Linking di-2-ethylhexyl phthalate (DEHP) exposure to osteoporosis through population analysis, network toxicology, and experimental evidence

BACKGROUND: Osteoporosis is a major public health problem, and environmental toxicants such as di(2-ethylhexyl) phthalate (DEHP) have been implicated as potential risk factors. However, the molecular mechanisms linking DEHP exposure with osteogenic impairment remain unclear. METHODS: The association between DEHP exposure and osteoporosis risk using NHANES data, and employed network toxicology and molecular docking to identify key regulatory targets. To further verify these predictions, wet-lab experiments including Western blotting and quantitative PCR (qPCR) were conducted in osteoblast-related cells under control (CON), osteoporosis (OP), DEHP, and combined OP+DEHP conditions. RESULTS: Epidemiological analysis revealed that higher DEHP exposure was associated with increased osteoporosis risk. In the fully adjusted model, participants in the highest quartile of ln∑DEHP had higher odds of osteoporosis compared with those in the lowest quartile (OR = 1.32, 95% CI = 0.76-1.66, P for trend <0.001). Network toxicology analysis identified HDAC1 as a central hub gene, while RUNX2 emerged as a key osteogenic regulator. Western blotting and qPCR further demonstrated significant upregulation of HDAC1 and downregulation of RUNX2, with the most pronounced changes observed in the OP+DEHP group. CONCLUSION: These results suggest that DEHP exposure may contribute to osteogenic impairment and increased osteoporosis risk, potentially through epigenetic dysregulation involving HDAC1 and suppression of RUNX2.