The MafG/Bach1-Lcn2 transcriptional axis drives ferroptosis in sepsis-induced acute lung injury via disrupting redox homeostasis.

Abstract

BACKGROUND AND OBJECTIVE: Sepsis-induced acute lung injury (SALI) is a life-threatening condition with high mortality, intimately linked to the disruption of intracellular redox homeostasis. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has been implicated in sepsis-related organ dysfunction. However, its upstream transcriptional regulators, particularly within alveolar epithelial cells, remain poorly defined. This study aims to investigate the role of the transcription factor MafG and its novel interaction with Bach1 in driving ferroptosis during SALI. METHODS: A murine model of sepsis was established via cecal ligation and puncture (CLP). For in vitro studies, MLE-12 cells were treated with conditioned media from LPS-stimulated macrophages. Gene expression was modulated using siRNA and adeno-associated virus (AAV)-mediated knockdown. Molecular interactions were assessed by co-immunoprecipitation and mass spectrometry. Transcriptional regulation was evaluated by luciferase reporter assays. Redox and ferroptosis markers, including lipid ROS, MDA, GSH, Gpx4, and Slc7a11, were measured. The therapeutic potential of Anemoside B4 (AB4) was investigated through molecular docking, surface plasmon resonance (SPR) assays, and in vivo administration. RESULTS: MafG was significantly upregulated in the lungs of septic mice and in CM stimulated alveolar epithelial cells. MafG overexpression exacerbated ferroptosis, while its knockdown conferred protection. Mechanistically, MafG formed a functional heterodimer with Bach1, which directly engages the Lcn2 promoter and drives its transcriptional activation. Lcn2 upregulation drove iron accumulation and lipid peroxidation, culminating in ferroptosis. Overexpression of Lcn2 reversed the anti-ferroptotic effects caused by MafG silencing. In vivo, AAV-shMafG treatment mitigated lung injury, improved redox balance (evidenced by decreased MDA and GSSG, and increased GSH levels), and enhanced survival. Furthermore, we identified AB4 as a potential MafG inhibitor and demonstrated its protective efficacy in vivo. CONCLUSION: The MafG/Bach1-Lcn2 axis represents a novel transcriptional pathway that promotes ferroptosis in SALI by exacerbating oxidative damage. This signaling axis is a promising therapeutic target, and AB4 shows potential as a lead compound for intervention.