Neutrophil extracellular traps aggravate blood-brain barrier disruption via ZBP1/FSP1-mediated ferroptosis after traumatic brain injury.

Ferroptosis plays a crucial role in secondary brain injury following traumatic brain injury (TBI). Neutrophil extracellular traps (NETs) formation has also been implicated in secondary injury after TBI. However, the relationship between NETs, blood-brain barrier (BBB) disruption, and ferroptosis remains unclear. In this study, we found that levels of NET-related biomarkers in the plasma of TBI patients were significantly elevated and positively correlated with ICAM-1 and vWF. Moreover, inhibiting NET formation via peptidylarginine deiminase 4 (PAD4) deficiency reduced ferroptosis and BBB damage. In vitro experiments demonstrated that NETs exacerbated ferroptosis in hCMEC/D3 cells, leading to BBB disruption. Knockdown of ZBP1 and overexpression of FSP1 both reversed NETs-induced ferroptosis in endothelial cells and alleviated BBB damage. Additionally, we observed a close relationship between ZBP1 and FSP1. Collectively, our findings suggest that inhibiting NETs formation can mitigate ferroptosis and BBB damage, while targeting ZBP1 and FSP1 may offer potential therapeutic strategies for improving outcomes after TBI.