Effect of Radon Inhalation on Murine Brain Proteins: Investigation Using Proteomic and Multivariate Analyses

Radon is a known risk factor for lung cancer; however, it can be used beneficially, such as in radon therapy. We have previously reported the enhancement of antioxidant effects associated with trace amounts of oxidative stress as one of the positive biological effects of radon inhalation. However, the biological effects of radon inhalation are incompletely understood, and more detailed and comprehensive studies are required. Although several studies have used proteomics to investigate the effects of radon inhalation on body proteins, none has focused on brain proteins. In this study, we evaluated the expression status of proteins in murine brains using proteomic and multivariate analyses to identify those whose expressions changed following two days of radon inhalation at a concentration of 1,500 Bq/m3. We found associations of radon inhalation with the expressions of seven proteins related to neurotransmission and heat shock. These proteins may be proposed as biomarkers indicative of radon inhalation. Although further studies are required to obtain the detailed biological significance of these protein alterations, this study contributes to the elucidation of the biological effects of radon inhalation as a low-dose radiation.