Neutrophil extravasation and NETosis in decompression illness lung injury: A P-selectin/PSGL-1/NOX2/PAD4 axis governed pathway validated by multi-model interrogation.

Decompression illness (DCI) is a multi-system pathological syndrome triggered by rapid environmental pressure reduction, leading to multi-organ damage, including pulmonary injury. Through integrated transcriptomic and proteomic analyses, this study reveals that P-selectin activates neutrophil NADPH oxidase 2 (NOX2) and peptidylarginine deiminase 4 (PAD4) via its receptor PSGL-1, forming a cascade signaling network that regulates neutrophil extravasation and extracellular trap (NETosis) formation, playing a pivotal role in DCI-induced lung injury. By pioneering a human lung organoid-on-a-chip (OOC)-based bionic DCI in vitro model, we dynamically simulated the pathological progression of DCI and systematically validated, for the first time in a human-derived experimental system, the central role of endothelial barrier injury-mediated neutrophil transendothelial extravasation and NETosis in DCI-related pulmonary damage. Furthermore, in vivo pharmacological interventions confirmed the therapeutic potential of targeting P-selectin/PSGL-1 interactions or inhibiting the NOX2/PAD4 signaling axis in mitigating DCI lung injury. These findings not only provide an innovative theoretical framework for elucidating the molecular pathology of DCI-induced pulmonary injury, but also establish a translational foundation for developing precision therapies based on neutrophil extravasation regulation and NETosis balance strategies.