Effects of space proton radiation and simulated μG effects on the embryonic mouse hypothalamic N38 cells

초록

Background: Space exploration poses unique challenges to living organisms, subjecting them to conditions such as space radiation and microgravity (G). Understanding the molecular responses to these factors is crucial for ensuring the well-being of astronauts. This study investigates the effects of space radiation and G on the transcriptomic changes of the embryonic mouse hypothalamic cell line N38 (mHypoE-N38). Aim: This study aims to characterize and analyze the transcriptomic changes in the mHypoEN38 cell line exposed to simulated space environments, including space radiation, simulated G, and their combination. Method: Four experimental groups of mHypoE-N38 cells were established: ground condition (GC; control), space radiation (1 Gy of Proton Radiation), μG (Simulated G), and a combination of space radiation and simulated G. Transcriptomic sequencing (RNA-seq) was performed, and the results were compared among the experimental groups and the ground condition. Results: A total of 355 differentially expressed genes (DEGs; p-value < 0.05, |fold change| 2) were identified. Notably, UCN2 and UGT1A5 genes exhibited increased expression in all three experimental groups compared to the GC group, suggesting a shared regulatory mechanism with potential consequences for brain function during space missions. Moreover, the study revealed significant alterations in genes belonging to the Usp17l family, particularly the USP17l gene. USP17l encodes for a thiol-dependent deubiquitinase known to regulate cell growth and survival. This finding indicates a potential impact on cellular homeostasis and survival mechanisms in response to the simulated space environment. Furthermore, genes associated with the Zscan4 family, including ZSCAN4, known for its role in telomere maintenance and critical features of mouse embryonic stem (ES) cells, were also significantly altered, suggesting potential effects on telomere dynamics.