ZBP1-driven pyroptosis-associated alveolar macrophages exacerbate epithelial dysfunction in sepsis

The lung is highly vulnerable to inflammatory injury during sepsis, and acute lung injury (ALI) is a major cause of mortality in critically ill patients. Pyroptosis amplifies immune responses by promoting the release of inflammatory cytokines, and Z-DNA binding protein 1 (ZBP1) has emerged as a key upstream regulator of programmed cell death and inflammatory signaling. Nevertheless, the contribution of ZBP1 to human sepsis-induced ALI and its associated cellular programs remains poorly defined. Here, by integrating single-cell RNA sequencing data from bronchoalveolar lavage fluid (BALF) of patients with sepsis-induced ALI and from septic mouse lungs, we identified a distinct subset of pyroptosis-associated macrophages that expands during disease progression and exhibits ZBP1-dependent inflammasome activation. ZBP1 activation promoted inflammasome assembly, induced macrophage pyroptosis, and released pro-inflammatory mediators that impaired mitochondrial function and barrier integrity of alveolar type II (AT2) epithelial cells. ZBP1 deficiency markedly attenuated macrophage-AT2 inflammatory signaling and reduced the inflammatory amplification loop. Collectively, these findings identify ZBP1-mediated macrophage pyroptosis as a critical mechanism driving epithelial dysfunction during sepsis-induced ALI and provide a rationale for developing ZBP1-targeted strategies to restore immune–epithelial homeostasis and prevent organ failure in sepsis.