Jiaxiang Zhou, Huisheng Yuan, Xiudong Kuang, Zhikai Wang, Hongkun Chen, Qian Du, Qinghong Fan, Jianfeng Li, Manman Gao, Zhiyu Zhou
To investigate the potential molecular links between nonylphenol (NP) exposure and osteonecrosis of the femoral head (ONFH), we employed an integrated strategy combining network toxicology, transcriptomic analysis, weighted gene co-expression network analysis (WGCNA), machine learning, immune infiltration analysis, molecular docking, molecular dynamics simulation, and independent dataset validation. Based on the GSE123568 discovery dataset of steroid-induced ONFH and steroid-exposed non-ONFH controls, 391 differentially expressed genes were identified, including 123 upregulated and 268 downregulated genes. Intersection of DEGs with WGCNA-derived module genes yielded 342 SONFH-associated candidate genes for subsequent analysis. NP-related targets were collected from CTD, SwissTargetPrediction, and Target Net databases, and 40 overlapping genes were identified as potential NP-related ONFH targets. PPI network analysis highlighted 10 key genes, while LASSO regression, random forest, and SVM-RFE identified PECAM1, CXCR2, and MAP2K3 as common core feature genes. Integrated candidate genes were mainly associated with inflammation, oxidative stress, vascular regulation, extracellular matrix remodeling, endocrine-lipid metabolic disturbance, and bone metabolism. ROC analysis showed that the candidate gene set discriminated SONFH samples from steroid-exposed non-ONFH controls in the discovery dataset, with an AUC of 0.967. Immune infiltration analysis revealed that PECAM1 was significantly correlated with multiple immune cell subsets. Molecular docking and a 100 ns molecular dynamics simulation provided exploratory structural support for a potential NP-PECAM1 interaction. In summary, PECAM1 may represent a prioritized candidate node linking NP-related molecular perturbations with SONFH/ONFH-associated endothelial-immune dysregulation.