Obstructive voiding disorder (CVD) is a common disease during aging in men, and while less common, it also occurs in women. The proposed experiments concern the role of prenatal and postnatal (lifespan) exposure to bisphenol A (BPA) on the development of OVD in both male and female SD rats reared and treated with different doses of BPA under a GLP protocol at the National Center for Toxicological Research (NCTR). Preliminary studies with both male and female rats and mice show that changes in periurethral gland development and malformations of the urethra are caused by estrogenic chemicals, including BPA, but specific effects are different at low and high doses. Preliminary studies also show that prenatal exposure to BPA results in OVD in male mice exposed to exogenous estrogen during adulthood. The hypothesis is that fetal exposure to low doses of BPA will predispose both male and female SD rats to development of OVD during aging as a result of continued exposure to the same dose of BPA during postnatal life.
In aim 1 the investigators will examine the effects of BPA on male and female fetal (gestation day 21) periurethral gland structure (using computer-assisted reconstruction of serial sections) and function of epithelium and stroma, using laser capture microdissection (LCM) coupled with next generation sequencing (NGS) for examination of gene expression and epigenetic changes in DNA, as well as immunohistochemistry (IHC) to identify specific cell types, proliferation and apoptosis.
In aim 2 the urethra will be collected from adult male and female rats that develop OVD or at specific ages in non-diseased controls. The investigators will examine periurethral gland and stroma structure and function using the same outcomes described for fetuses (histopathology, immunohistochemistry, LCM) to capture epithelial and stromal cells for analysis of mRNA and genomic DNA using NGS to determine transcriptomal profiles and to determine genome-wide methylation profiles of genomic DNA. The combination of detailed morphological and functional analyses of fetal and adult urethral tissues exposed to different doses of BPA is highly innovative.
Obstructive voiding disorder (OVD) commonly occurs during aging in men and at a lower frequency it also occurs in women. The causes of OVD are at present unknown, making decisions about appropriate therapy difficult. We have developed an animal model for OVD in male mice that involves exposing fetuses to the estrogenic chemical bisphenol A (BPA). The proposed research offers the potential to determine the role of the ubiquitous environmental contaminant BPA in the etiology of a common disease ofthe urinary tract.
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