title: Systems toxicology identifies mechanistic impacts of 2-amino-4,6-dinitrotoluene (2A-DNT) exposure in Northern Bobwhite.
abstract: BACKGROUND
  A systems toxicology investigation comparing and integrating transcriptomic and proteomic results was conducted to develop holistic effects characterizations for the wildlife bird model, Northern bobwhite (Colinus virginianus) dosed with the explosives degradation product 2-amino-4,6-dinitrotoluene (2A-DNT). A subchronic 60 d toxicology bioassay was leveraged where both sexes were dosed via daily gavage with 0, 3, 14, or 30 mg/kg-d 2A-DNT. 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 proteome expression were investigated in liver for both sexes and kidney in males, at 30 mg/kg-d.
  
  
  RESULTS
  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 gene and protein expression when investigating higher-order functional responses including statistically enriched gene networks and canonical pathways, especially when connected to toxicological outcomes of 2A-DNT exposure. Analysis of networks statistically enriched for both transcripts and proteins demonstrated 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 assays, transcript expression and protein expression each implicated peroxisome proliferator-activated receptor (PPAR) nuclear signaling as a primary molecular target in the 2A-DNT exposure with significant downstream enrichment of PPAR-regulated pathways including lipid metabolic pathways and gluconeogenesis suggesting impaired bioenergetic potential.
  
  
  CONCLUSIONS
  Although the differential expression of transcripts and proteins was largely unique, the consensus of functional pathways and gene networks enriched among transcriptomic and proteomic datasets provided the identification of many critical metabolic functions underlying 2A-DNT toxicity as well as impaired PPAR signaling, a key molecular initiating event known to be affected in di- and trinitrotoluene exposures.
authors.affiliation: Environmental Laboratory, US Army Engineer Research and Development Center, EL-EP-P, 3909 Halls Ferry Rd, Vicksburg, MS, 39180, USA. kurt.a.gust@usace.army.mil.
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Gust
authors.affiliation: Institute for Digital Biology, Mississippi State University, Starkville, MS, 39762, USA. bnanduri@cvm.msstate.edu.
authors.forename: Bindu
authors.initials: B
authors.lastname: Nanduri
authors.affiliation: Translational Genomics Research Institute, Phoenix, AZ, 85004, USA. rawat.arun@gmail.com.
authors.forename: Arun
authors.initials: A
authors.lastname: Rawat
authors.affiliation: Environmental Laboratory, US Army Engineer Research and Development Center, EL-EP-P, 3909 Halls Ferry Rd, Vicksburg, MS, 39180, USA. mitchell.s.wilbanks@usace.army.mil.
authors.forename: Mitchell S
authors.initials: MS
authors.lastname: Wilbanks
authors.affiliation: Badger Technical Services, San Antonio, TX, 71286, USA. chooyaw@hotmail.com.
authors.forename: Choo Yaw
authors.initials: CY
authors.lastname: Ang
authors.affiliation: Conestoga-Rovers & Associates, Dallas, TX, 75234, USA. drj0054@gmail.com.
authors.forename: David R
authors.initials: DR
authors.lastname: Johnson
authors.affiliation: University of Arizona, School of Animal and Comparative Biomedical Sciences, Tucson, AZ, 85721, USA. jkpendarvis@email.arizona.edu.|Bio5 Institute, University of Arizona, Tucson, AZ, 85721, USA. jkpendarvis@email.arizona.edu.
authors.forename: Ken
authors.initials: K
authors.lastname: Pendarvis
authors.affiliation: IFXworks LLC, 2915 Columbia Pike, Arlington, VA, 22204, USA. xianfeng.chen@ifxworks.com.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Chen
authors.affiliation: US Army Public Health Command, Aberdeen Proving Ground, Aberdeen, MD, 21010, USA. michael.j.quinn104.civ@mail.mil.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Quinn
authors.affiliation: US Army Public Health Command, Aberdeen Proving Ground, Aberdeen, MD, 21010, USA. mark.s.johnson.civ@mail.mil.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Johnson
authors.affiliation: University of Arizona, College of Agriculture and Life Sciences, Tucson, AZ, 85721, USA. dean@cals.arizona.edu.
authors.forename: Shane C
authors.initials: SC
authors.lastname: Burgess
authors.affiliation: Environmental Laboratory, US Army Engineer Research and Development Center, EL-EP-P, 3909 Halls Ferry Rd, Vicksburg, MS, 39180, USA. edward.j.perkins@usace.army.mil.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Perkins
mesh_terms: D000814:Aniline Compounds / Q000633:toxicity*; D000818:Animals; D001681:Biological Assay / Q000379:methods; D003088:Colinus / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D053834:Explosive Agents / Q000633:toxicity; D005260:Female; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D020543:Proteome / Q000187:drug effects / Q000378:metabolism; D040901:Proteomics / Q000379:methods
chemical_list: D000814:Aniline Compounds; D053834:Explosive Agents; D020543:Proteome; C035208:2-amino-4,6-dinitrotoluene