Lipoxin A 4 / FPR2 Signaling Mitigates Ferroptosis of Alveolar Epithelial Cells via NRF2 ‐Dependent Pathway During Lung Ischemia–Reperfusion Injury

ABSTRACT Post‐lung transplant (LTx) injury can involve sterile inflammation due to ischemia–reperfusion injury (IRI) that contributes to allograft dysfunction. In this study, we investigated the cell‐specific role of ferroptosis (excessive iron‐mediated cell death) in mediating lung IRI and investigated if specialized pro‐resolving mediators such as Lipoxin A4 (LxA 4 ) can protect against ferroptosis in lung IRI. Single‐cell RNA sequencing analysis of lung tissue from post‐LTx patients was performed, and lung IRI was evaluated in C57BL/6 (WT), formyl peptide receptor 2 knockout ( Fpr2 −/− ) and nuclear factor erythroid 2‐related factor 2 knockout ( Nrf2 −/− ) mice using a hilar‐ligation model with or without LxA 4 administration. Furthermore, the protective efficacy of LxA 4 was evaluated employing a murine orthotopic LTx model and in vitro studies using alveolar type II epithelial (ATII) cells. The results show differential expression of ferroptosis‐related genes in post‐LTx patient samples compared to healthy controls. A significant increase in the levels of oxidized lipids and a reduction in the levels of intact lipids were observed in mice subjected to IRI compared to shams. Importantly, LxA 4 treatment attenuated pulmonary dysfunction, ferroptosis, and inflammation in WT mice subjected to lung IRI, but not in Fpr2 −/− or Nrf2 −/− mice after IRI. In the murine LTx model, LxA 4 treatment increased PaO 2 levels and attenuated lung IRI. Mechanistically, LxA 4 ‐mediated protection involves an increase in NRF2 activation and glutathione concentration as well as a decrease in MDA levels in ATII cells. In summary, our results collectively show that LxA 4 /FPR2 signaling on ATII cells mitigates ferroptosis via NRF2 activation and protects against lung IRI.