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ABSTRACT:
PROVIDER: PRJNA748534 | ENA |
REPOSITORIES: ENA
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Project description:Custom D. magna gene expression microarray (Design ID: 023710, Agilent Technologies)were used to characterise gene expression profiles of Daphnia magna neoantes exposed to silver nanoparticles ( AgNPs ) or silver nitrate ( AgNO3 ) for 24 hours.
2016-04-01 | E-MTAB-4041 | biostudies-arrayexpress
Project description:Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk- and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24h of exposure, but with a recovery at 48h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24h, but not at 48h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms. mRNA profiles of whole zebrafish embryos at 24 and 48 hours post-fertilisation (hpf) exposed to silver in nano, bulk and ionic forms were generated by deep sequencing using HT-SuperSAGE (Illumina GA2).
2013-06-17 | E-GEOD-38125 | biostudies-arrayexpress
Project description:Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk- and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24h of exposure, but with a recovery at 48h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24h, but not at 48h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms.
2013-06-17 | GSE38125 | GEO
Project description:From the result of the gene expression analyses of human hepatoma cell line, HepG2, a number of genes associated with cell proliferation and DNA repair were distinctively up-regulated by Ag-nanoparticle exposure, suggesting that Ag-nanoparticles might stimulate cell proliferation and DNA damage, which are considered to be mechanisms playing an important role for carcinogenesis and tumor progression. The inductions of these genes involved in cell proliferation were also observed in PS-nanoparticles and Ag2CO3-exposed cells. In addition, the inductions of DNA repair-associated genes were also observed in Ag2CO3-exposure. These results suggest that both “nanoshape” and “silver” can cause the inductions of these gene expression patterns. Furthermore, cysteine, a strong ionic silver ligand partially abolished these gene expressions induced by silver nanoparticles. Ionic silver sourced from Ag-nanoparticles could not fully explain these gene expressions.
2009-06-01 | GSE14452 | GEO
Project description:Effects of silver nanoparticles (Ag NPs) on freshwater species have been reported in several studies, but there is not information on the potential long-term consequences of a previous exposure. In this work, we investigated the long-term effects of maltose-coated Ag NPs (20 nm) and of ionic silver (10 µg/L) after 21 days of exposure and at 6 months post-exposure (mpe) in adult zebrafish. Exposure resulted in significant silver accumulation in the whole body of fish exposed to ionic silver, but not in those exposed to Ag NPs. However, autometallography revealed metal accumulation in the liver and intestine of fish treated with the two silver forms and especially in the intestine of fish exposed to Ag NPs. X-ray microanalysis showed the presence of silver in gills, liver and intestine and of Ag NPs in gill and liver cells. Inflammation and hyperplasia were evident in the gills after both treatments and these histopathological conditions remained at 6 mpe. According to the hepatic transcriptome analysis, at 3 days ionic silver regulated a larger number of transcripts (410) than Ag NPs (129), while at 21 days Ag NPs provoked a stronger effect (799 vs 165 regulated sequences). Gene ontology terms such as “metabolic processes” and “response to stimulus” appeared enriched after all treatments, while “immune system” or “reproductive processes” were specifically enriched after the exposure to Ag NPs. This suggests that the toxicity of Ag NPs may not be solely related to the release of Ag ions, but also to the NP form. No evident effects were found on protein oxidation or on hepatocyte lysosomal membrane stability during exposure, but effects recorded on liver lysosomes and persistent damage on gill tissue at 6 mpe could indicate potential for long-term effects in exposed fish.
2018-06-12 | GSE89653 | GEO
Project description:Applications for silver nanomaterials in consumer products are rapidly expanding, creating an urgent need for toxicological examination of the exposure potential and ecological effects of silver nanoparticles (AgNPs). The integration of genomic techniques into environmental toxicology has presented new avenues to develop exposure biomarkers and investigate the mode of toxicity of novel chemicals. In the present study we used a 15k oligonucleotide microarray for Daphnia magna, a freshwater crustacean and common indicator species for toxicity, to differentiate between particle specific and ionic silver toxicity and to develop exposure biomarkers for citrate-coated and PVP-coated AgNPs. Gene expression profiles revealed that AgNO3 and AgNPs have distinct expression profiles suggesting different modes of toxicity. However, the gene expression profiles of the different coated AgNPs were similar revealing similarities in the cellular effects of these two particles. Major biological processes disrupted by the AgNPs include protein metabolism and signal transduction. In contrast, AgNO3 caused a downregulation of developmental processes, particularly in sensory development. Metal responsive and DNA damage repair genes were induced by the PVP AgNPs, but not the other treatments. In addition, two specific biomarkers were developed for the environmental detection of PVP AgNPs; although further verification under different environmental conditions is needed. We exposed Daphnia magna to the 1/10 LC50 and LC25 of citrate coated and PVP-coated Ag nanoparticles and Ag+ as AgNO3 for 24-h. For each exposure condition, we performed 6 replicate exposures with 5 individuals in each. All exposures were compared to a unexposed laboratory control.
2012-08-04 | E-GEOD-35150 | biostudies-arrayexpress
Project description:The toxicity of silver and zinc oxide nanoparticles is hypothesised to be mediated by dissolved metal ions and cerium dioxide nanoparticles (CeO2 NPs) are hypothesised to induce toxicity specifically by oxidative stress dependant on their surface redox state. To test these hypotheses, RNAseq was applied to characterise the molecular responses of cells to metal nanoparticle and metal ion exposures. The human epithelial lung carcinoma cell line A549 was exposed to different CeO2 NPs with different surface charges, micron-sized and nano-sized silver particles and silver ions, micron-sized and nano-sized zinc oxide particles and zinc ions, or control conditions, for 1 hour, 6 hours and 24 hours. Concentrations were the lower of either EC20 or 128 micrograms/mL. Transcriptional responses were characterised by RNAseq transcriptomics using an Illumina HiSeq2500 .
2018-02-01 | E-MTAB-5734 | biostudies-arrayexpress
Project description:Nanoparticles are compounds of emerging concern with largely unknown risks for human and ecological health. It is crucial to evaluate their potential biological impact to prevent unintended adverse effects on human health and the environment. We analyzed the transcriptional effects of polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) and silver nitrate (AgNO3) on the fathead minnow (Pimephales promelas) to understand their potential toxicity and adverse outcomes. We also tested the feasibility of the fathead minnow as an alternative species to elucidate potential adverse effects on humans. Fathead minnow females were exposed to either 4 µg/L of AgNO3 or 70 µg/L of PVP-AgNPs for 96h. Microarray analyses were performed on liver and brain. Functional analysis identified potential toxicity pathways and molecular initiating events (MIEs) that were confirmed with functional assays. Data suggested that AgNO3 and PVP-AgNPs had both common and distinct transcriptional effects. The nanoparticles were linked to neurotoxicity and oxidative stress, and identified as a dopamine receptor antagonist. Silver nitrate was also identified as a potential neurotoxicant and was confirmed as adrenergic and cannabinoid receptors antagonist. While silver nitrate and PVP-AgNPs were both potential neurotoxicants, they appeared to act through different MIEs. Fathead minnow is a promising alternative species to elucidate potential adverse effects of relevance to human health. We analyzed the transcriptional effects of polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) and silver nitrate (AgNO3) on the fathead minnow (Pimephales promelas) to understand their potential toxicity and adverse outcomes. FHM were obtained from Aquatic Biosystems (Fort Collins, CO), held in aerated dechlorinated tap water and fed three times daily with Zeigler® AquaTox Feed Gardners, PA, USA). Fathead minnow females were exposed to either 4 µg/L of AgNO3 or 70 µg/L of PVP-AgNPs (Luna Innovations, Blackburn, VA) for 96h at 24°C ± 1 with a 90% water change at 48 hours. Microarray analyses were performed on liver and brain.
2013-11-01 | E-GEOD-46520 | biostudies-arrayexpress
Project description:Despite considerable research effort devoted to the study of the effects of silver nanoparticles on mammalian cells in recent years, data on the potential long terms effects of this nanomaterial remain scarce, and centered on epithelial cells. The aim of this study was to explore the effects of silver nanoparticles on macrophages. To this end, RAW 264.7 murine macrophages were exposed to either 1 µg/ml silver nanoparticles for 20 days, i.e. a chronic exposure scheme, or to 20 µg/ml silver nanoparticles for 24 hours, i.e. an acute exposure scheme. A proteomic study was then conducted to study and compare the cellular responses to both exposure schemes. They proved to be essentially different, and stronger for the chronic exposure scheme. Targeted validation studies showed effects of chronic exposure to silver nanoparticles on detoxifying enzymes such as biliverdin reductase B, which was increased, and on central metabolism enzymes such as triose phosphate isomerase, which activity decreased under chronic exposure to silver nanoparticles. Chronic exposure to silver nanoparticles also induced a decrease of reduced glutathione content, a decreased phagocytic activity and reduced macrophages responses to lipopolysaccharide, as exemplified by nitric oxide and interleukin 6 production. Overall, chronic exposure to silver nanoparticles induced stronger effects than acute exposure on macrophages in the metabolic (glutathione level, mitochondrial potential) and functional (phagocytosis, cytokine production) parameters tested.
2020-12-21 | PXD016379 | Pride
Project description:Despite considerable research effort devoted to the study of the effects of silver nanoparticles on mammalian cells in recent years, data on the potential long terms effects of this nanomaterial remain scarce, and centered on epithelial cells. The aim of this study was to explore the effects of silver nanoparticles on macrophages. To this end, RAW 264.7 murine macrophages were exposed to either 1 µg/ml silver nanoparticles for 20 days, i.e. a chronic exposure scheme, or to 20 µg/ml silver nanoparticles for 24 hours, i.e. an acute exposure scheme. A proteomic study was then conducted to study and compare the cellular responses to both exposure schemes. They proved to be essentially different, and stronger for the chronic exposure scheme. Targeted validation studies showed effects of chronic exposure to silver nanoparticles on detoxifying enzymes such as biliverdin reductase B, which was increased, and on central metabolism enzymes such as triose phosphate isomerase, which activity decreased under chronic exposure to silver nanoparticles. Chronic exposure to silver nanoparticles also induced a decrease of reduced glutathione content, a decreased phagocytic activity and reduced macrophages responses to lipopolysaccharide, as exemplified by nitric oxide and interleukin 6 production. Overall, chronic exposure to silver nanoparticles induced stronger effects than acute exposure on macrophages in the metabolic (glutathione level, mitochondrial potential) and functional (phagocytosis, cytokine production) parameters tested.
2024-09-09 | PXD016051 | Pride