ABSTRACT: Toxicogenomic effects of nano- and bulk TiO2 particles in the soil nematode Carnorhabditis elegans using juglone as a positive control for oxidative stress
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:Little progress has been made in studying the toxicity of realistic 'non-pristine' forms of nanoparticles that presents in real soil environment. It is presently unkown whether the transformed nanoparticles in realistic environment exerts an adverse effect to rhizobium-legume symbiosis on molecular level. We used microarray to investigate the toxicogenomic responses of the model legume Medicago truncatula following 30 days exposure to three different types of biosolids (control biosolids (control BS), a mixture of Ag, ZnO and TiO2 manufactured nanomaterials added biosolids (Nano BS) and a corresponding bulk metals added biosolids (Bulk BS) ) amended soil that were aged for 6 months prior to exposure in pot experiment. Our Genechip® Medicago Genome Array is designed specially to monitor gene expression in Medicago truncatula, Medicago sativa, and the symbiotic organism Sinorhizobium meliloti. For our study, RNA were extracted from shoots and roots of Medicago truncatula that exposure to control, Bulk and Nano BS treatments for 30 days, and used for all hybridization on Affymetrix microarray. The objective of our study is to investigate the molecular mechanisms of toxicity of Nano BS in comparison with their counterpart Bulk BS treatment, using a commercial Medicago truncatula microarrays.
Project description:In order to evaluate the identification of genes and pathways, the global gene expression profiles were assessed in response to UV, TiO2 and UV+TiO2 on nematode, Caenorhabditis elegans. We performed whole genome DNA microarray experiments using age synchronized young adult C. elegans population exposed to UV, TiO2 and UV+TiO2 for 24h. We used whole genome microarrays to screen for global changed in C. elegans transcription profiles and with subsequent quantitative analysis conducted on selected genes.
Project description:Little progress has been made in studying the toxicity of realistic 'non-pristine' forms of nanoparticles that presents in real soil environment. It is presently unkown whether the transformed nanoparticles in realistic environment exerts an adverse effect to rhizobium-legume symbiosis on molecular level. We used microarray to investigate the toxicogenomic responses of the model legume Medicago truncatula following 30 days exposure to three different types of biosolids (control biosolids (control BS), a mixture of Ag, ZnO and TiO2 manufactured nanomaterials added biosolids (Nano BS) and a corresponding bulk metals added biosolids (Bulk BS) ) amended soil that were aged for 6 months prior to exposure in pot experiment.
Project description:In order to evaluate the identification of genes and pathways, the global gene expression profiles were assessed in response to UV, TiO2 and UV+TiO2 on nematode, Caenorhabditis elegans. We performed whole genome DNA microarray experiments using age synchronized young adult C. elegans population exposed to UV, TiO2 and UV+TiO2 for 24h. We used whole genome microarrays to screen for global changed in C. elegans transcription profiles and with subsequent quantitative analysis conducted on selected genes. Young adults C. elegans were selected for RNA extraction and hybridization on Affymetrix microarrays.
Project description:The nematode C. elegans was exposed to TiO2 nanoparticles (NPs) to evaluate the ecotoxicity of TiO2 nanoparticles. We used the DNA microarray method to understand changes in gene expression after the exposure to TIO2 NPs. We identified various genes involved in metal detoxification as well as in regulating worm development.
Project description:To confirm the suitability of C. elegans as a model organism, preliminary gene expression experiments were performed using juglone (5-hydroxy-1,4-naphthoquinone; 97% pure; Sigma-Aldrich, St-Louis, MO), an ROS-generator, as a positive control of oxidative stress (d'Arcy Doherty et al. 1987; Leiers et al. 2003). Reproduction tests were initially performed to establish the sub-lethal effect concentrations used in the microarray experiments.
Project description:RNA microarray was performed to evaluate the efficacy of silicon nano-particles on renal transcriptomes of rats against ischemia reperfusion injury. We compared the transcriptomes of ischemia reperfusion injury model rats with or without oral administration of silicon nano-particles. We also tried to check whether the oral silicon nano-particles intake downregulated the biological processes related to oxidative stress.
