177,338 research outputs found
Impact of microplastics and associated contaminants on reproduction and development: a comparative and multidisciplinary study on mechanisms of action and protective strategies
No full textThe always increasing use of disposable and plastic-made materials has inevitably allowed the spread in each compartment of the environment of new toxic contaminants. Once released, plastic is degraded into smaller particles that can reach the micro and nano scale size, known as microplastics (MPs). The impact of these substances on living beings is worrying, since they are continuously exposed, especially via the food web. Many research pointed out the ecological consequences of MPs, both on the environment and in aquatic and terrestrial wildlife, however their interaction with cells and tissues, at molecular level, remains still largely unknown. In addition, MPs can adsorb organic chemicals form the surrounding medium, increasing the exposure of wildlife to a mixture of toxic substances (the so-called Trojan-Horse effect). Once ingested or adsorbed through water and food, MPs may potentially have toxic effects on all the body districts, but one of the most susceptible systems is surely the reproductive one, since, in our era, a decline in gamete quality and fertility rate is evidenced, mostly due to the environmental factors. Considering that reproduction ensure the species survival, that it is constantly threatened by environmental pollutants, this project aims to reveal the reprotoxicity of MPs, alone or in combination with Bisphenol A and cadmium, on the reproductive function: from gametogenesis to embryo/larval development, as well as on the hypothalamus-pituitary-gonad axis and on metabolic pathways related to reproduction. The strength of the project lies in its multidisciplinary and multilevel approach, that goes from molecular to the organism level, in the attempt to clarify modes and mechanisms of action, at a comparative level, with the use of invertebrate and vertebrate animal models, aquatic and terrestrial, as well as murine and human cell lines.
The project intends not only to explore the mysterious fate of toxicity of MPs in the various animal models, to provide robust scientific data to improve health risk assessments and management for MPs, but also, and especially, to find molecules that could be used in preventing or counteracting their toxicity. Keeping this in mind, the efficiency of bioactive molecules, including those present in dietary supplements and nutraceuticals (i.e. melatonin, zinc, D-aspartate, beta-caryophyllene, algal phycocolloids) will be tested. All the participating Units, together with several stranger collaborators, will cooperate assembling their expertise in the field of comparative reproduction, physiology and ecotoxicology, aiming to an integrate approach that will have significant impacts in scientific, ecological and social fields. Public engagement and correct dissemination of project results will be undertaken through different channels, to contribute to a better understanding of the problem of environmental and health effects of MPs pollution, at local, national and international levels
CADMIUM UPTAKE AND DISTRIBUTION IN TISSUES OF SEA BREAM WITH DIFFERENT CADMIUM EXPOSURE HISTORIES: CORRELATION WITH METALLOTHIONEIN LEVELS
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GLYPHOSATE: TOXIC OR NOT TOXIC, THIS IS THE QUESTION
No full textThe potential toxicity of Glyphosate-based herbicides (GBHs), a
broad spectrum herbicides widely used in agricultural, industrial
and urban areas, is a great matter of debate. Although considered
non-toxic and not an irritant (EPA) and no carcinogenic to
humans (EFSA), converging evidence suggests that GBHs pose
serious health risk on non-target wildlife. Many studies demonstrate
that GBHs threaten the reproduction interfering with the
activity of aromatase, an important enzyme involved in the production
of estrogen.1 Moreover, in fish and mammals GBHs cause
the raise of oxidative stress markers and tissues alterations.2,3
Hence, the question about the glyphosate (Gly) toxicity is still
open. To concur to answer to this question, we investigated the
effects of Gly exposure on the wall lizard Podarcis sicula, a suitable
bioindicator of soil pollution. Adult P. sicula specimens were
divided in 3 groups (n=6): 2 groups exposed to pure Gly 0.1 and
1 mg/L, respectively, via gavage every other day for 3 weeks;
group 3 received by gavage the same dose of tap water (100 μL).
The results demonstrate that both Gly doses affect the male
gonad. Spermatogenesis is slightly slower, spermatocytes II fuse
to form rosette-shaped arrangement, spermatids appear damaged
and cells in degeneration are evident in the tubules lumen.
Changes in the expression of estrogen and androgen receptors
and aromatase have been also detected. In females, the ovary is
not affected by Gly exposure, no matter the dose.
Livers show signs of suffering, regardless of the animals sex. The
increase in melanocytes degranulation and nodular/cystic formations,
mainly consisting of collagen fibers, have been observed.
The liver of Gly-treated males also displays the biosynthetic
alterations typical of an estrogenic contamination: hepatocytes,
in fact, contain transcripts for both vitellogenin and estrogen
receptors. Data suggest that Gly exposure in a vertebrate commonly
inhabiting the fields potentially exposed to GBHs causes
reproductive and tissue toxicity, with possible health implications
for wild and breeding animals, as well human populations
Morphological and Molecular Evidence of Active Principle Glyphosate Toxicity on the Liver of the Field Lizard Podarcis siculus
No full textA comparative review on estrogen receptors in the reproductive male tract of non mammalian vertebrates
No full textEstrogen receptors alpha (ERα) and beta (ERβ) are transcription factors known to be involved in the regulation of many complex physiological processes in mammals. They are expressed primarily in the reproductive tract of all vertebrates females, thus indicating important and conserved functions in female reproductive success. ERs are also present in physiological different tissues as bone, brain, liver, skin and adipose tissues, in both females and males. In the latter, ERs have been found also in the genital tract, supporting the findings of a complex role for estrogen in spermatogenesis and, more generally, in male reproduction. This review provides an overview and update on ERα and ERβ expression and synthesis in male reproductive tract of non-mammalian vertebrates, with focus on their role in germ cells proliferation, maturation and survival. Data from studies on fish, amphibians, reptiles and birds were collated and common or species-specific distribution highlighted. The widespread distribution of estrogen receptors in testicular cells and ducts of all vertebrates so far investigated suggests that whatever are the roles that estrogens may exert on these structures, they are phylogenetically conserved and are possibly related to the physiological support given to achieve male reproductive success
Exposure to dichlorodiphenyldichloroethylene (DDE) and metallothionein levels in rats fed with normocaloric or high-fat diet: A review
No full textThe growing number of studies on metallothioneins (MTs), cysteine-rich metal-binding proteins, have been disclosing new functions of these proteins. Thanks to their inducibility, they were considered to play a pivotal role in regulating trace metals homeostasis and in detoxification from heavy metals; nowadays, it is known that they are involved in various physiological and pathological processes, such as regulation of apoptosis, elimination of free radicals, and protection of nucleic acids against toxic insults. MT induction has been demonstrated following stress factors other than heavy metals, such as endocrine-disrupting chemicals, insecticides, and herbicides. However, retrieved data are often controversial: in some cases, xenobiotics elicit MT expression and synthesis; under different conditions, they lead to a decrease in cellular MT content. This review describes the MT response to dichlorodiphenyltrichloroethane (DDT) contamination in mammalian tissues. In particular, attention focuses on changes in MT expression, synthesis, and localization in rat liver, kidneys, and testes following oral administration of dichlorodiphenyldichloroethylene (DDE), the main metabolite of DDT, under normal dietary conditions or in combination with a high fat diet potentially able to increase the cellular uptake of this lipophilic pesticide. The potential connection between MT expression and synthesis, lipophilic substances and trace metals availability is also discussed
Vanadium Modulates Proteolytic Activities and MMP-14-Like Levels during Paracentrotus lividus Embryogenesis
No full textThe increasing industrial use of vanadium (V), as well as its recent medical use in various pathologies has intensified its environmental release, making it an emerging pollutant. The sea urchin embryo has long been used to study the effects induced by metals, including V. In this study we used an integrated approach that correlates the biological effects on embryo development with proteolytic activities of gelatinases that could better reflect any metal-induced imbalances. V-exposure caused morphological/morphometric aberrations, mainly concerning the correct distribution of embryonic cells, the development of the skeleton, and the embryo volume. Moreover, V induced a concentration
change in all the gelatinases expressed during embryo development and a eduction in their total proteolytic activity. The presence of three MMP-like gelatinases (MMP-2, -9, and -14) was also demonstrated and their levels depended on V-concentration. In particular, the MMP-14-like protein modified its expression level during embryo development in a time- and dose-dependent manner. This enzyme also showed a specific localization on filopodia, suggesting that primary mesenchyme cells (PMCs) could be responsible for its synthesis. In conclusion, these results indicate that an integrated study among morphology/morphometry, proteolytic activity, and MMP-14 expression constitutes an important response profile to V-action
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