In order for humankind to advance into space, it is necessary to overcome health risks caused by space environmental stress such as space radiation and micro-gravity environment. The Nrf2 gene activates a group of biological defense genes and acts protectively against various stresses on the ground, so it was considered to be effective in space.This research, which examines and demonstrates this, was adopted as a feasibility study for the use of the International Space Station (ISS) "Kibo", which was publicly solicited by JAXA. An ISS long-term stay experiment was conducted on transgenic mice (knockout mice) in which the Nrf2 gene was disabled.

　In April 2018, a total of 4 male wild-type and Nrf2 gene knockout mice were launched from the Kennedy Space Center and bred in Kibo.After staying in orbit for about 6 days, all 12 animals survived and returned.This is the world's first survival return of a gene knockout mouse after staying in space.Analysis of mice revealed that Nrf30 was activated in various organs by staying in space.In addition, changes in gene expression and blood metabolites in each organ of Nrf12 gene knockout mice were also confirmed for the first time, and some of them were the same changes as human age-related changes.In addition, hypertrophy of white adipocyte size, which is also seen in age-related changes, was observed in space-staying mice.

　From the results of this research, it was found that Nrf2 works to maintain health by stopping the acceleration of age-related changes due to space environmental stress.In the future, in addition to overcoming health risks while staying in space, clinical application to the prevention and treatment of various age-related diseases on the ground is expected.

Paper information:[Communications Biology] Nrf2 contributes to the weight gain of mice during space travel