Astrobiology Science Conference 2010 (2010) 5201.pdf

THE INFLUENCE OF MICROGRAVITY ON ASTRONAUT HEALTH: GLOBAL STUDY OF MICROGRAVITY EFFECTS ON HUMAN STEM CELLS. E. Blaber1,2, H. Marcal3, L.J.R. Foster2, and B.P. Burns1,2 1Australian Centre for Astrobiology, 2School of Biotechnology and Biomolecular Sciences, and 3The Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW, Australia. email: [email protected]

Background: The hostile environment of all three germ cell lineages. This study utilised an ex- space is known to have an impact on human physiol- pression proteomic approach (2D gel electrophoresis ogy, and astronauts are faced with several health risks and Fourier-Transform mass spectrometry) to generate during both short and long duration spaceflight. Some a comparative expression profile of cells grown under of these health problems include bone loss, muscle SMG conditions. Additionally, scanning electron mi- atrophy, cardiac dysrhythmias, and altered orientation. croscopy (SEM) was used to analyse the morphologi- This year marks the 40th anniversary of our first steps cal adaptations of cells to SMG conditions and control on the moon, and within decades it is hoped that hu- conditions. man kind will have established a settlement on Mars. Results: Generation of 2D gel protein maps The bioastronautics field has emerged in life sciences enabled the visualisation of a vastly different proteo- to ensure the health and safety of humans during space mic profile of NCCIT cells grown under SMG com- travel by addressing the medical issues encountered. pared to control samples. Additionally, results demon- As humans advance to exploratory planetary missions, strated that 64% of proteins identified from cells their ability to survive is dependent on the ability to grown in simulated microgravity were not found in adapt to and/or counteract the hostile environment of control samples. Isolated proteins were categorised space which is known to have an impact on human based on their sub-cellular location and then organised physiology. One of the major issues encountered in into 17 functional categories. These included proteins space is the absence of gravity. Although a wide range involved in cell regulation and signal transduction. of research has been conducted into the systemic ef- Specifically this study found the presence of a particu- fects of microgravity on human physiology, an area lar protein involved in the degradation of bone under that has received insufficient attention is the effect of SMG conditions as well as several proteins known to microgravity on cellular function. To gain a compre- effect intracellular calcium levels. Additionally several hensive understanding of these issues, the effects proteins identified in SMG were found to be associated microgravity has on the human body at a cellular level with cell motility and cell division as well as impacting need to be analysed as life’s basic processes are con- physiological systems such as the immune system and ducted at this stage. the musculoskeletal system. Proteins with antioxidant Aims: The aim of the present study was to functions were found to be decreased in SMG, thus employ a global approach to examine the effect of mi- indicating that microgravity imposes oxidative stress crogravity on a stem cell line. These are the cells that on these cells. As the functional units of a cell are all other cells emanate from and ultimately regenerate proteins, these results suggest that microgravity has a organs in the human body, and thus an ideal platform significant impact on cell function. to begin to understand the effects of microgravity at Conclusions: To the best of our knowledge, the cellular level. this is the first study conducted that has investigated Methods: A NASA rotating-wall vessel the effect of SMG on an embryonic stem cell line and (RWV) bioreactor was used to simulate microgravity demonstrated a significant alteration in human cell (SMG) conditions. The RWV bioreactor is a NASA- function as a result of growth in microgravity condi- designed tissue culture vessel which is used to simulate tions. Specific proteins were identified and linked to microgravity whilst reducing the shear and turbulence pathways that are affected by microgravity, and these that is associated with impeller driven and stirred proteins can then be tentatively correlated to observed bioreactors. The system is based on two important de- health problems encountered in microgravity. This sign principles: solid body rotation about a horizontal research is critical to both space science and cell biol- axis, and oxygenation by active or passive diffusion ogy due to its vast potential to decipher the effect of through a silicone rubber membrane. By incorporating microgravity on humans at a cellular level as well as the design principles of solid body rotation and mem- regeneration of tissues in the human body, and to use brane oxygenation, the RWV is an extremely low these alterations to solve ground based medical prob- shear, low turbulence, microgravity environment, thus lems. These preliminary findings points to potential allowing for the culture of high density three- detrimental effects to the health of astronauts and dimensional mammalian cells. The effect of micro- therefore may also have detrimental effects on the suc- gravity was analysed on a human embryonic stem cell cess of a mission. line (NCCIT) that has the potential to differentiate into