IL-27 Aggravates Sepsis-Induced ARDS by Driving Macrophage Ferroptosis Through Activation of NCOA4-Mediated Ferritinophagy.

BACKGROUND: Acute respiratory distress syndrome (ARDS) induced by sepsis is a clinical syndrome characterized by high morbidity and mortality rates. This study aims to clarify the effects of recombinant mouse IL-27 protein on macrophage ferritinophagy, macrophage polarization, and its interventional role in sepsis-induced ARDS. METHODS: This study utilized wild-type (WT) and IL-27 receptor knockout (IL-27R(-/-)) mice to establish a cecal ligation and puncture (CLP)-induced sepsis model. The post-modeling mice were randomly divided into four groups: control group, CLP model group, IL-27 combined with CLP treatment group, and IL-27+CLP+PROTAC NCOA4 degrader-1 (Compound V3, CV3) combined treatment group. For the in vitro experiments using RAW 264.7 cells and Bone Marrow-Derived Macrophages (BMDMs), the cells were divided into four main groups as follows: the control group, the lipopolysaccharide (LPS) model group, the LPS+IL-27 treatment group, and the LPS+IL-27+CV3 combination treatment group. RESULTS: This study investigates the role of IL-27 in exacerbating ferritinophagy and ferroptosis in macrophages and septic lung injury, and explores the therapeutic potential of the NCOA4 degrader CV3. We found that IL-27 synergizes with LPS to enhance NCOA4-mediated ferritinophagy, leading to increased degradation of FTH1, upregulation of LC3A/B, and promotion of ferroptosis. Ferritinophagy amplification drove M1 macrophage polarization and inflammatory cytokine release. CV3, a PROTAC-based NCOA4 degrader, effectively disrupted the NCOA4-FTH1 interaction, inhibited ferritinophagy, and mitigated ferroptosis and inflammation. In murine models of sepsis-induced ARDS, CV3 alleviated lung injury, restored antioxidant defenses, and reduced ferroptosis. Notably, IL-27R(-/-) mice were resistant to IL-27-induced exacerbation of ferritinophagy and lung injury, confirming the specificity of IL-27 signaling. CONCLUSION: These findings reveal a potential mechanistic link between NCOA4-mediated ferritinophagy and sepsis-associated ARDS pathogenesis. Targeting this pathway with CV3 may offer a novel therapeutic strategy, which warrants further investigation.