RÉSUMÉ
The presence of the organotin compound tributyltin (TBT) in aquatic ecosystems has been a serious environmental problem for decades. Although a number of studies described the negative impact of TBT on mollusks at different levels, investigations connected to its potential effects during embryogenesis have been neglected. For a better understanding of the impact of TBT on mollusks, in the present study, embryos of previously TBT-treated or not treated specimens of the great pond snail (Lymnaea stagnalis) were exposed to 100 ng L-1 TBT from egg-laying (single-cell stage) until hatching. According to our results, TBT significantly delayed hatching and caused shell malformation. TBT transiently decreased the locomotion (gliding) and also reduced the feeding activity, demonstrating for the first time that this compound can alter the behavioral patterns of molluscan embryos. The heart rate was also significantly reduced, providing further support that cardiac activity is an excellent indicator of metal pollution in molluscan species. At the histochemical level, tin was demonstrated for the first time in TBT-treated hatchlings with intensive reaction in the central nervous system, kidney, and hepatopancreas. Overall, the most notable effects were observed in treated embryos derived from TBT treated snails. Our findings indicate that TBT has detrimental effects on the development and physiological functions of Lymnaea embryos even at a sub-lethal concentration, potentially influencing their survival and fitness. Highlighting our observations, we have demonstrated previously unknown physiological changes (altered heart rate, locomotion, and feeding activity) caused by TBT, as well as visualized tin at the histochemical level in a molluscan species for the first time following TBT exposure. Further studies are in progress to reveal the cellular and molecular mechanisms underlying the physiological and behavioral changes described in the present study.
Sujet(s)
Embryon non mammalien , Développement embryonnaire , Lymnea , Trialkyl-stannanes , Polluants chimiques de l'eau , Animaux , Trialkyl-stannanes/toxicité , Lymnea/effets des médicaments et des substances chimiques , Lymnea/embryologie , Polluants chimiques de l'eau/toxicité , Embryon non mammalien/effets des médicaments et des substances chimiques , Développement embryonnaire/effets des médicaments et des substances chimiques , Comportement animal/effets des médicaments et des substances chimiques , Locomotion/effets des médicaments et des substances chimiques , Rythme cardiaque/effets des médicaments et des substances chimiques , Comportement alimentaire/effets des médicaments et des substances chimiquesRÉSUMÉ
Organotin compounds (OTs) are endocrine disruptors that induce imposex in hundreds of gastropods, but little is known about their underlying molecular mechanisms. This study aimed to investigate the endocrine toxicity and molecular responses to tributyltin (TBT) and triphenyltin (TPT) exposure in the whelk Reishia clavigera, which often serves as a biomonitor for OT contamination. Over a 120-day exposure to environmentally relevant concentrations of TBT (1000 ng L-1) and TPT (500 ng L-1), we observed a significant increase in penis length in both male and female whelks. Notably, TPT exhibited a stronger potency in inducing pseudo-penis development and female sterility, even at a half dose of TBT. Bioaccumulation analysis also revealed higher persistence and accumulation of TPT in whelk tissues compared to TBT. Differential expression analysis identified a substantial number of differentially expressed genes (DEGs), with TPT exposure eliciting more DEGs than TBT. Our results demonstrated that OTs induced xenobiotic metabolism and metabolic dysregulation in the digestive gland, impaired multiple cellular functions and triggered neurotoxicity in the nervous system, and disrupted lipid homeostasis and oxidative stress in the gonads. Furthermore, imposex was possibly associated with disturbances in retinoic acid metabolism, nuclear receptor signaling, and neuropeptide activity. When compared to TBT, TPT exhibited a more pronounced endocrine-disrupting effect, attributable to its higher bioaccumulation and substantial interruption of transcriptional regulation, OT detoxification, and biosynthesis of retinoic acids in R. clavigera. Our results, therefore, highlight the importance of considering the differences in bioaccumulation and molecular toxicity between TBT and TPT in future risk assessments of these contaminants. Overall, our study provided molecular insights into the toxicity and transcriptome profiles in R. clavigera exposed to TBT and TPT, shedding light on the endocrine-disrupting effects and reproductive impairment in female gastropods.
Sujet(s)
Perturbateurs endocriniens , Gastropoda , Analyse de profil d'expression de gènes , Composés organiques de l'étain , Trialkyl-stannanes , Polluants chimiques de l'eau , Animaux , Trialkyl-stannanes/toxicité , Composés organiques de l'étain/toxicité , Perturbateurs endocriniens/toxicité , Gastropoda/effets des médicaments et des substances chimiques , Gastropoda/génétique , Femelle , Mâle , Polluants chimiques de l'eau/toxicité , Transcriptome/effets des médicaments et des substances chimiques , Troubles du développement sexuel/induit chimiquementRÉSUMÉ
Tributyltin (TBT) and mercury (Hg) are endocrine-disrupting chemicals that individually cause reproductive complications. However, the reproductive consequences of exposure to a mixture of TBT plus Hg are not well known. We hypothesized that exposure to a mixture of TBT plus Hg would alter hypothalamic-pituitary-gonadal (HPG) axis function. Female rats were exposed to this mixture daily for 15 days, after which chemical accumulation in the tissues, morphology, hormone levels, inflammation, fibrosis, and protein expression in the reproductive organs were assessed. Increases in tin (Sn) and Hg levels were detected in the serum, HPG axis, and uterus of TBT-Hg rats. TBT-Hg rats exhibited irregular estrous cycles. TBT-Hg rats showed an increase in gonadotropin-releasing hormone (GnRH) protein expression and follicle-stimulating hormone (FSH) levels and a reduction in luteinizing hormone (LH) levels. Reduced ovarian reserve, antral follicles, corpora lutea (CL) number, and estrogen levels and increased atretic and cystic follicles were found, suggesting that TBT-Hg exposure exacerbated premature ovarian insufficiency (POI) features. Furthermore, TBT-Hg rats exhibited increased ovarian mast cell numbers, expression of the inflammatory markers IL-6 and collagen deposition. Apoptosis and reduced gland number were observed in the uteri of TBT-Hg rats. A reduction in the number of pups/litter for 90 days was found in TBT-Hg rats, suggesting impaired fertility. Strong negative correlations were found between serum and ovarian Sn levels and ovarian Hg levels and ovarian reserve and CL number. Collectively, these data suggest that TBT plus Hg exposure leads to abnormalities in the HPG axis, exacerbating POI features and reducing fertility in female rats.
Sujet(s)
Perturbateurs endocriniens , Fécondité , Ovaire , Insuffisance ovarienne primitive , Trialkyl-stannanes , Utérus , Animaux , Femelle , Trialkyl-stannanes/toxicité , Insuffisance ovarienne primitive/induit chimiquement , Fécondité/effets des médicaments et des substances chimiques , Ovaire/effets des médicaments et des substances chimiques , Ovaire/métabolisme , Ovaire/anatomopathologie , Perturbateurs endocriniens/toxicité , Utérus/effets des médicaments et des substances chimiques , Utérus/métabolisme , Mercure/toxicité , Rat Sprague-Dawley , Axe hypothalamohypophysaire/effets des médicaments et des substances chimiques , Axe hypothalamohypophysaire/métabolisme , Hormone lutéinisante/sang , Hormone folliculostimulante/sang , Hormone de libération des gonadotrophines/métabolisme , Cycle oestral/effets des médicaments et des substances chimiques , RatsRÉSUMÉ
This study explores the impact of environmental pollutants on nuclear receptors (CAR, PXR, PPARα, PPARγ, FXR, and LXR) and their heterodimerization partner, the Retinoid X Receptor (RXR). Such interaction may contribute to the onset of non-alcoholic fatty liver disease (NAFLD), which is initially characterized by steatosis and potentially progresses to steatohepatitis and fibrosis. Epidemiological studies have linked NAFLD occurrence to the exposure to environmental contaminants like PFAS. This study aims to assess the simultaneous activation of nuclear receptors via perfluorooctanoic acid (PFOA) and RXR coactivation via Tributyltin (TBT), examining their combined effects on steatogenic mechanisms. Mice were exposed to PFOA (10 mg/kg/day), TBT (5 mg/kg/day) or a combination of them for three days. Mechanisms underlying hepatic steatosis were explored by measuring nuclear receptor target gene and lipid metabolism key gene expressions, by quantifying plasma lipids and hepatic damage markers. This study elucidated the involvement of the Liver X Receptor (LXR) in the combined effect on steatosis and highlighted the permissive nature of the LXR/RXR heterodimer. Antagonistic effects of TBT on the PFOA-induced activation of the Pregnane X Receptor (PXR) and Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) were also observed. Overall, this study revealed complex interactions between PFOA and TBT, shedding light on their combined impact on liver health.
Sujet(s)
Caprylates , Fluorocarbones , Trialkyl-stannanes , Animaux , Trialkyl-stannanes/pharmacologie , Caprylates/pharmacologie , Souris , Fluorocarbones/toxicité , Fluorocarbones/pharmacologie , Mâle , Souris de lignée C57BL , Récepteurs hépatiques X/métabolisme , Foie/métabolisme , Foie/effets des médicaments et des substances chimiques , Foie/anatomopathologie , Récepteurs X des rétinoïdes/métabolisme , Stéatose hépatique/métabolisme , Stéatose hépatique/induit chimiquement , Stéatose hépatique/anatomopathologie , Récepteurs cytoplasmiques et nucléaires/métabolisme , Métabolisme lipidique/effets des médicaments et des substances chimiques , Stéatose hépatique non alcoolique/métabolisme , Stéatose hépatique non alcoolique/anatomopathologie , Stéatose hépatique non alcoolique/induit chimiquementRÉSUMÉ
One of the top ecological priorities is to find sensitive indicators for pollution monitoring. This study focuses on the bioconcentration and responses (condition index, survival, oxygen consumption, heart rates, and oxidative stress and neurotoxic effect biomarkers) of mussels from the Volga River basin, Dreissena polymorpha and Dreissena bugensis, to long-term exposure to toxic chemicals such as tributyltin (TBT, 25 and 100 ng/L) and copper (Cu, 100 and 1000 µg/L). We found that TBT was present in the tissues of zebra and quagga mussels in comparable amounts, whereas the bioconcentration factor of Cu varied depending on its concentration in water. Differences in responses between the two species were revealed. When exposed to high Cu concentrations or a Cu-TBT mixture, quagga mussels had a lower survival rate and a longer heart rate recovery time than zebra mussels. TBT treatment caused neurotoxicity (decreased acetylcholinesterase activity) and oxidative stress (increased levels of thiobarbituric acid reactive substances) in both species. TBT and Cu levels in mussel tissues correlated positively with the condition index, but correlated with the level of acetylcholinesterase in the mussel gills. The principal component analysis revealed three main components: the first consists of linear combinations of 14 variables reflecting TBT water pollution, TBT and Cu levels in mussel tissues, and biochemical indicators; the second includes Cu water concentration, cardiac tolerance, and mussel size; and the third combines weight, metabolic rate, and heart rates. Quagga mussels are less tolerable to contaminants than zebra mussels, so they may be used as a sensitive indicator.
Sujet(s)
Marqueurs biologiques , Cuivre , Dreissena , Stress oxydatif , Trialkyl-stannanes , Polluants chimiques de l'eau , Animaux , Polluants chimiques de l'eau/toxicité , Dreissena/effets des médicaments et des substances chimiques , Dreissena/métabolisme , Marqueurs biologiques/métabolisme , Cuivre/toxicité , Trialkyl-stannanes/toxicité , Stress oxydatif/effets des médicaments et des substances chimiques , Rythme cardiaque/effets des médicaments et des substances chimiques , Branchies/métabolisme , Branchies/effets des médicaments et des substances chimiques , Acetylcholinesterase/métabolismeRÉSUMÉ
Tributyltin (TBT) is an endocrine-disrupting chemical (EDC) related to reproductive dysfunctions. However, few studies have investigated the effects of TBT exposure on mammary gland development. Thus, we assessed whether subacute TBT exposure causes irregularities in mammary gland development. We administered TBT (100 and 1,000â¯ng/kg/day for 30 days) to female rats from postnatal day (PND) 25 to PND 55, and mammary gland development, morphology, inflammation, collagen deposition, and protein expression were evaluated. Abnormal mammary gland development was observed in both TBT groups. Specifically, TBT exposure reduced the number of terminal end buds (TEBs), type 1 (AB1) alveolar buds, and type 2 (AB2) alveolar buds. An increase in the lobule and differentiation (DF) 2 score was found in the mammary glands of TBT rats. TBT exposure increased mammary gland blood vessels, mast cell numbers, and collagen deposition. Additionally, both TBT rats exhibited intraductal hyperplasia and TEB-like structures. An increase in estrogen receptor alpha (ERα), progesterone receptor (PR), and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) - positive cells was observed in the mammary glands of TBT rats. A strong negative correlation was observed between CYP19A1- positive cells and TEB number. In addition, CYP19A1 - positive cells were positively correlated with mammary gland TEB-like structure, ductal hyperplasia, inflammation, and collagen deposition. Thus, these data suggest that TBT exposure impairs mammary gland development through the modulation of CYP19A1 signaling pathways in female rats.
Sujet(s)
Aromatase , Perturbateurs endocriniens , Glandes mammaires animales , Rat Sprague-Dawley , Trialkyl-stannanes , Animaux , Femelle , Trialkyl-stannanes/toxicité , Glandes mammaires animales/effets des médicaments et des substances chimiques , Glandes mammaires animales/anatomopathologie , Glandes mammaires animales/croissance et développement , Glandes mammaires animales/métabolisme , Perturbateurs endocriniens/toxicité , Aromatase/métabolisme , Aromatase/génétique , Récepteur alpha des oestrogènes/métabolisme , RatsRÉSUMÉ
Tributyltin chloride (TBTC) is known to have effects and mechanisms in various diseases; however, whether TBTC is detrimental to joints and causes osteoarthritis (OA), as well as its underlying mechanism, has not yet been fully elucidated. The present study explored the effects of TBTC on rat chondrocytes, as well as on mouse OA. The toxicity of TBTC toward rat chondrocytes was detected using a lactate dehydrogenase (LDH) leakage assay and cell viability was evaluated using the Cell Counting Kit8 assay. The results showed that TBTC decreased the viability of rat chondrocytes and increased the LDH leakage rate in a concentrationdependent manner. Moreover, compared with in the control group, TBTC increased the expression levels of interleukin (IL)1ß, IL18, matrix metalloproteinase (MMP)1, MMP13, NLR family pyrin domain containing 3 (NLRP3), caspase1, PYD and CARD domain containing, and gasdermin D in chondrocytes. Furthermore, knockdown of NLRP3 reversed the TBTCinduced increases in LDH leakage and NLRP3 inflammasomeassociated protein levels. In vivo, TBTC exacerbated cartilage tissue damage in mice from the OA group, as evidenced by the attenuation of safranin O staining. In conclusion, TBTC may aggravate OA in mice by promoting chondrocyte damage and inducing pyroptosis through the activation of NLRP3 and caspase1 signaling. The present study demonstrated that TBTC can cause significant damage to the articular cartilage; therefore, TBTC contamination should be strictly monitored.
Sujet(s)
Chondrocytes , Protéine-3 de la famille des NLR contenant un domaine pyrine , Arthrose , Pyroptose , Trialkyl-stannanes , Animaux , Chondrocytes/métabolisme , Chondrocytes/effets des médicaments et des substances chimiques , Chondrocytes/anatomopathologie , Protéine-3 de la famille des NLR contenant un domaine pyrine/métabolisme , Protéine-3 de la famille des NLR contenant un domaine pyrine/génétique , Pyroptose/effets des médicaments et des substances chimiques , Souris , Rats , Arthrose/métabolisme , Arthrose/anatomopathologie , Arthrose/étiologie , Mâle , Inflammation/métabolisme , Inflammation/anatomopathologie , Inflammation/induit chimiquement , Caspase-1/métabolisme , Inflammasomes/métabolisme , Survie cellulaire/effets des médicaments et des substances chimiques , Interleukine-1 bêta/métabolisme , Transduction du signal/effets des médicaments et des substances chimiquesRÉSUMÉ
Organotin compounds (OTC), tri-, di- and monobutyl tin, were determined in the tissues of marbled electric ray (Torpedo marmorata) in the Adriatic Sea. Marbled electric ray specimens were provided by local fishermen from three localities in the northern Adriatic: area close to the shipyard in Seca, the natural protected area Strunjan Nature Reserve and along the west Istrian coast. To assess the concentration of OTC in the environment, sediment samples were also analysed. After an adequate extraction of OTC from both matrices, their concentrations were determined by GC-ICP-MS. The results indicate that the accumulation of TBT (tributyltin) and DBT (dibutyltin) in the marbled electric ray is related to the possible pollution sources, since their total concentrations were significantly higher (p < 0.001) in the area close to the shipyard (up to 69 µg Sn kg-1, w.w.) in comparison to the other two areas less affected by direct pollution (up to 7 µg Sn kg-1, w.w.). TBT concentrations ranged from 2 to 42 µg Sn kg-1, w.w., DBT concentrations were in the range from 2 to 22 µg Sn kg-1, w.w., and MBT concentrations were mostly below the detection limit with the highest up to 4 µg Sn kg-1, w.w. The proportion of the three determined congener concentrations in sediment samples indicate a temporally older pollution with these compounds, with prevailing DBT and MBT concentrations up to 30 µg Sn kg-1, w.w., and much lower TBT concentrations up to 7 µg Sn kg-1, w.w. According to our results, marbled electric ray could be considered as an ideal bioindicator of environmental pollution due to its ecological characteristics.
Sujet(s)
Surveillance de l'environnement , Composés organiques de l'étain , Polluants chimiques de l'eau , Composés organiques de l'étain/analyse , Composés organiques de l'étain/métabolisme , Animaux , Polluants chimiques de l'eau/analyse , Polluants chimiques de l'eau/métabolisme , Bioaccumulation , Trialkyl-stannanes/analyse , Trialkyl-stannanes/métabolisme , Sédiments géologiques/composition chimique , Paracentrotus/métabolismeRÉSUMÉ
Tributyltin chloride (TBTC) is a ubiquitous environmental pollutant with various adverse effects on human health. Exosomes are cell - derived signaling and substance transport vesicles. This investigation aimed to explore whether exosomes could impact the toxic effects caused by TBTC via their transport function. Cytotoxicity, DNA and chromosome damage caused by TBTC on MCF-7 cells were analyzed with CCK-8, flow cytometry, comet assay and micronucleus tests, respectively. Exosomal characterization and quantitative analysis were performed with ultracentrifugation, transmission electron microscope (TEM) and bicinchoninic acid (BCA) methods. TBTC content in exosomes was detected with Liquid Chromatography-Mass Spectrometry (LC-MS). The impacts of exosomal secretion on the toxic effects of TBTC were analyzed. Our data indicated that TBTC caused significant cytotoxicity, DNA and chromosome damage effects on MCF-7 cells, and a significantly increased exosomal secretion. Importantly, TBTC could be transported out of MCF-7 cells by exosomes. Further, when exosomal secretion was blocked with GW4869, the toxic effects of TBTC were significantly exacerbated. We concluded that TBTC promoted exosomal secretion, which in turn transported TBTC out of the source cells to alleviate its toxic effects. This investigation provided a novel insight into the role and mechanism of exosomal release under TBTC stress.
Sujet(s)
Altération de l'ADN , Exosomes , Trialkyl-stannanes , Humains , Exosomes/effets des médicaments et des substances chimiques , Exosomes/métabolisme , Trialkyl-stannanes/toxicité , Cellules MCF-7 , Altération de l'ADN/effets des médicaments et des substances chimiques , Transport biologique/effets des médicaments et des substances chimiques , Polluants environnementaux/toxicité , Survie cellulaire/effets des médicaments et des substances chimiquesRÉSUMÉ
BACKGROUND: Exposure to obesogenic chemicals has been reported to result in enhanced adipogenesis, higher adipose tissue accumulation, and reduced ovarian hormonal synthesis and follicular function. We have reported that organotins [tributyltin (TBT) and triphenyltin (TPT)] dysregulate cholesterol trafficking in ovarian theca cells, but, whether organotins also exert lipogenic effects on ovarian cells remains unexplored. OBJECTIVE: We investigated if environmentally relevant exposures to organotins [TBT, TPT, or dibutyltin (DBT)] induce lipid dysregulation in ovarian theca cells and the role of the liver X receptor (LXR) in this effect. We also tested the effect of TBT on oocyte maturation and neutral lipid accumulation, and lipid-related transcript expression in cumulus cells and preimplantation embryos. METHODS: Primary theca cell cultures derived from human and ovine ovaries were exposed to TBT, TPT, or DBT (1, 10, or 50 ng/ml). The effect of these chemical exposures on neutral lipid accumulation, lipid abundance and composition, lipid homeostasis-related gene expression, and cytokine secretion was evaluated using liquid chromatography-mass spectrometry (LC-MS), inhibitor-based methods, cytokine secretion, and lipid ontology analyses. We also exposed murine cumulus-oocyte complexes to TBT and evaluated oocyte maturation, embryo development, and lipid homeostasis-related mRNA expression in cumulus cells and blastocysts. RESULTS: Exposure to TBT resulted in higher intracellular neutral lipids in human and ovine primary theca cells. In ovine theca cells, this effect was dose-dependent, independent of cell stage, and partially mediated by LXR. DBT and TPT resulted in higher intracellular neutral lipids but to a lesser extent in comparison with TBT. More than 140 lipids and 9 cytokines were dysregulated in TBT-exposed human theca cells. Expression of genes involved in lipogenesis and fatty acid synthesis were higher in theca cells, as well as in cumulus cells and blastocysts exposed to TBT. However, TBT did not impact the rates of oocyte maturation or blastocyst development. DISCUSSION: TBT induced dyslipidemia in primary human and ovine theca cells, which may be responsible for some of the TBT-induced fertility dysregulations reported in rodent models of TBT exposure. https://doi.org/10.1289/EHP13955.
Sujet(s)
Composés organiques de l'étain , Cellules thécales , Trialkyl-stannanes , Femelle , Humains , Animaux , Ovis , Souris , Cellules thécales/métabolisme , Trialkyl-stannanes/métabolisme , Trialkyl-stannanes/pharmacologie , Lipides/pharmacologie , Cytokines/métabolismeRÉSUMÉ
Tributyltin (TBT) is a biocide used in the formulation of antifouling paints and it is highly harmful. Despite the ban, the compound persists in the environment, contaminating marine foodstuffs and household products. Therefore, considering the route of exposure to the contaminant, the gastrointestinal tract (GIT) acts as an important barrier against harmful substances and is a potential biomarker for understanding the consequences of these agents. This work aimed to evaluate histological and neuronal alterations in the duodenum of male Wistar rats that received 20 ng/g TBT and 600 ng/g via gavage for 30 consecutive days. After the experimental period, the animals were euthanized, and the duodenum was intended for neuronal histochemistry (total and metabolically active populations) and histological routine (morphometry and histopathology). The results showed more severe changes in neuronal density and intestinal morphometry in rats exposed to 20 ng/g, such as total neuronal density decrease and reduction of intestinal layers. In rats exposed to 600 ng/g of TBT, it was possible to observe only an increase in intraepithelial lymphocytes. We conclude that TBT can be more harmful to intestinal homeostasis when consumed in lower concentrations.
Sujet(s)
Duodénum , Plasticité neuronale , Rat Wistar , Trialkyl-stannanes , Animaux , Trialkyl-stannanes/toxicité , Mâle , Plasticité neuronale/effets des médicaments et des substances chimiques , Plasticité neuronale/physiologie , Duodénum/effets des médicaments et des substances chimiques , Duodénum/anatomopathologie , Neurones/effets des médicaments et des substances chimiques , Neurones/anatomopathologie , Rats , Muqueuse intestinale/effets des médicaments et des substances chimiques , Muqueuse intestinale/anatomopathologie , Système nerveux entérique/effets des médicaments et des substances chimiques , Système nerveux entérique/anatomopathologieRÉSUMÉ
Tributyltin (TBT) is the chemical substance commonly used worldwide to prevent biofouling of vessels. Due to its ability to bioaccumulate and biomagnify, even after being banned, significant concentrations of TBT can be detected in sediment, affecting marine and human life. Although studies have shown that direct exposure to TBT alters physiological parameters in mammals, the relationship between exposure to TBT during pregnancy and lactation, considered critical windows for metabolic programming, has not been fully elucidated. Our hypothesis is that offspring whose mothers were exposed to TBT during critical stages of development may exhibit dysfunctions in endocrine-metabolic parameters. We used pregnant Wistar rats that were divided into groups and received the following treatments from gestational day 7 until the end of lactation by intragastric gavage: vehicle (ethanol 0.01%; Control), low TBT dose (100 ng/kg of body weight (bw)/day; TBT100ng) and high TBT dose (1000 ng/kg bw/day; TBT1000ng). Dams and offspring at birth and weaning (21 days old) were studied. Maternal exposure to TBT promoted dose-dependent changes in dams. The findings for adiposity, milk composition and lipid profile were more pronounced in TBT100 ng dam; however, thyroid morphology was altered in TBT1000 ng dam. Female offspring were differentially affected by the dose of exposure. At birth, females in the TBT100ng group had low body weight, lower naso-anal length (NAL), and higher plasma T4, and at weaning, females in the TBT100ng group had lower insulin and leptin levels. Females in the TBT1000ng group had lower NAL at birth and lower leptinemia and weight of white adipose tissue at weaning. Male offspring from TBT groups showed high T3 at birth, without biometric alterations at birth or weaning. Despite these findings, both sexes exhibited dose-dependent morphological changes in the thyroid gland. Thus, maternal exposure to TBT constitutes an important route of contamination for both dams and offspring.
Sujet(s)
Lactation , Exposition maternelle , Effets différés de l'exposition prénatale à des facteurs de risque , Rat Wistar , Glande thyroide , Trialkyl-stannanes , Animaux , Femelle , Trialkyl-stannanes/toxicité , Rats , Grossesse , Mâle , Glande thyroide/effets des médicaments et des substances chimiques , Lactation/effets des médicaments et des substances chimiques , Animaux nouveau-nés , Perturbateurs endocriniens/toxicité , Lait/composition chimique , Lait/métabolismeRÉSUMÉ
Tributyltin (TBT) is one of the most harmful contaminants ever released into the aquatic environment. Despite being banned, it is still present at many locations throughout the world. Its degradation in sediment mainly occurs through microbial biodegradation, a process that remains unclear. This study therefore aimed at better understanding TBT biodegradation in estuarine sediment and the microbial community associated with it. Microcosm experiments were set up, embracing a range of environmental control parameters. Major community shifts were recorded, mainly attributed to the change in oxygen status. The highest percentage of degradation (36,8%) occurred at 4 °C in anaerobic conditions. These results are encouraging for the in-situ bioremediation of TBT contaminated muddy sediment in temperate ports worldwide. However, with TBT able to persist in the coastal environment for decades when undisturbed in anoxic sediment, further research is needed to fully understand the mechanisms that triggered this biodegradation observed in the microcosms.
Sujet(s)
Dépollution biologique de l'environnement , Estuaires , Sédiments géologiques , Trialkyl-stannanes , Polluants chimiques de l'eau , Trialkyl-stannanes/métabolisme , Trialkyl-stannanes/toxicité , Sédiments géologiques/composition chimique , Sédiments géologiques/microbiologie , Polluants chimiques de l'eau/métabolisme , Polluants chimiques de l'eau/analyse , Bactéries/métabolisme , Microbiote/effets des médicaments et des substances chimiquesRÉSUMÉ
Tributyltin (TBT), an organotin endocrine-disrupting substance, is recognized as one of the important toxic environmental pollutants. The present study was carried out to investigate the toxic effects of TBT on behavior and the ovary of adult zebrafish with a focus on oxidative stress markers and oocyte maturation. Adult zebrafish were exposed to three different concentrations (125, 250, and 500â¯ng/L of water) of TBT for 28 days. TBT exposure produced a concentration-dependent negative effect on the body weight and behavior (anxiety-like symptoms) of adult zebrafish. Alterations in the activity of superoxide dismutase (SOD) and catalase (CAT), the total antioxidant capacity of ovarian tissue by the highest exposure level of TBT resulted in lipid peroxidation as indicated by increased malondialdehyde (MDA) level. The numbers of early-vitellogenic oocytes were significantly increased in zebrafish exposed to TBT as low as 125â¯ng/L. However, the numbers and size of fully-grown (mature) oocytes were significantly reduced in the highest exposure group only. Correlation between the MDA level and pre-vitellogenic oocytes in the 500â¯ng/L group indicated that lipid peroxidation prevented the maturation of pre-vitellogenic oocytes. TBT exposure produced significant histological changes in the ovary as evidenced by disturbed maturation of oocytes. In conclusion, TBT adversely affected the maturation of oocytes in zebrafish ovary through oxidative stress-mediated mechanisms.
Sujet(s)
Comportement animal , Catalase , Peroxydation lipidique , Malonaldéhyde , Ovocytes , Ovaire , Stress oxydatif , Superoxide dismutase , Trialkyl-stannanes , Polluants chimiques de l'eau , Danio zébré , Animaux , Trialkyl-stannanes/toxicité , Stress oxydatif/effets des médicaments et des substances chimiques , Femelle , Ovaire/effets des médicaments et des substances chimiques , Ovaire/métabolisme , Ovaire/anatomopathologie , Ovocytes/effets des médicaments et des substances chimiques , Ovocytes/métabolisme , Superoxide dismutase/métabolisme , Comportement animal/effets des médicaments et des substances chimiques , Polluants chimiques de l'eau/toxicité , Malonaldéhyde/métabolisme , Peroxydation lipidique/effets des médicaments et des substances chimiques , Catalase/métabolisme , Perturbateurs endocriniens/toxicitéRÉSUMÉ
Tributyltin (TBT) can be used as an antifouling agent with anticorrosive, antiseptic and antifungal properties and is widely used in wood preservation and ship painting. However, it has recently been found that TBT can be harmful to aquatic organisms. In this study, to gain insight into the effects of TBT with respect to the development of the cardiovascular system in zebrafish embryos, zebrafish embryos were exposed to different concentrations of TBT solutions (0.2 µg/L, 1 µg/L, and 2 µg/L) at 2 h post-fertilization (hpf) TBT exposure resulted in decreased hatchability and heart rate, deformed features such as pericardial edema, yolk sac edema, and spinal curvature in zebrafish embryos, and impaired heart development. Expression of cardiac development-related genes (vmhc, myh6, nkx2.5, tbx5a, gata4, tbx2b, nppa) is dysregulated. Transgenic zebrafish Tg (fli1: EGFP) were used to explore the effects of TBT exposure on vascular development. It was found that TBT exposure could lead to impaired development of intersegmental vessels (ISVs), common cardinal vein (CCV), subintestinal vessels (SIVs) and cerebrovascular. The expression of vascular endothelial growth factor (VEGF) signaling pathway-related genes (flt1, flt4, kdr, vegfa) was downregulated. Biochemical indices showed that ROS and MDA levels were significantly elevated and that SOD and CAT activities were significantly reduced. The expression of key genes for prostacyclin synthesis (pla2, ptgs2a, ptgs2b, ptgis, ptgs1) is abnormal. Therefore, it is possible that oxidative stress induced by TBT exposure leads to the blockage of arachidonic acid (AA) production in zebrafish embryos, which affects prostacyclin synthesis and consequently the normal development of the heart and blood vessels in zebrafish embryos.
Sujet(s)
Système cardiovasculaire , Stress oxydatif , Trialkyl-stannanes , Danio zébré , Animaux , Danio zébré/embryologie , Trialkyl-stannanes/toxicité , Stress oxydatif/effets des médicaments et des substances chimiques , Système cardiovasculaire/effets des médicaments et des substances chimiques , Polluants chimiques de l'eau/toxicité , Embryon non mammalien/effets des médicaments et des substances chimiquesRÉSUMÉ
To understand the underlying molecular mechanisms, mouse bone marrow mesenchymal stem cells (BMSCs) and zebrafish embryos were exposed to the control group and Tributyltin (TBT) group (10 ng/L, environmental concentration) for 48 h, respectively. The expression profiles of RNAs were investigated using whole-transcriptome analysis in mouse BMSCs or zebrafish embryos after TBT exposure. For mouse BMSCs, the results showed 2,449 differentially expressed (DE) mRNAs, 59 DE miRNAs, 317 DE lncRNAs, and 15 circRNAs. Similarly, for zebrafish embryos, the results showed 1,511 DE mRNAs, 4 DE miRNAs, 272 DE lncRNAs, and 28 circRNAs. According to KEGG pathway analysis showed that DE RNAs were mainly associated with immune responses, signaling, and cellular interactions. Competing endogenous RNA (ceRNA) network analysis revealed that the regulatory network of miRNA-circRNA constructed in zebrafish embryos was more complex compared to that of mouse BMSCs.
Sujet(s)
Cellules souches mésenchymateuses , microARN , ARN long non codant , Trialkyl-stannanes , Animaux , Souris , Danio zébré/métabolisme , ARN circulaire/génétique , ARN circulaire/métabolisme , ARN long non codant/génétique , ARN long non codant/métabolisme , Analyse de profil d'expression de gènes , microARN/génétique , microARN/métabolisme , ARN messager/métabolisme , Cellules souches mésenchymateuses/métabolismeRÉSUMÉ
Organotin compounds are persistent pollutants and are considered chemicals of high environmental concern. In the present study, the distribution and degradation of tributyltin were evaluated in field sediments and through an ex situ experiment. For this, sediment samples from two locations were analysed: Luis Piedrabuena Harbour, with higher maritime traffic, and Cerro Avanzado, which receives less impact from anthropogenic activities. The results indicated that pollution levels at Luis Piedrabuena Harbour have decreased compared with studies performed 9 years ago for the same area. On the contrary, traces of organotin compounds have been found for the first time at Cerro Avanzado. Moreover, the butyltin degradation index indicated that organotin compounds undergo an advanced degradation process in the collected samples at both sites. Ex situ experiments revealed a limited capacity of sediments to retain tributyltin, and suggested an active role of bioturbation activity in the degradation of these compounds. In addition, visualisation using chemometric techniques (principal components analysis) allowed a simpler analysis of two sediment characteristics: the degree of contamination and the degradation levels of organotin compounds.
Sujet(s)
Composés organiques de l'étain , Trialkyl-stannanes , Polluants chimiques de l'eau , Composés organiques de l'étain/analyse , Sédiments géologiques/composition chimique , Argentine , Polluants chimiques de l'eau/analyse , Surveillance de l'environnement/méthodes , Trialkyl-stannanes/analyseRÉSUMÉ
Tributyltin (TBT) is widely used in various commercial applications due to its biocidal properties. Toxicological and genotoxicological data on TBT exposure to amphibians is insufficient. Our study aimed to determine the acute toxicity and genotoxic potential of TBT in Fejervarya limnocharis tadpoles. Furthermore, oxidative stress was also investigated in TBT-treated tadpoles. Tadpoles of Gosner stage (26-30) were screened and subjected to increasing concentrations of TBT (0, 3, 7, 11, 15, 19, 23 µg/L) for determining the LC50 values for 24 h, 48 h, 72 h, and 96 h. LC50 values of TBT for 24 h, 48 h, 72 h, and 96 h were found to be 19.45, 15.07, 13.12, and 11.84 µg/L respectively. Based on the 96 h LC50 value (11.84 µg/L), tadpoles were exposed to different sub-lethal concentrations of TBT for the evaluation of its genotoxic potential and effects on oxidative balance. The role of TBT on survivability, growth, and time to metamorphosis was also assessed. TBT exposure significantly altered the life history traits measured, increased mortality, and delayed the time taken to metamorphosis. Results indicated significant induction of micronucleus (MN, p < 0.001) and other erythrocytic nuclear aberrations (ENA, p < 0.01) in the TBT-treated groups. Significant alterations in comet parameters and oxidative balance were also observed in the treated groups. The present study findings might add to the cause of the gradual population decline seen in the amphibians. This study also demonstrates the alteration of the life-history traits, oxidative balance, and DNA damage upon TBT exposure which can have long-term consequences for the anuran amphibian F. limnocharis.
Sujet(s)
Trialkyl-stannanes , Polluants chimiques de l'eau , Animaux , Anura , Métamorphose biologique , Trialkyl-stannanes/toxicité , Larve , Stress oxydatif , Altération de l'ADN , Polluants chimiques de l'eau/toxicitéRÉSUMÉ
Aquatic organisms are exposed to low concentrations of neuro-active chemicals, many of them acting also as neuroendocrine disruptors that can be hazardous during earlier embryonic stages. The present study aims to assess how exposure early in live to environmental low concentrations of two selective serotonin reuptake inhibitors (SSRIs), fluoxetine and sertraline, and tributyltin (TBT) affected cognitive, metabolic and cardiac responses in the model aquatic crustacean Daphnia magna. To that end, newly brooded females were exposed for an entire reproductive cycle (3-4 days) and the response of collected juveniles in the first, second and third consecutive broods, which were exposed, respectively, as embryos, provisioned and un-provisioned egg stages, was monitored. Pre-exposure to the selected SSRIs during embryonic and egg developmental stages altered the swimming behaviour of D. magna juveniles to light in a similar way reported elsewhere by serotonergic compounds while TBT altered cognition disrupting multiple neurological signalling routes. The studied compounds also altered body size, the amount of storage lipids in lipid droplets, heart rate, oxygen consumption rates and the transcription of related serotonergic, dopaminergic and lipid metabolic genes in new-born individuals, mostly pre-exposed during their embryonic and provisioning egg stages. The obtained cognitive, cardiac and metabolic defects in juveniles developed from exposed sensitive pre-natal stages align with the "Developmental Origins of Health and Disease (DoHAD)" paradigm.
Sujet(s)
Inbiteurs sélectifs de la recapture de la sérotonine , Trialkyl-stannanes , Polluants chimiques de l'eau , Animaux , Femelle , Humains , Inbiteurs sélectifs de la recapture de la sérotonine/toxicité , Daphnia magna , Sérotonine/métabolisme , Exposition maternelle , Daphnia/physiologie , Cognition , Polluants chimiques de l'eau/analyseRÉSUMÉ
Organotin compounds (OTs) accumulate in fish easily, however, research on their influencing factors is still limited. This study collected 25 species of fish with different diets, habitats, and age from the Three Gorges Reservoir (TGR), the largest deep-water river channel-type reservoir in China, and analyzed the accumulation characteristics of OTs in these fish. The results showed that tributyltin (TBT) and triphenyltin (TPhT) were the dominant OTs in fish from the TGR. The correlation between OTs concentration and age, body length, and body weight varied with fish species. The concentrations of TBT and TPhT in carnivorous fish (mean, 25.78 and 11.69 ng Sn/g dw, respectively) were higher than those in other diet fish (P<0.01), but there was no significant difference in fish at different habitat water layers (P>0.05). In addition, the degradation rates of TBT and TPhT in different fish species were all below 50%. In summary, the accumulation of TBT and TPhT in fish is mainly influenced by diet, and both TBT and TPhT were difficult to degrade in fish. These results reveal the pollution characteristics of OTs in fish from the TGR, and can improve our understanding of the factors influencing TBT and TPhT accumulation in freshwater fish.