Bisphenol A bis (2,3-dihydroxypropyl) ether (BADGE.2H2O) is a component of commercial liquid epoxy resins commonly used in the food-packing industry and in dental sealants. There is evidence that it has significant estrogenic activity. Nur77 plays a crucial role in the regulation of certain genes involved in LH-mediated steroidogenesis in testicular Leydig cells. It was previously demonstrated that Bisphenol A (BPA) stimulates Nur77 gene induction and steroidogenesis. In this study, we investigated the effects of BADGE.2H2O on Nur77 gene expression and steroidogenesis. Northern blot analysis showed that it increased the expression of Nur77 mRNA and protein, and transient transfection assays demonstrated that it increased the promoter activity and transactivation of Nur77. It also increased the expression of certain steroidogenic genes, such as StAR and 3?-HSD. Finally, over-expression of a dominant negative Nur77 cDNA via adenoviral infection reduced BADGE.2H2O-mediated progesterone biosynthesis. These results indicate that BADGE.2H2O disrupts testicular steroidogenesis by increasing Nur77 gene expression.

Keywords: 3beta-HSD, BADGE.2H2O, Leydig Cells, Nur77, Orphan Nuclear Receptor, StAR, Steroidogenesis