Gene expression changes in mouse brain after exposure to low-dose ionizing radiation

Int J Radiat Biol. 2003 Oct;79(10):759-75. doi: 10.1080/09553000310001610961.

Abstract

Purpose: To characterize the cellular functions associated with the altered transcript profiles of mouse brain exposed to low-dose in vivo gamma-irradiation.

Materials and methods: Cerebral RNA was isolated at 30 min and 4 h after whole-body irradiation at 0.1 or 2 Gy, hybridized to random oligonucleotide arrays, and evaluated for time and dose-response patterns by multifactorial analyses.

Results: Brain irradiation modulated the expression patterns of 1574 genes, of which 855 showed more than 1.5-fold variation. about 30% of genes showed dose-dependent variations, including genes exclusively affected by 0.1 Gy. About 60% of genes showed time-dependent variation with more genes affected at 30 min than at 4 h. Early changes involved signal transduction, ion regulation and synaptic signalling. Later changes involved metabolic functions including myelin and protein synthesis. Low-dose radiation also modulated the expression of genes involved in stress response, cell-cycle control and DNA synthesis/repair.

Conclusions: Doses of 0.1 Gy induced changes in gene expression that were qualitatively different from those at 2 Gy. The findings suggest that low-dose irradiation of the brain induces the expression of genes involved in protective and reparative functions, while down-modulating genes involved in neural signalling activity.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Brain / metabolism
  • Brain / radiation effects*
  • Dose-Response Relationship, Radiation
  • Gamma Rays
  • Gene Expression Regulation / radiation effects*
  • Genome
  • Male
  • Mice
  • Molecular Sequence Data
  • Oligonucleotide Array Sequence Analysis / methods*
  • RNA / genetics*
  • RNA / metabolism
  • RNA / radiation effects*
  • Radiation Dosage
  • Radiation, Ionizing
  • Sequence Analysis, RNA / methods*
  • Transcription, Genetic / radiation effects*

Substances

  • RNA