ROle of Apoptosis in Lymphocyte Depression (ROALD) - 03.04.15
ROle of Apoptosis in Lymphocyte Depression (ROALD) will determine the role of programmed apoptosis (cell death) in loss of T-lymphocyte (white blood cells originating in the thymus) activity in microgravity. Science Results for Everyone
Who killed T-cell? Microgravity, in the space station, with apoptosis. This investigation looked at how spaceflight influences immune cell function, including the role of programmed cell death (apoptosis) in loss of T-lymphocytes, a type of white blood cell. Results of this investigation demonstrate that 48 hours of microgravity on-board the space station increased signs of programmed cell death such as DNA fragmentation. The findings provide a molecular background for immune dysfunction observed in astronauts and reveal potential new markers for monitoring crew health. Data seem to support the hypothesis of a regulatory mechanism that could be valid under microgravity conditions and involved in depression of the immune system. Experiment Details
Sponsoring Space Agency
European Space Agency (ESA)
ISS Expedition Duration
October 2008 - April 2009
Previous ISS Missions
http://eea.spaceflight.esa.int/ ^ back to top
- ROle of Apoptosis in Lymphocyte Depression (ROALD) will to determine the role of programmed cell death (apoptosis) in loss of T-lymphocyte activity in microgravity.
- Various aspects of the apoptotic process will be assessed, using human T-lymphocytes, by analyzing gene expressions of metabolites of reactive oxygen species and membrane properties.
Experiments performed during spaceflight clearly show that several cellular processes, such as oxidative metabolism, growth rate, signal transduction and gene expression, are modified under conditions of weightlessness. For example, these alterations are associated with atrophy in heart, muscle and bone. In particular, dramatic effects of conditions similar to those that occur during exposure of cells to microgravity have been shown on the activation of human lymphocytes in vitro, and have been associated with:
- Altered distribution and downregulation of protein kinase C
- Reduced expression of interleukin-2 and its receptor
- Microtubule anomalies and growth retardation
- Altered cytoskeletal gene expression.
It has been suggested that reduced growth response in lymphocytes during spaceflight might be linked to apoptosis, based on morphological anomalies and cDNA microarray analysis of space-flown human lymphoblastoid (Jurkat) cells. Though there is no coherent explanation for these observations, and it is not known which biomolecules might act as gravity responders, recent evidence seems to suggest that inhibition of lymphocyte proliferation depends on alterations occurring within the first few hours of microgravity. In this context, 5-Lipoxygenase (5-LOX) plays a central role in interleukin-2 expression and activation of human lymphocytes, and is involved in the initiation of programmed death (apoptosis) triggered by several stimuli in different human cells. Remarkably, recent in vitro studies performed in the course of the 28th parabolic flight campaign of the European Space Agency have demonstrated that low gravity (approximately 10-2g) directly enhances the catalytic efficiency of pure lipoxygenase, up to approximately 4-fold over the ground (1g) controls. In this project, we plan to ascertain whether or not Space conditions might induce apoptosis in human lymphocytes through a 5-LOX-mediated pathway. The possible involvement of mitochondrial alterations in the apoptotic program will be also investigated.
The experiment will further our understanding of the mechanisms by which microgravity and spaceflight factors influence immune cell function. In particular the effect on activation of apoptosis has not been explored. Although preparatory experiments can be performed with ground based techniques, such as the Random Positioning Machine (RPM) the effect of microgravity and cosmic radiation for the duration required for this experiment can only be explored using an orbiting space vehicle.^ back to top
The experiment will be uploaded on Space Shuttle in passive thermal control unit to maintain the temperature above +25°C to ensure good viability of the samples. Upon arrival to ISS, the ECs are installed in the Kubik incubator, pre-warmed to +37°C. Experiment operations are performed automatically, once installed in Kubik following a short pre-incubation period the experiment is started by adding activator. A first set of samples is transferred to frozen stowage (-20°C or colder) for 3-hours after activation, while the remaining samples are fixed with RNAlaterTM at 24-hours and 48-hours after activation, then transferred to frozen stowage. Samples must be maintained frozen following completion of the experiment, including during download.
The information on this page is provided courtesy of the ESA Erasmus Experiment Archive.^ back to top
Battista N, Meloni MA, Bari M, Mastrangelo N, Galleri G, Rapino C, Dainese E, Finazzi-Agro A, Pippia P, Maccarrone M. 5-Lipoxygenase-dependent apoptosis of human lyphocytes in the International Space Station: data from the ROALD experiment. Federation of American Societies for Experimental Biology Journal. 2012; 26(5): 1791-1798. DOI: 10.1096/fj.11-199406. PMID: 22253478.
Ground Based Results Publications
Battista N, Rapino C, Gasperi V, Finazzi-Agro A, Maccarrone M. Effect of RNAlater on lipoxygenase activity and expression, and immune cell apoptosis: opening the gate to the "ROALD" experiment aboard the space shuttle. Journal of Gravitational Physiology. 2007 July; 14(1): P131-132. PMID: 18372734.
Maccarrone M, Battista N, Meloni MA, Bari M, Galleri G, Pippia P, Cogoli A, Finazzi-Agro A. Creating conditions similar to those that occur during exposure of cells to microgravity induces apoptosis in human lymphocytes by 5-lipoxygenase-mediated mitochondrial uncoupling and cytochrome c release. Journal of Leukocyte Biology. 2003; 73: 472-481.
Model of microgravity-induced apoptosis in human lymphocytes. Image courtesy of ESA.
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