The small protein MafG plays a critical role in MC3T3-E1 cell apoptosis induced by simulated microgravity and radiation

Microgravity and radiation exposure-induced bone damage is one of the most significant alterations in astronauts after long-term spaceflight. However, the underlying mechanism is still largely unknown. Recent ground-based simulation studies have suggested that this impairment is likely mediated by increased production of reactive oxygen species (ROS) during spaceflight. The small Maf protein MafG is a basic-region leucine zipper-type transcription factor, and it globally contributes to regulation of anti-oxidant and metabolic networks. Our research investigated the role of MafG in the process of apoptosis induced by simulated microgravity and radiation in MC3T3-E1 cells. We found that simulated micro-gravity or radiation alone decreased MafG expression and elevated apoptosis in MC3T3-E1 cells, and combined simulated microgravity and radiation treatment aggravated apoptosis. Meanwhile, under normal conditions, increased ROS levels facilitated apoptosis and downregulated the expression of MafG in MC3T3-E1 cells. Overexpression of MafG decreased apoptosis induced by simulated microgravity and radiation. These findings provide new insight into the mechanism of bone damage induced by micro-gravity and radiation during space flight.& nbsp; (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Experimental findings have shown that simulated microgravity or radiation can decrease MafG expression and increase apoptosis in MC3T3-E1 cells; meanwhile, increased ROS levels facilitate apoptosis in cells.