Deciphering the air pollution-osteoarthritis relationship: insights from network toxicology, integrated machine...

Mounting evidence suggests an association between air pollution and the pathogenesis of osteoarthritis (OA), yet the underlying molecular mechanisms remain largely unexplored. This study aims to systematically decipher the mechanistic link between common air pollutants and OA using an integrated computational approach. We employed a novel strategy combining network toxicology, machine learning, and molecular docking. Potential target genes of seven air pollutants (benzene, SO₂, NO, CO, NO₂, toluene, O₃) were retrieved from predictive databases. OA-related genes were identified from synovial tissue gene expression datasets from the GEO database. Machine learning algorithms were applied to construct diagnostic models and identify hub genes. Immune infiltration analysis was performed using CIBERSORTx. Molecular docking simulations were conducted to validate the interactions between pollutants and hub gene proteins.We identified eight hub genes (S1PR4, HRH4, NR2E3, FOLH1, PIM1, CA2, MMP9, and HTR2A) that are central to the pollutant-OA interaction. Enrichment analysis indicated their involvement in neuroactive ligand-receptor interactions and immune-related pathways. Immune infiltration revealed a remodeled OA microenvironment characterized by altered macrophage polarization and T-cell subsets. The Naïve Bayes model, built upon these genes, demonstrated robust diagnostic performance. Crucially, molecular docking confirmed spontaneous binding (binding energy < 0 kcal/mol) between all seven pollutants and the eight hub proteins, with toluene exhibiting the strongest overall affinity in silico. Collectively, our integrative analysis generates novel hypotheses regarding molecular and immune mechanisms that may link air pollution exposure to OA pathogenesis, providing a framework for future experimental validation.