title: Simulated microgravity decreases apoptosis in fetal fibroblasts.
abstract: Space travel is a major challenge for human beings. Especially, the mechanisms through which space conditions might alter animal development have been questioned for a long time. The two major physical stress factors that are of relevance in this context are space radiation and weightlessness. While it has been extensively shown that high doses of ionizing radiation induce deleterious effects on embryonic development, so far, little is known about the potential harmful effects of radiation in combination with microgravity on the developing organism. In the present study, we investigated the effects of simulated microgravity on irradiated STO mouse fetal fibroblast cells using a random positioning machine (RPM). Radiation-induced cell cycle changes were not affected when cells were subjected to simulated microgravity for 24 h. Moreover, no morphological differences were observed in irradiated samples exposed to simulated microgravity compared to cells that were exclusively irradiated. However, microgravity simulation significantly decreased the level of apoptosis at all doses as measured by caspase-3 activity and it prevented cells from undergoing radiation-induced size increase up to 1 Gy.
authors.affiliation: Laboratory of Molecular and Cellular Biology, Institute for Environment,                     Health and Safety, Belgian Nuclear Research Centre, SCK•CEN, Mol, Belgium.
authors.forename: Michaël
authors.initials: M
authors.lastname: Beck
authors.forename: Kevin
authors.initials: K
authors.lastname: Tabury
authors.forename: Marjan
authors.initials: M
authors.lastname: Moreels
authors.forename: Paul
authors.initials: P
authors.lastname: Jacquet
authors.forename: Patrick
authors.initials: P
authors.lastname: Van Oostveldt
authors.forename: Winnok H
authors.initials: WH
authors.lastname: De Vos
authors.forename: Sarah
authors.initials: S
authors.lastname: Baatout
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology* / Q000528:radiation effects; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology / Q000528:radiation effects; D002460:Cell Line; D004789:Enzyme Activation / Q000528:radiation effects; D005333:Fetus; D005347:Fibroblasts / Q000378:metabolism* / Q000528:radiation effects; D051379:Mice; D014893:Weightlessness; D018474:Weightlessness Simulation
chemical_list: D053148:Caspase 3