Project description:Background: N6-methyladenosine (m6A) is the most prominent epitranscriptomic modification to RNA in eukaryotes, but it’s role in adaptive changes within the gestational environment are poorly understood. Nano titanium dioxide (TiO2) exposure is common during pregnancy, though the impact fetal progeny is not entirely understood. We propose that gestational exposure to nano-TiO2 contributes to cardiac m6A methylation in fetal offspring and indirectly contributes to mitochondrial dysfunction.
Project description:Background: N6-methyladenosine (m6A) is the most prominent epitranscriptomic modification to RNA in eukaryotes, but it’s role in adaptive changes within the gestational environment are poorly understood. Nano titanium dioxide (TiO2) exposure is common during pregnancy, though the impact fetal progeny is not entirely understood. We propose that gestational exposure to nano-TiO2 contributes to cardiac m6A methylation in fetal offspring and indirectly contributes to mitochondrial dysfunction.
Project description:The toxicity and toxicogenomics of selected anatase and rutile nanoparticles (NP) and bulk titanium dioxide (TiO2) particles were evaluated in the soil nematode Caenorhabditis elegans. Results indicated that bulk or nano-TiO2 particles were slightly toxic to soil nematode C. elegans, as measured by reproduction EC50 values ranging from 4 to 32 mg/L. Whole-genome microarray results indicated that the regulation of glutathione-S-transferase gst-3, cytochrome P450 cypp33-c11, stress resistance regulator scl-1, oxidoreductase wah-1, and embryonic development pod-2 genes were significantly affected by nano-sized and bulk TiO2 particles. More specifically, it was determined that anatase particles exerted a greater effect on metabolic pathways, whereas rutile particles had a greater effect on developmental processes. The up-regulation of the pod-2 gene corroborated the phenotypic effect observed in the reproduction test. Our results demonstrated that C. elegans is a good genomic model for nano-TiO2 toxicity assessment.
Project description:Pulmonary exposure to high doses of nanoparticles (NP) leads to well characterized lung toxicity in addition to long-term NP retention. However, pulmonary NP accumulation and toxicity following low dose exposures are not well described. In the present study we sought to: (1) investigate particle retention in mouse lungs following intratracheal instillation of varying doses of nano-sized titanium dioxide (nano-TiO2) and (2) determine the effects of long-term particle accumulation on pulmonary systems. Female C57BL/6 mice were exposed to rutile nano-TiO2 (primary size of 20.6 nm and surface area of 107.7 m2/g) via single intratracheal instillations of 18, 54 and 162 µg/mouse and sampled 1, 3 and 28 days post-exposure. The deposition of nano-TiO2 in the lungs was assessed using Nanoscale Hyperspectral Microscope. DNA microarrays, pathway-specific real-time RT-PCR (qPCR) and gene-specific qPCR arrays, and tissue protein analyses were employed to characterize pulmonary responses. Hyperspectral mapping showed dose-dependent retention of nano-TiO2 in the lungs up to 28 days post-exposure time. Retention did not correlate with the extent of inflammatory neutrophil influx into the lungs. DNA microarray analysis showed altered expression of approximately 3000 genes across all treatment groups (±1.3 fold; p<0.1). Several inflammatory mediators changed in a dose- and time-dependent manner at both the mRNA and protein levels. Although the low dose exposure failed to induce observable inflammation, significant changes in the expression of genes and proteins associated with inflammation were observed. Moreover, diminished (or absent) neutrophil influx in the low and medium dose groups was correlated with negative regulation of genes associated with ion homeostasis and muscle regulation. Gene expression changes for several inflammatory mediators have previously been noted in mice exposed to the same nano-TiO2 via inhalation. Our results suggest that retention of nano-TiO2 in the absence of inflammation and effective clearance can perturb calcium and ion homeostasis, and affect smooth muscle activities over time.
Project description:Pulmonary exposure to high doses of nanoparticles (NP) leads to well characterized lung toxicity in addition to long-term NP retention. However, pulmonary NP accumulation and toxicity following low dose exposures are not well described. In the present study we sought to: (1) investigate particle retention in mouse lungs following intratracheal instillation of varying doses of nano-sized titanium dioxide (nano-TiO2) and (2) determine the effects of long-term particle accumulation on pulmonary systems. Female C57BL/6 mice were exposed to rutile nano-TiO2 (primary size of 20.6 nm and surface area of 107.7 m2/g) via single intratracheal instillations of 18, 54 and 162 M-BM-5g/mouse and sampled 1, 3 and 28 days post-exposure. The deposition of nano-TiO2 in the lungs was assessed using Nanoscale Hyperspectral Microscope. DNA microarrays, pathway-specific real-time RT-PCR (qPCR) and gene-specific qPCR arrays, and tissue protein analyses were employed to characterize pulmonary responses. Hyperspectral mapping showed dose-dependent retention of nano-TiO2 in the lungs up to 28 days post-exposure time. Retention did not correlate with the extent of inflammatory neutrophil influx into the lungs. DNA microarray analysis showed altered expression of approximately 3000 genes across all treatment groups (M-BM-11.3 fold; p<0.1). Several inflammatory mediators changed in a dose- and time-dependent manner at both the mRNA and protein levels. Although the low dose exposure failed to induce observable inflammation, significant changes in the expression of genes and proteins associated with inflammation were observed. Moreover, diminished (or absent) neutrophil influx in the low and medium dose groups was correlated with negative regulation of genes associated with ion homeostasis and muscle regulation. Gene expression changes for several inflammatory mediators have previously been noted in mice exposed to the same nano-TiO2 via inhalation. Our results suggest that retention of nano-TiO2 in the absence of inflammation and effective clearance can perturb calcium and ion homeostasis, and affect smooth muscle activities over time. This experiment consists of three different dosages of TiO2, e.g., low (18 ug), medium (54 ug) and high (162 ug), and one control. There are 3 time points for each treatment and control group, e.g., day 1, day 3 and day 28. Each dose or time point has 5-6 biological replicates. There are total 65 samples (arrays)
Project description:Seed germination of a terrestrial plant constitute dynamic changes in various physiological processes related to growth and development. These physiological processes can be affected by various abiotic and biotic stressors. Here we looked at how the two commonly used nanoparticles, nano-titania (TiO2) and nano-ceria (CeO2) can impact the underlying mechanisms associated with germination at genome level. We used microarrays to detail the global programme of gene expression underlying various physiological processes associated with growth and development, and identified distinct classes of up-regulated genes during this process.
Project description:Metal oxide engineered nanoparticles, which are widely used in diverse applications, are known to impact terrestrial plants. These nanoparticles have a potential to induce changes in plant tissue transcriptomes, and thereby the productivity. Here we looked at how the two commonly used nanoparticles, nano-titania (TiO2) and nano-ceria (CeO2) can impact the underlying mechanisms associated plant growth at genome level. We used microarrays to detail the global programme of gene expression underlying various physiological processes associated with growth and development, and identified distinct classes of up-regulated genes during this process.
Project description:Seed germination of a terrestrial plant constitute dynamic changes in various physiological processes related to growth and development. These physiological processes can be affected by various abiotic and biotic stressors. Here we looked at how the two commonly used nanoparticles, nano-titania (TiO2) and nano-ceria (CeO2) can impact the underlying mechanisms associated with germination at genome level. We used microarrays to detail the global programme of gene expression underlying various physiological processes associated with growth and development, and identified distinct classes of up-regulated genes during this process. 12 day old Arabidopsis germinants were selected for RNA extraction and hybridization on Affymetrix microarrays. Arabidopsis seeds were individually exposed to 500mg/L concentration of nano-titania and nano-ceria for 12 days, followed by extraction of RNA for Microarray analysis. 0.1M KCl was used as control for nano-titania, whereas sterilized millipore water was used as control for nano-ceria.
Project description:Today, nanoparticles are used in various commercial products. One of the most common nanoparticles is titanium dioxide (TiO2). It has a catalytic activity and UV absorption (λ<400 nm), and it generates reactive oxygen species (ROS). The catalytic activity of TiO2 nanoparticle is capable of killing a wide range of microorganisms. In the environment, nanoparticles form structures consisting of primary particles, and their aggregates and agglomerates. These compounds are defined NOAA (nano-objects, and their aggregates and agglomerates greater than 100 nm). The unique properties of TiO2 nanoparticles can be maintained in the environment, thus, the growing use of TiO2 nanoparticles is raising concerns about the environmental risks. The assessment of biological and ecological effects of TiO2-NOAA is necessary. In our previous study, we assessed the effect of TiO2-NOAA on microbes by using Saccharomyces cerevisiae and Escherichia coli. It was shown that TiO2-NOAA decomposed methylene blue under UV irradiation. It suggested that TiO2-NOAA generated ROS under UV irradiation. However, TiO2-NOAA did not show growth inhibition in minimal agar medium under UV irradiation. By adding TiO2-NOAA in medium, colony formation was observed with UV intensity that inactivates microbes. Moreover, TiO2-NOAA adsorbed microbes. These results suggested that the amount of ROS generated by TiO2-NOAA was not enough to inactivate microbes, and TiO2-NOAA might protect microbes from UV. In this study, we assessed the effect of TiO2-NOAA in more detail by using S. cerevisiae. We used DNA microarray analysis for qualitative assessment. Further, we carried out quantitative assessment by using Real Time RT-PCR method for characteristic genes in DNA microarray analysis. To compare yeast cells in various conditions, six kinds of treatment conditions were prepared (Condition 1. adsorbed fraction to TiO2-NOAA under UV, 2. non-adsorbed fraction to TiO2-NOAA under UV, 3. adsorbed fraction to TiO2-NOAA without UV, 4. non-adsorbed fraction to TiO2-NOAA without UV, 5. irradiated UV and 6. negative control). From the result of DNA microarray analysis, the most number of genes was altered in Condition 1, followed by Condition 3 and 5. The genes related to oxidative stress, and the genes related to synthesis of trehalose and glycogen were significantly up-regulated of yeast cells in Condition 1 and 5, and Condition 1 and 3, respectively. These results suggest that yeast cells suffer oxidative stress by TiO2-NOAA under UV, and they also suffer membrane damage by TiO2-NOAA itself, as a result, they reserve energy sources. From the result of Real Time RT-PCR, genes related to oxidative stress (GRE2, SOD2) were up-regulated in Condition 1 and 3, however, these expression levels in each condition were not significant. And genes related to synthesis of trehalose and glycogen (GSY1, TPS2) were up-regulated in Condition 1 and 3. These results suggest that oxidative stress is caused not by TiO2-NOAA but by UV. It is also suggested that yeast cells were damaged at their membranes by TiO2-NOAA, as a result, genes related to synthesis of trehalose and glycogen were up-regulated. Thus, we suggest that the effect of TiO2-NOAA on yeast cells under UV irradiation is greater due to TiO2-NOAA itself than due to ROS generated by TiO2-NOAA.
Project description:Metal oxide engineered nanoparticles, which are widely used in diverse applications, are known to impact terrestrial plants. These nanoparticles have a potential to induce changes in plant tissue transcriptomes, and thereby the productivity. Here we looked at how the two commonly used nanoparticles, nano-titania (TiO2) and nano-ceria (CeO2) can impact the underlying mechanisms associated plant growth at genome level. We used microarrays to detail the global programme of gene expression underlying various physiological processes associated with growth and development, and identified distinct classes of up-regulated genes during this process. 29 day old Arabidopsis plants were selected for RNA extraction from roots and rosette leaves, followed by hybridization on Affymetrix microarrays. Arabidopsis plants were exposed twice during the germination stage (Days 0 and 4), and once during the primary rosette stage (Day 17), to 500mg/L concentration of nano-titania and nano-ceria, followed by extraction of RNA from 29-day old plant tissues (roots and rosette leaves) for Microarray analysis. 0.1mM KCl was used as control for nano-titania, whereas sterilized millipore water was used as control for nano-ceria.