The human health risk during space mission may have cause from solar particle events and galactic cosmic rays comprised of energy proton and high energy charge particles as well as the secondary radiation from the shielding and human tissues. The Martian regolith is one of important shielding materials during Mars exploration. The biological effects of Martian environment and the secondary radiation remain uncertain. The investigators detected primary and secondary radiation tracks of high energy proton (1 GeV/n), high energy iron (1 GeV/n), and carbon (290 MeV/n) with and without Martian regolith simulant using a 1.67 uM pixel detector, and investigated the effect of secondary radiation from Martian regolith on DNA damage and cell survival in hippocamapal neuronal cells.
Investigators found that DNA damage response signaling persists longer in hippocampal neuronal cells exposed to high LET radiation (56Fe (1Gev/n)) than to low LET radiation (proton (1Gev/n)). High LET radiation induced higher phosphorylation of Tip60, expression of p53, p21, and PUMA than low LET radiation. GSK3 inhibitors reduced Tip60 phosphoryaltion, p53, and PUMA expression. Inhibition of GSK3 activity reduced the cell killing of hippocampal neuronal cells following exposure to high LET radiation. High LET radiation induced more apoptosis, senescence, and autophagy than low LET radiation. This suggests that high LET radiation may sustain DNA damage signaling and change cellular homeostasis of energy and growth, implying the risk to the central nervous system (CNS).
The radiation tracks have been detected at 2 cGy to 8 cGy of proton, iron, and carbon radiation beams using this pixel detector. When Martian regolith put on the surface of a pixel detector, the secondary radiation tracks were captured by the pixel detector. Using live imaging of mCherry 53BP1 in mouse hippocampal neuronal cells, the investigators found that DNA damage tracks are formed in cells behind Martian regolith with high energy proton, but reduced DNA damage tracks in cells behind Martian regolith with high energy iron particles. Martin regolith between proton beams and cell flasks reduced the cell survival of hippocampal neuronal cells using clonogenic assay. The secondary radiation from Martian regolith also decreased neurite outgrowth and cell viability of mouse primary hippocampal neuronal cells. Further study on the effect of secondary radiation from Martian regolith on neuronal cells is warranted.
No datasets exist for this study. A final report was archived.
|Mission||Launch/Start Date||Landing/End Date||Duration|