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In recent decades, the global vanadium (V) industry has been steadily growing, together with interest in the potential use of V compounds as therapeutics, leading to V release in the marine environment and making it an emerging pollutant. Since climate change can amplify the sensitivity of marine organisms already facing chemical contamination in coastal areas, here, for the first time, we investigated the combined impact of V and global warming conditions on the development of Paracentrotus lividus sea urchin embryos. Embryo-larval bioassays were carried out in embryos exposed for 24 and 48 h to sodium orthovanadate (Na3VO4) under conditions of near-future ocean warming projections (+3 °C, 21 °C) and of extreme warming at present-day marine heatwave conditions (+6 °C, 24 °C), compared to the control temperature (18 °C). We found that the concomitant exposure to V and higher temperature caused an increased percentage of malformations, impaired skeleton growth, the induction of heat shock protein (HSP)-mediated cell stress response and the activation of apoptosis. We also found a time- and temperature-dependent increase in V bioaccumulation, with a concomitant reduction in intracellular calcium ions (Ca2+). This work demonstrates that embryos' sensitivity to V pollution is increased under global warming conditions, highlighting the need for studies on multiple stressors. [ABSTRACT FROM AUTHOR]

Simple Summary: The use of the herbicide glyphosate in agriculture exposes wildlife to this substance. In this review, data obtained using the lizard Podarcis siculus as an unconventional model organism were collected and analyzed. This is to answer the question of whether occasional exposure to glyphosate can endanger the reproductive health of terrestrial vertebrates, shifting the balance of agricultural ecosystems, in which these animals play an important role by feeding on phytopathogenic organisms. The results state that glyphosate affects the liver and gonads, inducing many morphological and molecular alterations and acting as an endocrine disruptor. The data also validate the common field lizard as a valuable model organism that can provide an assessment of the toxic effect of environmental contaminants. By sharing physiological processes and reproductive mechanisms with many other animals, both aquatic and terrestrial, the information gleaned from the lizard can be transferred to other vertebrates and can serve as a starting point for the recovery of endangered wildlife. Soil contaminants (herbicides, pesticides, and heavy metals) are among the main causes of change in terrestrial ecosystems. These substances lead to a general loss of biodiversity, both of flora and fauna and being able to biomagnify and pass through the food chain, they can endanger the survival of terrestrial vertebrates at the top of this chain. This review analyzes the risks associated with exposure to glyphosate, the active principle of many herbicide products, for the reproductive health of the field lizard (Podarcis siculus) potentially exposed to the substance in its natural habitat; therefore, introducing it as a possible model organism. Data demonstrate that glyphosate is toxic for this animal, affecting the health of the reproductive organs, both in males and females, and of the liver, the main detoxifying organ and closely involved in the female reproductive process. Sharing structural and functional characteristics of these organs with many other vertebrates, the information obtained with this reptile represents a wake-up call to consider when analyzing the cost/benefit ratio of glyphosate-based substances. The data clearly demonstrate that the P. siculus lizard can be considered a good target organism to study the reproductive risk assessment and hazards of exposure to soil contaminants on wild terrestrial vertebrates. [ABSTRACT FROM AUTHOR]

Glyphosate (Gly) is a broad-spectrum herbicide widely used thanks to its high efficiency and low toxicity. However, evidence exists of its toxic effects on non-target organisms. Among these, the animals inhabiting agricultural fields are particularly threatened. Recent studies demonstrated that exposure to Gly markedly affected the morphophysiology of the liver and testis of the Italian field lizard Podarcis siculus. The present study aimed to investigate the effects of the herbicide on the female reproductive system of this lizard in order to have a full picture of Gly-induced reproductive impairment. The animals were exposed to 0.05 and 0.5 μg/kg of pure Gly by gavage for 3 weeks. The results demonstrated that Gly, at both doses tested, profoundly interfered with ovarian function. It induced germ cells' recruitment and altered follicular anatomy by anticipating apoptotic regression of the pyriform cells. It also induced thecal fibrosis and affected oocyte cytoplasm and zona pellucida organizations. At the functional levels, Gly stimulated the synthesis of estrogen receptors, suggesting a serious endocrine-disrupting effect. Overall, the follicular alterations, combined with those found at the level of the seminiferous tubules in males, suggest serious damage to the reproductive fitness of these non-target organisms, which over time could lead to a decline in survival. [ABSTRACT FROM AUTHOR]

In the second article of Soria-Tiedemann et al. [[2]], starting from the information that Arachidonate 15-lipoxygenase (Alox15) and Glutathione peroxidase 4 (Gpx4) enzymes are both involved in sperm maturation, the authors explored the potential roles of these enzymes in acrosomal exocytosis and in vitro fertilization. Taking advantage of previous data demonstrating the high toxicity of this herbicide on the liver of these animals [[11]], the authors evaluated testicular structure, steroidogenesis and estrogen receptor expression/localization after oral exposure to Gly. In the study by Ge et al. [[5]], the effect of a drop in temperature on zebrafish spawning was investigated and key genes, hub pathways and important biological processes closely associated with female spawning were identified through the transcriptomic analysis of zebrafish brain tissue. Fertility rates in animals have shown a progressive decrease in recent decades, and reproductive toxicity is considered an important regulatory endpoint in health hazard assessment. [Extracted from the article]

Spermatogenesis is a genetically driven differentiation process that occurs in the testis and leads to the formation of spermatozoa. This process is extensively studied in several experimental models, particularly in vertebrates that share the morphological structure and functionality of the mammalian testis. Although reptiles are not generally considered biological models, the lizard Podarcis siculus has represented a suitable organism for the study of spermatogenesis over the years. In this lizard, the process of spermatogenesis is regulated by the interaction between systemic factors such as gonadotropins and local factors, i.e., molecules produced by the somatic and germinal cells of the testis. Many exogenous substances are able to alter the production of these regulative factors, thus altering the course of spermatogenesis, and P. siculus has proven to be an excellent model for studying the effects of various endogenous or exogenous substances on mechanisms underlying spermatogenesis. This review summarizes the available data on the effects of different substances on the control of spermatogenesis, highlighting the induced morphological and molecular alterations. Overall, the data show that sex hormone levels as well as the final stages of spermatogenesis are most affected by an imbalance of endogenous compounds or contamination by environmental pollutants. This is helpful for the male individual, since the damage, not affecting the spermatogonial stem cells, can be considered transient and not irreversible. [ABSTRACT FROM AUTHOR]

The 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 reduction 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. [ABSTRACT FROM AUTHOR]

Dichlorodiphenyldichloroethylene (DDE) is an environmental pollutant that accumulates in adipose tissue through the food chain. Hypercaloric, high-fat diet is considered to promote the accumulation of toxic lipophilic substances in tissues, whereas the loss of body fat through caloric restriction results in a recirculation of these substances. In rats, oral administration of DDE causes the onset of tissues damage; the concomitant intake of a high-fat diet ameliorates tissues status, probably because of the entrapment of the lipophilic substance in fat depots. Recent evidence demonstrates that DDE alters the expression of metallothioneins, proteins involved in cellular defense from oxidative stress, in a diet- and tissue-specific manner. This study is aimed to verify if 2 weeks of caloric restriction after the oral DDE treatment can modify metallothionein gene expression in tissues of high-fat fed rats. Real-time PCR analysis demonstrates that metallothionein gene expression after calorie restriction is tissue-specific and strongly influenced by both previous dietary conditions and DDE exposure. To avoid misleading conclusions on the interference of toxic xenobiotics on metallothionein gene expression is particularly important to consider the tissue, the cellular conditions, and the nutritional status of the animals, especially when the protein is used as an index of cells health. [ABSTRACT FROM AUTHOR]

Vanadium toxicology is a topic of considerable importance as this metal is widely used in industrial and biomedical fields. However, it represents a potential emerging environmental pollutant because wastewater treatment plants do not adequately remove metal compounds that are subsequently released into the environment. Vanadium applications are limited due to its toxicity, so it is urgent to define this aspect. This metal is associated with sea urchin embryo toxicity as it perturbs embryogenesis and skeletogenesis, triggering several stress responses. Here we investigated its bioaccumulation and the correlation with cellular and molecular developmental pathways. We used cytotoxic concentrations of 1 mM and 500 μM to perform quantitative analyses, showing that vanadium accumulation interferes with calcium uptake during sea urchin development and provokes a disruption in the biomineralization process. At the end of the whole treatment, the accumulation of vanadium was about 14 and 8 μg for embryos treated respectively with 1 mM and 500 μM, showing a dose-dependent response. Then, we monitored the cell signaling perturbation, analyzing key molecular markers of cell survival/cell death mechanisms and the DNA fragmentation associated with apoptosis. This paper clarifies vanadium's trend to accumulate directly into embryonic cells, interfering with calcium uptake. In addition, our results indicate that vanadium can modulate the ERK pathway and activate a cell-selective apoptosis. These results endorse the sea urchin embryo as an adequate experimental model to study metal-related cellular/molecular responses. [ABSTRACT FROM AUTHOR]

The expansion of agriculture produces a steady increase in habitat fragmentation and degradation due to the increased use of pesticides and herbicides. Habitat loss and alteration associated with crop production play an important role in reptile decline, among which lizards are particularly endangered. In this study, we evaluated testicular structure, steroidogenesis, and estrogen receptor expression/localization after three weeks of oral exposure to glyphosate at 0.05 and 0.5 μg/kg body weight every other day in the field lizard Podarcis siculus. Our results show that glyphosate affected testicular morphology, reduced spermatogenesis, altered gap junctions and changed the localization of estrogen receptors in germ cells, increasing their expression; the effects were mostly dose-dependent. The result also demonstrates that glyphosate, at least at these concentrations, did not influence steroidogenesis. Overall, the data indicate that this herbicide can disturb the morphophysiology of the male lizard's reproductive system, with obviously detrimental effects on their reproductive fitness. The effects of glyphosate must be considered biologically relevant and could endanger the reproductive capacity not only of lizards but also of other vertebrates, including humans; a more controlled and less intensive use of glyphosate in areas devoted to crop production would therefore be advisable. [ABSTRACT FROM AUTHOR]

The cleidoic eggs of oviparous reptiles are protected from the external environment by membranes and a parchment shell permeable to water and dissolved molecules. As a consequence, not only physical but also chemical insults can reach the developing embryos, interfering with gene expression. This review provides information on the impact of the exposure to cadmium contamination or thermal stress on gene expression during the development of Italian wall lizards of the genus Podarcis. The results obtained by transcriptomic analysis, although not exhaustive, allowed to identify some stress-reactive genes and, consequently, the molecular pathways in which these genes are involved. Cadmium-responsive genes encode proteins involved in cellular protection, metabolism and proliferation, membrane trafficking, protein interactions, neuronal transmission and plasticity, immune response, and transcription regulatory factors. Cold stress changes the expression of genes involved in transcriptional/translational regulation and chromatin remodeling and inhibits the transcription of a histone methyltransferase with the probable consequence of modifying the epigenetic control of DNA. These findings provide transcriptome-level evidence of how terrestrial vertebrate embryos cope with stress, giving a key to use in population survival and environmental change studies. A better understanding of the genes contributing to stress tolerance in vertebrates would facilitate methodologies and applications aimed at improving resistance to unfavourable environments. [ABSTRACT FROM AUTHOR]

The potential toxicity of glyphosate, a widely used broad-spectrum herbicide, is currently a great matter of debate. As vertebrate insectivores, lizards protect plants from herbivorous insects increasing plant biomass via the trophic cascade and represent an important link between invertebrates and higher predators. A negative effect of glyphosate on lizards' survival could have major impacts at the ecological levels. In this study, we investigated the effects of the exposure to low doses of glyphosate on the liver of the wall lizard Podarcis siculus, a suitable bioindicator of soil pollution. Two different doses of pure glyphosate (0.05 and 0.5 μg/kg body weight) were orally administered every other day for 3 weeks to sexually mature males and females. The results demonstrated that both doses, despite being very low, are toxic for the liver that showed clear signs of suffering, regardless of sex. The histological analysis provided a scenario of severe hepatic condition, which degenerated until the appearance of fibrotic formations. The morphological observations were consistent with a loss of liver physiological functions. Immunocytochemical investigations allowed us to detect an involvement of antioxidant/cytoprotective proteins, such as superoxide dismutase 1 (Cu/Zn SOD, known as SOD1), glutathione peroxidase 1 (GPx1), metallothionein (MT), and tumor suppressor protein 53, (p53) suggesting that the liver was trying to react against stress signals and damage induced by glyphosate. Finally, in situ hybridization and Real-Time PCR analysis showed the upregulation of estrogen receptor α and vitellogenin gene expression, thus demonstrating the xenoestrogenic action of glyphosate. The imbalance of the hormonal homeostasis could threaten the lizards' reproductive fitness and survival, altering the trophic cascade. [ABSTRACT FROM AUTHOR]

Oxidative stress plays a key role in steatohepatitis induced by both xenobiotic agents and high fat diet (HFD). The present study aimed to evaluate hepatic oxidative stress and anti-oxidant systems response in rats exposed to HFD and/or non-toxic dose of dichlorodiphenyldichloroethylene (DDE), the first metabolite of dichlorodiphenyltrichloroethane. Groups of 8 rats were so treated for 4 weeks: 1- standard diet (N group); 2- standard diet plus DDE (10 mg/kg b.w.) (N+DDE group); 3- HFD (D group); 4- HFD plus DDE (D+DDE group). Oxidative stress was analyzed by determining malondialdehyde as lipid peroxidation product, while the anti-oxidant systems were evaluating by measuring the levels of the principal cytosolic and mitochondrial antioxidant proteins and enzymes, namely superoxide dismutase 1 and 2 (SOD1, SOD2), glutathione peroxidase 1 (GPx1) and uncoupling protein 2 (UCP2) involved in the control of hepatic reactive oxygens species (ROS) accumulation. The results showed malondialdehyde accumulation in livers of all groups, confirming the pro-oxidant effects of both HFD and DDE, but with a greater effect of DDE in absence of HFD. In addition, we found different levels of the analyzed anti-oxidant systems in the different groups. DDE mainly induced UCP2 and SOD2, while HFD mainly induced GPx1. Noteworthy, in the condition of simultaneous exposure to DDE and HFD, the anti-oxidant response was more similar to the one induced by HFD than to the response induced by DDE. Present findings confirmed that both HFD and xenobiotic exposure induced hepatic oxidative stress and showed that the anti-oxidant defense response was not the same in the diverse groups, suggesting that UCP2 induction could be an adaptive response to limit excessive ROS damage, mainly in condition of xenobiotic exposure. [ABSTRACT FROM AUTHOR]

Metallothionein is well known for its detoxificant and anti‐oxidant properties and has been shown to be effective to prevent hydroxyl radical‐generated DNA degradation. The purpose of this investigation was to analyze the combined effect of two factors promoting cellular oxidative‐stress, that is, the administration of the pesticide dichloro–diphenyl–dichloroethylene (DDE) and a high fat diet, on metallothionein expression and synthesis in rat liver and kidney. DDE is the main metabolite of dichloro–diphenyl–trichloroethane (DDT), and is commonly found in the food chain and in all tissues of living organisms, carried by the fats. Male Wistar rats were fed with a standard (N) or a high fat (HF) diet and exposed to DDE (10 mg/kg body mass, N + DDE and HF + DDE groups) or vehicle (corn oil, N, and HF groups) via gavage every day for 28 days. Tissues histology was determined by light microscopy analysis; differences in metallothionein gene expression and synthesis by real‐time PCR and western blot, respectively. Finally, protein cellular localization was established by immunocytochemistry. The results showed a different involvement of metallothionein in defending tissues from HF‐ and DDE‐induced oxidative stress, suggesting that hepatic and renal cells use different strategies against pro‐oxidant species. In both cell types a marked increase in the metallothionein content was observed in the nucleus, with a concomitant drop of the cytoplasmatic protein, either under HF‐ and DDE‐stress conditions; however, no synergistic or additive effects were observed between the action of fats and pesticide. These findings reinforce the role of metallothionein in protecting DNA from oxidative damage. [ABSTRACT FROM AUTHOR]

Spermatogenesis is a fascinating biological process aiming to generate haploid spermatozoa from diploid spermatogonia through a specific hormonal network between gonadotropins and steroids. Increasing evidence suggests that the primary female sex hormone estrogen plays an active role in this process. This research points out on the role of estrogen during lizard spermatogenesis by using three experimental approaches: (1) exposure to an analogue of nonsteroidal estrogen as Clomiphene citrate that acts both as estrogen agonist and antagonist; (2) exposure to the gonadotropin FSH; and (3) exposures to FSH followed by Clomiphene. Histological and immunohistochemical results demonstrate that in the lizard Podarcis sicula during the mating period, Clomiphene as well as FSH determines the breakdown of spermatogenesis and the epididymal regression, presumably through estrogens input as indirectly demonstrated by the appearance of ERα and vitellogenin in the liver. The ability of Clomiphene to restore the gonadal natural condition after FSH treatment is also demonstrated. Finally, data indicate that lizard testis and epididymis control their morphophysiology regulating the intracellular presence of ERα. [ABSTRACT FROM AUTHOR]

Plants of the urban environment are exposed to a wide range of pollutants, including heavy metals. This research studies in situ the eco-physiological and antioxidant responses of holm oak ( Q. ilex) leaves to Pb and Cd to assess the mechanisms of metal tolerance in this species, widely used as biomonitor. Leaves of plants grown at parks and roadsides were analyzed for photosynthetic activity, Pb and Cd concentration in tissues and cell-free extracts, thiol groups, D1 and Rubisco protein content, ascorbic acid (AsA) amount, and catalase (CAT) activity. The main results evidenced that Cd concentration was higher in leaves collected at the park out from the downtown; whereas Pb was most abundant in leaves sampled at the roadside nearby the highway. Pb in cell-free extracts was higher in park than in roadside leaves. Although Cd in the leaf tissues was twofold lower than Pb, it was more abundant than Pb in cellular extracts deprived of all particulate matter. Leaves responded to different concentration of Cd and Pb modulating some eco-physiological and biochemical traits, roadside leaves showed reduced leaf lamina, higher content of photosynthetic pigments, hydrogen peroxide, and AsA, as well as higher CAT activity compared to park leaves. In the roadside leaves, a stress condition for photosynthetic apparatus can be hypothesized on the basis of the decline of photochemical activity, the increase of NPQ, and the reduction of Rubisco and D1 protein content. The elevated presence of thiol groups in these leaves suggests a possible role of Pb and Cd in activation of antioxidant responses. [ABSTRACT FROM AUTHOR]

Metallothioneins (MTs) are an evolutionary conserved multigene family of proteins whose role was initially identified in binding essential metals. The physiological role of MT, however, has been revealed to be more complex than expected, since not only are MTs able to bind to toxic heavy metals, but many isoforms have shown specialized and alternative functions. Within this uncertainty, the information available on MTs in non-mammalian vertebrates, particularly in neglected tetrapods such as the reptiles, is even more scant. In this review, we provide a summary of the current understanding on metallothionein presence and function in the oviparous lizard Podarcis sicula, highlighting the results obtained by studying MT gene expression in most representative adult and embryonic tissues. The results demonstrate that in adults, cadmium induces MT transcription in a dose- and tissue-specific manner. Thus, the MT mRNAs appear, at least in some cases, to be an unsuitable tool for detecting environmental ion contamination. In early embryos, maternal RNAs sustain developmental needs for MT protein until organogenesis is well on its way. At this time, transcription starts, but again in a tissue- and organ-specific manner, suggesting an involvement in alternative roles. In conclusion, the spatiotemporal distribution of transcripts in adults and embryos definitively confirms that MT has deserved the title of elusive protein. [ABSTRACT FROM AUTHOR]

In this study, our aim was to determine whether caspase 3 plays a role, during previtellogenesis, in the ovarian follicular epithelium of the lizard Podarcis sicula. We investigated the presence and localization of proform and active caspase 3 by enzyme assay, Western blotting and immunocytochemistry. In parallel, a fragment of caspase 3 was cloned for the first time in this species, sequenced and used for in situ hybridization to localize messengers and analysed by a phylogenetic survey to shed light on its homology with reptilian caspases. Results demonstrated that: (1) the follicle cells expressed a caspase of the 3/7 group and the mRNA for caspase 3 was transcribed in the stem phase and was completely translated during cell differentiation; (2) the proform protein was stored during the differentiated (nurse) stage and activated at the end of previtellogenesis provoking the degeneration of cells; (3) the predicted protein sequence, although partial, had a strong similarity with the known reptilian caspases 3. The epithelial cells of the ovarian follicle, therefore, do not employ caspase 3 during the nurse stage but, instead, prepare for apoptosis long before the process actually begins. The relevance of this strategy is discussed. [ABSTRACT FROM AUTHOR]

In the last years, worldwide organic farming has grown exponentially; as a consequence, the use of animal manure as a soil fertility source has become the principal agricultural choice. However, the use of manure as fertilizer can increase the amount of steroid hormone metabolites in the soil. In southern Italy, lacertidae lizards are the most abundant vertebrate group in agroecosystems and have been identified as potential model species for ecotoxicological studies. The aim of this study was to understand if the manure applied in organic farming has estrogen-like effects in the lizard Podarcis sicula. Adult male lizards were captured in two organic agricultural fields (manure-treated sites) and in an uncultivated field (control site). Lizards from the two organic farms displayed hepatic biosynthetic alterations typical of an estrogenic contamination; hepatocytes contained both vitellogenin and estrogen receptor alpha transcripts and proteins, detected by in situ hybridization and immunocytochemistry. The same cells did not show cadmium, lead and metallothionein accumulation, indicative of the lack of inorganic contamination. These findings suggest that exogenous estrogens, arising from the use of manure, could affect the welfare of wild animals and animal breeding, leading to bioaccumulation of estrogens in food chain, with possible risk for human consumers. For this reason, organic farming should implement the use of sustainable practices such as crop rotation to preserve the soil biological activity, rather than organic manure as fertilizer. [ABSTRACT FROM AUTHOR]

Obesity and dietary fats are well known risk factors for the pathogenesis of neurodegenerative diseases. The analysis of specific markers, whose brain level can be affected by diet, might contribute to unveil the intersection between inflammation/obesity and neurodegeneration. Haptoglobin (Hpt) is an acute phase protein, which acts as antioxidant by binding free haemoglobin (Hb), thus neutralizing its pro-oxidative action. We previously demonstrated that Hpt plays critical functions in brain, modulating cholesterol trafficking in neuroblastoma cell lines, beta-amyloid (Aß) uptake by astrocyte, and limiting Aß toxicity on these cells. A major aim of this study was to evaluate whether a long term (12 or 24 weeks) high-fat diet (HFD) influences Hpt and Hb expression in rat hippocampus. We also assessed the development of obesity-induced inflammation by measuring hippocampal level of TNF-alpha, and the extent of protein oxidation by titrating nitro-tyrosine (N-Tyr). Hpt concentration was lower (p < 0.001) in hippocampus of HFD rats than in control animals, both in the 12 and in the 24 weeks fed groups. HFD was also associated in hippocampus with the increase of Hb level (p < 0.01), inflammation and protein oxidative modification, as evidenced by the increase in the concentration of TNF-alpha and nitro-tyrosine. In fact, TNF-alpha concentration was higher in rats receiving HFD for 12 (p < 0.01) or 24 weeks (p < 0.001) compared to those receiving the control diet. N-Tyr concentration was more elevated in hippocampus of HFD than in control rats in both 12 weeks (p = 0.04) and 24 weeks groups (p = 0.01), and a positive correlation between Hb and N-Tyr concentration was found in each group. Finally, we found that the treatment of the human glioblastoma-astrocytoma cell line U-87 MG with cholesterol and fatty acids, such as palmitic and linoleic acid, significantly impairs (p < 0.001) Hpt secretion in the extracellular compartment. We hypothesize that the HFD-dependent decrease of Hpt in hippocampus, as associated with Hb increase, might enhance the oxidative stress induced by free Hb. Altogether our data, identifying Hpt as a molecule modulated in the brain by dietary fats, may represent one of the first steps in the comprehension of the molecular mechanisms underlying the diet-related effects in the nervous system. [ABSTRACT FROM AUTHOR]

ABSTRACT Lizards are soil surface animals that represent an important link between invertebrates and higher predators. Being part of wild fauna, they can be affected by contamination from anthropic activities and in particular, pesticides and chemical substances of various nature that reach the soil surface directly or through fall out. Among these substances, heavy metals such as cadmium may exert particularly marked toxic effect on both adult and embryos. In lizards, recent studies show that cadmium may cause developmental defects, including alteration of eye development, with appearance of unilateral microphthalmia and retinal folding. In the present study, the effects of cadmium incubation on retinal development were investigated demonstrating that cadmium interferes with cell cycle regulation by increasing proliferation. An increased expression of Otx2 and Pax6 genes, markers of retinal differentiation, was also found. However, the cellular localization of Pax6 and Otx2 transcripts did not change in treated embryos: in the early stages of retinogenesis, the two genes were expressed in all retinal cells; in the differentiated retina, Otx2 remained in the cellular bodies of retinal cells forming the nuclear and the ganglion layers, whereas Pax6 was expressed only in the cells of the inner nuclear and the ganglion layers. Data suggest that the increased expression of Pax6 and Otx2 could be ascribed to the hyperproliferation of retinal cells rather than to an effective gene overexpression. J. Exp. Zool. 321A: 207-219, 2014. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The exposure to environmental toxicants such cadmium (Cd) is an important research area in wildlife protection. In this study, the effect of Cd oral administration on the ovarian structure and function and on reproductive performance of the Italian wall lizard Podarcis sicula was studied. In vivo, adult female lizards were randomly assigned to three groups. Cd was given with food in single dose and in multiple doses 3 days/week for 4 weeks at dose of 1.0 μg/g body weight. Following euthanasia, the ovaries were removed and analyzed for morpho-functional changes. Results demonstrated that Cd increases prefollicular germ cells number; the evaluation of the number of follicles detects significantly higher number of atretic growing follicles, whereas primary follicles remain unchanged with respect to controls. After Cd treatments, follicles are deformed by the presence of large protrusions and a general dysregulation in the follicle organization is observed. The zona pellucida is also affected. Cd causes alteration in sugar metabolism and in metallothionein gene expression. Finally, Cd administration significantly reduces clutch size and dramatically increases embryo mortality. In conclusion, data here described show that Cd induces morpho-functional alterations in lizard follicles and indicates that these are responsible for a significant impairment of oogenesis. The effects of the dose are time independent, persisting essentially unchanged regardless of single or multiple administration, so it can be concluded that even occasional, sublethal Cd contamination may significantly impair reproductive performance in these animals. © 2011 Wiley Periodicals, Inc. Environ Toxicol 28: 553-562, 2013. [ABSTRACT FROM AUTHOR]

The concentration of cadmium and lead ions was determined in digestive gland and mantle of mussels ( Mytilus galloprovincialis) from five aquaculture stations located in the Gulf of Naples ( Southern Italy, Tyrrhenian Sea). Metallothionein ( MT) levels in the same tissues were also evaluated. This gulf represents a greatly urbanized area, characterized by an important commercial port and past industrial activities, terminated in the last decade of the 20th century. The results were compared with those obtained from mussels cultivated in a more pristine neighbouring area. Data demonstrate that the amount of both metals found in mussels harvested at the highly anthropogenic sites in the Gulf of Naples was comparable with that found in mussels from the more naturalistic site. The content of both cadmium and lead was not related with that of MT. Indeed, the amount of both metals in the digestive gland was greater than in the mantle, whereas the MT preferentially accumulated in the mantle. Possibly, the MT content in mantle was associated to the physiological function of the tissue, rather than heavy metals exposure. [ABSTRACT FROM AUTHOR]

The article offers information on the spatiotemporal changes in metallothionein gene expression during embryogenesis of Podarcis sicula. It states that lizard embryos are nutritionally independent from their environment. The egg prepares for development by storing reserve organelles, proteins and RNAs, during the early phases of oogenesis to allow the zygote transform into a juvenile. It investigates the localization of the metallothionein (MT) transcripts by in situ hybridization during the developmental stages of Podarcis sicula.

The distribution and potential bioaccumulation of dietary and waterborne cadmium and lead in tissues of sea bream ( Sparus aurata), a major aquaculture species, was studied in relation to three different fish farming systems. Metallothionein levels in fish tissues were also evaluated. Results demonstrate that metal concentrations in various tissues significantly vary among fish culture systems. Different tissues show different capacity for accumulating heavy metals. The content of both cadmium and lead is not strictly correlated with that of metallothionein. Indeed, the marked accumulation of both metals in liver, as well as the high lead content found in gills and kidney, are not accompanied by a concomitant accumulation of metallothioneins in these tissues. No correlation is present between heavy metals and metallothionein content in muscle tissue. The results also demonstrate that cadmium accumulates mainly via dietary food, whereas lead accumulation is not of food origin. Noteworthy is that the concentration of the two metals found in muscle in all instances is lower than the limits established by European Union legislation for fish destined for human consumption. [ABSTRACT FROM AUTHOR]

The growing presence of lanthanides in the environment has drawn the attention of the scientific community on their safety and toxicity. The sources of lanthanides in the environment include diagnostic medicine, electronic devices, permanent magnets, etc. Their exponential use and the poor management of waste disposal raise serious concerns about the quality and safety of the ecosystems at a global level. This review focused on the impact of lanthanides in marine organisms on reproductive fitness, fertilization and embryonic development, using the sea urchin as a biological model system. Scientific evidence shows that exposure to lanthanides triggers a wide variety of toxic insults, including reproductive performance, fertilization, redox metabolism, embryogenesis, and regulation of embryonic gene expression. This was thoroughly demonstrated for gadolinium, the most widely used lanthanide in diagnostic medicine, whose uptake in sea urchin embryos occurs in a time- and concentration-dependent manner, correlates with decreased calcium absorption and primarily affects skeletal growth, with incorrect regulation of the skeletal gene regulatory network. The results collected on sea urchin embryos demonstrate a variable sensitivity of the early life stages of different species, highlighting the importance of testing the effects of pollution in different species. The accumulation of lanthanides and their emerging negative effects make risk assessment and consequent legislative intervention on their disposal mandatory. [ABSTRACT FROM AUTHOR]

In aquatic organisms, cadmium exposure occurs from ovum to death and the route of absorption is particularly wide, being represented by skin, gills and gastrointestinal tract, through which contaminated water and/or preys are ingested. It is known that cadmium interferes with the gut; however, less information is available on cadmium effects on an important component of the gut, namely goblet cells, specialized in mucus synthesis. In the present work, we studied the effects of two sublethal cadmium concentrations on the gut mucosa of Danio rerio. Particular attention was paid to changes in the distribution of glycan residues, and in metallothionein expression in intestinal cells. The results show that cadmium interferes with gut mucosa and goblet cells features. The effects are dose- and site-dependent, the anterior gut being more markedly affected than the midgut. Cadmium modifies the presence and/or distribution of glycans in the brush border and cytoplasm of enterocytes and in the goblet cells' cytoplasm and alters the metallothionein expression and localization. The results suggest a significant interference of cadmium with mucosal efficiency, representing a health risk for the organism in direct contact with contamination and indirectly for the trophic chain. [ABSTRACT FROM AUTHOR]

Organisms from yeast to mammals contain cysteine-rich, heavy metal binding proteins termed metallothioneins. The putative roles of these proteins are trace metal homeostasis and detoxification of poisonous heavy metals. The highly conserved chemical composition and the structural constraints led to the conclusion that metallothioneins of different origin must display remarkably similar features. The present review aims at surveying the studies carried out on the metallothioneins of Antarctic Notothenioidei, a dominating fish group endowed of a number of striking adaptive characters, including reduced (or absent) hematocrit and presence of antifreeze glycoproteins. Given the unique peculiarities of the Antarctic environment, a comparative study of the features of notothenioid metallothioneins could provide new insights into the role of these proteins in physiology and toxicology. The results summarized here show that the metallothioneins of this fish group display a number of features at the level of evolution, expression pattern, structure and function remarkably different from those of mammal metallothioneins. [ABSTRACT FROM AUTHOR]

Metallothioneins (MTs) are nonenzymatic low molecular weight proteins, that play an important role in the homeostasis and detoxification of heavy metals in a large variety of organisms. These proteins are endowed with striking features, including an unusual amino acid composition characterized by the presence of 20 cysteines out of a total of 60 residues and absence of secondary structure elements. It is generally accepted that MTs underwent few modifications during evolution because of these structural and functional constraints. Such a conclusion is founded on the studies carried out mostly on MTs of mammalian origin. For such a reason, we have decided to compare the MTs of homeothermic and poikilothermic organisms, such as mammals and fish, with the specific aim to put in relation phylogenetic divergence and structural/functional adaptation to temperature. We have included in our analysis also Antarctic Notothenioids, a fish group characterized by genetic isolation and cold-adaptation to a particular harsh environment. We have determined the average hydropathic index of ancestral MT sequences and used them to infer the temperatures of the environment housing the hypothetical ancestor organisms. Finally, we have derived phylogenetic relationships of MT molecules from the pairwise comparison of their three-dimensional structures. [ABSTRACT FROM AUTHOR]

The distribution of metallothionein and metallothionein mRNA was examined in brain, liver and kidney of the red-blooded Antarctic fish Notothenia coriiceps. Basal levels of metallothionein were detected by silver saturation assay; the analysis showed large differences in the metallothionein content, with an increasing amount in kidney, liver and brain, respectively. Reverse transcriptase-mediated polymerase chain reaction was used to amplify two distinct metallothionein cDNA species from RNA extracted from the three tissues examined. Northern blot analysis revealed a high constitutive expression of metallothionein mRNA in kidney, in spite of the low metallothionein content found in this tissue. The analysis of the distribution of the two metallothionein transcripts, termed MT-1 and MT-2, in the tissues showed that the MT-2 transcript was the major form of the metallothionein mRNA in kidney and brain, whilst in liver the expression levels of the two metallothionein transcripts were comparable. This tissue-specific expression of isometallothioneins in the Antarctic fish suggests the presence of an organ-specific regulation of the metallothionein genes. [ABSTRACT FROM AUTHOR]

The biological mechanisms linking nutrition and antioxidants content of the diet with cardiovascular protection are subject of intense investigation. It has been demonstrated that dietary supplementation with cow, donkey or human milk, characterized by distinct nutritional properties, triggers significant differences in the metabolic and inflammatory status through the modulation of hepatic and skeletal muscle mitochondrial functions. Cardiac mitochondria play a key role for energy-demanding heart functions, and their disfunctions is leading to pathologies. Indeed, an altered heart mitochondrial function and the consequent increased reactive oxygen species (ROS) production and inflammatory state, is linked to several cardiac diseases such as hypertension and heart failure. In this work it was investigated the impact of the milk consumption on heart mitochondrial functions, inflammation and oxidative stress. In addition, it was underlined the crosstalk between mitochondrial metabolic flexibility, lipid storage and redox status as control mechanisms for the maintenance of cardiovascular health. [ABSTRACT FROM AUTHOR]

The 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. [ABSTRACT FROM AUTHOR]

Environmental chemicals can be introduced by consuming contaminated foods. The environmental chemical dichlorodiphenyldichloroethylene (DDE), a persistent metabolite of dichlorodiphenyltrichloroethane (DDT), can affect spermatogenesis. Our study aims to evaluate, by using spectrophotometric analyses, western blot, and immunohistochemistry, the adaptive responses in testis of adult rats treated with a non-toxic dose of DDE, alone or in association with a high-fat diet (HFD). Four experimental groups were performed: N (normal diet); D (HFD); D + DDE (HFD + DDE); N + DDE (normal diet + DDE). D group showed a reduction in antioxidant capacity, and increases in lipid peroxidation, apoptosis, and proliferation associated with morphological impairment. A reduction in androgen receptor (AR) and serum testosterone levels were also found. DDE-treated groups exhibited higher lipid peroxidation levels compared to N and D, associated with pronounced defect in antioxidant capacity, apoptosis, cellular proliferation, as well as with tissue damage. Moreover, decreases in AR and serum testosterone levels were found in DDE-treated groups vs. N and D. In conclusion, HFD and DDE produced cellular stress leading to antioxidant impairment, apoptosis, and decreases in AR and serum testosterone levels associated with tissue damage. Cellular proliferation could be used as an adaptation to counterbalance the occurred damage, maintaining a pool of tubules that follow physiological maturation. [ABSTRACT FROM AUTHOR]