AIM To investigate the mechanism of mitoNEET-mediated mitochondrial pathway of ferroptosis in diabetic vascular injury.

METHODS  Diabetic mice (db/db) and wild-type (WT) controls were compared for endothelium-dependent vasodilation, vascular histomorphology, reactive oxygen species (ROS) generation, and mitochondrial ultrastructure under electron microscopy to characterize diabetic vascular injury. Further, db/db mice were treated with ferroptosis inhibitor (Fer-1), mitochondrial antioxidant (mitoTEMPO), or iron chelator (DFO) to evaluate the effects of targeting mitochondrial pathway ferroptosis on vascular injury and explore the molecular mechanisms.

RESULTS  Db/db mice exhibited impaired endothelium-dependent vasodilation in the descending aorta (P<0.01), elevated serum endothelin-1 (ET-1) levels (P<0.01), disorganized aortic architecture, increased ROS production (P<0.01), and mitochondrial structural damage. Fer-1 significantly improved endothelium-dependent vasodilation (P<0.05) and reduced serum ET-1 levels (P<0.05) in db/db mice. Fer-1, mitoTEMPO, and DFO interventions ameliorated descending aortic histoarchitecture, alleviated fibrosis, reduced tissue ROS (P<0.01), and partially restored mitochondrial structure. MitoNEET, a key mitochondrial outer membrane iron transporter, was upregulated in high glucose and high lipid -injured endothelial cells (P<0.01), accompanied by decreased protein expression of ferroptosis marker GPX4 (P<0.05) and reduced mitochondrial membrane potential. Fer-1, mitoTEMPO, and DFO downregulated mitoNEET (P<0.05), upregulated GPX4 (P<0.05), suppressed endothelial ferroptosis, and restored mitochondrial membrane potential (P<0.05).

CONCLUSION  Mitochondrial pathway ferroptosis contributes significantly to diabetic vascular injury. Ferroptosis inhibitors alleviate this injury by suppressing ferroptosis. MitoNEET mediates high glucose and high lipid-induced endothelial ferroptosis, providing novel insights and therapeutic targets for preventing diabetic vascular injury.