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

Elucidation of a new mechanism in bone metabolism using the changes of gravity vector/parameter – 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	Elucidation of a new mechanism in bone metabolism using the changes of gravity vector/parameter
Research Group Leader	Masahiro Chatani Assistant Professor, Department of Pharmacology, School of Dentistry, Showa University Website https://sites.google.com/view/masahiro-chatani (*Written in Japanese) http://www10.showa-u.ac.jp/~dpharmc/index.html (*Written in Japanese)
Research Collaborator(s)	Masamichi Takami Professor, Department of Pharmacology, School of Dentistry, Showa University Akira Kudo Visiting Professor, Department of Pharmacology, School of Dentistry, Showa University Specially Appointed Professor, Collaboration Center for Design and Manufacturing, Tokyo Institute of Technology

If the gravity of the Earth is twice or half of its size, what kind of changes will be found in the living body? Will it be the same system as skeletal system, muscular system, nervous system, circulatory system currently acquired by organisms? Probably the answer is "No", the living thing should obtain its own system corresponding to each gravity environment, like the Martian people H. G. Wells imagined.

Bone is an organization that supports the body environment and enables exercise under a gravity. Since bone forms a complex three-dimensional structure adapted to the gravity environment, it is unlikely that bone cells worked without sensing gravity. However, the details of the gravity sensing mechanism of the cells are not yet known.

Gravity is thought to be one of the important factors related to the control of bone metabolism, since bone mass decreases on the International Space Station, that is, in the state of microgravity. As a result of analysis of osteoclasts and osteoblasts through two space experiments using medaka, osteoclasts were activated under a microgravity environment, and a part of GR (glucocorticoid receptor) signaling was elevated (Chatani M et al, Sci Rep 2015, Chatani M et al, Sci Rep 2016). Based on the results obtained in these space experiments, we will perform hypergravity experiments on the ground and simulated microgravity experiments with clinostat and clarify the gravity action in bone metabolism.