Dataset Information

Systems Toxicology Identifies Mechanistic Impacts of 2-amino-4,6-dinitrotoluene (2-ADNT) Exposure in Northern Bobwhite

ABSTRACT: A systems toxicology investigation comparing and integrating transcriptomic and proteomic results was conducted to pursue a holistic understanding of the effects of the explosives degradation product 2-amino-4,6-dinitrotoluene (2A-DNT) dosing on the health of the wildlife bird model, Northern bobwhite (Colinus virginianus). A subchronic 60d toxicology bioassay was leveraged where both sexes were dosed via daily gavage with 0, 3, 14, or 30 mg/kg-d 2-ADNT. Effects on global transcript expression were investigated in liver and kidney tissue using custom microarrays for C. virginianus in both sexes at all doses, while effects on the proteome expression were investigated in liver for both sexes and kidney in males, all at the 30 mg/kg-d dose. As expected, transcript expression was not directly indicative of protein expression in response to 2A-DNT. However, a high degree of correspondence was observed among platforms when investigating higher-order functional responses including statistically enriched gene networks and canonical pathways, especially when connected to toxicological outcomes of 2A-DNT exposure. Specifically, comparison of gene networks statistically enriched from differentially expressed transcripts and for proteins showed common responses including inhibition of programmed cell death and arrest of cell cycle in liver tissues at 2A-DNT doses that caused liver necrosis and death in females. Additionally, both transcript and protein expression in liver tissue was indicative of induced phase I and II xenobiotic metabolism potentially as a mechanism to detoxify and excrete 2A-DNT. Nuclear signaling, transcript expression and protein expression assays each implicated PPAR nuclear signaling as a primary molecular target in the 2A-DNT exposure with significant downstream enrichment of PPAR-regulated pathways including various lipid metabolic pathways and gluconeogenesis suggesting impaired bioenergetic potential. Although the relative expression of transcripts and proteins within enriched pathways was at times divergent, transcript expression assays identified many critical metabolic pathways involved in 2A-DNT toxicity as well as impaired PPAR signaling, a key molecular initiating event known to be affected in di- and tri-nitrotoluene exposures.

ORGANISM(S): Colinus virginianus

PROVIDER: GSE59910 | GEO | 2015/07/01

SECONDARY ACCESSION(S): PRJNA257048

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:A systems toxicology investigation comparing and integrating transcriptomic and proteomic results was conducted to pursue a holistic understanding of the effects of the explosives degradation product 2-amino-4,6-dinitrotoluene (2A-DNT) dosing on the health of the wildlife bird model, Northern bobwhite (Colinus virginianus). A subchronic 60d toxicology bioassay was leveraged where both sexes were dosed via daily gavage with 0, 3, 14, or 30 mg/kg-d 2-ADNT. Effects on global transcript expression were investigated in liver and kidney tissue using custom microarrays for C. virginianus in both sexes at all doses, while effects on the proteome expression were investigated in liver for both sexes and kidney in males, all at the 30 mg/kg-d dose. As expected, transcript expression was not directly indicative of protein expression in response to 2A-DNT. However, a high degree of correspondence was observed among platforms when investigating higher-order functional responses including statistically enriched gene networks and canonical pathways, especially when connected to toxicological outcomes of 2A-DNT exposure. Specifically, comparison of gene networks statistically enriched from differentially expressed transcripts and for proteins showed common responses including inhibition of programmed cell death and arrest of cell cycle in liver tissues at 2A-DNT doses that caused liver necrosis and death in females. Additionally, both transcript and protein expression in liver tissue was indicative of induced phase I and II xenobiotic metabolism potentially as a mechanism to detoxify and excrete 2A-DNT. Nuclear signaling, transcript expression and protein expression assays each implicated PPAR nuclear signaling as a primary molecular target in the 2A-DNT exposure with significant downstream enrichment of PPAR-regulated pathways including various lipid metabolic pathways and gluconeogenesis suggesting impaired bioenergetic potential. Although the relative expression of transcripts and proteins within enriched pathways was at times divergent, transcript expression assays identified many critical metabolic pathways involved in 2A-DNT toxicity as well as impaired PPAR signaling, a key molecular initiating event known to be affected in di- and tri-nitrotoluene exposures. The animal exposure design is presented in a study by Quinn et al (2010). Five treatment groups consisting of 12 male and 12 female bobwhites each were administered 2A-DNT at 0, 0.5, 3, 14, or 30 mg/kg/day via oral gavage for 60 days. Controls received a volume of corn oil equivalent to the mean volume given to birds in the highest dose group without compound. Microarray hybridizations were conducted using completely randomized design experiments including a 2 x 4 factorial treatment arrangement to investigate the conditions: sex (male and female) and 2A-DNT dose (control, 3, 14, and 30 mg/kg-d) for both liver and kidney tissues. All conditions included 4 biological replicates. REFERENCE: Quinn Jr. MJ, McFarland CA, LaFiandra EM, Bazar MA, Johnson MS (2010) Acute, subacute, and subchronic exposure to 2A-DNT (2-amino-4,6-dinitrotoluene) in the northern bobwhite (Colinus virginianus) Ecotoxicology 19:945-952.

Project description:Primary biliary cholangitis (PBC) is a liver-specific autoimmune disease. Treatment of PBC with ursodeoxycholic acid (UDCA) is not sufficient to prevent disease progression, new and creative approaches to treating patients with PBC are urgently required. Double-negative T (DNT) cells, unique regulatory T cells, play crucial roles in maintaining immune system homeostasis. However, both the absolute number and proportion of liver DNT cells were reduced in PBC patients. Hence, it is worth pursuing that whether replenishment of DNT cells can improve the hepatic function and pathology of PBC. In this study, adoptive transfer of DNT cells significantly decreases plasma levels of ALT, AST, AMA-M2 and IgM in both dnTGFβ RII and 2OA-BSA-immunized PBC mouse models. In addition, DNT cells exhibit a strong suppression on liver T cells. While combination therapy with DNT cells and UDCA predominantly ameliorate liver inflammation and extensively inhibit hepatic T and B cells. In vitro study further reveals that UDCA promotes the proliferation of DNT cells, increased functional molecule perforin and reduced inhibitory molecule NKG2A and EPCR expression, resulting in augmenting the suppressive function of DNT cells via FXR/JNK signaling pathway in both mice and human DNT cells. In conclusion, UDCA augments the suppressive function of DNT cells via FXR/JNK. A single transfer of DNT cells in combination with UDCA strongly ameliorates PBC in mice. This study provides a potential application of DNT cell-based therapy for PBC. Methods: The DNT cells incubation with anti-CD3/CD28 antibodies were stimulated with UDCA (60uM) for 48 hours, then transcriptome sequencing studies were performed on DNT cells RNA.Transcriptome sequencing libraries were generated using NEBNext® Ultra™ RNA Library Prep Kit for Illumina® (NEB, USA) following manufacturer’s recommendations and sequenced on an Illumina Hiseq platform (Illumina, San Diego, CA). Sequences were aligned to the reference genome with TopHat and processed with Cufflinks, which quantifies each transcript in each sample using reference annotations produced by the University of California Santa Cruz UCSC. Differentially expressed genes with a fold change of >=1.41 and pvalue <= 0.05 between UDCA treated and control DNT cells were submitted to GO and KEGG enrichment analysis, which uses unbiased methods to assess pathway enrichment.

Project description:Metabolic challenges experienced by dairy cows during the transition between pregnancy and lactation (also known as peripartum), are of considerable interest from a nutrigenomic perspective. The mobilization of large amounts of non-esterified fatty acids (NEFA) leads to an increase in NEFA uptake in the liver, the excess of which can cause hepatic accumulation of lipids and ultimately fatty liver. Interestingly, peripartum NEFA activate the peroxisome proliferator-activated receptor (PPAR), a transcriptional regulator with known nutrigenomic properties. The study of PPAR activation in the liver of periparturient dairy cows is thus crucial; however, current in vitro models of the bovine liver are inadequate, and the isolation of primary hepatocytes is prohibitive and error-prone. The objective of the current study was to evaluate the use of precision-cut liver slices (PCLS) from liver biopsies as a model for PPAR activation in periparturient dairy cows. Four cows were enrolled in the experiment, and PCLS from each were prepared prepartum (-10 DIM) and postpartum (+10 DIM) and treated with a variety of PPAR agonists and antagonist. Gene expression was assayed through RT-qPCR and RNAseq, and intracellular triglyceride concentration was measured. PCLS treated with PPARγ agonist rosiglitazone displayed upregulation of canonical PPAR targets ACADVL and LIPC in the postpartum, while a PPARδ agonists increased expression of PPAR target PDK4; no gene expression changes were detected in the prepartum, and triglyceride concentrations were unchanged between treatments. Transcriptome sequencing revealed considerable differences in response to PPAR agonist, mainly related to pathways involved with lipid metabolism and the immune response. Among differentially expressed genes, a subset of 91 genes were identified as novel putative PPAR targets in the bovine liver, by cross-referencing our results with a publicly-available dataset of predicted PPAR target genes, and supplementing our finding with prior literature. Our results provide important insights on the use of PCLS as a model for assaying PPAR activation in the peripartum.

Project description:Munitions constituents (MCs) including hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), and TNT derivatives are recognized to elicit aberrant neuromuscular responses in many species. The onset of seizures resulting in death was observed in the avian model Northern bobwhite after oral dosing with RDX beginning at 8 mg/kg/day in subacute (14 days) exposures, whereas affective doses of the TNT derivative, 2,6-dinitrotoluene (2,6-DNT), caused gastrointestinal impacts, lethargy, and emaciation in subacute and subchronic (60 days) exposures. To assess and contrast the potential neurotoxicogenomic effects of these MCs, a Northern bobwhite microarray was developed consisting of 4119 complementary DNA (cDNA) features enriched for differentially-expressed brain transcripts from exposures to RDX and 2,6-DNT. RDX affected hundreds of genes in brain tissue, whereas 2,6-DNT affected few (M-bM-^IM-$ 17), indicating that 2,6-DNT exposure had relatively little impact on the brain in comparison to RDX. Birds exhibiting RDX-induced seizures accumulated over 20M-CM-^W more RDX in brain tissues in comparison to non-seizing birds even within a common dose. In parallel, expression patterns were unrelated among seizing and non-seizing birds exposed to equivalent RDX doses. In birds experiencing seizures, genes related to neuronal electrophysiology and signal transduction were significantly affected. Comparative toxicology revealed strong similarity in acute exposure effects between RDX and the organochlorine insecticide dichlorodiphenyltrichloroethane (DDT) regarding both molecular mechanisms and putative mode of action. In a manner similar to DDT, we hypothesize that RDX elicits seizures by inhibition of neuronal cell repolarization postaction potential leading to heightened neuronal excitability and seizures facilitated by multiple molecular mechanisms. Northern Bobwhite 60 Day 2,6-DNT Exposure, Brain Tissue Investigation (High Laser Intensity Scan): Juvenile male and female Northern bobwhite (12 weeks of age) were dosed with 2,6-DNT by daily gavage (0, 5, 10, 40, or 60 mg/kg/day). Each treatment group included 12 replicates per sex. Microarray experiments were conducted in a balanced interwoven-loop design using Cyanine-3 (Cy3) and A647. This experiment investigated the 60-day 2,6-DNT exposure comparing controls and the highest affective 2,6-DNT dose (60 mg/kg/day) in males and females, with all groups including three biological replicates for a total of 24 microarrays. To broaden signal detection, each microarray was scanned at high and low laser power to resolve low-intensity spots and reduce signal saturation, respectively (Skibbe et al., 2006). This dataset represents the High Intensity Scan.

Project description:Munitions constituents (MCs) including hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), and TNT derivatives are recognized to elicit aberrant neuromuscular responses in many species. The onset of seizures resulting in death was observed in the avian model Northern bobwhite after oral dosing with RDX beginning at 8 mg/kg/day in subacute (14 days) exposures, whereas affective doses of the TNT derivative, 2,6-dinitrotoluene (2,6-DNT), caused gastrointestinal impacts, lethargy, and emaciation in subacute and subchronic (60 days) exposures. To assess and contrast the potential neurotoxicogenomic effects of these MCs, a Northern bobwhite microarray was developed consisting of 4119 complementary DNA (cDNA) features enriched for differentially-expressed brain transcripts from exposures to RDX and 2,6-DNT. RDX affected hundreds of genes in brain tissue, whereas 2,6-DNT affected few (M-bM-^IM-$ 17), indicating that 2,6-DNT exposure had relatively little impact on the brain in comparison to RDX. Birds exhibiting RDX-induced seizures accumulated over 20M-CM-^W more RDX in brain tissues in comparison to non-seizing birds even within a common dose. In parallel, expression patterns were unrelated among seizing and non-seizing birds exposed to equivalent RDX doses. In birds experiencing seizures, genes related to neuronal electrophysiology and signal transduction were significantly affected. Comparative toxicology revealed strong similarity in acute exposure effects between RDX and the organochlorine insecticide dichlorodiphenyltrichloroethane (DDT) regarding both molecular mechanisms and putative mode of action. In a manner similar to DDT, we hypothesize that RDX elicits seizures by inhibition of neuronal cell repolarization postaction potential leading to heightened neuronal excitability and seizures facilitated by multiple molecular mechanisms. Northern Bobwhite 60 Day 2,6-DNT Exposure, Brain Tissue Investigation (Low Laser Intensity Scan): Juvenile male and female Northern bobwhite (12 weeks of age) were dosed with 2,6-DNT by daily gavage (0, 5, 10, 40, or 60 mg/kg/day). Each treatment group included 12 replicates per sex. Microarray experiments were conducted in a balanced interwoven-loop design using Cyanine-3 (Cy3) and A647. This experiment investigated the 60-day 2,6-DNT exposure comparing controls and the highest affective 2,6-DNT dose (60 mg/kg/day) in males and females, with all groups including three biological replicates for a total of 24 microarrays. To broaden signal detection, each microarray was scanned at high and low laser power to resolve low-intensity spots and reduce signal saturation, respectively (Skibbe et al., 2006). This dataset represents the Low Intensity Scan.

Dataset Information

Systems Toxicology Identifies Mechanistic Impacts of 2-amino-4,6-dinitrotoluene (2-ADNT) Exposure in Northern Bobwhite

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets