• Kenta Horie, Tamotsu Kato, Takashi Kudo, Hiroki Sasanuma, Maki Miyauchi, Nobuko Akiyama, Takahisa Miyao, Takao Seki, Tatsuya Ishikawa, Yuki Takakura, Masaki Shirakawa, Dai Shiba, Michito Hamada, Hyojung Jeon, Nobuaki Yoshida, Jun-Ichiro Inoue, Masafumi Muratani, Satoru Takahashi, Hiroshi Ohno, and Taishin Akiyama.
• Laboratory for Immune Homeostasis, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan.
• Sci Rep. 2019 Dec 27; 9 (1): 19866.

AbstractThe environment experienced during spaceflight may impact the immune system and the thymus appears to undergo atrophy during spaceflight. However, molecular aspects of this thymic atrophy remain to be elucidated. In this study, we analysed the thymi of mice on board the international space station (ISS) for approximately 1 month. Thymic size was significantly reduced after spaceflight. Notably, exposure of mice to 1 × g using centrifugation cages in the ISS significantly mitigated the reduction in thymic size. Although spaceflight caused thymic atrophy, the global thymic structure was not largely changed. However, RNA sequencing analysis of the thymus showed significantly reduced expression of cell cycle-regulating genes in two independent spaceflight samples. These reductions were partially countered by 1 × g exposure during the space flights. Thus, our data suggest that spaceflight leads to reduced proliferation of thymic cells, thereby reducing the size of the thymus, and exposure to 1 × g might alleviate the impairment of thymus homeostasis induced by spaceflight.

13 keywords...

hide…