Modulation of inflammatory gene expression by the ribotoxin deoxynivalenol involves coordinate regulation of the transcriptome and translatome

Toxicol Sci. 2013 Jan;131(1):153-63. doi: 10.1093/toxsci/kfs266. Epub 2012 Sep 11.

Abstract

The trichothecene deoxynivalenol (DON), a common contaminant of cereal-based foods, is a ribotoxic mycotoxin known to activate innate immune cells in vivo and in vitro. Although it is recognized that DON induces transcription and mRNA stabilization of inflammation-associated mRNAs in mononuclear phagocytes, it is not known if this toxin affects translation of selected mRNA species in the cellular pool. To address this question, we employed a focused inflammation/autoimmunity PCR array to compare DON-induced changes in profiles of polysome-associated mRNA transcripts (translatome) to total cellular mRNA transcripts (transcriptome) in the RAW 264.7 murine macrophage model. Exposure to DON at 250 ng/ml (0.84 µM) for 6 h induced robust expression changes in inflammatory response genes including cytokines, cytokine receptors, chemokines, chemokine receptors, and transcription factors, with 73% of the changes being highly comparable within transcriptome and translatome populations. When expression changes of selected representative inflammatory response genes in the polysome and cellular mRNA pools were quantified in a follow-up study by real-time PCR, closely coordinated regulation of the translatome and transcriptome was confirmed; however, modest but significant differences in the relative expression of some genes within the two pools were also detectable. Taken together, DON's capacity to alter translation expression of inflammation-associated genes appears to be driven predominantly by selective transcription and mRNA stabilization that have been reported previously; however, a small subset of these genes appear to be further regulated at the translational level.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cell Culture Techniques
  • Cell Line
  • Cytokines / genetics*
  • Down-Regulation
  • Macrophages / drug effects*
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mice
  • Protein Biosynthesis / drug effects*
  • Protein Biosynthesis / immunology
  • RNA, Messenger / genetics*
  • Real-Time Polymerase Chain Reaction
  • Transcriptome / drug effects*
  • Transcriptome / immunology
  • Trichothecenes / toxicity*
  • Up-Regulation

Substances

  • Cytokines
  • RNA, Messenger
  • Trichothecenes
  • deoxynivalenol