The combined effect of simulated microgravity and radiation on chromosome aberrations in human peripheral blood lymphocytes

Abstract

To u n d e r s t a n d t h e c o m b i n e d e f f e c t o f microgravity (μG) and space radiation on cellsis an important requirement for the anticipated space travel by humans. Cultured cells, such as human fibroblasts and lymphoblasts, were used in previous studies, and we observed changes in the expression of some cell-cycle-related genes and increased chromosome aberrations (CAs) in these cells under simulated μG. In this study, we investigated the combined effect of μG and space radiation on human peripheral blood lymphocytes. Whole blood was irradiated with X-ray or carbon-ion (C-ion) beam while being exposed to simulated μG using a threedimensional clinostat. The frequency of CA was assessed using the three-color fluorescence in situ hybridization on chromosome spreads of colcemid-induced prematurely condensed chromosomes in lymphocytes during the first cell division post irradiation. Compared with the cells irradiated at 1G, the frequency of CA was increased in cells simultaneously exposed to simulated μG and radiation even though cells were irradiated by the same doses (0.5-1.0 Gy). This result is similar to those of our previous studies in which we used human lymphoblast TK6 cells and human fibroblast 1BR-hTERT cells. These ground-based experiments give insights into the biological effects of the space environment where radiation and μG coexist.

Adaptation and Changes in Actin Dynamics and Cell Motility as Early Responses of Cultured Mammalian Cells to Altered Gravitational Vector

“…The custom-made 3D clinostat (Portable Microgravity Simulator PMS-CSTI; Advanced Engineering Services Co. Ltd. (AES), Ibaraki, Japan) has been described and characterized by Ikeda et al [ 64 ] and used extensively by our group [ 18 , 19 , 64 , 65 , 66 ]. It is housed in the laboratory of Dr. Akihisa Takahashi, Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.…”

Genomic Changes Driven by Radiation-Induced DNA Damage and Microgravity in Human Cells

“…Since chromosome exchanges, especially translocations, are positively correlated with many cancers [77,78], it is a good biomarker to assess cancer risk for the astronauts. Ground-based studies also showed increased chromosome aberrations with simultaneously exposed to radiation and simulated microgravity [79][80][81].…”

Differential Gene Expression in Human Fibroblasts Simultaneously Exposed to Ionizing Radiation and Simulated Microgravity

“…Space flight conditions differ to those on Earth due to cosmic ionizing radiation (IR) and the absence of gravity, known as microgravity (µG), both of which pose health risk factors to humans, causing complex DNA damage and genome instability [1][2][3][4][5]. It is crucial to gain more insights on these factors, as astronauts will be continuously exposed to them in long-duration exploration missions, such as those to the Moon or Mars, which require humans to remain in space for days, months and even years.…”