Project description:Environmental pollution is a worldwide problem, and metals are the largest group of contaminants in soil. Microarray toxicogenomic studies with ecologically relevant organisms such as springtails, supplement traditional ecotoxicological research, but are presently rather descriptive. Classifier analysis, a more analytical application of the microarray technique, is able to predict biological classes of unknown samples. We used the uncorrelated shrunken centroid (USC) method to classify gene expression profiles of the springtail Folsomia candida exposed to soil spiked with six different metals (barium, cadmium, cobalt, chromium, lead, and zinc). We identified a gene set (classifier) of 188 genes that can discriminate between six different metals present in soil, which allowed us to predict the correct classes for samples of an independent test set with an accuracy of 83% (error rate = 0.17). This study shows further that in order to apply classifier analysis to actual contaminated field soil samples, more insight and information is needed on the transcriptional responses of soil organisms to different soil types (properties) and mixtures of contaminants.
Project description:Classical ecotoxicological test and high-throughput molecular tools (microarray) were conducted on C. elegans to assess the effectiveness and ecosafety of a nanoremediation strategy applied to a highly polluted soil environment with heavy metals (HMs). We stablished a profiled gene expression in C. elegans exposed to the polluted soil, treated and untreated with nZVI. The results obtained showed that the percentage of differentially expressed genes decreased with the exposure time to nZVI. The expression profile of genes associated with stress response, metal toxicity, proteolysis, immune response, and cuticle development resulted affected. At short term, when a more effective HMs immobilization has occurred genes related to specific heavy metal detoxification mechanisms or to response to metal stress, were down regulated. After longer exposure time, we found decreased effectiveness of nZVI and increased HMs toxicity, whereas the transcriptional oxidative and metal-induced responses were attenuated.
Project description:From the results of gene expression analyses of HepG2 under the exposure of 2,3-Dimethoxy-1,4-naphthoquinone (DMNQ), N-nitrosodimethylamine (DMN), phenol and six heavy metals We showed that biological action of six heavy metals were clearly related to that of DMNQ and distinguishable from the other chemicals. These results suggest that oxidative stress is major apparent biological action of high dose heavy metals, supporting the previous reports. Keywords: other
Project description:Environmental pollution is a worldwide problem, and metals are the largest group of contaminants in soil. Microarray toxicogenomic studies with ecologically relevant organisms such as springtails, supplement traditional ecotoxicological research, but are presently rather descriptive. Classifier analysis, a more analytical application of the microarray technique, is able to predict biological classes of unknown samples. We used the uncorrelated shrunken centroid (USC) method to classify gene expression profiles of the springtail Folsomia candida exposed to soil spiked with six different metals (barium, cadmium, cobalt, chromium, lead, and zinc). We identified a gene set (classifier) of 188 genes that can discriminate between six different metals present in soil, which allowed us to predict the correct classes for samples of an independent test set with an accuracy of 83% (error rate = 0.17). This study shows further that in order to apply classifier analysis to actual contaminated field soil samples, more insight and information is needed on the transcriptional responses of soil organisms to different soil types (properties) and mixtures of contaminants. Gene expression was measured in springtails after exposure of 2 days to soil containing either EC10 or EC50 of 6 different metals. The exposure experiment was performed in two separate series (1 and 2), both containing a separate non-spiked (LUFA 2.2) soil control. Also, two field soil samples were tested. The samples were divided into a separate training set and a validation set for USC classifier analysis.
Project description:Heavy metals residue in the natural ecosystem had become one global environmental problem that was eager to solve. Due to the non-biodegradability, organism could deposit excessive heavy metals elements into tissues. Existing literature proposed that prolonged heavy metals enrichment had comprehensive toxicity to multi-organs of vertebrates. However, little research focus on the molecular mechanism for the hepatotoxicity of heavy metal enrichment to Chiroptera. In the present study, ten Hipposideros armiger individuals from Yingde City (YD, relatively pollution-free) and Chunwan City (CW, excessive heavy metals emission) were dissected while environment samples were also obtained. To corroborate the toxicity mechanism of heavy metals to bats liver, multi-omics, pathology and molecular biology methods were performed. Our results showed that more Cd and Pb elements were significantly enriched in bats liver and food sources in the CW group. In addition, prolonged heavy metals accumulation disturbed the hepatic transcription profiling associated with solute carriers family, ribosome pathway, ATP usage and heat shock proteins. Excessive heavy metals enrichment also altered the relative abundance of typical gut microbe taxa to inhibit the tight-junction protein expression. We also found that the levels of superoxide dismutase, glutathione peroxidase and glutathione were decreased while ROS density and malondialdehyde content were elevated after excessive heavy metals enrichment. Besides, hepatic fat accumulation and inflammation injury were also observed under the excessive heavy metals enrichment while the metabolism biomarkers contents were decreased. Therefore, prolonged heavy metals enrichment would induce a series of hepatotoxicity by disturbing the microbes-gut-liver axis and hepatic transcription modes, which could decrease the overall metabolism level in bats. Our study provided protection strategy for biodiversity conservation and raised public attention to environment pollution.
Project description:The stress response of the soil bacterium Sinorhizobium meliloti towards elevated concentrations of the heavy metals cadmium and zinc was analyzed via transcriptional profiling.