PTGS2 and KPNA2 as key mediators of DEHP-induced osteoarthritis: From network prediction to machine learning and dynamic simulation validation.

Di(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer, has drawn increasing concern due to its high exposure potential. Although DEHP exposure has been associated with osteoarthritis (OA), its molecular mechanisms remain insufficiently defined. In this study, 271 DEHP-related OA targets were identified from public databases and functionally characterized using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) , and gene set enrichment analysis (GSEA) analyses, revealing enrichment in chondrocyte differentiation, inflammatory regulation, and PI3K-Akt/MAPK signaling. Machine learning approaches, including LASSO and SVM, further narrowed these to seven core targets, among which THRA, BAG3, PTGS2, KPNA2, and FGF1 exhibited strong diagnostic performance. Molecular docking and dynamics simulations confirmed stable DEHP-protein interactions and highlighted PTGS2 and KPNA2 as key targets. Western blot analyses demonstrated that the overexpression of KPNA2 and PTGS2 accelerates OA progression, whereas their knockdown mitigates DEHP-induced cartilage injury. Collectively, this study elucidates DEHP-mediated OA mechanisms, identifies PTGS2 and KPNA2 as central regulators, and provides mechanistic insight into the joint toxicity of DEHP.