Professor Igor Koturbash, MD, PhD, and his collaborators recently published an article titled “Long-term effects of combined exposures to simulated microgravity and galactic cosmic radiation on the mouse lung: sex-specific epigenetic reprogramming” in Radiation and Environmental Biophysics.
This study examines how space-like conditions—including simulated microgravity and galactic cosmic radiation (GCR)—affect the lungs of male and female mice at the epigenetic (or “above” the genetic) level. Researchers exposed mice to different doses of radiation and simulated weightlessness to see if these factors caused long-term epigenetic changes, particularly in DNA methylation, which regulates proper expression of genetic information.
Nine months after exposure, male mice showed increased levels of DNA methylation in specific genetic regions (LINE-1 elements) associated with genomic stability. This was linked to higher levels of enzymes that control DNA methylation. Female mice, however, showed a trend toward reduced DNA methylation, though the changes were less pronounced. These sex-specific differences suggest that males and females may respond differently to space radiation at the epigenetic level.
The findings are important because they suggest that DNA methylation of selective genomic loci (for instance, LINE-1) could serve as a long-term biomarker of radiation exposure. Understanding these genetic effects is crucial for planning deep-space missions, as prolonged exposure to cosmic radiation and microgravity may have lasting health consequences for astronauts. Additionally, the study highlights the need to consider sex differences in radiation risk assessment.