Project description:The use of a systems biology approach to analyze common and specific mechanisms of liver toxicity induced by munitions compounds TNT, 2,6-DNT, 2,4-DNT, 4A-DNT, and 2A-DNT The munitions compound 2,4,6-trinitrotoluene (TNT), its environmental degradation products 2-amino-4,6-dinitrotoluene (2A-DNT) and 4-amino-2,6-dinitrotoulene (4A-DNT), and two other munitions, 2,4-dinitrotoluene (2,4-DNT) and 2,4-dinitrotoluene (2,6-DNT) contaminate contaminate land, water and retired ammunitions plants. The release of these compounds to the environment is due to military activities and a series of manufacturing processes. Although toxicity has been characterized for these compounds, little is known of their mechanism of action. Here we describe to use an integrative systems biology approach including toxicology, pathology, transcriptomics, metabolomics, gene function classification, pathway analysis and gene network modeling to try to understand the mechanisms of toxicity of these compounds.
Project description:Small organisms can be used as biomonitoring tools to assess chemicals in the environment. Chemical stressors are especially hard to assess and monitor when present as complex mixtures. Here, Daphnia magna were exposed for 24 hours to five different munitions constituents 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), trinitrobenzene (TNB), dinitrobenzene (DNB), or 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) as well as to 8 different munitions mixtures and ground water contaminated with munitions constituents. To better understand possible mixture effects, gene expression changes from all treatments were compared using high-density microarrays. While mixtures and ground water exposures had genes and gene functions in common with single chemical exposures, unique functions were also affected, which was consistent with the non-additivity of chemical effects in these mixtures. The study consisted of three different experiments: (1) exposure to a concentration corresponding to 70% of 1/10th of the LC50 value of six individual MCs (TNT, 2,4-DNT, 2,6-DNT, DNB, TNB, RDX) and a control; (2) exposure to eight different laboratory mixtures of the previously mentioned MCs. Different combinations of MCs including four mixtures (Mixtures 5, 6, 7 and 8) representative of field collected groundwater from LAAP (Louisiana Army Ammunition Plant) were created; and (3) exposure to MC-contaminated ground water field-collected from 3 different wells (85, 108, and 141) at the LAAP. All exposures were conducted for 24h.
Project description:To determine toxicant specific effects of Ordnance Related Compound (ORC) exposure we performed microarray hybridizations with RNA isolated from Daphnia magna following different ORC exposures at the 1/10 LC50. The gene expression profiles revealed toxicant specific gene expression profiles allowed for the identification of specific biomarkers of exposure. Keywords: ecotoxicogenomic exposure study We exposed Daphnia magna the 1/10 LC50 of different Ordnance Related Compounds (Cu, Zn, Pb, WO4, RDX, TNT, 2-ADNT, 2-ADNT, TNB, DNB, 2,4-DNT, and 2,6-DNT) for 24 hours. For each exposure condition, we performed 3 exposures and 2 technical replicates (as dye swap) for each exposure (6 microarrays total, except TNT and Cu). All exposures were compared to a unexposed laboratory control (MHRW media).
Project description:Small organisms can be used as biomonitoring tools to assess chemicals in the environment. Chemical stressors are especially hard to assess and monitor when present as complex mixtures. Here, Daphnia magna were exposed for 24 hours to five different munitions constituents 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), trinitrobenzene (TNB), dinitrobenzene (DNB), or 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) as well as to 8 different munitions mixtures and ground water contaminated with munitions constituents. To better understand possible mixture effects, gene expression changes from all treatments were compared using high-density microarrays. While mixtures and ground water exposures had genes and gene functions in common with single chemical exposures, unique functions were also affected, which was consistent with the non-additivity of chemical effects in these mixtures.
Project description:2,4-dinitrotoluene (2,4-DNT), a nitroaromatic used in industrial and explosive manufacturing processes, is known to contaminate artillery ranges, demilitarization areas and munitions manufacturing facilities. Previous transcriptomic and lipidomic studies identified energy metabolism as a principle biochemical process affected by 2,4-DNT where up-stream effects on PPARα signaling were hypothesized as themolecular initiating event for these effects. Here, the validity of this hypothetical adverse outcome pathway (AOP) was assessed by testing the hypothesis that 2,4-DNT-induced perturbations in PPARα signaling and resultant downstream deficits in energy metabolism, especially from lipids, would result in organism-level impacts on exercise endurance. PPARα knock-out (-/-) and wild-type (WT) mice were exposed for 14 days to vehicle or 2,4-DNT at a dose (134 mg/kg/day) that did not exhibit overt systemic toxicity. Mice performed an exercise challenge (forced swim) 1 day after the last dose. 2,4-DNT decreased swim times in WT and PPARα (-/-) mice, but the effect was significantly less in PPARα (-/-) mice indicating the critical of PPARα in mediating 2,4-DNT-induced energy metabolism deficits. 2,4-DNT caused down-regulation of transcripts involved in fatty acid metabolism, gluconeogenesis, triacylglycerol catabolism, and the pentose phosphate pathway, and 2,4-DNT treated wild-type mice had decreased serum trigylcerides and increased serum glucose versus 2,4-DNT treated PPARα (-/-) mice. Our results support the hypothesis that 2,4-DNT perturbs PPARα signaling as a molecular initiating event therefore impacting energy metabolism, especially lipid metabolism, producing reduced exercise endurance in mice.
Project description:2,4-dinitrotoluene (2,4-DNT), a nitroaromatic used in industrial and explosive manufacturing processes, is known to contaminate artillery ranges, demilitarization areas and munitions manufacturing facilities. Previous transcriptomic and lipidomic studies identified energy metabolism as a principle biochemical process affected by 2,4-DNT where up-stream effects on PPARα signaling were hypothesized as themolecular initiating event for these effects. Here, the validity of this hypothetical adverse outcome pathway (AOP) was assessed by testing the hypothesis that 2,4-DNT-induced perturbations in PPARα signaling and resultant downstream deficits in energy metabolism, especially from lipids, would result in organism-level impacts on exercise endurance. PPARα knock-out (-/-) and wild-type (WT) mice were exposed for 14 days to vehicle or 2,4-DNT at a dose (134 mg/kg/day) that did not exhibit overt systemic toxicity. Mice performed an exercise challenge (forced swim) 1 day after the last dose. 2,4-DNT decreased swim times in WT and PPARα (-/-) mice, but the effect was significantly less in PPARα (-/-) mice indicating the critical of PPARα in mediating 2,4-DNT-induced energy metabolism deficits. 2,4-DNT caused down-regulation of transcripts involved in fatty acid metabolism, gluconeogenesis, triacylglycerol catabolism, and the pentose phosphate pathway, and 2,4-DNT treated wild-type mice had decreased serum trigylcerides and increased serum glucose versus 2,4-DNT treated PPARα (-/-) mice. Our results support the hypothesis that 2,4-DNT perturbs PPARα signaling as a molecular initiating event therefore impacting energy metabolism, especially lipid metabolism, producing reduced exercise endurance in mice.
Project description:2,4-dinitrotoluene (2,4-DNT), a nitroaromatic used in industrial and explosive manufacturing processes, is known to contaminate artillery ranges, demilitarization areas and munitions manufacturing facilities. Previous transcriptomic and lipidomic studies identified energy metabolism as a principle biochemical process affected by 2,4-DNT where up-stream effects on PPARα signaling were hypothesized as themolecular initiating event for these effects. Here, the validity of this hypothetical adverse outcome pathway (AOP) was assessed by testing the hypothesis that 2,4-DNT-induced perturbations in PPARα signaling and resultant downstream deficits in energy metabolism, especially from lipids, would result in organism-level impacts on exercise endurance. PPARα knock-out (-/-) and wild-type (WT) mice were exposed for 14 days to vehicle or 2,4-DNT at a dose (134 mg/kg/day) that did not exhibit overt systemic toxicity. Mice performed an exercise challenge (forced swim) 1 day after the last dose. 2,4-DNT decreased swim times in WT and PPARα (-/-) mice, but the effect was significantly less in PPARα (-/-) mice indicating the critical of PPARα in mediating 2,4-DNT-induced energy metabolism deficits. 2,4-DNT caused down-regulation of transcripts involved in fatty acid metabolism, gluconeogenesis, triacylglycerol catabolism, and the pentose phosphate pathway, and 2,4-DNT treated wild-type mice had decreased serum trigylcerides and increased serum glucose versus 2,4-DNT treated PPARα (-/-) mice. Our results support the hypothesis that 2,4-DNT perturbs PPARα signaling as a molecular initiating event therefore impacting energy metabolism, especially lipid metabolism, producing reduced exercise endurance in mice.
Project description:2,4-dinitrotoluene (2,4-DNT), a nitroaromatic used in industrial and explosive manufacturing processes, is known to contaminate artillery ranges, demilitarization areas and munitions manufacturing facilities. Previous transcriptomic and lipidomic studies identified energy metabolism as a principle biochemical process affected by 2,4-DNT where up-stream effects on PPAR? signaling were hypothesized as themolecular initiating event for these effects. Here, the validity of this hypothetical adverse outcome pathway (AOP) was assessed by testing the hypothesis that 2,4-DNT-induced perturbations in PPAR? signaling and resultant downstream deficits in energy metabolism, especially from lipids, would result in organism-level impacts on exercise endurance. PPAR? knock-out (-/-) and wild-type (WT) mice were exposed for 14 days to vehicle or 2,4-DNT at a dose (134 mg/kg/day) that did not exhibit overt systemic toxicity. Mice performed an exercise challenge (forced swim) 1 day after the last dose. 2,4-DNT decreased swim times in WT and PPAR? (-/-) mice, but the effect was significantly less in PPAR? (-/-) mice indicating the critical of PPAR? in mediating 2,4-DNT-induced energy metabolism deficits. 2,4-DNT caused down-regulation of transcripts involved in fatty acid metabolism, gluconeogenesis, triacylglycerol catabolism, and the pentose phosphate pathway, and 2,4-DNT treated wild-type mice had decreased serum trigylcerides and increased serum glucose versus 2,4-DNT treated PPAR? (-/-) mice. Our results support the hypothesis that 2,4-DNT perturbs PPAR? signaling as a molecular initiating event therefore impacting energy metabolism, especially lipid metabolism, producing reduced exercise endurance in mice. RNA was isolated from liver tissue of vehicle or 2,4-DNT treated wild-type or PPAR? (-/-) mice (n=6) and RT-PCR performed to analyze genes involved in fatty acid metabolism
Project description:2,4-dinitrotoluene (2,4-DNT), a nitroaromatic used in industrial and explosive manufacturing processes, is known to contaminate artillery ranges, demilitarization areas and munitions manufacturing facilities. Previous transcriptomic and lipidomic studies identified energy metabolism as a principle biochemical process affected by 2,4-DNT where up-stream effects on PPARα signaling were hypothesized as themolecular initiating event for these effects. Here, the validity of this hypothetical adverse outcome pathway (AOP) was assessed by testing the hypothesis that 2,4-DNT-induced perturbations in PPARα signaling and resultant downstream deficits in energy metabolism, especially from lipids, would result in organism-level impacts on exercise endurance. PPARα knock-out (-/-) and wild-type (WT) mice were exposed for 14 days to vehicle or 2,4-DNT at a dose (134 mg/kg/day) that did not exhibit overt systemic toxicity. Mice performed an exercise challenge (forced swim) 1 day after the last dose. 2,4-DNT decreased swim times in WT and PPARα (-/-) mice, but the effect was significantly less in PPARα (-/-) mice indicating the critical of PPARα in mediating 2,4-DNT-induced energy metabolism deficits. 2,4-DNT caused down-regulation of transcripts involved in fatty acid metabolism, gluconeogenesis, triacylglycerol catabolism, and the pentose phosphate pathway, and 2,4-DNT treated wild-type mice had decreased serum trigylcerides and increased serum glucose versus 2,4-DNT treated PPARα (-/-) mice. Our results support the hypothesis that 2,4-DNT perturbs PPARα signaling as a molecular initiating event therefore impacting energy metabolism, especially lipid metabolism, producing reduced exercise endurance in mice. RNA was isolated from liver tissue of vehicle or 2,4-DNT treated wild-type or PPARα (-/-) mice (n=6) and RT-PCR performed to analyze genes involved in fatty acid metabolism