<i>Fusobacterium nucleatum</i> drives endothelial cell senescence by disrupting NOX4/NRF2 balance

ABSTRACT Endothelial cell senescence plays a critical role in the development of atherosclerosis. Fusobacterium nucleatum ( Fn ), a periodontal pathogen, has demonstrated pro-atherosclerotic effects, yet its role in endothelial senescence remains underexplored. This study aimed to elucidate whether and how Fn drives endothelial senescence and contributes to atherosclerosis. In vivo , chronic Fn infection accelerated atherosclerotic plaque progression, increased oxidative stress and vascular senescence, and impaired endothelial function. In vitro studies revealed that Fn induces dose- and time-dependent ROS production, disrupts redox homeostasis, and promotes endothelial senescence and dysfunction. Mechanistically, early infection transiently activated NRF2 via AKT-dependent inhibition of GSK3β, enhancing antioxidant defenses, but prolonged infection suppressed NRF2 activity due to AKT dephosphorylation and GSK3β activation, sustaining NOX4 upregulation and exacerbating oxidative stress. This redox imbalance amplified oxidative stress, aggravated endothelial dysfunction, and promoted cellular senescence. Pharmacological inhibition of NOX4 or GSK3β restored redox balance, reduced senescence, and improved endothelial function. These findings highlight the NOX4/NRF2 axis as a potential therapeutic target for vascular aging and atherosclerosis associated with chronic periodontal infection. IMPORTANCE In this study, we (i) demonstrated how Fusobacterium nucleatum ( Fn ) infection triggers a complex interplay between oxidative stress and antioxidant defense mechanisms in endothelial cells, highlighting the critical role of the NOX4/NRF2 axis in driving endothelial senescence; (ii) revealed that early Fn infection activates NRF2, leading to transient antioxidant responses, but prolonged infection leads to NRF2 degradation, increasing oxidative stress and exacerbating endothelial dysfunction; and (iii) showed that targeting NOX4 or GSK3β restores redox balance, alleviates endothelial senescence, and improves vascular function. Our findings suggest that chronic oral infections, such as those caused by Fn , may contribute to vascular aging and the progression of atherosclerosis, underscoring the importance of oral health in preventing systemic cardiovascular diseases. This study provides new insights into the mechanisms of microbial-driven vascular aging and identifies potential therapeutic targets for combating age-related cardiovascular diseases.