Project description:The lung response to inhalation exposure to oil vapor particles was investigated in a rat model. Adult male Sprague-Dawley rats were exposed by whole-body inhalation to air or an aerosol containing oil vapor particles at concentrations of 300 ppm, 6 hours/day for 1 day (shot-term) or 300 ppm, 6 hours/day, 4 days/week for 4 weeks (long-term). The control and oil vapor exposed rats were euthanized at post-exposure time intervals of 1 and 28 days and lung toxicity determined. Analysis of bronchoalveolar lavage parameters of toxicity such as lactate dehydrogenase activity, oxidant generation, and inflammation did not reveal any significant lung toxicity in the oil vapor exposed rats. Approximately 50 genes each were found significantly differentially expressed in both the short- and long-term exposure groups of the rats at the one-day post-exposure time interval. The data obtained from the present study demonstrated that oil vapor inhalation exposure, under the exposure conditions employed in the present study, did not result in any significant lung toxicity in the rats despite the gene expression changes detected.
Project description:Purpose:To help identify molecular regulatory mechanisms of developmental toxicity for fish exposed to Deepwater Horizon (DWH) oil, microRNA profiles in red drum larvae exposed to different DWH oils (source/mass and artificially weathered oil) were evaluated using High Throughput Sequencing (HTS). Methods:Total microRNA profiles of 48 hpf red drum larvae after source oil (0.135%, 0.27%, and 0.54%) and slick oil (1.25%, 2.5% and 5%) exposure were generated by deep sequencing, in triplicate, using Illumina NextSeq 500. Results: Source and slick oil significantly dysregulated the expression of miR-18a, miR-27b, and miR-203a across all exposure concentrations. The target genes of these miRNAs were predominantly involved in the neuro-cardio system development processes and associated key signaling pathways such as axonal guidance signaling, CREB signaling in neurons, synaptic long-term potentiation pathway, calcium signaling and role of NFAT in cardiac hypertrophy.
Project description:Fish oil, olive oil, and coconut oil dietary supplementation have several cardioprotective benefits, but it is not established if they can protect against air pollution-induced adverse effects. We hypothesized that these dietary supplements would attenuate ozone-induced systemic and pulmonary effects. Male Wistar Kyoto rats were fed either a normal diet, or a diet enriched with fish, olive, or coconut oil starting at 4 weeks of age for 8 weeks. Animals were then exposed to air or ozone (0.8 ppm), 4h/day for 2 consecutive days. The fish oil diet completely abolished phenylephrine-induced vasoconstriction that was increased following ozone exposure in the animals fed all other diets. Only the fish oil diet increased baseline levels of bronchoalveolar lavage fluid (BALF) markers of lung injury and inflammation. Ozone-induced pulmonary injury/inflammation were comparable in rats on normal, coconut oil, and olive oil diets with altered expression of markers in animals fed the fish oil diet. Fish oil, regardless of exposure, led to enlarged, foamy macrophages in the BALF that coincided with decreased mRNA expression of cholesterol transporters, cholesterol receptors, and nuclear receptors in the lung. Serum miRNA profile was assessed using small RNA-sequencing in normal and fish oil groups and demonstrated marked depletion of a variety of miRNAs, several of which were of splenic origin. No ozone-specific changes were noted. Collectively, these data indicate that while fish oil offered protection from ozone-induced aortic vasoconstriction, it increased pulmonary injury/inflammation and impaired lipid transport mechanisms resulting in foamy macrophage accumulation, demonstrating the need to be cognizant of potential off-target pulmonary effects that might offset the overall benefit of this vasoprotective dietary supplement.
Project description:Purpose:To help identify molecular mechanisms and pathways potentially involved in the developmental toxicity for fish exposed to Deepwater Horizon (DWH) oil, transcriptomic profiles in mahi-mahi (Coryphaena hippurus) embryos exposed to different DWH oils (source and artificially weathered oil) were evaluated at different critical windows of development using High Throughput Sequencing (HTS). Methods:Total mRNA profiles of 24, 48, 96 hpf mahi-mahi larvae after slick and source oil exposure were generated by deep sequencing, in triplicate, using Illumina HiSeq2500. qRT–PCR validation was performed using SYBR Green assays. Results: Exposure to slick oil induced more pronounced changes in gene expression over time than did exposure to source oil. Predominant transcriptomic responses included alteration of E1F2 signaling, steroid biosynthesis, ribosome biogenesis, perturbation in eye development and peripheral nervous, and activation of P450 pathway. Comparisons of changes of cardiac / Ca2+-associated genes with phenotypic responses revealed reduced heart rate and increased pericardial edema in larvae exposed to slick oil but not source oil.
Project description:Samples of oil and production water were collected from five wells of the Qinghai Oilfield, China, and subjected to GeoChip hybridization experiments for microbial functional diversity profiling. Unexpectedly, a remarkable microbial diversity in oil samples, which was higher than that in the corresponding water samples, was observed, thus challenging previously believed assumptions about the microbial diversity in this ecosystem. Hierarchical clustering separated oil and water samples, thereby indicating distinct functional structures in the samples. Genes involved in the degradation of hydrocarbons, organic remediation, stress response, and carbon cycling were significantly abundant in crude oil, which is consistent with their important roles in residing in oil. Association analysis with environmental variables suggested that oil components comprising aromatic hydrocarbons, aliphatic hydrocarbons, and a polar fraction with nitrogen-, sulfur-, and oxygen-containing compounds were mainly influential on the structure of the microbial community. Furthermore, a comparison of microbial communities in oil samples indicated that the structures were depth/temperature-dependent. To our knowledge, this is the first thorough study to profile microbial functional diversity in crude oil samples.
Project description:The effect of different diets (i.e. fish oil based vs vegetable oil based) on liver transcription profiles over the life history stages (freshwater and marine phases) of cultured Atlantic salmon (Salmo salar) were explored. Two groups of fish were raised from first feeding on different lipid containing diets; a) the standard 100% fish oil based diet, the other enriched with a blend of vegetable oils (75%) + fish oil (25%). Liver samples were taken from fish at four time points: two freshwater phase (as parr 36 weeks post hatch (wph); as pre-smolts, 52 wph) and two marine phase ( as post-smolts 55 wph; and as adult fish , 86 wph). A total of 96 cDNA microarray hybridisations - TRAITS / SGP Atlantic salmon 17k feature cDNA microarray - were performed ( 2 diets x 4 time points x 6 biological replicates x 2 -dye swap) using a comon pooled reference contol design.
Project description:This experiment was conducted in order to evaluate the potential contribution of oil droplets to the toxicity of dispersed oil to fish larvae. Atlantic cod larvae were exposed to five concentrations of either dispersed oil (D1-D5) (containing oil droplets [medium size 10-14 µm based on volume] and water soluble fraction [WSF]) or the filtered dispersion containing only WSF of oil (W1-W5) for four days and harvested for transcriptional analysis at 13 days post hatching. The most significant differently expressed genes were observed in cod larvae exposed to the highest concentration of the dispersed oil (containing 10.41 ± 0.46 µg ∑PAH/L), with CYP1A showing the strongest response. Functional analysis further showed that the top scored network as analyzed with Ingenuity Pathway Analysis was “Drug Metabolism, Endocrine System Development and Function, Lipid Metabolism”. Oil exposure also increased the expression of genes involved in bone resorption and decreased the expression of genes related to bone formation. In conclusion, oil exposure affects drug metabolism, endocrine regulation, cell differentiation and proliferation, apoptosis, fatty acid biosynthesis and tissue development in Atlantic cod larvae. The altered gene transcription was dominated by the WSF and the oil droplet fraction only had a moderate impact on the observed changes.
Project description:Purpose:To help identify molecular mechanisms and pathways potentially involved in the developmental toxicity for fish exposed to different concentrations of Deepwater Horizon (DWH) oil, transcriptomic profiles in mahi-mahi (Coryphaena hippurus) embryos exposed to different DWH oils (source and artificially weathered oil) were evaluated using High Throughput Sequencing (HTS). Methods:Total mRNA profiles of 48 hpf mahi-mah larvae after slick (0.5%, 1%, and 2%) and source/mass oil (0.125%, 0.25% and 5%) exposure were generated by deep sequencing, in triplicate, using Illumina NextSEQ v2. Results:To determine the potential biological impact of oil exposure at system level, a gene ontology (GO) term analysis on biological processes (BPs) was conducted by analyzing the DEGs using ToppGene. The profile of BPs was dose- and oil type- dependent. After exposure to 0.125% slick oil, the top enriched biological processes were RNA processing and RNA metabolism terms. Metabolic and catabolic process and terms associated with embryo development were some of the most enriched BPs at 0.25% slick oil. The top enriched BPs at 0.5% slick oil were organic acid metabolic process and cardiovascular system development. For source oil, cell cycle process, metabolic process, and RNA processing were the most enriched by 0.125% source oil exposure, which were also highly enriched by 0.25% source oil exposure, while more ‘response’ BPs were enriched by 0.25% source oil exposure, such as regulation of response to stress, response to endogenous stimulus, response to hormone, cellular response to light stimulus, etc. The most significantly enrich BP by 0.5% source oil was cardiovascular system development followed by organic acid metabolic process and cell junction assembly.
Project description:Purpose:To help identify molecular mechanisms and pathways potentially involved in the developmental toxicity for estuary fish exposed to different concentrations of Deepwater Horizon (DWH) oil, transcriptomic profiles in red drum (Sciaenops ocellatus) embryos exposed to different DWH oils (source/mass and artificially weathered oil) were evaluated using High Throughput Sequencing (HTS). Methods:Total mRNA profiles of 48 hpf red drum larvae after slick (1.25%, 2.5%, and 5%) and source/mass oil (0.135%, 0.27% and 0.54%) exposure were generated by deep sequencing, in triplicate, using Illumina NextSEQ v2. Results:To determine the potential biological impact of oil exposure at system level, a gene ontology (GO) term analysis on biological processes (BPs) was conducted by analyzing the DEGs using DAVID. After exposure to source oil, the top enriched biological processes were terms associated with oxidation-reduction process, metabolic process (e.g. steroid), and organism development. Similar biological processes were also among the most significant biological processes by slick oil exposure. Among the top biological process list a significant number of nervous system related terms were highly enriched by both source and slick oil exposure, including midbrain development, motor neuron axon guidance, nervous system development, eye development, neuron development, neuron differentiation etc.