing miR-1275 in MSC-EVs or modulating SLC39A14 levels in aged livers reversed MSC-EV-mediated mitigation of ferroptosis. Collectively, these findings revealed the novel therapeutic potential of MSC-EVs in attenuating aged HIRI, suggesting a promising treatment for improving prognosis and preventing serious complications in recipients of aged liver grafts during LT.