Mechanistic insights into di(2-ethylhexyl) phthalate exposure in obstructive sleep apnea: network toxicology and in vitro validation.

BACKGROUND: Di(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer and endocrine-disrupting chemical, has been associated with multiple adverse health outcomes. However, whether DEHP exposure contributes to poor outcomes in individuals with obstructive sleep apnea (OSA), particularly through interaction with chronic intermittent hypoxia (CIH), remains unclear. METHODS: We used NHANES data to assess the relationship between DEHP exposure and all-cause mortality in OSA patients. Environmental health-related targets of DEHP were identified through ChEMBL, SEA, and SwissTargetPrediction databases. OSA-related genes were compiled from GeneCards, OMIM, and CTD. Protein-protein interaction analysis and molecular docking were performed to explore potential molecular interactions. In vitro experiments were conducted in human bronchial epithelial cells using CCK-8 assays, LDH release assays, and RT-qPCR analysis. Concentration-dependent responses to DEHP exposure were evaluated, and the modifying effects of CIH, a hallmark feature of OSA, were further investigated. RESULTS: Increased DEHP exposure was significantly associated with a higher risk of all-cause mortality in OSA patients, with a non-linear dose-response relationship. Network toxicology analysis revealed key DEHP-related targets involved in inflammation, tissue remodeling, and apoptosis, such as AR, BCL2, CASP3, PRKCA, CTSS, and MMP9. Molecular docking provided structural evidence supporting potential interactions between DEHP and these proteins. In vitro experiments demonstrated concentration-dependent alterations in hub gene expression following DEHP exposure, characterized by increased expression of AR, CASP3, PRKCA, CTSS, and MMP9 and decreased expression of BCL2. These molecular responses were further enhanced under combined DEHP exposure and CIH conditions. CONCLUSION: DEHP exposure was associated with increased mortality risk among individuals with OSA. DEHP induced concentration-dependent changes in OSA-related hub gene expression, which were further enhanced by intermittent hypoxia, providing potential insights into the biological effects of DEHP exposure in OSA.