JAK2/STAT1-mediated HMGB1 translocation increases inflammation and cell death in a ventilator-induced lung injury model.

Janus kinase 2/signal transducer and activators of transcription 1 (JAK2/STAT1) signaling is a common pathway that contributes to numerous inflammatory disorders, including different forms of acute lung injury (ALI). However, the role of JAK2/STAT1 in ventilator-induced lung injury (VILI) and its underlying mechanism remain unclear. In this study, using lipopolysaccharide (LPS) inhalation plus mechanical ventilation as VILI mouse model, we found that the administration of JAK2 inhibitor AZD1480 markedly attenuated lung destruction, diminished protein leakage, and inhibited cytokine release. In addition, when mouse macrophage-like RAW 264.7 cells were exposed to LPS and cyclic stretch (CS), AZD1480 prevented cell autophagy, reduced apoptosis, and suppressed lactate dehydrogenase release by downregulating JAK2/STAT1 phosphorylation levels and inducing HMGB1 translocation from the nucleus to the cytoplasm. Furthermore, HMGB1 and STAT1 knockdown attenuated LPS+CS-induced autophagy and apoptosis in RAW 264.7 cells. In conclusion, these findings reveal the connection between the JAK2/STAT1 pathway and HMGB1 translocation in mediating lung inflammation and cell death in VILI, suggesting that these molecules may serve as novel therapeutic targets for VILI.