Living in Space
Integral Understanding of life-regulation mechanism from "SPACE"

The effect of space radiation in vascular endothelial cell through micronuclei formation – Publicly Invited Research 2018－2019

1. A01 Ogura
2. A01 H. Takahashi
3. A01 S. Takahashi
4. A01 Michiue
5. A01 Hinoi
6. A01 Tsumoto
7. A01 Nikawa
8. A01 Chatani
9. A01 Kawakami
10. A01 Akiyama
11. A01 Tomita

1. A02 Shinohara
2. A02 Mieda
3. A02 Maekawa
4. A02 Abe
5. A02 Ohgami
6. A02 Kawano
7. A02 Takano

1. A03 Suzuki
2. A03 Nakamura
3. A03 Harada
4. A03 Kobayashi
5. A03 Miyamoto
6. A03 Funayama
7. A03 Kakinuma

1. B01 Lazarus
2. B01 Kato
3. B01 Kunieda
4. B01 Kitaya
5. B01 Sawano

Research Subject	The effect of space radiation in vascular endothelial cell through micronuclei formation
Research Group Leader	Junya Kobayashi Professor, Department of Radiological Sciences, International University of Health and Welfare Graduate School Website https://www.iuhw.ac.jp/daigakuin/staff/cat/cat10/9187.html (*Written in Japanese)
Research Collaborator(s)	Ikue Hayashi Assistant Professor, Graduate School of Biomedical & Health Sciences, Hiroshima University Kumiko Anno Associate Professor, Faculty of Human Science, Hiroshima Bunkyo Women's University

The spacemen, who stay in outer space for long term, are exposed with space radiation. Major composition of space radiation, ionizing radiation (IR) causes double-strand breaks (DSBs) into genomic DNA and also stimulates the accumulation of reactive oxygen species (ROS), which could induce cellular oxidative stress responses. As spacemen stay in properly shielded spacecraft or space station, it is suggested that they might be exposed with low dose rate of irradiation for long term. Such exposure might lead to increase relative influence of oxidative stress compared with the biological effects by DSB damage.   

The studies of A-bomb survivors have clearly shown the effect about tumorigenesis with exposure to more than 100 mGy of IR, while the relationship between the exposure and cardiovascular disease through inflammatory cytokine pathway was recently suggested, but the detail of mechanisms is unclear. It was currently reported that cGAS accumulates on certain type of micronuclei, which are induced with exposure to high dose of IR, and such accumulation activates cGAS and subsequently induces secretion of inflammatory cytokines, which could lead to cellular dysfunction in adjacent un-irradiated cells through cellular senescence (lower figure).