Exploratory analysis of benzo(a)pyrene-associated osteoarthritis targets based on network toxicology and In vitro validation

Abstract

Benzo(a)pyrene (BaP), a widespread environmental pollutant, has been implicated in osteoarthritis (OA) development, yet underlying mechanisms remain unclear. This study aimed to elucidate the molecular mechanisms of BaP-induced OA through integrative network toxicology and experimental validation. Overlapping genes between BaP exposure and OA were identified from multiple databases (CTD, SwissTargetPrediction, NCBI, Malacards, and OMIM). Protein–protein interaction networks and enrichment analyses were performed to identify core targets and pathways. Microarray data (GSE117527) of BaP-treated human primary T lymphocytes were analyzed for differentially expressed genes. Experimental validation was conducted using human primary T lymphocytes and CHON-001 chondrocytes through Western blotting, qPCR, ELISA, and conditioned media co-culture experiments. We identified 915 overlapping genes between BaP and OA, with 17 core targets including TP53, TNF, and AKT. Transcriptomic analysis revealed the PI3K/AKT signaling pathway as a critical regulatory hub. BaP exposure significantly activated PI3K/AKT phosphorylation and upregulated TNF-α and IL-6 expression and secretion in T lymphocytes. Notably, conditioned media from BaP-stimulated T lymphocytes significantly exacerbated CHON-001 apoptosis and reduced viability compared to direct BaP exposure, demonstrating potent indirect toxicity mediated by immune cells. BaP exposure is associated with OA pathogenesis through a co-occurring network involving PI3K/AKT pathway activation and immune-mediated inflammatory responses. The discovery of T lymphocyte-mediated indirect toxicity provides novel insights into environmental pollutant-related osteoarthritis.