A load of mice to hypergravity causes AMPK alpha repression with liver injury, which is overcome by preconditioning loads via Nrf2

作者：Lee Sang Gil; Lee Chan Gyu; Wu Hong Min; Oh Choong Sik; Chung So Won; Kim Sang Geon^*

来源：Scientific Reports, 2015, 5(1): 15643.

DOI：10.1038/srep15643

An understanding of the effects of hypergravity on energy homeostasis is necessary in managing proper physiological countermeasures for aerospace missions. This study investigated whether a single or multiple load(s) of mice to hypergravity has an effect on molecules associated with energy metabolism. In the liver, AMPK alpha level and its signaling were repressed 6 h after a load to +9 Gz hypergravity for 1 h, and then gradually returned toward normal. AMPK alpha level was restored after 3 loads to +9 Gz, suggestive of preconditioning adaptation. In cDNA microarray analyses, 221 genes were differentially expressed by +9 Gz, and the down-regulated genes included Nrf2 targets. Nrf2 gene knockout abrogated the recovery of AMPK alpha elicited by 3 loads to +9 Gz, indicating that Nrf2 plays a role in the adaptive increase of AMPK alpha. In addition, +9 Gz stress decreased STAT3, FOXO1/3 and CREB levels, which was attenuated during the resting time. Similarly, apoptotic markers were enhanced in the liver, indicating that the liver may be vulnerable to hypergravity stress. Preconditioning loads prevented hepatocyte apoptosis. Overall, a load of mice to +9 Gz hypergravity causes AMPK alpha repression with liver injury, which may be overcome by multiple loads to hypergravity as mediated by Nrf2.

• 出版日期2015-10-23