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| 2. |
- Cappellini, Francesca, et al.
(författare)
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Dry Generation of CeO2 Nanoparticles and Deposition onto a Co-Culture of A549 and THP-1 Cells in Air-Liquid Interface-Dosimetry Considerations and Comparison to Submerged Exposure
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Relevant in vitro assays that can simulate exposure to nanoparticles (NPs) via inhalation are urgently needed. Presently, the most common method employed is to expose lung cells under submerged conditions, but the cellular responses to NPs under such conditions might differ from those observed at the more physiological air-liquid interface (ALI). The aim of this study was to investigate the cytotoxic and inflammatory potential of CeO2 NPs (NM-212) in a co-culture of A549 lung epithelial cells and differentiated THP-1 cells in both ALI and submerged conditions. Cellular dose was examined quantitatively using inductively coupled plasma mass spectrometry (ICP-MS). The role of serum and LPS-priming for IL-1 beta release was further tested in THP-1 cells in submerged exposure. An aerosol of CeO2 NPs was generated by using the PreciseInhale (R) system, and NPs were deposited on the co-culture using XposeALI (R). No or minor cytotoxicity and no increased release of inflammatory cytokines (IL-1 beta, IL-6, TNF alpha, MCP-1) were observed after exposure of the co-culture in ALI (max 5 mu g/cm(2)) or submerged (max 22 mu g/cm(2)) conditions. In contrast, CeO2 NPs cause clear IL-1 beta release in monocultures of macrophage-like THP-1, independent of the presence of serum and LPS-priming. This study demonstrates a useful approach for comparing effects at various in-vitro conditions.
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| 3. |
- Di Bucchianico, Sebastiano, et al.
(författare)
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Calcium-dependent cyto- and genotoxicity of nickel metal and nickel oxide nanoparticles in human lung cells
- 2018
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Ingår i: Particle and Fibre Toxicology. - : BMC. - 1743-8977. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Genotoxicity is an important toxicological endpoint due to the link to diseases such as cancer. Therefore, an increased understanding regarding genotoxicity and underlying mechanisms is needed for assessing the risk with exposure to nanoparticles (NPs). The aim of this study was to perform an in-depth investigation regarding the genotoxicity of well-characterized Ni and NiO NPs in human bronchial epithelial BEAS-2B cells and to discern possible mechanisms. Comparisons were made with NiCl2 in order to elucidate effects of ionic Ni. Methods: BEAS-2B cells were exposed to Ni and NiO NPs, as well as NiCl2, and uptake and cellular dose were investigated by transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry (ICP-MS). The NPs were characterized in terms of surface composition (X-ray photoelectron spectroscopy), agglomeration (photon cross correlation spectroscopy) and nickel release in cell medium (ICP-MS). Cell death (necrosis/apoptosis) was investigated by Annexin VFITC/PI staining and genotoxicity by cytokinesis-block micronucleus (cytome) assay (OECD 487), chromosomal aberration (OECD 473) and comet assay. The involvement of intracellular reactive oxygen species (ROS) and calcium was explored using the fluorescent probes, DCFH-DA and Fluo-4. Results: NPs were efficiently taken up by the BEAS-2B cells. In contrast, no or minor uptake was observed for ionic Ni from NiCl2. Despite differences in uptake, all exposures (NiO, Ni NPs and NiCl2) caused chromosomal damage. Furthermore, NiO NPs were most potent in causing DNA strand breaks and generating intracellular ROS. An increase in intracellular calcium was observed and modulation of intracellular calcium by using inhibitors and chelators clearly prevented the chromosomal damage. Chelation of iron also protected against induced damage, particularly for NiO and NiCl2. Conclusions: This study has revealed chromosomal damage by Ni and NiO NPs as well as Ni ionic species and provides novel evidence for a calcium-dependent mechanism of cyto- and genotoxicity.
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| 4. |
- Gliga, Anda R., et al.
(författare)
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RNA-sequencing reveals long-term effects of silver nanoparticles on human lung cells
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Despite a considerable focus on the adverse effects of silver nanoparticles (AgNPs) in recent years, studies on the potential long-term effects of AgNPs are scarce. The aim of this study was to explore the effects of AgNPs following repeated low-dose, long-term exposure of human bronchial epithelial cells. To this end, the human BEAS-2B cell line was exposed to 1 mu g/mL AgNPs (10 nm) for 6 weeks followed by RNA-sequencing (RNA-Seq) as well as genome-wide DNA methylation analysis. The transcriptomics analysis showed that a substantial number of genes (1717) were differentially expressed following AgNP exposure whereas only marginal effects on DNA methylation were observed. Downstream analysis of the transcriptomics data identified several affected pathways including the 'fibrosis' and 'epithelial-mesenchymal transition' (EMT) pathway. Subsequently, functional validation studies were performed using AgNPs of two different sizes (10 nm and 75 nm). Both NPs increased collagen deposition, indicative of fibrosis, and induced EMT, as evidenced by an increased invasion index, anchorage independent cell growth, as well as cadherin switching. In conclusion, using a combination of RNA-Seq and functional assays, our study revealed that repeated low-dose, long-term exposure of human BEAS-2B cells to AgNPs is pro-fibrotic, induces EMT and cell transformation.
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| 5. |
- Gliga, Anda R., et al.
(författare)
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Silver nanoparticles modulate lipopolysaccharide-triggered Toll-like receptor signaling in immune-competent human cell lines
- 2020
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Ingår i: Nanoscale Advances. - : ROYAL SOC CHEMISTRY. - 2516-0230. ; 2:2, s. 648-658
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Tidskriftsartikel (refereegranskat)abstract
- Silver (Ag) nanoparticles are commonly used in consumer products due to their antimicrobial properties. Here we studied the impact of Ag nanoparticles on immune responses by using cell lines of monocyte/macrophage and lung epithelial cell origin, respectively. Short-term experiments (24 h) showed that Ag nanoparticles reduced the lipopolysaccharide (LPS)-induced secretion of pro-inflammatory cytokines in THP-1 cells under serum-free conditions. ICP-MS analysis revealed that cellular uptake of Ag was higher under these conditions. Long-term exposure (up to 6 weeks) of BEAS-2B cells to Ag nanoparticles also suppressed pro-inflammatory cytokine production following a brief challenge with LPS. Experiments using reporter cells revealed that Ag nanoparticles as well as AgNO3 inhibited LPS-triggered Toll-like receptor (TLR) signaling. Furthermore, RNA-sequencing of BEAS-2B cells indicated that Ag nanoparticles affected TLR signaling pathways. In conclusion, Ag nanoparticles reduced the secretion of pro-inflammatory cytokines in response to LPS, likely as a result of the release of silver ions leading to an interference with TLR signaling. This could have implications for the use of Ag nanoparticles as antibacterial agents. Further in vivo studies are warranted to study this.
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| 6. |
- Latvala, Siiri, et al.
(författare)
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Nickel release, ROS generation and toxicity of Ni and NiO micro- and nanoparticles
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Occupational exposure to airborne nickel is associated with an elevated risk for respiratory tract diseases including lung cancer. Therefore, the increased production of Ni-containing nanoparticles necessitates a thorough assessment of their physical, chemical, as well as toxicological properties. The aim of this study was to investigate and compare the characteristics of nickel metal (Ni) and nickel oxide (NiO) particles with a focus on Ni release, reactive oxygen species (ROS) generation, cellular uptake, cytotoxicity and genotoxicity. Four Ni-containing particles of both nano-size (Ni-n and NiO-n) and micron-size (Ni-m1 and Ni-m2) were tested. The released amount of Ni in solution was notably higher in artificial lysosomal fluid (e.g. 80–100 wt% for metallic Ni) than in cell medium after 24h (ca. 1–3 wt% for all particles). Each of the particles was taken up by the cells within 4 h and they remained in the cells to a high extent after 24 h post-incubation. Thus, the high dissolution in ALF appeared not to reflect the particle dissolution in the cells. Ni-m1 showed the most pronounced effect on cell viability after 48 h (alamar blue assay) whereas all particles showed increased cytotoxicity in the highest doses (20–40 μg cm2) when assessed by colony forming efficiency (CFE). Interestingly an increased CFE, suggesting higher proliferation, was observed for all particles in low doses (0.1 or 1 μg cm-2). Ni-m1 and NiO-n were the most potent in causing acellular ROS and DNA damage. However, no intracellular ROS was detected for any of the particles. Taken together, micron-sized Ni (Ni-m1) was more reactive and toxic compared to the nano-sized Ni. Furthermore, this study underlines that the low dose effect in terms of increased proliferation observed for all particles should be further investigated in future studies.
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| 7. |
- Åkerlund, Emma, et al.
(författare)
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Genotoxic and mutagenic properties of Ni and NiO nanoparticles investigated by comet assay,-H2AX staining, Hprt mutation assay and ToxTracker reporter cell lines
- 2018
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Ingår i: Environmental and Molecular Mutagenesis. - : Wiley. - 0893-6692 .- 1098-2280. ; 59:3, s. 211-222
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Tidskriftsartikel (refereegranskat)abstract
- Nickel (Ni) compounds are classified as carcinogenic to humans but the underlying mechanisms are still poorly understood. Furthermore, effects related to nanoparticles (NPs) of Ni have not been fully elucidated. The aim of this study was to investigate genotoxicity and mutagenicity of Ni and NiO NPs and compare the effect to soluble Ni from NiCl2. We employed different models; i.e., exposure of (1) human bronchial epithelial cells (HBEC) followed by DNA strand break analysis (comet assay and -H2AX staining); (2) six different mouse embryonic stem (mES) reporter cell lines (ToxTracker) that are constructed to exhibit fluorescence upon the induction of various pathways of relevance for (geno)toxicity and cancer; and (3) mES cells followed by mutagenicity testing (Hprt assay). The results showed increased DNA strand breaks (comet assay) for the NiO NPs and at higher doses also for the Ni NPs whereas no effects were observed for Ni ions/complexes from NiCl2. By employing the reporter cell lines, oxidative stress was observed as the main toxic mechanism and protein unfolding occurred at cytotoxic doses for all three Ni-containing materials. Oxidative stress was also detected in the HBEC cells following NP-exposure. None of these materials induced the reporter related to direct DNA damage and stalled replication forks. A small but statistically significant increase in Hprt mutations was observed for NiO but only at one dose. We conclude that Ni and NiO NPs show more pronounced (geno)toxic effects compared to Ni ions/complexes, indicating more serious health concerns. Environ. Mol. Mutagen. 59:211-222, 2018.
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