TXNIP mediates ferroptosis in a bronchopulmonary dysplasia mouse model by regulating the SLC7A11/GPX4 pathway

Bronchopulmonary dysplasia (BPD) is one of the most common respiratory diseases in preterm infants. Studies have shown that ferroptosis is involved in the pathogenesis of BPD, and thioredoxin-interacting protein (TXNIP)-mediated oxidative stress also plays a role in its development. The solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway is one of the key pathways regulating ferroptosis. This study aimed to investigate the mechanism by which TXNIP regulates SLC7A11/GPX4 pathway-mediated ferroptosis in BPD. Mice were randomly divided into ten treatment groups: Air, Hyperoxia, Hyperoxia + RSL3, Hyperoxia + Ferrostatin-1, Hyperoxia + Ad-shNC, Hyperoxia + Ad-shTXNIP, Hyperoxia + Ad-vector, Hyperoxia + Ad-TXNIP, Hyperoxia + Ad-shSLC7A11, and Hyperoxia + Ad-shTXNIP + Ad-shSLC7A11. Lung tissues were collected for hematoxylin and eosin (H&E) staining to observe pathological changes, and transmission electron microscopy (TEM) was used to examine mitochondrial morphology. Real-time quantitative polymerase chain reaction (qPCR) was performed to measure the mRNA expression of TXNIP, SLC7A11, and GPX4. Western blotting was used to analyze the protein levels of TXNIP, SLC7A11, and GPX4. GPX4 activity was determined using an enzyme-linked immunosorbent assay (ELISA). Additionally, glutathione (GSH), malondialdehyde (MDA), and ferrous iron (Fe²⁺) levels in lung tissues were measured using corresponding detection kits. H&E staining and TEM confirmed successful modeling of lung injury after hyperoxia. MDA and Fe²⁺ increased, GSH decreased, and GPX4 activity declined after hyperoxia. TXNIP mRNA and protein were upregulated by hyperoxia, while SLC7A11 and GPX4 were downregulated. Ferroptosis activation exacerbated lung injury, whereas inhibition alleviated it. TXNIP overexpression using adenovirus serotype 5 (Ad5) aggravated ferroptosis in BPD, and this was ameliorated by TXNIP knockdown. Knockdown of the upstream signal SLC7A11 increased ferroptosis in BPD, and simultaneous knockdown of TXNIP and SLC7A11 reversed the ferroptosis reduction. In conclusion, in the BPD model, TXNIP expression was increased, and TXNIP promoted ferroptosis by downregulating the SLC7A11/GPX4 pathway. These findings suggest that gene therapy targeting TXNIP knockdown using adenovirus as a vector may serve as a therapeutic strategy for BPD.