Abstract: To investigate whether the simulated microgravity effect affects the expression of CLOCK and BMAL1 through NRF2, the clinostat was used to simulate the microgravity effect. The results showed that the simulated microgravity effect significantly reduced the expression level of NRF2 and significantly increased intracellular ROS level. The expression of CLOCK and BMAL1 decreased significantly, the oscillation rhythm was weakened, the period was shortened, and the phase was changed. Then overexpression of NRF2 could reverse the rhythm changes caused by microgravity effect, and the expression rhythm of CLOCK and BMAL1 was enhanced. The results suggested that the simulated microgravity effect might regulate the expression oscillation of CLOCK and BMAL1 through NRF2.

Key words: circadian, microgravity, NRF2, CLOCK, BMAL1