Molecular mechanisms of endocrine disruptors: Interference with the endocrine system activity

Endocrine disrupting chemicals (EDCs) are an heterogeneous group of compounds able to interfere with hormonal functions by mimicking the endogenous hormones. This feature makes them able to interact with different cellular and molecular targets that affect all the biological functions of organisms. Many EDCs have a structural similarity with several endogenous hormones and this allows them to interact physically with specific receptors even though with different binding affinities each time. In this review we have collected some of the various and manifold molecular mechanisms activated by EDCs. Of these, the receptor-mediated pathway prevails; it is based on the interaction with estrogen receptors (ERs). However, this is not the only way they can use to determine endocrine interference. Several in vitro and in vivo studies have shown the existence of non-receptor and non-genomic pathways that are much faster and trigger a number of signal transduction pathways that control multiple cellular functions such as proliferation, differentiation and motility. Finally, several EDCs affect the hypothalamus-pituitary axis and the hormonal systems involved in the thyroid and the adrenal glands. Their wide presence in the environment and the multiple exposure paths to which we are constantly subjected, make EDCs a very wide health problem. Determining the specific molecular mechanisms that they are able to activate is an important step in trying to reduce the risk associated with their presence in our daily lives

Estrogenic and anti-androgenic endocrine disrupting chemicals and their impact on the male reproductive system

Endocrine disrupting chemicals (EDCs) are identified for their ability to perturb the homeostasis of endocrine system and hormonal balance. The male reproductive system is under close control of hormones and each change in their concentration and time of exposition and action can induce a deregulation of its physiology. In this review we summarize the most recent studies on two main categories of EDCs with different action: the estrogenic bisphenol A and alkylphenols and the anti-androgenic phthalates. This review describes the main effects of these substances on male reproductive system

HSP90 and pCREB alterations are linked to mancozeb-dependent behavioral and neurodegenerative effects in a marine teleost

The pesticide mancozeb (mz) is recognized as a potent inducer of oxidative stress due to its ability to catalyze the production of reactive oxygen species plus inhibiting mitochondrial respiration thus becoming an environmental risk for neurodegenerative diseases. Despite numerous toxicological studies on mz have been directed to mammals, attention on marine fish is still lacking. Thus, it was our intention to evaluate neurobehavioral activities of ornate wrasses (Thalassoma pavo) exposed to 0.2mg/l of mz after a preliminary screening test (0.07-0.3mg/l). Treated fish exhibited an evident (p1000%) while exploratory attitudes (total arm entries) diminished (-50%; p<0.05) versus controls during spontaneous exploration tests. Moreover, they showed evident enhancements (+111%) of immobility in the cylinder test. Contextually, strong (-88%; p<0.01) reductions of permanence in light zone of the Light/Dark apparatus along with diminished crossings (-65%) were also detected. Conversely, wrasses displayed evident enhancements (160%) of risk assessment consisting of fast entries in the dark side of this apparatus. From a molecular point of view, a notable activation (p<0.005) of the brain transcription factor pCREB occurred during mz-exposure. Similarly, in situ hybridization supplied increased HSP90 mRNAs in most brain areas such as the lateral part of the dorsal telencephalon (Dl; +68%) and valvula of the cerebellum (VCe; +35%) that also revealed evident argyrophilic signals. Overall, these first indications suggest a possible protective role of the early biomarkers pCREB and HSP90 against fish toxicit

Nonylphenol effects on human prostate non tumorigenic cells

Nonylphenol (NP) is an industrial chemical with estrogenic activity both in vivo and in vitro; estrogens play a critical role in the development of prostate and may be the cause of some pathological states, including cancer. In this study we examined the effects of NP on human prostate non tumorigenic epithelial cells (PNT1A) investigating on cell proliferation, interaction with estrogen receptors (ERs) and gene expression of genes involved in prostate diseases. We found that NP affects cell proliferation at 10(-6)M, promoting a cytoplasm-nucleus translocation of ERα and not ERβ, like the natural estrogen 17β-estradiol (E2). Moreover, we showed that NP enhances gene expression of key regulators of cell cycle. Estrogen selective antagonist ICI182780 in part reverted the observed effects of NP. These results confirm the estrogenic activity of NP and suggest that other transduction pathways may be involved in NP action on prostate

Catestatin and GABAAR related feeding habits rely on dopamine, ghrelin plus leptin neuroreceptor expression variations

Catestatin (CST), an endogenously small sympathoinhibitory peptide is capable of interfering with the major cerebral neuroreceptor-blocking site, i.e. γ-aminobutyric acidA receptor (GABAAR) system especially in limbic brain areas that are involved with feeding behaviors. The GABAARergic-related effects seem to derive from its interaction with other molecular neuroreceptors such as dopaminergic, ghrelin and leptinergic. In this context, the present study aimed to investigate probable feeding responses (eating and drinking) induced by treatment with CST and the GABAAR antagonist bicucullin (BIC) alone or simultaneously (CST+BIC) in the Syrian hibernating hamster (Mesocricetus auratus) model. Hamsters that received these compounds via intracerebroventricular infusions displayed notable variations of feeding and drinking bouts. In particular, an anorexigenic response was evident following treatment with CST while BIC evoked a significant increase of eating and drinking behaviors. Surprisingly when both agents were given simultaneously, a predominating anorexigenic response was detected as shown by evident CST-dependent reduction of feeding bouts. Contextually such behaviors, especially those following the combined treatment were tightly correlated with the significantly increased cerebral dopamine receptor 1 (D1) plus reduced ghrelin receptor (GhsR) and leptin receptor (LepR) transcript levels. Overall, the anorexigenic effect of CST deriving from its tight interaction with GABAARs activity plus D1 and GhsR transcripts tends to propose these neuronal elements as pivotal factors responsible for feeding disorders

Polystyrene nanoparticles internalization in human gastric adenocarcinoma cells

The increase in the use of nanoparticles, as a promising tool for drug delivery or as a food additive, raises questions about their interaction with biological systems, especially in terms of evoked responses. In this work, we evaluated the kinetics of uptake of 44 nm (NP44) and 100 nm (NP100) unmodified polystyrene nanoparticles (PS-NPs) in gastric adenocarcinoma (AGS) cells, as well as the endocytic mechanism involved, and the effect on cell viability and gene expression of genes involved in cell cycle regulation and inflammation processes. We showed that NP44 accumulate rapidly and more efficiently in the cytoplasm of AGS compared to NP100; both PS-NPs showed an energy dependent mechanism of internalization and a clathrin-mediated endocytosis pathway. Dose response treatments revealed a non-linear curve. PS-NPs also affected cell viability, inflammatory gene expression and cell morphology. NP44 strongly induced an up-regulation of IL-6 and IL-8 genes, two of the most important cytokines involved in gastric pathologies. Our study suggests that parameters such as time, size and concentration of NPs must be taken carefully into consideration during the development of drug delivery systems based on NPs and for the management of nanoparticles associated risk factors

Aquatic Pollution and Risks to Biodiversity: The Example of Cocaine Effects on the Ovaries of Anguilla anguilla

Pollution is one of the main causes of the loss of biodiversity, currently one of the most important environmental problems. Important sources of aquatic pollution are illicit drugs, whose presence in waters is closely related to human consumption; their psychoactive properties and biological activity suggest potential adverse effects on non-target organisms, such as aquatic biota. In this study, we evaluated the effect of an environmentally relevant concentration of cocaine (20 ng L-1), an illicit drug widely found in surface waters, on the ovaries of Anguilla anguilla, a species critically endangered and able to accumulate cocaine in its tissues following chronic exposure. The following parameters were evaluated: (1) the morphology of the ovaries; (2) the presence and distribution of enzymes involved in oogenesis; (3) serum cortisol, FSH, and LH levels. The eels exposed to cocaine showed a smaller follicular area and a higher percentage of connective tissue than controls (p &lt; 0.05), as well as many previtellogenic oocytes compared with controls having numerous fully vitellogenic and early vitellogenic oocytes. In addition, the presence and location of 3β-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase, and P450 aromatase differed in the two groups. Finally, cocaine exposure decreased FSH and LH levels, while it increased cortisol levels. These findings show that even a low environmental concentration of cocaine affects the ovarian morphology and activity of A. anguilla, suggesting a potential impact on reproduction in this species

Effects of environmental cocaine concentrations on COX and caspase-3 activity, GRP-78, ALT, CRP and blood glucose levels in the liver and kidney of the European eel (Anguilla anguilla)

Abstract Cocaine is one of the most widely used illicit drugs in the world, and as a result of incomplete removal by sewage treatment plants it is found in surface waters, where it represents a new potential risk for aquatic organisms. In this study we evaluated the influence of environmental concentrations of cocaine on the liver and the kidney of the European eel (Anguilla anguilla). The eels were exposed to 20 ng L−1 of cocaine for fifty days, after which, three and ten days after the interruption of cocaine exposure their livers and kidneys were compared to controls. The general morphology of the two organs was evaluated, as well as the following parameters: cytochrome oxidase (COX) and caspase-3 activities, as markers of oxidative metabolism and apoptosis activation, respectively; glucose-regulated protein (GRP)78 levels, as a marker of endoplasmic reticulum (ER)-stress; blood glucose level, as stress marker; serum levels of alanine aminotransferase (ALT), as a marker of liver injury and serum levels of C-reactive protein (CRP), as a marker of the inflammatory process. The liver showed morphologic alterations such as necrotic areas, karyolysis and pyknotic nuclei, while the kidneys had dilated glomeruli and the renal tubules showed pyknotic nuclei and karyolysis. In the kidney, the alterations persisted after the interruption of cocaine exposure. In the liver, COX and caspase-3 activities increased (COX: P = 0.01; caspase-3: P = 0.032); ten days after the interruption of cocaine exposure, COX activity returned to control levels (P = 0.06) whereas caspase-3 activity decreased further (P = 0.012); GRP78 expression increased only in post-exposure recovery specimens (three days: P = 0.007 and ten days: P = 0.008 after the interruption of cocaine exposure, respectively). In the kidney, COX and caspase-3 activities increased (COX: P = 0.02; caspase-3: P = 0.019); after the interruption of cocaine exposure, COX activity remained high (three days: P = 0.02 and ten days: P = 0.029 after the interruption of cocaine exposure, respectively) whereas caspase-3 activity returned to control values (three days: P = 0.69 and ten days: P = 0.67 after the interruption of cocaine exposure, respectively). Blood glucose and serum ALT and CRP levels increased (blood glucose: P = 0.01; ALT: P = 0.001; CRP: 0.015) and remained high also ten days after the interruption of cocaine exposure (blood glucose: P = 0.009; ALT: P = 0.0031; CRP: 0.036). These results suggest that environmental cocaine concentrations adversely affected liver and kidney of this species

Triclosan and estradiol effects on human prostate cells

Xenoestrogens are estrogen-mimicking compounds that are commonly found in personal care products and pesticides. The activity of xenoestrogens in the human body involves interference with estrogen receptor binding. Triclosan (TCS), a lesserknown xenoestrogen, is a broad-spectrum antibacterial commonly used in cosmetics, toothpastes, soap and other consumer products. The widespread use of TCS and its detection in human breast milk, urine and serum have raised concerns regarding its association with various health outcomes. Recent evidence suggests that TCS may play a role in cancer development, perhaps through its estrogenicity. In the present work we have studied the effects of TCS and Estrogen (E2) on human prostate adenocarcinoma epithelial cells (LNCaP) in order to highlight estrogen and xenoestrogen influence on human prostate. Although androgens are the most important hormones in the normal development of the male reproductive system, more recently, it has been suggested a central role for estrogen in male reproductive system and it has been hypothesized that high level of estrogens may disturb the endocrine control of the male reproductive capability. We examined the effects of TCS and E2 on the proliferation of the LNCaP through MTT assay. They were both able to increase cell proliferation at concentration of 10-8 M after 24h of treatment. In order to study estrogen receptor (ER) involvement, we evaluated the cellular localization and expression of ERs with immunofluorescence and western blot techniques after treatment with TCS and E2. Finally, through Real Time PCR analysis we have investigated gene expression of several molecular targets of estrogen pathway. We have observed that treatment with TCS and E2 induced an upregulation of Ki-67, cyclin D1 and cyclin E. We have also observed an upregulation of proinflammatory cytochines Il-1β after TCS and E2 treatment. These results confirm the estrogenic activity of TCS and suggest that estrogen and xenoestrogens may interfere with molecular pathways of prostate physiolog