RESUMEN
Roundup Transorb® (RDT) is the most popular glyphosate-based herbicide (GHB) used in agriculture, and its impact extends to non-target organisms. The annual killifish Austrolebias charrua is an endangered species endemic to southern South America and inhabits temporary ponds. This study evaluates the effects of RDT concentrations (0.065 and 5 mg/L GAE) on A. charrua exposed for 96 h. Gene expression of cat, sod2, gstα, gclc, and ucp1 was evaluated on the liver and gills. Highlighting that even at low concentrations permitted by Brazilian legislation, the RDT can have adverse effects on A. charrua.
Asunto(s)
Antioxidantes , Glicina , Glifosato , Herbicidas , Contaminantes Químicos del Agua , Animales , Contaminantes Químicos del Agua/toxicidad , Herbicidas/toxicidad , Glicina/análogos & derivados , Glicina/toxicidad , Proyectos Piloto , Fundulidae/genética , Expresión Génica/efectos de los fármacos , Superóxido Dismutasa/metabolismo , Hígado/metabolismo , Hígado/efectos de los fármacos , Brasil , Branquias/metabolismo , Peces KilliRESUMEN
The cyanobacterium Synechococcus elongatus PCC 7942 holds significant potential as a biofactory for recombinant protein (RP) production due to its capacity to harness light energy and utilize CO2. This study aimed to enhance RP production by integration of native promoters and magnetic field application (MF) in S. elongatus PCC 7942. The psbA2 promoter, which responds to stress conditions, was chosen for the integration of the ZsGreen1 gene. Results indicated successful gene integration, affirming prior studies that showed no growth alterations in transgenic strains. Interestingly, exposure to 30 mT (MF30) demonstrated a increase in ZsGreen1 transcription under the psbA2 promoter, revealing the influence of MF on cyanobacterial photosynthetic machinery. This enhancement is likely attributed to stress-induced shifts in gene expression and enzyme activity. MF30 positively impacted photosystem II (PSII) without disrupting the electron transport chain, aligning with the "quantum-mechanical mechanism" theory. Notably, fluorescence levels and gene expression with application of 30 mT were significantly different from control conditions. This study showcases the efficacy of utilizing native promoters and MF for enhancing RP production in S. elongatus PCC 7942. Native promoters eliminate the need for costly exogenous inducers and potential cell stress. Moreover, the study expands the scope of optimizing RP production in photoautotrophic microorganisms, providing valuable insights for biotechnological applications.
Asunto(s)
Synechococcus , Regiones Promotoras Genéticas , Synechococcus/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMEN
In the field of shrimp aquaculture, the utilization of probiotics represents a promising avenue, due to the well-documented benefits conferred by these microorganisms. In the current study, a Bacillus subtilis strain, referred to as strain E, was isolated from the gastrointestinal tract of the shrimp Litopenaeus vannamei and subsequently identified via molecular methods and phylogeny. The probiotic potential of strain E was characterized, and its application as a feed shrimp additive was evaluated in a 45-day experiment. Several parameters were assessed, including zootechnical performance, muscle tissue proximate composition, hepatopancreas lipid concentration, and the expression of genes associated with digestion, amino acid metabolism, and antioxidant defense mechanisms in various shrimp tissues. Although no significant impact on zootechnical performance was observed, supplementation with strain E led to an increase in lipid concentration within both muscle and hepatopancreas tissues. Furthermore, a marked decrease in the expression of genes linked to digestion and amino acid metabolism was noted. These findings suggest that the addition of the B. subtilis strain E to shrimp feed may enhance nutrient absorption and modulate the expression of genes related to digestion and amino acid metabolism.
Asunto(s)
Bacillus subtilis , Penaeidae , Animales , Bacillus subtilis/genética , Penaeidae/genética , Penaeidae/metabolismo , Aminoácidos/metabolismo , Digestión , Lípidos , Inmunidad InnataRESUMEN
This study aimed to analyze the effect of magnetic field (MF) application on the metabolism of Synechococcus elongatus PCC 7942. Concentrations of biomass, carbohydrate, protein, lipid, and photosynthetic pigments (chlorophyll-a, C-phycocyanin, allophycocyanin and phycoerythrin) were determined. In cultures with MF application (30 mT for 24 h d-1), there were increases of 47.5% in total protein content, 87.4% in C-phycocyanin, and 332.8% in allophycocyanin contents, by comparison with the control. Allophycocyanin is the most affected pigment by MF application. Therefore, its biosynthetic route was investigated, and four genes related to its synthesis were found. However, the analysis of the gene expression showed no statistical differences from the control culture, which suggests that induction of such genes may occur soon after MF application with consequent stabilization over time. MF application may be a cost-effective alternative to increase production of compounds of commercial interest by cyanobacteria.
Asunto(s)
Ficocianina , Synechococcus , Ficocianina/genética , Ficocianina/metabolismo , Ficobiliproteínas/metabolismo , Ficobiliproteínas/farmacología , Synechococcus/genética , Campos MagnéticosRESUMEN
It is known that probiotic microorganisms play important roles in the composition of the intestinal microbiota. Also, probiotics can affect the paracellular and transcellular transport mechanisms performed by intestinal cells. The aim of this work was to evaluate the effect of the potential probiotic Bacillus subtilis KM0 on the profile of the gut microbiota and transcription of genes related to intestinal transport of zebrafish (Danio rerio). Zebrafish was exposed by immersion to B. subtilis KM0 for 48 h, and the intestines were collected for metataxonomic analysis and transcription of genes related to transcellular and paracellular transports. Although exposure to B. subtilis changed the intestinal microbiota profile of zebrafish, the diversity indices were not altered. A decrease in the number of genera of potentially pathogenic bacteria (Flavobacterium, Plesiomonas, and Pseudomonas) and downregulation in transcription of transcellular transport genes (cubn and amn) were observed. B. subtilis KM0 strain had the expected probiotic effect, by interfering with the proliferation of potentially pathogenic bacteria and decreasing the transcription of genes codifying for signals involved with a mechanism that can be used for invasion by pathogens. The present study demonstrated that, even with a short-term exposure, a bacterium with probiotic potential such as the KM0 strain of B. subtilis can modify the profile of the host's intestinal microbiota, with an impact on the regulation of intestinal genes related to mechanisms that can be used for invasion by pathogenic bacteria.
Asunto(s)
Microbioma Gastrointestinal , Probióticos , Animales , Bacillus subtilis/genética , Pez Cebra/microbiología , Intestinos/microbiologíaRESUMEN
Overexpression of growth hormone (GH) in gh-transgenic zebrafish of a highly studied lineage F0104 has earlier been reported to cause increased muscle growth. In addition to this, GH affects a broad range of cellular processes in transgenic fish, such as morphology, physiology, and behavior. Reports show changes such as decreased sperm quality and reduced reproductive performance in transgenic males. It is hypothesized that microRNAs are directly involved in the regulation of fertility potential during spermatogenesis. The primary aim of our study was to verify whether gh overexpression disturbs the sperm miRNA profile and influences the sperm quality in transgenic zebrafish. We report a significant increase in body weight of gh-transgenic males along with associated reduced sperm motility and other kinetic parameters in comparison to the non-transgenic group. MicroRNA transcriptome sequencing of gh-transgenic zebrafish sperms revealed expressions of 186 miRNAs, among which six miRNA were up-regulated (miR-146b, miR-200a-5p, miR-146a, miR-726, miR-184, and miR-738) and sixteen were down-regulated (miR-19d-3p, miR-126a-5p, miR-126b-5p, miR-22a-5p, miR-16c-5p, miR-20a-5p, miR-126b-3p, miR-107a-3p, miR-93, miR-2189, miR-202-5p, miR-221-3p, miR-125a, miR-125b-5p, miR-126a-3p, and miR-30c-5p) in comparison to non-transgenic zebrafish. Some of the dysregulated miRNAs were previously reported to be related to abnormalities in sperm quality and reduced reproduction ability in other species. In this study, an average of 134 differentially expressed miRNAs-targeted genes were predicted using the in silico approach. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis demonstrated that the genes of affected pathways were primarily related to spermatogenesis, sperm motility, and cell apoptosis. Our results suggested that excess GH caused a detrimental effect on sperm microRNAome, consequently reducing the sperm quality and reproductive potential of zebrafish males.
RESUMEN
Reference genes (RGs) must have a stable expression in tissues in all experimental conditions to normalize real-time quantitative reverse transcription PCR (qRT-PCR) data. F0104 is a highly studied lineage of zebrafish developed to overexpress the growth hormone (GH). It is assumed that the transgenic process may influence the expression levels of commonly used RGs. The objective of the present study was to make a comprehensive analysis of stability of canditade RGs actb1, actb2, b2m, eif2s2, eef1a1, gapdh, rplp2, rpl7, rpl13α, tuba1, and rps18, in gh-transgenic and non-transgenic zebrafish. Liver, brain, intestine and muscle samples from both groups had qRT-PCR results analyzed by dCt, geNorm, NormFinder, BestKeeper, and RefFinder softwares. Consensus analyses among software concluded that rpl13α, rpl7, and eef1a1 are the most stable genes for zebrafish, considering the studied groups and tissues. Gapdh, rps18, and tuba1 suffered variations in stability among different tissues of both groups, and so, they were listed as the genes with lowest stability. Results from an average pairwise variations test indicated that the use of two RGs would generate reliable results for gene expression analysis in the studied tissues. We conclude that genes that are commonly used in mammals for qRT-PCR assays have low stability in both non-transgenic and gh-transgenic zebrafish reinforcing the importance of using species-specific RGs.
Asunto(s)
Hormona del Crecimiento/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/normas , Proteínas de Pez Cebra/genética , Pez Cebra/genética , Animales , Animales Modificados Genéticamente , Química Encefálica , Intestinos/química , Hígado/química , Músculo Esquelético/química , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Estándares de Referencia , Programas InformáticosRESUMEN
Dietary supplements are commonly used by animals and humans and play key roles in diverse systems, such as the immune and reproductive systems, and in metabolism. Essential oils (EOs), which are natural substances, have potential for use in food supplementation; however, their effects on organisms remain to be elucidated. Here, we examine the effects of dietary Aloysia triphylla EO supplementation on zebrafish behavior, metabolism, stress response, and growth performance. We show that fish fed diets containing A. triphylla EO presented an anxiolytic response, with reduced exploratory activity and oxygen consumption; no changes were observed in neuroendocrine stress axis functioning and growth was not impaired. Taken together, these results suggest that the A. triphylla EO supplementation is a strong candidate for use in feed, since it ensures fish welfare (anxiolytic behavior) with decreased oxygen consumption. This makes it suitable for use in high-density production systems without causing damage to the neuroendocrine stress axis and without growth performance being impaired.
Asunto(s)
Conducta Animal/efectos de los fármacos , Suplementos Dietéticos , Aceites de Plantas/administración & dosificación , Verbenaceae/química , Pez Cebra/fisiología , Animales , Consumo de Oxígeno/efectos de los fármacos , Extractos Vegetales/farmacología , Estrés Fisiológico/efectos de los fármacos , Pez Cebra/crecimiento & desarrolloRESUMEN
The method usually employed to stimulate gonadal maturation and spawning of captive shrimp involves unilateral eyestalk ablation, which results in the removal of the endocrine complex responsible for gonad-inhibiting hormone (GIH) synthesis and release. In the present study, RNAi technology was used to inhibit transcripts of GIH in Litopenaeus vannamei females. The effect of gene silencing on gonad development was assessed by analyzing the expression of GIH and vitellogenin, respectively, in the eyestalk and ovaries of L. vannamei females, following ablation or injection with dsRNA-GIH, dsRNA-IGSF4D (non-related dsRNA), or saline solution. Histological analyses were performed to determine the stage of gonadal development and to assess the diameter of oocytes throughout the experimental procedure. Only oocytes at pre-vitellogenesis and primary vitellogenesis stages were identified in females injected with dsRNA-GIH, dsRNA-IGSF4D, or saline solution. Oocytes at all developmental stages were observed in eyestalk-ablated females, with predominance of later stages, such as secondary vitellogenesis and mature oocytes. Despite achieving 64, 73, and 71% knockdown of eyestalk GIH mRNA levels by 15, 30, and 37 days post-injection (dpi), respectively, in dsRNA-GIH-injected females, the expected increase in ovary vitellogenin mRNA expression was only observed on the 37th dpi. This is the first report of the use of RNAi technology to develop an alternative method to eyestalk ablation in captive L. vannamei shrimps.
Asunto(s)
Proteínas Portadoras/genética , Hormonas de Invertebrados/genética , Ovario/crecimiento & desarrollo , Inducción de la Ovulación/métodos , Penaeidae/genética , Interferencia de ARN , Vitelogénesis/genética , Animales , Femenino , Técnicas de Silenciamiento del Gen/métodos , Silenciador del Gen , Ovario/citología , Penaeidae/crecimiento & desarrollo , Factores de Transcripción/genéticaRESUMEN
It has been reported that nuclear translocation of growth hormone receptor (GHR) may directly activate cell proliferation in mammals and birds. However, this phenomenon has not yet been described in fish. Recently, we have developed a transgenic zebrafish that overexpresses GHR in a muscle-specific manner. Considering that this transgenic model exhibits hyperplasic muscle growth, the present work aims at verifying the relationship between GHR nuclear translocation and muscle cell proliferation. This relationship was evaluated by the phosphorylation state of the proliferative MEK/ERK pathway, expression of nuclear import-related genes, immunostaining of phospho-histone H3 (PH3) as a proliferation marker, and nuclear GHR localization. The results showed a significant decrease in the phosphorylation state of ERK1/2 proteins in transgenics. Moreover, there was an increase in expression of three out of four importin genes analyzed parallel to a large flow of GHR displacement toward and into the nucleus of transgenic muscle cells. Also, transgenics presented a marked increase in PH3 staining, which indicates cell proliferation. These findings, as far as we know, are the first report suggesting a proliferative action of GHR in fish as a consequence of its increased nuclear translocation. Thus, it appears that the nuclear migration of cytokine receptors is a common event among different taxonomic groups. In addition, the results presented here highlight the possibility that these membrane proteins may be involved more directly than previously thought in the control of genes related to cell growth and proliferation.
Asunto(s)
Músculo Esquelético/metabolismo , Receptores de Somatotropina/metabolismo , Transporte Activo de Núcleo Celular , Animales , Animales Modificados Genéticamente , Hiperplasia/metabolismo , Sistema de Señalización de MAP Quinasas , Músculo Esquelético/patología , Pez CebraRESUMEN
Hybridization between hawksbill (Eretmochelys imbricata) and loggerhead (Caretta caretta) breeding groups is unusually common in Bahia state, Brazil. Such hybridization is possible because hawksbill and loggerhead nesting activities overlap temporally and spatially along the coast of this state. Nevertheless, the destinations of their offspring are not yet known. This study is the first to identify immature hawksbill × loggerhead hybrids (n = 4) from this rookery by analyzing the mitochondrial DNA (mtDNA) of 157 immature turtles morphologically identified as hawksbills. We also compare for the first time modeled dispersal patterns of hawksbill, loggerhead, and hybrid offspring considering hatching season and oceanic phase duration of turtles. Particle movements varied according to season, with a higher proportion of particles dispersing southwards throughout loggerhead and hybrid hatching seasons, and northwards during hawksbill season. Hybrids from Bahia were not present in important hawksbill feeding grounds of Brazil, being detected only at areas more common for loggerheads. The genetic and oceanographic findings of this work indicate that these immature hybrids, which are morphologically similar to hawksbills, could be adopting behavioral traits typical of loggerheads, such as feeding in temperate waters of the western South Atlantic. Understanding the distribution, ecology, and migrations of these hybrids is essential for the development of adequate conservation and management plans.
RESUMEN
Growth hormone (GH) is an important regulator of immune functions in vertebrates, and it has been intensively reported a series of stimulatory actions of this hormone over on the immune system. Within aquaculture, overexpression of GH has been considered a promising alternative for promoting higher growth rates in organisms of commercial interest. Considering the various pleiotropic effects of GH, there are still few studies that aim to understand the consequences of the excess of GH on the physiological systems. In this context, our goal was to present the effects of the overexpression of GH on immune parameters using a model of zebrafish (Danio rerio) that overexpress this hormone. The results showed that GH transgenic zebrafish had 100% of mortality when immunosuppressed with dexamethasone, revealing a prior weakening of the immune system in this lineage. Morphometric analysis of thymus and head kidney revealed a reduction in the area of these structures in transgenic zebrafish. Moreover, the phenotypic expression of CD3 and CD4 thymocytes was also depreciated in transgenic zebrafish. Furthermore, a decrease was noted in the expression of genes RAG-1 (60%), IKAROS (50%), IL-1ß (55%), CD4 (60%) and CD247 (40%), indicating that development parameters, of innate and acquired immunity, are being harmed. Based on these results, it can be concluded that the excess of GH impairs the immune functions in GH transgenic zebrafish, indicating that the maintenance of normal levels of this hormone is essential for the functioning of immunological activities.
Asunto(s)
Regulación de la Expresión Génica , Hormona del Crecimiento/genética , Sistema Inmunológico/fisiopatología , Pez Cebra/genética , Pez Cebra/inmunología , Inmunidad Adaptativa , Animales , Animales Modificados Genéticamente/genética , Animales Modificados Genéticamente/metabolismo , Hormona del Crecimiento/metabolismo , Riñón Cefálico/crecimiento & desarrollo , Riñón Cefálico/metabolismo , Inmunidad Innata , Inmunohistoquímica/veterinaria , Timo/crecimiento & desarrollo , Timo/metabolismo , Pez Cebra/crecimiento & desarrolloRESUMEN
Growth hormone (GH) transgenesis has been postulated as a biotechnological tool for improving growth performance in fish aquaculture. However, GH is implied in several other physiological processes, and transgenesis-induced GH excess could lead to unpredictable collateral effects, especially on reproductive traits. Here, we have used two-years-old transgenic zebrafish males to evaluate the effects of GH-transgenesis on spermatic parameters and reproductive success. Transgenic spermatozoa were analyzed in terms of motility, motility period, membrane integrity, mitochondrial functionality, DNA integrity, fertility and hatching rate. We have also performed histological analyses in gonad, in order to verify the presence of characteristic cell types from mature testes. The results obtained have shown that, even in transgenic testes present in all cells in normal mature gonads, a significant general decrease was observed in all spermatic and reproductive parameters analyzed. These outcomes raise concerns about the viability of GH-transgenesis appliance to aquaculture and the environmental risks at the light of Trojan gene hypothesis.
Asunto(s)
Hormona del Crecimiento/fisiología , Reproducción/fisiología , Espermatozoides/fisiología , Pez Cebra/fisiología , Animales , Animales Modificados Genéticamente , Membrana Celular/fisiología , Hormona del Crecimiento/genética , Histocitoquímica/veterinaria , Masculino , Mitocondrias/fisiología , Reproducción/genética , Motilidad Espermática/genética , Motilidad Espermática/fisiología , Estadísticas no Paramétricas , Pez Cebra/genéticaRESUMEN
The presence of higher level of exogenous growth hormone (GH) in transgenic animals could lead to several physiological alterations. A GH transgenic zebrafish (Danio rerio) line was compared to nontransgenic (NT) samples of the species through a DDRT-PCR approach, with the goal of identifying candidate differentially expressed transcripts in brain tissues that could be involved in GH overexpression. Densitometric analyses of two selected amplification products, p300 and ADCY2, pointed to a significant lower gene expression in the transgenic zebrafish (104.02 ± 57.71; 224.10 ± 91.73) when compared to NT samples (249.75 ± 30.08; 342.95 ± 65.19). The present data indicate that p300 and ADCY2 are involved in a regulation system for GH when high circulating levels of this hormone are found in zebrafishes.
Asunto(s)
Animales Modificados Genéticamente/genética , Encéfalo/metabolismo , Hormona del Crecimiento/genética , Pez Cebra/genética , Animales , Animales Modificados Genéticamente/metabolismo , Regulación de la Expresión Génica , Hormona del Crecimiento/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Pez Cebra/metabolismoRESUMEN
The aim of this study was to evaluate the effects of growth hormone (GH) overexpression on the gene expression profile of multiple components of the antioxidant defense system (ADS) of different genotypes of a GH-transgenic zebrafish (Danio rerio) model. Several ADS-related genes were analyzed by semiquantitative reverse transcription-PCR in the liver of hemizygous (HE) and homozygous (HO) transgenic zebrafish. The results showed a significant reduction in the glutamate cysteine ligase catalytic subunit (GCLC) and the gene expression of two glutathione S-transferase (GST) isoforms and an increase in the glutathione reductase gene in the HO group compared to non-transgenic controls. The expression of the Cu, Zn-superoxide dismutase (SOD1) and catalase (CAT) genes was reduced in HO and HE groups, respectively. Among the ten genes analyzed, two were altered in HE transgenic zebrafish and five were altered in HO transgenic zebrafish. These findings indicate a genotype-dependent gene expression profile of the ADS-related genes in the liver of our GH-transgenic zebrafish model and are in agreement with the general effects of GH hypersecretion in the fish and mouse, which involves a reduction in the capability of the tissues to deal with oxidative stress situations. The GH-transgenic zebrafish model used here seems to be an interesting tool for analyzing the effect of different GH expression levels on physiological processes.
Asunto(s)
Animales Modificados Genéticamente/metabolismo , Antioxidantes/metabolismo , Perfilación de la Expresión Génica , Hormona del Crecimiento/genética , Hígado/enzimología , Modelos Animales , Pez Cebra/metabolismo , Animales , Animales Modificados Genéticamente/genética , Regulación de la Expresión Génica , Genotipo , Glutamato-Cisteína Ligasa/genética , Glutamato-Cisteína Ligasa/metabolismo , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Hemicigoto , Homocigoto , Estrés Oxidativo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Pez Cebra/genéticaRESUMEN
The aim of the present study was to analyse the morphology of white skeletal muscle in males and females from the GH-transgenic zebrafish (Danio rerio) lineage F0104, comparing the expression of genes related to the somatotrophic axis and myogenesis. Histological analysis demonstrated that transgenic fish presented enhanced muscle hypertrophy when compared to non-transgenic fish, with transgenic females being more hypertrophic than transgenic males. The expression of genes related to muscle growth revealed that transgenic hypertrophy is independent from local induction of insulin-like growth factor 1 gene (igf1). In addition, transgenic males exhibited significant induction of myogenin gene (myog) expression, indicating that myog may mediate hypertrophic growth in zebrafish males overexpressing GH. Induction of the α-actin gene (acta1) in males, independently from transgenesis, also was observed. There were no significant differences in total protein content from the muscle. Our results show that muscle hypertrophy is independent from muscle igf1, and is likely to be a direct effect of excess circulating GH and/or IGF1 in this transgenic zebrafish lineage.
Asunto(s)
Animales Modificados Genéticamente/genética , Hormona del Crecimiento/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Músculo Esquelético/patología , Regulación hacia Arriba , Pez Cebra/genética , Animales , Modelos Animales de Enfermedad , Femenino , Hormona del Crecimiento/genética , Humanos , Hipertrofia/genética , Hipertrofia/metabolismo , Factor I del Crecimiento Similar a la Insulina/genética , Masculino , Desarrollo de Músculos/genética , Músculo Esquelético/metabolismo , Factores Sexuales , Pez Cebra/metabolismoRESUMEN
The K562 cell line (chronic myeloid leukemia), sensitive to chemotherapy (non-MDR), and the Lucena cell line, resistant to chemotherapy (MDR) were investigated. The results suggest that both cell lines possess CD34+CD38- profiles of hematopoietic stem cell markers. The promoter regions of ABCB1, ABCG2 and ABCC1 genes contain binding sites for the Oct-4 transcripton factor, which is also considered a marker of tumor stem cells. Lucena cells showed an over-expression of the ABCB1 gene and a high expression of the Oct-4, ABCG2 and ABCC1 genes as compared to K562 cells.
Asunto(s)
Biomarcadores de Tumor/genética , Resistencia a Múltiples Medicamentos/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Células Madre Neoplásicas/metabolismo , ADP-Ribosil Ciclasa 1/genética , ADP-Ribosil Ciclasa 1/metabolismo , Subfamilia B de Transportador de Casetes de Unión a ATP , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/genética , Antígenos CD34/genética , Antígenos CD34/metabolismo , Antígenos de Superficie/genética , Antígenos de Superficie/metabolismo , Sitios de Unión , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Resistencia a Múltiples Medicamentos/fisiología , Resistencia a Antineoplásicos/genética , Regulación Leucémica de la Expresión Génica , Humanos , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Proteínas de Neoplasias/genética , Células Madre Neoplásicas/patología , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Regiones Promotoras GenéticasRESUMEN
In fishes, arsenic (As) is absorbed via the gills and is capable of causing disturbance to the antioxidant system. The objective of present study was to evaluate antioxidant responses after As exposure in gills of zebrafish (Danio rerio, Cyprinidae). Fish were exposed for 48 h to three concentration of As, including the highest As concentration allowed by current Brazilian legislation (10 microg As/L). A control group was exposed to tap water (pH 8.0; 26 degrees C; 7.20 mg O(2)/L). As exposure resulted in (1) an increase (p<0.05) of glutathione (GSH) levels after exposure to 10 and 100 microg As/L, (2) an increase of the glutamate cysteine ligase (GCL) activity in the same concentrations (p<0.05), (3) no significant differences in terms of glutathione reductase, glutathione-S-transferase and catalase activities; (4) a significantly lower (p<0.05) oxygen consumption after exposure to 100 microg As/L; (4) no differences in terms of oxygen reactive species generation and lipid peroxidation content (p>0,05). In the gills, only inorganic As was detected. Overall, it can be concluded that As affected the antioxidant responses increasing GCL activity and GSH levels, even at concentration considered safe by Brazilian legislation.
Asunto(s)
Antioxidantes/metabolismo , Arsénico/toxicidad , Branquias/metabolismo , Pez Cebra/metabolismo , Animales , Arsénico/metabolismo , Branquias/efectos de los fármacos , Glutatión/metabolismo , Glutatión Reductasa/metabolismo , Glutatión Transferasa/metabolismo , Peroxidación de Lípido , Consumo de Oxígeno/efectos de los fármacosRESUMEN
The objective of this study was to evaluate the time-course effects of UV-B exposure on expression of genes involved in the DNA repair system of zebrafish (Danio rerio) hepatocytes, a highly competent species in terms of damage repair induced by UV radiation. For gene expression analysis (RT-PCR), cells were exposed to 23.3 mJ cm(-2) UV-B, which was the dose that affected viable cell number (reduction of 30% when compared with the control group) and produced no visual alteration on cell morphology. The early response observed (6 h) showed induction in the expression of the CDKI gene (cyclin-dependent kinase inhibitor) and genes related to DNA damage repair (mainly XPC and DDB2), while the late response observed (24 h) was more related to up-regulation of p53 and genes involved in cell cycle arrest (gadd45a, cyclinG1). In all times analyzed, the anti-apoptotic gene Bcl-2 was down-regulated. Another interesting result observed was the up-regulation of the Apex-1 gene after UV-B exposure, which could indicate the induction of oxidative lesions in the DNA molecule. In conclusion, these results demonstrate an activation of the DNA repair system in hepatocytes of zebrafish exposed to UV-B radiation, mainly involving the participation of p53.