Simulated microgravity potentiates generation of reactive oxygen species in cells

Abstract

Microgravity (MG) and space radiation are two major environmental factors of space environment. Ionizing radiation generates reactive oxygen species (ROS) which plays a key role in radiation-induced DNA damage. Interestingly, simulated microgravity (SMG) also increases ROS production in various cell types. Thus, it is important to detect whether SMG could potentiate ROS production induced by genotoxins including radiation, especially at a minimal level not sufficient to induce detectable ROS. In this study, we treated mouse embryonic stem (MES) cells with H2O2 and SMG for 24 h. The concentration of H2O2 used was within 30 μmol/L at which intracellular ROS was the same as that in untreated cells. Exposure of cells to SMG for 24 h did not induce significantly higher levels of intracellular ROS than that of control cells either. Simultaneous exposure of cells to both SMG- and H2O2-induced ROS and apoptosis in MES cells. Although incubation in medium containing 5 or 30 μmol/L H2O2 induced a small enhancement of DNA double-strand breaks (DSBs), the addition of SMG treatment dramatically increased DSB levels. Taken together, SMG can significantly potentiate the effects of H2O2 at a low concentration that induce a small or negligible change in cells on ROS, apoptosis, and DNA damage. The results were discussed in relation to the combined effects of space radiation and MG on human body in this study.

Microgravity modulates effects of chemotherapeutic drugs on cancer cell migration

“…Molecular insights that might guide such further work would include the cell type dependence of the effect of microgravity on ROS generation which we have shown in this work. Along these lines, simulated microgravity was shown to increase ROS generation in mouse embryonic cells (37). Interestingly, the increased ROS generation in K562 cells which we have shown is consistent with the reported inhibition of K562 proliferation by simulated μg (4).…”

Metabolic Pathways of the Warburg Effect in Health and Disease: Perspectives of Choice, Chain or Chance

“…However, improved, more sophisticated transgenic mouse models will allow better discrimination between cause and effect when exploring metabolic disorders. Despite only partial mimicry, simulated microgravity ground experiments can suffice to potentiate the effect of ROS [ 153 ] shown to exacerbate the effects of heavy ion radiation in human B lymphoblasts [ 154 ]. Dedicated heavy-ion radiobiology research centers, e.g., the NASA Space radiation laboratory at Brookhaven, are pivotal for improving space-relevant radiobiology knowledge and exploration of how heavy-ion species might be exploited for focused anti-cancer therapy [ 155 ].…”

Microgravity induces autophagy via mitochondrial dysfunction in human Hodgkin’s lymphoma cells

“…The advent of human space exploration has produced novel research in to the effects of space travel on human health and diseases. In space, microgravity and cosmic radiation are considered the most consequential environmental factors 1 , 2 . Several studies have found that astronauts and experimental animals in space experience physiological changes owing to microgravity during and after space flights; the effects of microgravity include muscle atrophy, bone loss, immune dysregulation, and abnormal cellular functions 3 – 8 .…”