Epigenetic effects of silver nanoparticles and ionic silver in Tetrahymena thermophila
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PROVIDER: PRJNA662238 | ENA |
REPOSITORIES: ENA
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Project description:The widespread use of silver nanoparticles (Ag NPs) has raised substantial health risks to environmental and human beings. Although various negative effects had been reported, little is known about the epigenetic toxicity induced by Ag+ and Ag NPs. This study characterized physiological and lncRNA profiles to explore the toxic effects and epigenetic mechanisms in Tetrahymena thermophila on exposure to Ag+ and three types of Ag NPs. We found that both of Ag+ and Ag NPs exhibited strong growth-inhibiting effects on T. thermophila. The toxicity was mainly caused by high levels of reactive oxygen species (ROS), which subsequently led to lipid peroxidation and mitochondrial dysfunction. As a defense mechanism against oxidative stress, the protist elicited an antioxidant response. Importantly, 1250 lncRNAs were differentially expressed under Ag+ or Ag NPs exposure relative to the non-exposure control, which were clustered into 15 expression modules in weighted gene co-expression network analysis. These gene modules exhibited toxicant-specific expression patterns, indicating that they play various regulatory roles, including cell growth inhibition, cell membrane cation channel activation, and oxidoreductase activity promotion. Taken together, this research illuminates how post-transcriptional mechanisms of a ciliated protozoa regulate responses to Ag+ and Ag NPs toxicities.
2021-09-10 | GSE157616 | 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:We present a comprehensive transcriptome of ciliate T. thermophila using the Illumina RNA-seq platform. The data was generated from the six mRNA samples of growth, starvation and conjugation of Tetrahymena. Despite an AT rich genome, there are about 124.6 million reads mapped to T. thermophila genome. Using these mapped reads, we have significantly improved the previous genome annotation and investigated the gene expression. Besides, our result also provided a comprehensive understanding of the alternative splicing in T. thermophila, and suggested the existence of the regulated unproductive splicing and translation (RUST) in the single-celled eukaryote. RNA-seq for six samples of Tetrahymena growth, starvation and conjugation.
2012-03-15 | E-GEOD-27971 | 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: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.
2013-11-01 | GSE46520 | GEO
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:Tetrahymena thermophila Raw sequence reads
| PRJNA593714 | ENA
Project description:Tetrahymena thermophila Raw sequence reads
| PRJNA611686 | ENA