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1.
Gene ; 722: 144101, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31479714

RESUMO

The catadromous species, eels, invariably exposed to variable Ca2+ concentrations circumstance i.e., lagoon or ocean. They need to maintain Ca2+ homeostasis by exchanging Ca2+ under different culture conditions. To understand the effects of environmental Ca2+ to fish, three types of genes coding for voltage-dependent L-type calcium channels (cacnb1, 2, 3) were cloned by screening an A. marmorata cDNA library. Tissue distribution analysis of Western blot showed that Cacnb1, 2, 3 had a significantly high expression in gill; while mRNA results showed the expressions of cacnb1 and cacnb3 were predominated in skin tissue but only cacnb2 was expressed in intestine. Serum osmolality and Ca2+ concentrations of A.marmorata were increased in a high calcium environment while reduced in a low calcium environment within 7 days; however, they were not significantly different among Ca2+ treatments after the eels were acclimated for 7 days. We also examined the influence of ambient Ca2+ levels on cacnbs expression of eels. With the increasing of exposure time, mRNA and protein expressions of cacnb1 were up-regulated in high level of Ca2+ (10 mM) and down-regulated in deficient Ca2+ (0 mM) compared to the control Ca2+ (2 mM). However, the opposite results were observed in cacnb2 and cacnb3. Notably, the cacnb2 expression was not significant different among Ca2+ treatments on day 7. Our study provided the insightful evidence that cacnbs play important roles in maintaining Ca2+ homeostasis of fish.


Assuntos
Anguilla/metabolismo , Canais de Cálcio Tipo L/metabolismo , Cálcio/fisiologia , Aclimatação , Anguilla/sangue , Anguilla/genética , Animais , Cálcio/sangue , Canais de Cálcio Tipo L/química , Canais de Cálcio Tipo L/genética , Clonagem Molecular , Brânquias/metabolismo , Concentração Osmolar , RNA Mensageiro/metabolismo , Distribuição Tecidual
2.
Aquat Toxicol ; 214: 105233, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301545

RESUMO

The water bodies are greatly influenced by heavy metal contamination and global increasing temperature. Arsenic (As) is one of the most dangerous widespread pollutants that pose health threats to human, animals and fishes. Considering the above, the study has been carried out to delineate 96 h median lethal concentration of arsenic alone and in combination with high temperature (As-T, 34 °C) by conducting static non-renewable bio-assay acute toxicity in Pangasianodon hypophthalmus (average weight 6.25 ±â€¯0.69 g, length 5.32 cm). Effect of definitive doses such as 25, 26, 27, 28, 29 and 30 mg/L of As alone and in combination with high temperature (As-T) were evaluated on stress biomarkers and cellular metabolism of P. hypophthalmus. The lethal concentration (96 h LC50) of As alone and in combination with high temperature was found to be 28.16 mg/L and 26.88 mg/L, respectively. The stress biomarkers in terms of catalase, superoxide dismutase (SOD) and glutathione-s-transferase (GST) in liver, gill, brain and kidney, blood glucose and NBT were remarkable higher (p < 0.01) in comparison to unexposed group (control group). Brain neurotransmitter enzyme, AChE, immunological status (blood glucose and NBT) and cellular metabolic enzymes (lactate dehydrogenase LDH, malate dehydrogenase MDH, aspartate aminotransferase AST, and alanine aminotransferase ALT, glucose-6-phosphate dehydrogenase G6PDH and ATPase) were noticeably (p < 0.01) altered by As and As-T exposure. The histopathological study exhibited devastating changes with exposure to As and As-T such as bile stagnation, hepatocyte with irregular nucleus, eosinophilic granules in the cytoplasm, necrosis, and nuclear hypertrophy in liver and curling of secondary lamellae, hypertrophy of lamellar epithelium, blood congestion, incomplete fusion of secondary lamellae, complete fusion of several lamellae and aneurysm in gill. Overall results clearly indicate that acute exposure of As and high temperature led to pronounced deleterious alterations on stress biomarkers and cellular and metabolic activities of P. hypophthalmus.


Assuntos
Arsênico/toxicidade , Biomarcadores/metabolismo , Peixes-Gato/imunologia , Peixes-Gato/metabolismo , Temperatura Alta , Estresse Oxidativo , Estresse Fisiológico/efeitos dos fármacos , Testes de Toxicidade Aguda , Acetilcolinesterase/metabolismo , Animais , Antioxidantes/metabolismo , Glicemia/metabolismo , Catalase/metabolismo , Brânquias/metabolismo , Glutationa Transferase/metabolismo , Glicólise/efeitos dos fármacos , Dose Letal Mediana , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Metais Pesados/metabolismo , Neurotransmissores/metabolismo , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/toxicidade
3.
Bull Environ Contam Toxicol ; 103(2): 267-273, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31172221

RESUMO

The development of nanotechnology has drawn increased attention to the risks of nanoparticles (NPs). In this work, the near-infrared persistent luminescence imaging technique was used to track the biodistribution of NPs in vivo in zebrafish. Zebrafish were used as a vertebrate animal model to show NPs distribution and the effects of exposure. ZnGa2O4:Cr (ZGOC) was chosen as the probe in this work. In continuous exposure experiments, the results showed more particles accumulated in the intestines than in the gills in both groups. In both the gills and abdomen, the NPs contents were greater in the ZGOC-NH2-treated groups than in the ZGOC groups, and the NPs caused damage to the gills and intestines. Removal exposure experiments indicated that ZGOC and ZGOC-NH2 could be excreted from the body. The metabolism, excretion of NPs, the quantification and monitoring of NPs behavior in biological systems should be examined in further studies.


Assuntos
Nanopartículas/metabolismo , Poluentes Químicos da Água/farmacocinética , Peixe-Zebra/metabolismo , Animais , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Medições Luminescentes , Nanopartículas/química , Nanopartículas/toxicidade , Imagem Óptica , Propriedades de Superfície , Distribuição Tecidual , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
4.
Bull Environ Contam Toxicol ; 103(3): 405-410, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31203409

RESUMO

Global trends in pesticide use can increase aquatic pollution and affect resident fisheries. Crabs exposed to organophosphate pesticides, such as chlorpyrifos, may increase production of reactive oxygen species (ROS), affecting the pro-oxidant/antioxidant balance. Zichiopsis collastinensis crabs were exposed to environmentally relevant concentrations of chlorpyrifos (0.1 and 0.5 µg L-1). Effects on the oxidative stress enzymes catalase, superoxide dismutase, glutathione S-transferases, glutathione reductase, and on thiobarbituric acid reactive substances and hydrogen peroxide concentrations were evaluated at four intervals during 96 h exposures. Exposures caused decreased GST activity and increased H2O2 levels in gills. There were modifications of GST, CAT and SOD activities in the hepatopancreas after 12 h of exposure, and an increase of H2O2 levels at every exposure interval observed. The present study proved that chlorpyrifos lead to oxidative stress in Z. collastinensis. However other enzymatic/non-enzymatic responses should be further investigated in order to be included as part of a battery of biomarkers, together with H2O2 levels, which is a parameter highly recommended to be taken into account.


Assuntos
Braquiúros/fisiologia , Clorpirifos/toxicidade , Inseticidas/toxicidade , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Braquiúros/metabolismo , Catalase/metabolismo , Clorpirifos/metabolismo , Monitoramento Ambiental , Água Doce , Brânquias/metabolismo , Glutationa Redutase/metabolismo , Hepatopâncreas/enzimologia , Peróxido de Hidrogênio/metabolismo , Inseticidas/metabolismo , Estresse Oxidativo/fisiologia , Praguicidas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Alimentos Marinhos , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/toxicidade
5.
Sci Total Environ ; 685: 332-344, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31176220

RESUMO

The present study assessed the spatial and temporal variations on metal bioaccumulation and biochemical biomarker responses in oysters Crassostrea gasar transplanted to two different sites (S1 and S2) at the Laguna Estuarine System (LES), southern Brazil, over a 45-days period. A multi-biomarker approach was used, including the evaluation of lipid peroxidation (MDA) levels, and antioxidant defense enzymes (CAT, GPx, GR and G6PDH) and phase II biotransformation enzyme (GST) in the gills and digestive gland of oysters in combination with the quantification of Al, Cd, Cu, Pb, Fe, Ni and Zn in both tissues. The exposed oysters bioaccumulated metals, especially Al, Cd and Zn in gills and digestive gland, with most prominent biomarker responses in the gills. Results showed that GPx, GR and G6PDH enzymes offered an increased and coordinated response possibly against metal (Zn, Ni, Cd and Cu) contamination in gills. GST was inversely correlated to Cd levels, being its activity significantly lowered over the 45-d exposure periods at S2. On contrary, in digestive gland GST was slightly positively correlated to Cd, revealing a compensatory mechanism between tissues to protect oysters' cells against oxidative damages, since MDA levels also decreased. CAT also appeared to be involved in the cellular protection against oxidative stress, being increased in gills. However, CAT was negatively correlated to Al levels, which might suggest a possible inhibitory effect of this metal in the gills of C. gasar. Differences between tissues were evident by the Integrative Biomarker Responses version 2 (IBRv2) indexes, which showed different pattern between tissues when studying the sites and exposure periods separately. This study provided evidence for the effectiveness of using a multi-biomarker approach in oyster C. gasar to monitor estuarine metal pollution.


Assuntos
Crassostrea/fisiologia , Monitoramento Ambiental , Metais/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Brasil , Estuários , Brânquias/metabolismo , Inativação Metabólica , Peroxidação de Lipídeos/efeitos dos fármacos , Metais/toxicidade , Oxirredução , Estresse Oxidativo/fisiologia , Poluentes Químicos da Água/toxicidade
6.
Environ Pollut ; 251: 708-716, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31108304

RESUMO

DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) is the main component of SeaNine-211, a new antifouling agent that replaces tributyltin to prevent the growth of undesirable organisms on ships. There have been some studies on the toxicity of DCOIT, but the mechanism of DCOIT's toxicity to crustaceans still requires elucidation. This study examined the chronic toxicity (4 weeks) of 0, 3, 15, and 30 µg/L DCOIT to the Pacific white shrimp (Litopenaeus vannamei) from the aspects of growth and physiological and histological changes in the hepatopancreas and gills. A transcriptomic analysis was performed on the hepatopancreas to reveal the underlying mechanism of DCOIT in shrimp. The exposure to 30 µg/L DCOIT significantly reduced the survival and weight gain of L. vannamei. High Na+/K+-ATPase activity and melanin deposition were found in the gills after 4 weeks of 15 µg/L or 30 µg/L DCOIT exposure. The highest concentration of DCOIT (30 µg/L) induced changes in hepatopancreatic morphology and metabolism, including high anaerobic respiration and the accumulation of triglycerides. Compared with the exposure to 3 µg/L DCOIT, shrimp exposed to 15 µg/L DCOIT showed more differentially expressed genes (DEGs) than those in the control, and these DEGs were involved in biological processes such as starch and sucrose metabolism and choline metabolism in cancer. The findings of this study indicate that L. vannamei is sensitive to the antifouling agent DCOIT and that DCOIT can induce altered gene expression at a concentration of 15 µg/L and can interfere with shrimp metabolism, growth and survival at 30 µg/L.


Assuntos
Penaeidae/efeitos dos fármacos , Tiazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/metabolismo , Penaeidae/crescimento & desenvolvimento , Penaeidae/metabolismo , Ganho de Peso/efeitos dos fármacos
7.
Chemosphere ; 230: 1-13, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31100675

RESUMO

The broad utilisation of imidacloprid (IMI) in agriculture poses an increasing risk to aquatic organisms. However, the potential impacts on commercially important shellfish and chemical residues after exposure, are yet to be assessed. We investigated the levels of IMI in Sydney rock oyster (SRO) tissue during a three-day uptake and four-day depuration cycle using liquid chromatography-mass spectrometry. IMI was absorbed from the water, with significantly higher concentrations in the adductor muscles than the gills and digestive glands. Depuration was also fast with a significant drop in tissue concentrations after one day in clean water and complete elimination from all tissues except the digestive gland after four days. The distribution of IMI in SRO after direct exposure using mass spectrometry imaging demonstrated uptake and spatially resolved metabolism to hydroxyl-IMI in the digestive gland and IMI-olefin in the gills. We assessed the effects of IMI on filtration rate (FR), acetylcholinesterase (AChE) activity in the gills, and gene expression profiles in the digestive gland using transcriptomics. Exposure to 2 mg/L IMI reduced the FR of oysters on the first day, while exposure to 0.5 and 1 mg/L reduced FR on day four. IMI reduced the gill AChE activity and altered the digestive gland gene expression profile. This study indicates that commercially farmed SRO can uptake IMI from the water, but negative impacts were only detected at concentrations higher than currently detected in estuarine environments and the chemical residues can be effectively eliminated using simple depuration in clean water.


Assuntos
Acetilcolinesterase/metabolismo , Brânquias/metabolismo , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Ostreidae/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/metabolismo , Sistema Digestório/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Inseticidas/farmacocinética , Neonicotinoides/farmacocinética , Nitrocompostos/farmacocinética , Poluentes Químicos da Água/farmacocinética , Purificação da Água
8.
Aquat Toxicol ; 212: 154-161, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31128416

RESUMO

Elevated concentrations of nitrite develop occasionally in various aquatic habitats and aquaculture facilities, providing a potential danger for freshwater fish that take up nitrite via the gill chloride uptake mechanism. We studied the uptake, effects and metabolism of nitrite in blood, heart and skeletal muscle at two temperatures in striped catfish Pangasianodon hypophthalmus, a facultative air-breathing fish that is heavily cultivated in Southeast Asia. Exposure to 0.8 mM ambient nitrite increased blood [nitrite] and [methaemoglobin] (metHb) to high values at day 1, but values subsequently decreased towards controls at day 7. Blood [nitrite] and metHb content were unexpectedly higher at 27 °C (∼1.2 mM; 69% at day 1) than at 33 °C (∼0.9 mM; 55%), reflecting a lower nitrite uptake at the highest temperature, possibly via an increased reliance on air-breathing relative to water-breathing with temperature increase. A large fraction of the nitrite taken up was effectively eliminated by being detoxified to nitrate. Further, erythrocyte metHb reductase activity was increased during nitrite exposure, efficiently reducing metHb to functional haemoglobin. The uptake of nitrite into white skeletal musculature (main part of the fish) was much lower than into heart tissue. While heart [nitrite] was close to blood plasma levels, muscle [nitrite] peaked at ∼0.2 mM at day 1 and subsequently declined to ∼0.05 mM at day 7, which is below levels reported in various commercial cured meat products. Nitrite was partly metabolized to iron-nitrosyl, S-nitroso and N-nitroso compounds. The increase in nitros(yl)ated compounds was marginal in skeletal muscle and more pronounced in heart tissue.


Assuntos
Peixes-Gato , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Nitritos/metabolismo , Nitritos/toxicidade , Temperatura Ambiente , Aclimatação , Animais , Peixes-Gato/metabolismo , Cloretos/metabolismo , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Água Doce/química , Coração/efeitos dos fármacos , Hemoglobinas/metabolismo , Metemoglobina/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Miocárdio/química , Nitritos/sangue , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
9.
Aquat Toxicol ; 212: 54-69, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31075620

RESUMO

In this era of global climate change, ocean acidification is becoming a serious threat to the marine ecosystem. Despite this, it remains almost unknown how fish will respond to the co-occurrence of ocean acidification with other conventional environmental perturbations typically salinity fluctuation and high ammonia threat. Therefore, the present work evaluated the interactive effects of elevated pCO2, salinity reduction and high environmental ammonia (HEA) on the ecophysiological performance of European sea bass (Dicentrarchus labrax). Fish were progressively acclimated to seawater (32 ppt), to brackish water (10 ppt) and to hyposaline water (2.5 ppt). Following acclimation to different salinities for at least two weeks, fish were exposed to CO2-induced water acidification representing present-day (control pCO2, 400 µatm, LoCO2) and future (high pCO2, 1000 µatm, HiCO2) sea-surface CO2 level for 3, 7 and 21 days. At the end of each exposure period, fish were challenged with HEA for 6 h (1.18 mM representing 50% of 96 h LC50). Results show that, in response to the individual HiCO2 exposure, fish within each salinity compensated for blood acidosis. Fish subjected to HiCO2 were able to maintain ammonia excretion rate (Jamm) within control levels, suggesting that HiCO2 exposure alone had no impact on Jamm at any of the salinities. For 32 and 10 ppt fish, up-regulated expression of Na+/K+-ATPase was evident in all exposure groups (HEA, HiCO2 and HEA/HiCO2 co-exposed), whereas Na+/K+/2Cl- co-transporter was up-regulated mainly in HiCO2 group. Plasma glucose and lactate content were augmented in all exposure conditions for all salinity regimes. During HEA and HEA/HiCO2, Jamm was inhibited at different time points for all salinities, which resulted in a significant build-up of ammonia in plasma and muscle. Branchial expressions of Rhesus glycoproteins (Rhcg isoforms and Rhbg) were upregulated in response to HiCO2 as well as HEA at 10 ppt, with a more moderate response in 32 ppt groups. Overall, our findings denote that the adverse effect of single exposures of ocean acidification or HEA is exacerbated when present together, and suggests that fish are more vulnerable to these environmental threats at low salinities.


Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Ácidos/química , Amônia/toxicidade , Bass/fisiologia , Oceanos e Mares , Osmorregulação/efeitos dos fármacos , Salinidade , Amônia/sangue , Animais , Bass/sangue , Glicemia/metabolismo , Dióxido de Carbono/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Glicoproteínas/metabolismo , Concentração de Íons de Hidrogênio , Íons/sangue , Ácido Láctico/sangue , Músculos/efeitos dos fármacos , Músculos/metabolismo , Análise de Componente Principal , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Poluentes Químicos da Água/toxicidade
10.
Chemosphere ; 230: 144-156, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31103860

RESUMO

Ability of hexavalent chromium to accumulate and induce oxidative stress has been studied in the gills of Ctenopharyngodon idellus, with the resulting damage in the form of altered endogenous antioxidant enzyme activity and, histopathology in the tissue. The fish were exposed to 5.3 (C1) and 10.63 mg/L (C2) of hexavalent chromium and were scrutinised on 15th, 30th and 45th day of toxicant exposure. Oxidative stress studied in terms of lipid peroxidation and glutathione levels and the antioxidant enzymes activity also exhibited alterations. The histopathological modifications in gills announced lesions in the form of hyperplasia, aneurysm, lamellar fusion, focal proliferation, epithelial degeneration and necrosis with loss of lamellae, bringing irreversible damage on 45th day with mean degree of tissue change value of 100.35 ±â€¯10.69. Bioaccumulation of chromium, and increased anomalies in branchial tissue exhibited damage in concentration and time-dependent manner. The ultrastructural anomalies in the cellular morphology in the epithelial cells of filaments and lamellae, exhibited pleomorphic nuclei, swollen mitochondria, extensive vacuolation and loss of microridges in pavement cells. The tissue also displayed altered regulation of Nrf2 and Mt2 following Cr(VI) exposure with maximum downregulation on 45th day by 61 and 53%, respectively. PCA generated two principal components, PC1 (GSH, GST, CAT and SOD) and PC2 (DTC, MDA and Cr(VI) concentration). Thus, it can be concluded that accumulation of Cr(VI) induces alteration in the gene expression of Nrf2 and Mt2 leading to the development of oxidative stress, ensuing various pathological changes creating hindrance in fish survival.


Assuntos
Antioxidantes/metabolismo , Carpas/fisiologia , Cromo/toxicidade , Metalotioneína/genética , Poluentes Químicos da Água/toxicidade , Animais , Carpas/genética , Carpas/metabolismo , Expressão Gênica , Brânquias/metabolismo , Glutationa/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos
11.
PLoS Genet ; 15(4): e1008058, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30933982

RESUMO

In the skin and gill epidermis of fish, ionocytes develop alongside keratinocytes and maintain body fluid ionic homeostasis that is essential for adaptation to environmental fluctuations. It is known that ionocyte progenitors in zebrafish embryos are specified from p63+ epidermal stem cells through a patterning process involving DeltaC (Dlc)-Notch-mediated lateral inhibition, which selects scattered dlc+ cells into the ionocyte progenitor fate. However, mechanisms by which the ionocyte progenitor population is modulated remain unclear. Krüppel-like factor 4 (Klf4) transcription factor was previously implicated in the terminal differentiation of mammalian skin epidermis and is known for its bifunctional regulation of cell proliferation in a tissue context-dependent manner. Here, we report novel roles for zebrafish Klf4 in the ventral ectoderm during embryonic skin development. We found that Klf4 was expressed in p63+ epidermal stem cells of the ventral ectoderm from 90% epiboly onward. Knockdown or knockout of klf4 expression reduced the proliferation rate of p63+ stem cells, resulting in decreased numbers of p63+ stem cells, dlc-p63+ keratinocyte progenitors and dlc+ p63+ ionocyte progenitor cells. These reductions subsequently led to diminished keratinocyte and ionocyte densities and resulted from upregulation of the well-known cell cycle regulators, p53 and cdkn1a/p21. Moreover, mutation analyses of the KLF motif in the dlc promoter, combined with VP16-klf4 or engrailed-klf4 mRNA overexpression analyses, showed that Klf4 can bind the dlc promoter and modulate lateral inhibition by directly repressing dlc expression. This idea was further supported by observing the lateral inhibition outcomes in klf4-overexpressing or knockdown embryos. Overall, our experiments delineate novel roles for zebrafish Klf4 in regulating the ionocyte progenitor population throughout early stem cell stage to initiation of terminal differentiation, which is dependent on Dlc-Notch-mediated lateral inhibition.


Assuntos
Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Células Epidérmicas/citologia , Células Epidérmicas/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Padronização Corporal , Diferenciação Celular , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ectoderma/citologia , Ectoderma/embriologia , Ectoderma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Brânquias/citologia , Brânquias/embriologia , Brânquias/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Transporte de Íons , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Regiões Promotoras Genéticas , Receptores Notch/genética , Receptores Notch/metabolismo , Transativadores/genética , Transativadores/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/deficiência , Proteínas de Peixe-Zebra/genética
12.
Ecotoxicol Environ Saf ; 179: 127-134, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31030055

RESUMO

The increasing production of Ag nanoparticle (AgNP) containing products has inevitably led to a growing concern about their release into the aquatic environment, along with their potential behaviour, toxicity, and bioaccumulation in marine organisms exposed to NPs released from these products. Hence, this study is focused on the effects of AgNPs in Saccostrea glomerata (rock oyster) in artificial seawater (ASW); evaluating the NP's stability, dissolution, and bioaccumulation rate. AgNPs NM300K (20 ±â€¯5 nm) in concentrations of 12.5 µgL-1 and 125 µgL-1 were used to conduct the experiments, and were compared to a blank and a positive control of 12.5 µgL-1 AgNO3. Dissolution in ASW was measured by ICP-OES and stability was assessed by TEM after 1 h and 3, 5, and 7 days of exposure. Bioaccumulation in gills and digestive glands was measured after 7 days of exposure. The higher concentration of AgNPs induced more aggregation, underwent less dissolution, and showed less bioaccumulation, while the lower concentration showed less aggregation, more dissolution and higher bioaccumulation. Five biomarkers (EROD: ethoxyresorufin-o-deethylase, DNA strand breaks, LPO: lipid peroxidation, GST: glutathione S-transferase and GR: glutathione reductase) were analysed at 0, 3, 5 and 7 days. Significant differences compared to the initial day of exposure (day 0) were reported in DNA strand breaks after 5 and 7 days of exposure, GST, from the third day of exposure, in all the Ag samples, and in some samples for LPO and GR biomarkers, while no significant induction of EROD was observed. A combined effect for each type of treatment and time of exposure was also reported for DNA strand breaks and GST biomarkers measured at the digestive glands. In general, the significant inductions measured showed the following trend: 125 µgL-1 AgNPs >12.5 µgL-1 AgNPs ∼12.5 µgL-1 AgNO3 even though bioaccumulation followed the opposite trend.


Assuntos
Nanopartículas Metálicas/toxicidade , Ostreidae/efeitos dos fármacos , Ostreidae/metabolismo , Prata/metabolismo , Prata/toxicidade , Animais , Biomarcadores/metabolismo , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Íons/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Água do Mar/química
13.
Environ Pollut ; 249: 959-968, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30965548

RESUMO

Accurately predicting the accumulation and toxicity of metals in organisms is a challenging work in ecotoxicology. Here, we developed and validated a physiologically based toxicokinetic and toxicodynamic (PBTK-TD) model for adult zebrafish exposed to Cd and Pb. The model included the gill, liver, intestine, gonad, carcass, and brain, which were linked by blood circulation in the PBTK process and by dynamic relationships between the target organ concentrations and mortality in the TD process. Results showed that the PBTK sub-model can accurately describe and predict the uptake, distribution and disposition kinetics of Cd and Pb in zebrafish. The exchange rates and the accumulation of the metals in the organs were significantly different. For Cd, the highest exchange rate was between blood and liver, and the greatest accumulation of Cd occurred in the liver. For Pb, the greatest accumulation occurred in the gill. The TD sub-model further indicated that metal concentrations in the gill may effectively act as more suitable indicator of Cd and Pb toxic effect than whole body or other organs. The proposed PBTK-TD model is helpful to understanding the fundamental processes by which zebrafish regulate the uptake and disposition of metal and to quantitatively predicting metal toxicity.


Assuntos
Cádmio/toxicidade , Brânquias/efeitos dos fármacos , Chumbo/toxicidade , Modelos Biológicos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Cádmio/farmacocinética , Ecotoxicologia , Brânquias/metabolismo , Chumbo/farmacocinética , Especificidade de Órgãos , Distribuição Tecidual , Toxicocinética , Poluentes Químicos da Água/farmacocinética
14.
Mar Pollut Bull ; 141: 366-372, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955746

RESUMO

Concerns are growing about the presence of fluoxetine (FLX) in environmental matrices, as well as its harmful effects on non-target organisms. FLX in aquatic ecosystems has been detected in a range varying from pg/L to ng/L, while adverse effects have been reported in several organisms inhabiting freshwater and marine environments. The present study quantifies FLX concentrations in seawater samples from Santos Bay, Brazil and assesses metabolic responses and sublethal effects on the tropical brown mussel Perna perna. Levels of ethoxyresorufin­O­deethylase, dibenzylfluorescein dealkylase, glutathione S-transferase, glutathione peroxidase, cholinesterase, lipoperoxidation, and DNA damage were assessed in the gills and digestive gland of these animals, and lysosomal membrane stability was also assessed in hemocytes. FLX altered phase I and II enzyme activities, caused cytogenotoxic effects, and negatively impacted the overall health of mussels exposed to environmentally relevant concentrations. These findings contribute to characterize the risks of introducing this drug into the marine environment.


Assuntos
Dano ao DNA , Fluoxetina/toxicidade , Perna (Organismo)/efeitos dos fármacos , Água do Mar/química , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Brasil , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/metabolismo , Fluoxetina/análise , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Perna (Organismo)/citologia , Perna (Organismo)/genética , Perna (Organismo)/metabolismo , Clima Tropical , Poluentes Químicos da Água/análise
15.
Bull Environ Contam Toxicol ; 102(6): 802-810, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30937496

RESUMO

The aim of this study was to evaluate enzymatic (glutathione-S-transferase and catalase) and histological (branchial lesions) biomarkers in Ucides cordatus (Crustacea, Decapoda) from an industrial port region on the north coast of Brazil. The crabs were collected in two distinct locations of the Brazilian coast: A1 = region under influence of port activities; and A2 = low-impacted area. We performed histological examination in the gills and glutathione-S-transferase (GST) and catalase activity in the hepatopancreas. The most frequent and severe histological lesions were found in A1, especially rupture of pilaster cells and lamellar collapse. Catalase activity did not show a pattern capable of differentiating the two analyzed areas. On the other hand, GST activity presented a more pronounced response in the crabs of the port area (p < 0.05), coinciding with the most frequent branchial lesions in these same organisms. These results suggest that the species is susceptible to environmental stress, once alterations at different organizational levels were verified.


Assuntos
Braquiúros/efeitos dos fármacos , Estresse Fisiológico , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Braquiúros/metabolismo , Braquiúros/fisiologia , Brasil , Catalase/metabolismo , Monitoramento Ambiental , Brânquias/química , Brânquias/metabolismo , Glutationa Transferase/metabolismo , Hepatopâncreas/metabolismo , Poluentes Químicos da Água/análise
16.
Chemosphere ; 227: 580-588, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31009864

RESUMO

Copper ions (Cu) are essential to life maintenance, nonetheless, elevated concentrations can be hazardous. Acute and sub-chronic toxic effects of this metal are well known and are usually related to enzymatic inhibition, elevated ROS production and dysfunction of energy metabolism. Despite that, chronic studies are extremely rare. Therefore, the aim of this study was to assess the effects of chronic exposure to 5, 9 and 20 µg/L Cu (28 ad 345 days) on the energy metabolism and survival of the killifish Poecilia vivipara. To accomplish that, we evaluated the activity of enzymes related to aerobic (pyruvate kinase (PK); citrate synthase (CS)) and anaerobic metabolism (lactate dehydrogenase (LDH)) in whole-body (28 days) or in gills, liver and muscle (345 days) of exposed fish. Additionally, whole-body oxygen consumption was evaluated in fish exposed for 28 days and hepatic and muscular expression of genes involved in mitochondrial metabolism (cox I, II and III and atp5a1) was assessed in animals exposed for 345 days. Finally, final survival was evaluated. Following 28 days, Cu did not affect survival neither enzyme activities. However, increased whole-body oxygen consumption was observed in comparison to control condition. After 345 days, 76.8%, 63.9%, 60.9% and 0% survival were observed for control, 5, 9 and 20 µg/L groups, respectively. Animals exposed to 5 and 9 µg/L had a significant reduction in branchial and muscular LDH activity and in hepatic PK activity. Also, exposure to 9 µg/L significantly increased hepatic CS activity. For gene expression, Cu down-regulated muscular cox II (9 µg/L) and III (5 and 9 µg/L), and up-regulated hepatic atp5a1 (9 µg/L). Findings reported in the present study indicate that chronic exposure to Cu induces tissue-specific responses in key aspects of the energetic metabolism. In gills and muscle, Cu leads to reduced energy production through inhibition of anaerobic pathways and mitochondrial respiratory chain. This effect is paralleled by an increased ATP consumption in the liver, characterized by the augmented CS activity and atp5a1 expression. Finally, reduced PK activity indicate that oxidative stress may be involved with the observed outcomes.


Assuntos
Cobre/toxicidade , Metabolismo Energético/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , L-Lactato Desidrogenase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Poecilia/metabolismo , Piruvato Quinase/metabolismo , Testes de Toxicidade Crônica
17.
Aquat Toxicol ; 211: 92-104, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30954848

RESUMO

The impact of freshwater (FW) salinization on osmoregulation as well as tracheal gill morphology and function was examined in nymphs of the mayfly Hexagenia rigida following exposure to salt contaminated water (SCW, 7.25 g/l NaCl) for a 7-day period. Ionoregulatory homeostasis was perturbed in SCW exposed H. rigida nymphs as indicated by increased hemolymph Na+, K+ and Cl- levels as well as hemolymph pH and water content. Despite this, SCW did not alter gill Na+-K+-ATPase (NKA) or V-type H+-ATPase (VA) activity. In addition, NKA and VA immunolocalization in gill ionocytes did not show alterations in enzyme location or changes in ionocyte abundance. The latter observation was confirmed using scanning electron microscopy (SEM) to examine exposed tracheal gill ionocyte numbers. Ionocyte surface morphometrics also revealed that SCW did not change individual ionocyte surface area or ionocyte fractional surface area. Nevertheless, analysis of Na+ movement across the tracheal gill of mayfly nymphs using scanning ion-selective electrode technique indicated that FW nymphs acquired Na+ from surrounding water, while tracheal gills of SCW nymphs had the capacity to secrete Na+. Because Na+ secretion across the gill of SCW-exposed animals occurred in the absence of any change in (1) NKA and VA activity or (2) ionocyte numbers/surface exposure, it was reasoned that Na+ movement across the gill of SCW animals may be occurring, at least in part, through the paracellular pathway. The ultrastructure of tracheal gill septate junctions (SJs) supported this idea as they exhibited morphological alterations indicative of a leakier pathway. Data provide a first look at alterations in osmoregulatory mechanisms that allow H. rigida nymphs to tolerate sub-lethal salinization of their surroundings.


Assuntos
Ephemeroptera/efeitos dos fármacos , Água Doce/química , Brânquias/efeitos dos fármacos , Osmorregulação/efeitos dos fármacos , Cloreto de Sódio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ephemeroptera/metabolismo , Brânquias/metabolismo , Hemolinfa/metabolismo , Salinidade , Sódio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Equilíbrio Hidroeletrolítico/efeitos dos fármacos
18.
Aquat Toxicol ; 211: 105-115, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30965178

RESUMO

Lacustrine ecosystems have been altered by accelerating pollution, excessive nutrient and organic load, water abstraction, and are susceptible to climate change. Hence, suggesting sensitive and reliable biomarkers for early assessments of their status is of urgent need. In this study, two freshwater commercial fish species, Cyprinus carpio (carp) and Carassius gibelio (prussian carp) from two lakes (i.e. Koronia and Volvi, Northern Greece) with different anthropogenic pressures were used and a battery of biochemical and molecular biomarkers related to stress response were analyzed in fish gills and liver. In parallel, water physicochemical parameters (T, DO, pH, conductivity, salinity), BOD5 and nutrient (N-NO3, N-NO2, N-NH4, P-PO4) concentrations were measured. Results showed that Lake Koronia had higher conductivity and salinity values and N-NO2 concentrations. Levels of Heat Shock Response (HSR), MAPK phosphorylation, protein carbonylation, lipid peroxidation products, Bax/Bcl-2 ratio, ubiquitination and caspases were increased in gills and liver of both fish species sampled from Lake Koronia in relation to those of Lake Volvi. Likewise, liver lipid content was increased in both fish species sampled from Lake Koronia compared to those sampled from Lake Volvi. The results indicate and reflect the higher environmental degradation that prevails in Lake Koronia ecosystem in comparison to that of Lake Volvi. The fish species studied showed different susceptibility depending on the biomarkers examined. In addition, our results from both examined species provide insight into the mechanisms involved in acclimatization to stressful environments and support the role of the studied biomarkers as sensitive and reliable tools for ecological assessments of lake ecosystems in biomonitoring studies.


Assuntos
Cyprinidae/metabolismo , Monitoramento Ambiental/métodos , Lagos/química , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Ecossistema , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Grécia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Região do Mediterrâneo , Salinidade
19.
Aquat Toxicol ; 211: 181-192, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31003043

RESUMO

Inappropriate processing and disposal of electronic waste contributes to the contamination of aquatic systems by various types of pollutants such as the rare-earth elements (REE) in which lanthanum (La) is included. Knowledge on the toxicity of these elements in marine organisms is still scarce when compared to other metals such as mercury (Hg) and arsenic (As). Therefore, this study aims to assess the toxicity of La on the mussel Mytilus galloprovincialis, considered a good bioindicator of aquatic pollution, through the analysis of metabolic, oxidative stress, neurotoxicity and histopathological markers. Organisms were exposed to different concentrations of La for a period of 28 days (0, 0.1, 1, 10 mg/L) under controlled temperature (18 °C ± 1.0) and salinity (30 ± 1) conditions. La concentrations in mussels increased in higher exposure concentrations. La exposure demonstrated a biochemical response in mussels, evidenced by lowered metabolism and accumulation of energy reserves, activation of the antioxidant defences SOD and GPx as well as the biotransformation enzymes GSTs, especially at intermediate concentrations. Despite oxidative stress being shown by a decrease in GSH/GSSG, oxidative damage was avoided as evidenced by lower LPO and PC levels. Inhibition of the enzyme AChE demonstrated the neurotoxicity of La in this species. Histopathological indices were significantly different from the control group, indicating impacts in gonads, gills and digestive glands of mussels due to La. These results show that La can be considered a risk for marine organisms and thus its discharge into the environment should be monitored.


Assuntos
Lantânio/toxicidade , Mytilus/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Biotransformação , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/metabolismo , Sistema Digestório/patologia , Ecotoxicologia , Biomarcadores Ambientais/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Brânquias/patologia , Gônadas/efeitos dos fármacos , Gônadas/metabolismo , Gônadas/patologia , Lantânio/metabolismo , Mytilus/metabolismo , Poluentes Químicos da Água/metabolismo
20.
Mar Pollut Bull ; 141: 194-204, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955726

RESUMO

The effect of increasing ocean water temperature on morpho-functional traits of Antarctic marine species is under intense attention. In this work, we evaluated the effects of acute heat stress on the gills of the Antarctic haemoglobinless Chionodraco hamatus and the red blooded Trematomus bernacchii in terms of morphology, heat shock response, antioxidant defense and NOS/NO system. We showed in both species that the exposure to high temperature (4 °C) induced structural alterations, such as epithelial lifting and oedema of secondary lamellae. By immunolocalization we also observed that HSP-90, HSP-70, Xantine Oxidase, Heme Oxigenase and NOS are expressed in both species under control conditions. After heat stress the signals increase in C. hamatus being absent/or reduced in T. bernacchii. Our preliminary results suggest a specie-specific morpho-functional response of the gills of the two Antarctic teleosts to heat stress.


Assuntos
Monitoramento Ambiental/métodos , Brânquias/patologia , Resposta ao Choque Térmico , Perciformes/fisiologia , Animais , Regiões Antárticas , Apoptose/fisiologia , Feminino , Brânquias/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Masculino , Perciformes/metabolismo , Água do Mar/química , Especificidade da Espécie , Temperatura Ambiente
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