Interaction between nitric oxide and prostaglandin E2 pathways in pregnant rat uteri

Are the new phthalates safe? Evaluation of Diisononilphtalate (DINP) effects in porcine ovarian cell cultures

Phthalates are plasticizing chemicals, widely used in packaging materials and consumer products for several decades. These molecules have raised concerns because of their toxicity and their use have been restricted in several countries. Therefore, novel phthalates have been introduced. Among these, diisononilphtalate (DINP) is widely employed. However, its safety has not been properly addressed. Therefore, using a well validated granulosa cell model, collected from swine ovaries with a translational value, we studied potential DINP effects on important cellular functional parameters. In particular, we studied cell growth, steroidogenesis and redox status. Collected data showed that DINP stimulates (p < 0.05) cell growth, increases estrogen and inhibits progesterone production (p < 0.05), disrupts redox balance stimulating free radicals (p < 0.05) while reducing scavenger activities (p< 0.05). Taken together, DINP's impact on cultured swine granulosa cells provides cause for concern regarding its potential adverse effects on reproductive and endocrine functions.

Redox Status, Estrogen and Progesterone Production by Swine Granulosa Cells Are Impaired by Triclosan

Triclosan is a chlorinated biphenolic with a broad spectrum of antiseptic activities used in cosmetics and hygiene products. Continuous exposure can lead to absorption and bioaccumulation of this substance with harmful health effects. In fact, previous studies have shown that Triclosan acts as an endocrine-disrupting chemical on reproductive organs, with consequent negative effects on reproductive physiology. Therefore, to assess potential adverse impacts on fertility, we tested Triclosan on swine granulosa cells, a model of endocrine reproductive cells. We examined its effects on the main features of granulosa cell functions such as cell growth (BrdU incorporation and ATP production) and steroidogenesis (17-β estradiol and progesterone secretion). Moreover, since oxidant−antioxidant balance plays a pivotal role in follicular function, redox status markers (superoxide, hydrogen peroxide and nitric oxide production, enzymatic and non-enzymatic scavenging activity) were studied. Our results show that Triclosan significantly inhibits cell growth (p < 0.001), steroidogenesis (p < 0.001), superoxide and nitric oxide production (p < 0.001), while it increases (p < 0.05) enzymatic defense systems. Collectively, these data suggest a disruption of the main granulosa cell functions, i.e., proliferation and hormone production, as well as an imbalance in redox status. On these bases, we can speculate that Triclosan would impair granulosa cell functions, thus exerting negative effects on reproductive function. Further studies are needed to explore lower Triclosan concentrations and to unravel its mechanisms of action at gene level.

Perfluorooctanoic Acid (PFOA) Induces Redox Status Disruption in Swine Granulosa Cells

Perfluorooctanoic acid (PFOA) is employed in the production and processing of several plastic materials, mainly during the production of waterproof fabrics or nonstick cookware. PFOA is identified as a substance of very high concern, as it is classified as a persistent, bioaccumulative, and toxic (PBT) substance because of its persistence in the environment and its potential accumulation in organisms. Thus, safe levels of exposure cannot be established, and PFOA emissions should be minimized. PFOA has recently been linked to several health concerns in humans. In particular, a disruptive effect on redox status homeostasis has been documented, with a potential impairment of normal reproductive function that requires adequate oxidative balance. Therefore, the aim of the present study was to evaluate the effects of PFOA (2, 20, and 200 ng/mL) on ovarian granulosa cells, a model of reproductive cells. The obtained results reveal that PFOA stimulated cell viability (p < 0.05). Regarding the effects on free radical production, O2−, NO, and H2O2 were significantly inhibited (p < 0.05), while the nonenzymatic antioxidant power was not significantly modified. Collectively, the present results deserve attention since free radical molecules play a crucial role in ovarian follicle development leading to a successful ovulation.

Simazine, a triazine herbicide, disrupts swine granulosa cell functions

The triazine herbicide simazine is a pesticide commonly detected in surface and ground waters, although banned in most European countries since 2004. Concerns for humans and animal health result from its potential endocrine disrupting action, that can lead to reproductive disorders. The present in vitro study was undertaken to study simazine effects on swine granulosa cell function, namely cell viability, proliferation, steroidogenesis and NO production. Moreover, the ability of this substance to interfere with the angiogenetic process, a crucial event in reproductive function, was taken into account. Our data document that simazine treatment, at 0.1 or 10 μM concentration levels, stimulates granulosa cell proliferation and viability and impairs steroidogenesis, increasing in particular progesterone production. In addition, the in vitro angiogenesis bioassay revealed a significant simazine stimulatory effect on immortalized porcine Aortic Endothelial Cell proliferation. Collectively, these results show that simazine can display disruptive effects on ovarian cell functional parameters, possibly resulting in reproductive dysfunction. This hypothesis is also supported by the observed pro-angiogenetic properties of this herbicide, as already suggested for different endocrine disruptors.

Glyphosate affects swine ovarian and adipose stromal cell functions

Although Glyphosate (GLY) is a widely used pesticide, its effects on ovarian function and stem cell differentiation are still largely unknown. Therefore, as a contribution on this subject, the present work reports an investigation of the in vitro effects of GLY on swine granulosa cells and adipose stromal cells (ASCs). The effect of GLY at different doses (0.2, 4 and 16 μg/mL) was evaluated on granulosa cells growth (BrDU incorporation and ATP production), steroidogenesis (17-β estradiol and progesterone secretion) and redox status (superoxide and nitric oxide production and non-enzymatic scavenging activity). GLY has been shown to inhibit cell growth, 17-β estradiol and non-enzymatic scavenging activity and to increase progesterone and nitric oxide secretion (P < 0.05). In addition, GLY significantly decreased the viability of ASCs (P < 0.001), and inhibited their adipogenic differentiation. These data indicate that GLY alters the main features of granulosa cells and ASCS thus suggesting that GLY could affect both reproductive function and adipose tissues homeostasis.

Orexin system in swine ovarian follicles

Successful reproduction is strictly linked to metabolic cues. The orexins are a family of hypothalamic neurohormones, well known for their key role in the control of food intake and the involvement in several aspects of the reproductive process. The biological actions of both orexins are carried out through binding to the related Orexin 1 (OX1R) and Orexin 2 (OX2R) G-protein-coupled receptors. The purpose of this study was to investigate the presence of orexin system components in the porcine ovaries, to contribute to expand the knowledge about their pleiotropic role. First, we investigated the localization of orexin A (OXA) and its receptors by immunochemistry in different ovarian districts. Thereafter, we evaluated the expression of the prepro-orexin (PPO) gene and OXA effects on granulosa cell functions. Immunohistochemical study revealed the presence of orexinergic system components in porcine ovarian follicles. Moreover, our data show the expression of PPO messenger RNA in swine ovarian follicles >5 mm. In addition, OXA influences proliferation (P < 0.05), steroidogenic activity (P < 0.05), and redox status of granulosa cells (P < 0.05). Therefore, we hypothesize that OXA could exert a local physiological role in swine ovarian follicles even if further studies are required to deeply define the function of this pleiotropic system.

Bisphenol A interferes with swine vascular endothelial cell functions

Several studies have demonstrated that the endocrine disruptor bisphenol A (BPA) negatively affects animal and human health. An angiogenic process has been suggested among the events disrupted by this molecule, but the underlying mechanisms have not yet been clarified. The effect of BPA on angiogenesis was investigated by means of a bioassay previously validated in our laboratory. Using immortalized swine aortic endothelial cell line (AOC), the development of new blood vessels through a three-dimensional in vitro angiogenesis assay was evaluated. Subsequently, since vascular endothelial growth factor (VEGF) and nitric oxide (NO) are key players in the regulation of the angiogenic process, the effect of BPA on the production of these molecules by AOC was examined. BPA (10 μmol/L) stimulated AOC growth (p < 0.05) and VEGF production (p < 0.05), but did not modify NO levels. Our data suggest that the endocrine-disrupting effects of BPA could also be associated with the promotion of vascular growth, thus interfering with a physiologically finely tuned process resulting from a delicate balance of numerous molecular processes. The stimulatory effects of BPA on VEGF production may have negative implications, potentially switching the balance toward uncontrolled neovascularization. Moreover, since angiogenesis is involved in several pathologies, including cancer growth and progression, potential health risks of BPA exposure should be carefully monitored.

Transforming growth factor β signaling in uterine development and function

Transforming growth factor β (TGFβ) superfamily is evolutionarily conserved and plays fundamental roles in cell growth and differentiation. Mounting evidence supports its important role in female reproduction and development. TGFBs1-3 are founding members of this growth factor family, however, the in vivo function of TGFβ signaling in the uterus remains poorly defined. By drawing on mouse and human studies as a main source, this review focuses on the recent progress on understanding TGFβ signaling in the uterus. The review also considers the involvement of dysregulated TGFβ signaling in pathological conditions that cause pregnancy loss and fertility problems in women.