Bisphenol A drives the comorbidity of non-alcoholic fatty liver disease and osteoarthritis by targeting RHOB: Integrated multi-omics, single-cell analysis, and experimental validation.

BACKGROUND: This study focuses on exploring the co-morbid mechanisms by which Bisphenol A (BPA) induces non-alcoholic fatty liver disease (NAFLD) and osteoarthritis (OA). METHOD: This study identified potential BPA targets utilizing the SwissTargetPrediction database. These targets were integrated with genes associated with NAFLD and OA, which were screened via Weighted Gene Co-expression Network Analysis and differential gene expression analysis. To elucidate the underlying biological mechanisms, functional enrichment and immune infiltration analyses were conducted. Core genes associated with comorbidity were pinpointed via machine learning. The interactions and cellular localization were further validated by molecular docking, molecular dynamics simulations, and single-cell transcriptomics. Finally, in vitro experiments were employed to verify the effects on chondrocyte function, and hepatic lipid metabolism. RESULTS: Functional enrichment analysis indicates that BPA-induced NAFLD and OA comorbidity pathways are enriched in muscle cell proliferation, DNA metabolism, and inflammation pathways. RHOB has been identified as a core gene, participating in disease progression by regulating signaling pathways such as Hippo and IL-17. Single-cell sequencing revealed that RHOB is primarily expressed in hepatocytes and cholangiocytes in NAFLD, while enriching in HomC and EC cell clusters in OA. In vitro experiments confirmed that BPA exposure suppresses RHOB expression, thereby promoting lipid accumulation in hepatocytes and impairing chondrocyte function. Concurrently, rescue experiments demonstrated that its overexpression significantly reversed these pathological states. CONCLUSION: BPA exposure drives the co-morbidity of OA and NAFLD by inhibiting RHOB. Consequently, limiting BPA exposure or modulating the RHOB pathway represents a viable approach for intervening in related diseases.