Human chorionic gonadotropin (hCG) is a hormone of considerable importance in the establishment, promotion and maintenance of human pregnancy. It has been clearly demonstrated that hCG exerts multiple endocrine, paracrine and autocrine actions on a variety of gestational and non-gestational cells and tissues. These actions are directed to promote trophoblast invasiveness and differentiation, placental growth, angiogenesis in uterine vasculature, hormone production, modulation of the immune system at the maternal-fetal interface, inhibition of myometrial contractility as well as fetal growth and differentiation. In recent years, considerable interest has been raised towards the biological effects of environmental contaminants, particularly endocrine disrupting chemicals (EDCs). Emerging evidence suggests that prenatal exposure to selected EDCs can have a deleterious impact on the fetus and long-lasting consequences also in adult life. The results of the in vitro effects of commonly found EDCs, particularly Bisphenol A (BPA) and para-Nonylphenol (p-NP), indicate that these substances can alter hCG production and through this action could exert their fetal damage, suggesting that hCG could represent and become a potentially useful clinical biomarker of an inappropriate prenatal exposure to these substances.
This work aims to clarify the effect of dietary supplementation with Bisphenol A (BPA), a chemical widely present in beverage and food containers, on placental glucose transfer and pregnancy outcome. The study was performed on female Sprague Dawley rats fed with a diet containing BPA (2.5, 25 or 250 μg/Kg/day) for a period of a month (virgin state) plus 20 days during pregnancy. Western blot analysis and immunohistochemistry were performed in placental tissues for glucose type 1 transporter (GLUT1). Furthermore, human trophoblast, HTR8-SV/neo cells, were used to evaluate the effect of BPA on glucose transport and uptake. Studies in rats showed that food supplementation with BPA, produces a higher fetal weight (FW) to placenta weight (PW) ratio at the lowest BPA concentration. Such low concentrations also reduced maternal weight gain in late pregnancy and up-regulated placental expression of GLUT1. Treatment of HTR8-SV/neo with the non-toxic dose of 1 nM BPA confirmed up-regulation of GLUT1 expression and revealed higher activity of the transporter with an increase in glucose uptake and GLUT1 membrane translocation. Overall, these results indicate that prenatal exposure to BPA affects pregnancy and fetal growth producing changes in the placental nutrients-glucose transfer.
The identification of reproductive toxicants is a major scientific challenge for human health. Prenatal life is the most vulnerable and important time span of human development. For obvious ethical reasons, in vivo models cannot be used in human pregnancy, and animal models do not perfectly reflect human physiology. This review describes the in vitro test models representative of the human feto–maternal interface and the effects of environmental chemicals with estrogen-like activity, mainly bisphenol A and para-nonylphenol, with a particular emphasis on the effects at low, nontoxic doses similar to concentrations commonly detected in the population.
Bisphenol A (BPA) is a widespread environmental contaminant, found in human fluids and tissues. Maternal BPA exposure is associated with alterations in pregnancy outcomes. Because maternal uterine circulation plays a crucial role in normal placenta and fetal growth, we hypothesized that BPA compromises the function of uterine arteries (UAs) and fetoplacental development. Female rats were orally administered with BPA (2.5, 25 and 250 µg/kg/day) or with its vehicle (ethanol) for 30 days before pregnancy and during the first 20 days of pregnancy. To compare the effect of BPA in the reproductive vs. systemic circulation, it was tested on UAs and mesenteric arteries (MAs). Arteries were isolated and examined by pressure myography. Moreover, fetuses and placentas were weighed to provide an index of reproductive performance. In UAs of BPA-treated rats, lumen diameter, acetylcholine-relaxation and expressions of endothelial nitric oxide synthase 3 (NOS3), estrogen receptor α (ERα) and peroxisome proliferator-activated receptor ɣ (PPARɣ) were reduced. Conversely, no changes were observed in MAs. BPA treatment also reduced placental weights, while fetal weights were increased. For the first time, our results indicate that UAs represent a specific target of BPA during pregnancy and provide insight into the molecular mechanisms that underlie its negative effects on pregnancy outcomes.