NOX4 promotes cardiomyocyte ferroptosis-related injury in septic cardiomyopathy in associated with mitochondrial dysfunction and impaired NRF2 nuclear translocation.

Septic cardiomyopathy is a common early complication of sepsis, and its underlying mechanisms remain incompletely understood. In this study, we integrated transcriptomic differential expression analysis, a ferroptosis gene set, protein-protein interaction networks, and consensus machine-learning-based screening to identify NOX4 as a core ferroptosis-related candidate gene. Single-cell transcriptomic analysis further revealed that NOX4 upregulation was most pronounced in cardiomyocytes and was accompanied by enhanced intercellular communication. In the cecal ligation and puncture mouse model, pharmacological inhibition of NOX4 with Setanaxib improved survival and cardiac function, reduced myocardial injury biomarkers, alleviated histopathological damage, and partially reversed the dysregulation of ferroptosis-related markers. In the lipopolysaccharide-stimulated cardiomyocyte model, Setanaxib treatment or genetic silencing with si-NOX4 mitigated the accumulation of ferrous iron, lipid peroxidation, and reactive oxygen species, and partially restored the expression of NRF2, GPX4, SLC7A11, and ACSL4. Mechanistically, NOX4 inhibition attenuated mitochondrial dysfunction, including mitochondrial membrane depolarization, fragmentation, and respiratory dysfunction, and restored nuclear NRF2 levels and downstream antioxidant signaling. In addition, candidate compounds identified from the HERB database and evaluated by molecular docking and molecular dynamics simulations were predicted to exhibit stable binding features with NOX4. Collectively, these findings support a model in which NOX4 contributes to ferroptosis-related injury in septic cardiomyopathy in association with mitochondrial dysfunction and impaired NRF2-dependent antioxidant signaling.