Space experiment "Cellular Responses to Radiation in Space (CellRad)": Hardware and biological system tests. (November 2015)

• Record Type: Journal Article
• Authors: Hellweg, Christine E.; Dilruba, Shahana; Adrian, Astrid; Feles, Sebastian; Schmitz, Claudia; Berger, Thomas; Przybyla, Bartos; Briganti, Luca; Franz, Markus; Segerer, Jürgen; Spitta, Luis F.; Henschenmacher, Bernd; Konda, Bikash; Diegeler, Sebastian; Baumstark-Khan, Christa; Panitz, Corinna; Reitz, Günther
• Is Part Of: Life sciences in space research. Volume 7(2015)
• Page Start: 73
• Page End: 89
• Publication Date: 2015-11
• Subjects: ATM Ataxia telangiectasia mutated -- CellRad Cellular Responses to Radiation in Space -- CMV cytomegalovirus -- d2EGFP destabilized variant of EGFP -- DDR DNA damage response -- DSB double strand breaks -- DLR German Aerospace Center -- DMSO dimethyl sulfoxide -- ECDS Experiment Container Double Sealed -- EGFP Enhanced Green Fluorescent Protein -- EXU Exchangeable Unit -- FBS Fetal Bovine Serum -- FT-GSE Functional Test Ground Support Equipment -- γH2AX phosphorylated histone variant H2AX -- HEK Human Embryonic Kidney -- IL-1β interleukin 1β -- ISS International Space Station -- κB4 NF-κB response elements -- LET linear energy transfer -- MPU Multiwell Plate Unit -- miRNA microRNA -- NF-κB Nuclear Factor κB -- OD optical density -- Pm-147 promethium-147 -- PTFE polytetrafluorethylene -- ROS reactive oxygen species -- SDS sodium dodecyl sulphate -- TNF-α tumor necrosis factor α; Mammalian radiation response -- Microgravity -- Space experiment -- Biocompatibility -- Storage -- Nuclear factor κB; Space biology -- Periodicals; 571.0919
• DOI: 10.1016/j.lssr.2015.10.003
• Languages: English
• ISSNs: 2214-5524

Abstract

Abstract: One factor contributing to the high uncertainty in radiation risk assessment for long-term space missions is the insufficient knowledge about possible interactions of radiation with other spaceflight environmental factors. Such factors, e.g. microgravity, have to be considered as possibly additive or even synergistic factors in cancerogenesis. Regarding the effects of microgravity on signal transduction, it cannot be excluded that microgravity alters the cellular response to cosmic radiation, which comprises a complex network of signaling pathways. The purpose of the experiment "Cellular Responses to Radiation in Space" (CellRad, formerly CERASP) is to study the effects of combined exposure to microgravity, radiation and general space flight conditions on mammalian cells, in particular Human Embryonic Kidney (HEK) cells that are stably transfected with different plasmids allowing monitoring of proliferation and the Nuclear Factor κ B (NF- κ B) pathway by means of fluorescent proteins. The cells will be seeded on ground in multiwell plate units (MPUs), transported to the ISS, and irradiated by an artificial radiation source after an adaptation period at 0 × g and 1 × g . After different incubation periods, the cells will be fixed by pumping a formaldehyde solution into the MPUs. Ground control samples will be treated in the same way. For implementation ofCellRad in the Biolab on the International Space Station (ISS), tests of the hardware and the biological systems were performed. The sequence of different steps in MPU fabrication (cutting, drilling, cleaning, growth surface coating, and sterilization) was optimized in order to reach full biocompatibility. Different coatings of the foil used as growth surface revealed that coating with 0.1 mg/ml poly-D-lysine supports cell attachment better than collagen type I. The tests of prototype hardware (Science Model) proved its full functionality for automated medium change, irradiation and fixation of cells. Exposure of HEK cells to the β -rays emitted by the radiation source dose-dependently decreased cell growth and increased NF- κ B activation. The signal of the fluorescent proteins after formaldehyde fixation was stable for at least six months after fixation, allowing storage of the MPUs after fixation for several months before the transport back to Earth and evaluation of the fluorescence intensity. In conclusion, these tests show the feasibility ofCellRad on the ISS with the currently available transport mechanisms. Highlights: CellRad: combined exposure of human cells to microgravity and radiation. CellRad hardware prototype is biocompatible and fully functional. Exposure to β -ray source: dose-dependent growth reduction and NF- κ B activation. Stable fluorescence of reporter proteins d2EGFP and EGFP over 6 months after fixation.