Strain-specific induction of endometrial periglandular fibrosis in mice exposed during adulthood to the endocrine disrupting chemical bisphenol A.

The aim of this study was to compare effects of bisphenol A (BPA) on collagen accumulation in uteri of two mouse strains. Adult C57Bl/6N and CD-1 mice were exposed to dietary BPA (0.004-40mg/kg/day) or 17α-ethinyl estradiol (0.00002-0.001mg/kg/day) as effect control. An equine endometrosis-like phenotype with increased gland nesting and periglandular collagen accumulation was characteristic of unexposed C57Bl/6N, but not CD-1, endometrium. BPA non-monotonically increased gland nest density and periglandular collagen accumulation in both strains. Increased collagen I and III expression, decreased matrix metalloproteinase 2 (MMP2) and MMP14 expression, and increased immune response were associated with the endometrosis phenotype in the C57Bl/6N strain and the 30ppm BPA CD-1 group. The association between the pro-collagen shift in increased collagen expression and decreased MMP2 expression and activity implies that strain differences and BPA exposure alter regulation of endometrial remodeling and contribute to increased fibrosis, a component of several human uterine diseases.