Changes in Mitochondrial Homeostasis and Redox Status in Astronauts Following Long Stays in Space

Authors

Hiroko P. Indo, Kagoshima University, Japan
Hideyuki J. Majima, Kagoshima University, Japan
Masahiro Terada, The Jikei University School of Medicine, Japan
Shigeaki Suenaga, Kagoshima University, Japan
Kazuo Tomita, Kagoshima University, Japan
Shin Yamada, Japan Aerospace Exploration Agency, Japan
Akira Higashibata, Kagoshima University, Japan
Noriaki Ishioka, Kagoshima University, Japan
Takuro Kanekura, Kagoshima University, Japan
Ikuya Nonaka, National Center Hospital for Mental Nervous and Muscular Disorders, Japan
Clare L. Hawkins, The Heart Research Institute, Australia
Michael J. Davies, University of Copenhagen, Denmark
Daret K. St Clair, University of KentuckyFollow
Chiaki Mukai, Japan Aerospace Exploration Agency, Japan

Abstract

The effects of long-term exposure to extreme space conditions on astronauts were investigated by analyzing hair samples from ten astronauts who had spent six months on the International Space Station (ISS). Two samples were collected before, during and after their stays in the ISS; hereafter, referred to as Preflight, Inflight and Postflight, respectively. The ratios of mitochondrial (mt) to nuclear (n) DNA and mtRNA to nRNA were analyzed via quantitative PCR. The combined data of Preflight, Inflight and Postflight show a significant reduction in the mtDNA/nDNA in Inflight, and significant reductions in the mtRNA/nRNA ratios in both the Inflight and Postflight samples. The mtRNA/mtDNA ratios were relatively constant, except in the Postflight samples. Using the same samples, the expression of redox and signal transduction related genes, MnSOD, CuZnSOD, Nrf2, Keap1, GPx4 and Catalase was also examined. The results of the combined data from Preflight, Inflight and Postflight show a significant decrease in the expression of all of the redox-related genes in the samples collected Postflight, with the exception of Catalase, which show no change. This decreased expression may contribute to increased oxidative stress Inflight resulting in the mitochondrial damage that is apparent Postflight.

Document Type

Article

Publication Date

12-16-2016

Notes/Citation Information

Published in Scientific Reports, v. 6, article no. 39015, p. 1-10.

© The Author(s) 2016

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Digital Object Identifier (DOI)

https://doi.org/10.1038/srep39015

Funding Information

This study was supported in part by the JAXA-ISS Space Medicine Program Grant from the Japan Aerospace Exploration Agency.

Repository Citation

Indo, Hiroko P.; Majima, Hideyuki J.; Terada, Masahiro; Suenaga, Shigeaki; Tomita, Kazuo; Yamada, Shin; Higashibata, Akira; Ishioka, Noriaki; Kanekura, Takuro; Nonaka, Ikuya; Hawkins, Clare L.; Davies, Michael J.; St Clair, Daret K.; and Mukai, Chiaki, "Changes in Mitochondrial Homeostasis and Redox Status in Astronauts Following Long Stays in Space" (2016). Toxicology and Cancer Biology Faculty Publications. 57.
https://uknowledge.uky.edu/toxicology_facpub/57