ABSTRACT: Functional categorization of transcriptome in the species Symphysodon aequifasciatus Pellegrin 1904 (Perciformes: Cichlidae) exposed to benzo[a]pyrene and phenanthrene
Project description:This study aims to evaluate the transcriptome alterations, through cDNA libraries, associated with the effects of the combination of two PAHs, benzo[a]pyrene (0.5M-NM-<g/L) and phenanthrene (50M-NM-<g/L), present in crude oil, on specimens of Symphysodon aequifasciatus (discus fish) after 48h of exposure. The cDNA libraries were constructed according to the SOLiDTM SAGETM protocol for sequencing in the SOLiD v.3 Plus sequencer. The results were analyzed by bioinformatics and differentially expressed genes were categorized using the gene ontology program (AmiGO v.1.8). The functional categories (terms) found in the gene ontology and the gene network generated using STRING software were used to predict the adverse effects in the liver. In the present study, 27,127 genes (compared to Danio rerio database) were identified. Considering only those genes with a p-value less than or equal to 0.05 and a greater than or equal to two-fold change in expression across libraries, we found 804 genes, 438 down-regulated (54%) and 366 up-regulated genes (46%), in the experimental group compared to the control group. Out of this total, 327 genes were successfully categorized, 174 down-regulated and 153 up-regulated genes, using gene ontology tool. The final confidence gene network, analyzed in STRING, was composed by 199 nodes of proteins, 124 of them resulted in 274 interactions. The results showed that even an acute exposure of 48 h caused metabolic change in response to environmental contaminants, resulting in changes of cell integrity, changes in oxidation-reduction processes, disturbances of intracellular signaling and changes in the immune response of discus fish. Also the gene network interactions have showed no central interplay cluster, exhibiting interconnected clusters interactions and sparsely connected sub-networks. These findings highlight that even an acute and sublethal exposure of PAHs can cause metabolism changes that may affect this fish species survival rates. Our findings using the SAGE-method and the SOLiD sequencer showed that this is a powerful tool for gene expression analysis in discus fish, a non-model organism. Transcriptome analysis of differentially expressed genes in liver in benzo[a]pyrene and phenanthrene-exposed and non-exposed fish (N=6 per treatment)
Project description:The arctic ecosystems are increasingly exposed to pollution particularly from offshore petroleum extraction-related activities. The objective of the study is to map transcriptome responses in copepods of the arctic region in response to PAHs phenanthrene (Phe) and benzo[a]pyrene (BaP) found in crude-oil contaminants.
Project description:The arctic ecosystems are increasingly exposed to pollution particularly from offshore petroleum extraction-related activities. The objective of the study is to map transcriptome responses in copepods of the arctic region in response to PAHs phenanthrene (Phe) and benzo[a]pyrene (BaP) found in crude-oil contaminants.
Project description:The arctic ecosystems are increasingly exposed to pollution particularly from offshore petroleum extraction-related activities. The objective of the study is to map transcriptome responses in copepods of the arctic region in response to PAHs phenanthrene (Phe) and benzo[a]pyrene (BaP) found in crude-oil contaminants.
Project description:This study aims to evaluate the transcriptome alterations, through cDNA libraries, associated with the effects of the combination of two PAHs, benzo[a]pyrene (0.5μg/L) and phenanthrene (50μg/L), present in crude oil, on specimens of Symphysodon aequifasciatus (discus fish) after 48h of exposure. The cDNA libraries were constructed according to the SOLiDTM SAGETM protocol for sequencing in the SOLiD v.3 Plus sequencer. The results were analyzed by bioinformatics and differentially expressed genes were categorized using the gene ontology program (AmiGO v.1.8). The functional categories (terms) found in the gene ontology and the gene network generated using STRING software were used to predict the adverse effects in the liver. In the present study, 27,127 genes (compared to Danio rerio database) were identified. Considering only those genes with a p-value less than or equal to 0.05 and a greater than or equal to two-fold change in expression across libraries, we found 804 genes, 438 down-regulated (54%) and 366 up-regulated genes (46%), in the experimental group compared to the control group. Out of this total, 327 genes were successfully categorized, 174 down-regulated and 153 up-regulated genes, using gene ontology tool. The final confidence gene network, analyzed in STRING, was composed by 199 nodes of proteins, 124 of them resulted in 274 interactions. The results showed that even an acute exposure of 48 h caused metabolic change in response to environmental contaminants, resulting in changes of cell integrity, changes in oxidation-reduction processes, disturbances of intracellular signaling and changes in the immune response of discus fish. Also the gene network interactions have showed no central interplay cluster, exhibiting interconnected clusters interactions and sparsely connected sub-networks. These findings highlight that even an acute and sublethal exposure of PAHs can cause metabolism changes that may affect this fish species survival rates. Our findings using the SAGE-method and the SOLiD sequencer showed that this is a powerful tool for gene expression analysis in discus fish, a non-model organism.
Project description:MCF-7 and HepG2 cells were exposed to a range of concentrations of benzo(a)pyrene or benzo(e)pyrene (0-5 uM) for up to 48 h and gene expression analysis performed. Keywords: dose response
Project description:Assessing the potential carcinogenicity of human toxins represents an ongoing challenge. Chronic rodent bioassays predict human cancer risk with limited reliability, and are expensive and time-consuming. To identify alternative prediction methods, we evaluated a transcriptomics-based human in vitro model to classify carcinogens by their modes of action. The aim of this study was to determine the transcriptomic response and identify specific molecular signatures of polycyclic aromatic hydrocarbons (PAHs), which can be used as predictors of carcinogenicity of environmental toxins in human in vitro systems. We found that characteristic molecular signatures facilitate identification and prediction of carcinogens. To evaluate the change in gene expression levels, human hepatocellular carcinoma (HepG2) cells were exposed to nine different PAHs (benzo[a]pyrene, dibenzo[a,h]anthracene, 3-methylcholanthrene, naphthalene, chrysene, phenanthrene, benzo[a]anthracene, benzo[k]fluoranthene, and indeno[1,2,3-c,d]pyrene) for 48 h. Gene expression analysis was conducted using a 44K whole human genome microarray (Agilent Technologies, USA).
Project description:Benzo(a)pyrene is a well-established human carcinogen in humans and rodents. In the present study, we sought to determine the dose- and time-dependent changes in gene expression upon oral exposure to benzo(a)pyrene. Adult male B6C3F1 mice were exposed to four doses of benzo(a)pyrene or vehicle control for three days and sacrificed 4 or 24 hours after the final exposure.
Project description:Benzo(a)pyrene is a well-established human carcinogen in humans and rodents. In the present study, we sought to determine the dose- and time-dependent changes in gene expression upon oral exposure to benzo(a)pyrene. Adult male MutaTMMouse were exposed to three doses of benzo(a)pyrene or vehicle control (olive oil) for 28 days and sacrificed three days after the final exposure.