Project description:To further explore the biotoxicity mechanisms of zinc oxide nanoparticles (ZnO NPs) and the recovery strategies of the accordingly impaired Nitrosomonas europaea (N. europaea, ATCC 19718) cells, a genome-sequenced model ammonia-oxidizing bacterium (AOB) commonly detected in the activated sludge of biological wastewater treatment plants, whole-genome microarray analysis was applied to retrieve the induced transcriptional responses, after their physiological and metabolic activities were revealed.
Project description:To further explore the biotoxicity mechanisms of zinc oxide nanoparticles (ZnO NPs) and the recovery strategies of the accordingly impaired Nitrosomonas europaea (N. europaea, ATCC 19718) cells, a genome-sequenced model ammonia-oxidizing bacterium (AOB) commonly detected in the activated sludge of biological wastewater treatment plants, whole-genome microarray analysis was applied to retrieve the induced transcriptional responses, after their physiological and metabolic activities were revealed. The whole-genome expressions were measured after exposure to 50 ppm ZnO NPs and 12-hrs recovery incubation when the ammonia removal rate (ARA) declined by 10% in the chemostat bioreactor. Three independent experiments were performed for each experiment.
Project description:A comprehensive in vitro assessment of two commercial metal oxide nanoparticles, TiO2 and ZnO, was performed using human monocyte-derived macrophages (HMDM), monocyte-derived dendritic cells (MDDC), and T cell leukemia-derived cell line (Jurkat). TiO2 nanoparticles were found to be non-toxic whereas ZnO nanoparticles caused dose-dependent cell death. Subsequently, global gene expression profiling was performed to identify signaling pathways underlying the cytotoxicity caused by ZnO nanoparticles. Analysis was done with doses, 1ug/ml and 10ug/ml after 6 and 24 hours of exposure. Interestingly, 2703 genes were significantly differentially expressed in HMDM upon exposure to 10ug/ml ZnO nanoparticles, while in MDDCs only 12 genes were affected. In Jurkat cells, 980 genes were differentially expressed. It is noteworthy that the gene expression of metallothioneins was upregulated in all the three cell types. In addition to the common ZnO-inducible changes, a notable proportion of the genes were regulated in a cell type-specific manner. Using a panel of ZnO nanoparticles, we obtained an additional support that the cellular response to ZnO nanoparticles is caused by particle dissolution. Gene ontology analysis revealed that the top biological processes disturbed in HMDM and Jurkat cells were regulating cell death and growth. In addition, genes controlling immune system development were affected. Bioinformatics assessment showed that the top human disease category associated with ZnO-responsive genes in both HMDM and Jurkat cells was cancer. Overall, the study revealed novel genes and pathways for mediating ZnO nanoparticle-induced toxicity and demonstrated the value of assessing nanoparticle responses through combined transcriptomics and bioinformatics approach. Nanoparticles used in the study: ZnO-1 commercial (IBU-tec advanced materials AG), ZnO-2 (mandelic acid coated ZnO-1), ZnO-3 (mercaptopropyl-trimethoxysilane coated ZnO-1), ZnO-4 (methoxyl coated ZnO), ZnO-5 (diethylene glycol modified ZnO) and ZnO-9 (folic acid modified ZnO). Detailed particle production and characterization data can be found from the articles: Buerki-Thurnherr et al. 2012 Nanotoxicology and Tuomela et al.
Project description:To further explore and differentiate the biotoxicity mechanisms of individual nanoparticles (NPs) and NP mixture on Nitrosomonas europaea (N. europaea, ATCC 19718) at genetic level, a genome-sequenced model ammonia oxidizing bacterium (AOB) commonly detected in the activated sludge of biological wastewater treatment plants, the induced whole-genome expressions were analyzed with the high throughput Microarray technique, after the dose-dependent changes of N. europaea’s physiological, metabolic and AMO enzyme activities in single and dual component NP systems was evaluated. NP stress induced gene expressions were measured after 6hr exposure to 10 ppm nano-ZnO, 50 nano-TiO2 and their mixture.Three independent experiments were performed for each experiment.
Project description:A comprehensive in vitro assessment of two commercial metal oxide nanoparticles, TiO2 and ZnO, was performed using human monocyte-derived macrophages (HMDM), monocyte-derived dendritic cells (MDDC), and T cell leukemia-derived cell line (Jurkat). TiO2 nanoparticles were found to be non-toxic whereas ZnO nanoparticles caused dose-dependent cell death. Subsequently, global gene expression profiling was performed to identify signaling pathways underlying the cytotoxicity caused by ZnO nanoparticles. Analysis was done with doses, 1ug/ml and 10ug/ml after 6 and 24 hours of exposure. Interestingly, 2703 genes were significantly differentially expressed in HMDM upon exposure to 10ug/ml ZnO nanoparticles, while in MDDCs only 12 genes were affected. In Jurkat cells, 980 genes were differentially expressed. It is noteworthy that the gene expression of metallothioneins was upregulated in all the three cell types. In addition to the common ZnO-inducible changes, a notable proportion of the genes were regulated in a cell type-specific manner. Using a panel of ZnO nanoparticles, we obtained an additional support that the cellular response to ZnO nanoparticles is caused by particle dissolution. Gene ontology analysis revealed that the top biological processes disturbed in HMDM and Jurkat cells were regulating cell death and growth. In addition, genes controlling immune system development were affected. Bioinformatics assessment showed that the top human disease category associated with ZnO-responsive genes in both HMDM and Jurkat cells was cancer. Overall, the study revealed novel genes and pathways for mediating ZnO nanoparticle-induced toxicity and demonstrated the value of assessing nanoparticle responses through combined transcriptomics and bioinformatics approach. Nanoparticles used in the study: ZnO-1 commercial (IBU-tec advanced materials AG), ZnO-2 (mandelic acid coated ZnO-1), ZnO-3 (mercaptopropyl-trimethoxysilane coated ZnO-1), ZnO-4 (methoxyl coated ZnO), ZnO-5 (diethylene glycol modified ZnO) and ZnO-9 (folic acid modified ZnO). Detailed particle production and characterization data can be found from the articles: Buerki-Thurnherr et al. 2012 Nanotoxicology and Tuomela et al. Altogether 71 samples were analyzed: 3 biological replicates of HMDM samples (untreated control, 10ug/ml of ZnO-1, 6 and 24 hours), 3 biological replicates of MDDC samples (untreated control, 6 and 24 hours), 7 biological replicates of MDDC samples (10ug/ml of ZnO-1, 24 hours), 3 replicates of Jurkat cells (untreated control, 10ug/ml of ZnO-1, 6 and 24 hours), 3 replicates of Jurkat cells (untreated control, 10ug/ml of ZnO-2, ZnO-3, ZnO-5 or ZnO-9, or 10, 25, 50 or 100ug/ml of ZnO-4, 24 hours).
Project description:A comprehensive in vitro assessment of two commercial metal oxide nanoparticles, TiO2 and ZnO, was performed using human monocyte-derived macrophages (HMDM), monocyte-derived dendritic cells (MDDC), and T cell leukemia-derived cell line (Jurkat). TiO2 nanoparticles were found to be non-toxic whereas ZnO nanoparticles caused dose-dependent cell death. Subsequently, global gene expression profiling was performed to identify signaling pathways underlying the cytotoxicity caused by ZnO nanoparticles. Analysis was done with doses, 1µg/ml and 10µg/ml after 6 and 24 hours of exposure. Interestingly, 2703 genes were significantly differentially expressed in HMDM upon exposure to 10µg/ml ZnO nanoparticles, while in MDDCs only 12 genes were affected. In Jurkat cells, 980 genes were differentially expressed. It is noteworthy that the gene expression of metallothioneins was upregulated in all the three cell types. In addition to the common ZnO-inducible changes, a notable proportion of the genes were regulated in a cell type-specific manner. Using a panel of ZnO nanoparticles, we obtained an additional support that the cellular response to ZnO nanoparticles is caused by particle dissolution. Gene ontology analysis revealed that the top biological processes disturbed in HMDM and Jurkat cells were regulating cell death and growth. In addition, genes controlling immune system development were affected. Bioinformatics assessment showed that the top human disease category associated with ZnO-responsive genes in both HMDM and Jurkat cells was cancer. Overall, the study revealed novel genes and pathways for mediating ZnO nanoparticle-induced toxicity and demonstrated the value of assessing nanoparticle responses through combined transcriptomics and bioinformatics approach.
Project description:A comprehensive in vitro assessment of two commercial metal oxide nanoparticles, TiO2 and ZnO, was performed using human monocyte-derived macrophages (HMDM), monocyte-derived dendritic cells (MDDC), and T cell leukemia-derived cell line (Jurkat). TiO2 nanoparticles were found to be non-toxic whereas ZnO nanoparticles caused dose-dependent cell death. Subsequently, global gene expression profiling was performed to identify signaling pathways underlying the cytotoxicity caused by ZnO nanoparticles. Analysis was done with doses, 1M-BM-5g/ml and 10M-BM-5g/ml after 6 and 24 hours of exposure. Interestingly, 2703 genes were significantly differentially expressed in HMDM upon exposure to 10M-BM-5g/ml ZnO nanoparticles, while in MDDCs only 12 genes were affected. In Jurkat cells, 980 genes were differentially expressed. It is noteworthy that the gene expression of metallothioneins was upregulated in all the three cell types. In addition to the common ZnO-inducible changes, a notable proportion of the genes were regulated in a cell type-specific manner. Using a panel of ZnO nanoparticles, we obtained an additional support that the cellular response to ZnO nanoparticles is caused by particle dissolution. Gene ontology analysis revealed that the top biological processes disturbed in HMDM and Jurkat cells were regulating cell death and growth. In addition, genes controlling immune system development were affected. Bioinformatics assessment showed that the top human disease category associated with ZnO-responsive genes in both HMDM and Jurkat cells was cancer. Overall, the study revealed novel genes and pathways for mediating ZnO nanoparticle-induced toxicity and demonstrated the value of assessing nanoparticle responses through combined transcriptomics and bioinformatics approach. Altogether 90 samples were analyzed originating from three biological replicates of HMDM, MDDC or Jurkat cells containg untreated control cells, ZnO or TiO2 treated cells with doses 1M-BM-5g/ml and 10M-BM-5g/ml. The sample timepoints were 6 hours and 24 hours.
Project description:Manufactured nanomaterials (MNMs) are increasingly incorporated into consumer products that are disposed into sewage. In wastewater treatment, MNMs adsorb to activated sludge biomass where they may impact biological wastewater treatment performance, including nutrient removal. Here, we studied MNM effects on bacterial polyhydroxyalkanoate (PHA), specifically polyhydroxybutyrate (PHB), biosynthesis because of its importance to enhanced biological phosphorus (P) removal (EBPR). Activated sludge was sampled from an anoxic selector of a municipal wastewater treatment plant (WWTP), and PHB-containing bacteria were concentrated by density gradient centrifugation. After starvation to decrease intracellular PHB stores, bacteria were nutritionally augmented to promote PHB biosynthesis while being exposed to either MNMs (TiO2 or Ag) or to Ag salts (each at a concentration of 5 mg L-1). Cellular PHB concentration and PhyloChip community composition were analyzed. The final bacterial community composition differed from activated sludge, demonstrating that laboratory enrichment was selective. Still, PHB was synthesized to near-activated sludge levels. Ag salts altered final bacterial communities, although MNMs did not. PHB biosynthesis was diminished with Ag (salt or MNMs), indicating the potential for Ag-MNMs to physiologically impact EBPR through the effects of dissolved Ag ions on PHB producers.