Deletion of BTB and CNC homology 1 protects against Staphylococcus aureus-induced acute lung injury

BTB and CNC homology 1 (BACH1) plays a crucial role in the pathogenesis of acute lung injury (ALI) caused by gram-negative bacteria. However, its exact mechanisms and roles in Staphylococcus aureus (SA)-induced ALI, a gram-positive bacterial infection, remain incompletely understood. In this study, we generated a BACH1-knockout mouse model (BACH1-/-) to investigate the role of BACH1 and its underlying mechanisms in regulating the development of sepsis-induced acute lung injury (ALI). Elevated levels of BACH1 were observed in both serum samples from septic patients and mouse models. Deletion of BACH1 alleviated ALI symptoms induced by sepsis. In bone marrow-derived macrophages, BACH1 deletion or knockdown suppressed NF-κB p65 phosphorylation and the induction of pro-inflammatory cytokines. Mechanistic studies demonstrated that BACH1 downregulated tumor necrosis factor-alpha-induced protein 3 (TNFAIP3) mRNA expression by binding to its promoter region. These findings uncover inhibiting BACH1 may be a promising therapeutic strategy for treating gram-positive bacteria-induced ALI.