NINJ1 plays a vital role in the release of neutrophil extracellular traps during acute lung injury

Excessive neutrophil extracellular traps (NETs) formation is a significant contributor to acute lung injury (ALI), making its inhibition a novel therapeutic avenue to improve outcomes. In this study, we revealed that a novel pore-forming protein ninjurin-1 (NINJ1) was highly expressed in pro-inflammatory neutrophil subpopulations during ALI, using public single-cell RNA sequencing and hotspot analysis. Furthermore, we demonstrated that the NINJ1 oligomerization was essential for the NET release in neutrophils from both acute respiratory distress syndrome (ARDS) patients and ALI mice. Genetic ablation of Ninj1 in neutrophils abolished NET release, thereby attenuating pulmonary dysfunction and reducing ALI-related lethality. Mechanistically, we found that K45 and N60 are critical for NINJ1 oligomerization and subsequent NET release. In summary, our findings reveal a novel pore-forming protein-mediated mechanism for NET release and highlight NINJ1 as a potential therapeutic target for the treatment of ALI/ARDS. Schematic illustration. The novel pore-forming protein NINJ1 mediates the extrusion of NETs, thereby exacerbating pulmonary injury in ARDS/ALI. K45 and N60 are essential for NINJ1 oligomerization and subsequent NET release.