Cytoskeleton recovery after simulated space condition exposure

The impaired immune system activity in astronauts might be linked to morphological as well as motility alterations of monocytes. Previous studies on adherent monocyte cultures in real and simulated low gravity conditions showed that both cell shape and cytoskeletal components were changed compared to 1g conditions. Studies on dynamics of microtubule network repolymerization in both conditions after complete microtubule depolymerization showed a fast recovery within 24 hours. The aim of this present work was to investigate the re-organization of J-111 monocyte microtubules and microfilaments within 24 hours after simulated space conditions, low gravity and ionizing radiations. Radiation and microgravity were simulated within SCK•CEN using X-irradiation, The Random Positioning Machine (RPM) and Californium-252 as source of neutrons combined or not to the RPM. The immunostaining of β-tubulin and F-actin showed cytoskeletal alterations after ionizing radiations and simulated low gravity. Following the recovery dynamics of cytoskeleton proteins after space condition exposure, microfilament network appears re-established within 24 hours and microtubules recovery is already evident after 4 hours. Quantitative bioimaging analysis on cytoskeletal protein distribution is currently under progress. Determining the cytoskeletal alterations involved after simulated space conditions will allow to evaluate the health risk for the astronaut after space travel.