Combined Effects of Proton Radiation and Simulated Microgravity on the Cell Viability and ALP Activity of Murine Osteoblast Cells

Proton radiation (PR) and microgravity (mu G) are two key factors that impact living things in space. This study aimed to explore the combined effects of PR and simulated mu G (S mu G) on bone function. Mouse embryo osteoblast precursor cells (MC3T3-E1) were irradiated with proton beams and immediately treated with S mu G for 2 days using a three-dimensional clinostat. All samples were subjected to cell viability, alkaline phosphatase (ALP) activity and transcriptome assays. The results showed that cell viability decreased with increasing doses of PR. The peak ALP activity after PR or S mu G alone was lower than that obtained with the non-treatment control. No difference in cell viability or ALP activity was found between 1 Gy PR combined with S mu G (PR-S mu G) and PR alone. However, 4 Gy PR-S mu G resulted in decreased cell viability and ALP activity compared with those obtained with PR alone. Furthermore, Gene Ontology analysis revealed the same trend. These results revealed that PR-S mu G may lead to reductions in the proliferation and differentiation capacities of cells in a dose-dependent manner. Our data provide new insights into bone-related hazards caused by multiple factors, such as PR and mu G, in the space environment.

Automated summary

The combination of proton radiation (PR) and simulated microgravity (S mu G) may lead to reductions in cell proliferation and differentiation capacities in a dose-dependent manner. This study provides new insights into bone-related hazards caused by multiple factors, such as PR and microgravity, in the space environment.