Project description:Because of their small size, nanoparticles that enter the human body can easily penetrate biological barriers and can be circulated throughout the entire body, ultimately reaching the vascular endothelium. In this study aimed to identify cell reponses by distinguishing endothelial cell and exposing them to silver nanoparticles. The study also assesseed several gene expression levels that increased significantly in the microarray assay. We verified through microarray that 5 nm silver nanoparticles affect the variation of gene expression in cells, and a noticeable increase in the expression of interleukin (IL)-8 and IL-11 genes in early time was also verified. This study found that the variation on oxidative stress related genes in early time, amd among them the variation of metallothionein(MT), heme oxygenase 1(HO1), and heat shock 70kDa protein(HSP70) expression, was noticeable. This study finds that intracellular genes specifically respond to exposure to silver nanoparticles and that the expression of IL-11 among cytokines is noticeable.
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.
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.
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 .
Project description:In adult mammals, tissue damage after myocardial infarction induces myofibroblast differentiation and the formation of a permanent, functionally inert scar. However, the molecular mechanisms that govern myofibroblast differentiation and scarring remain poorly understood. Some vertebrates like zebrafish display a remarkable regenerative potential with only limited and transient fibrosis after tissue damage, including in the heart. Here, employing comparative expression profiling coupled with loss-of-function approaches, we identified the canonical Interleukin-11/Stat3 signaling axis as a core component of regeneration in zebrafish. Notably, animals with loss of Interleukin-11 receptor (Il11ra) function reach adulthood without overt developmental defects, but exhibit strongly impaired cardiac regeneration with increased myofibroblast differentiation and the formation of a permanent collagenous scar, similar to what is observed in adult mammals. Using zebrafish fate-mapping approaches, reporter lines and human primary cell culture methods, we provide evidence that Interleukin-11 signaling limits endothelial-to-myofibroblast transdifferentiation and maintains a pro-regenerative niche to promote cardiac regeneration. Altogether, our data reveal a vital role for endothelial Interleukin-11/Stat3 signaling in containing injury-induced cardiac fibrosis.
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.
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.
Project description:We examined effects of surface-coating (BPEI, CIT, PEG) of silver nanoparticles and time (6h, 12h, 24h) on gene expression in human liver cancer cells (HepG2)
Project description:Introduction: Environmental pollutants irritate and injure the bronchial elevator, thereby provoking disease progression in chronic obstructive pulmonary disease (COPD). Epithelial resilience mechanisms to environmental nanoparticles in health and disease are poorly characterized. Methods: We delineated the impact of prevalent pollutants such as carbon and zinc oxide nanoparticles, on cellular function and progeny in primary human bronchial epithelial cells (pHBEC) from end-stage COPD, early disease and pulmonary healthy individuals. After nanoparticle exposure of pHBECs at the air liquid interface, cell cultures were characterized by functional assays as well as transcriptome and protein analysis, complemented by single cell analysis in serial samples of pHBEC culture focussing on basal cell differentiation. Results: In end-stage COPD, environmentally abundant doses of zinc oxide nanoparticles (ZnO) aggravated a pro-secretory phenotype at the expense of the multi-ciliated epithelium alongside a reduction of barrier integrity and increased resilience towards cell damage. Similar effects on cellular composition and function were induced by co-treatment of early stage COPD pHEBC cultures with cigarette smoke extract. Time-resolved single cell transcriptomics revealed a unique end stage COPD associated basal cell state characterized by altered Wnt and Notch pathway activation. A conserved set of COPD specific genes persisted from this disease associated basal cell state into its differentiated progeny. Conclusion: We identified COPD stage specific gene program alterations in basal stem cells that affect the cellular composition of the bronchial elevator and may control epithelial resilience mechanisms in response to environmental nanoparticles. The identified phenomena likely inform treatment or prevention strategies.