Abstract

Stem Cell Regeneration in Space: Using Microgravity to Understand Earth-based Diseases

Elizabeth Blaber, Assistant Professor, Rensselaer Polytechnic Institute (RPI); Research Scientist, USRA/NASA Ames Research Center

During the last several decades of microgravity (mechanical unloading) research, significant progress has been made in the field of space biology that is shaping our understanding of how gravity regulates physiological processes. Exposure to microgravity during spaceflight results in tissue degeneration in multiple physiological systems including muscle atrophy, bone loss, immune deficiencies and cardiovascular impairment. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. Our experimental work in microgravity flight experiments have aimed to investigate the molecular, cellular and tissue aspects of the hypothesis that gravity mechanical loading regulates tissue regenerative health and includes studies of mouse bone tissue regeneration on the US Space Shuttle/ISS and the Russian Biosatellite BionM1, newt tail regeneration on the Russian Satellite Foton M2 and M3 and mouse embryonic stem cells on the US Space Shuttle/ISS. Through the use of large-scale genomics data sets and computational analysis using cross-species comparisons, this work has identified a load-dependent molecular regulator that likely impairs tissue regenerative capabilities in unloaded environments. The results from this work hold the promise of greater scientific understanding of how to maintain and monitor health during future voyages of space exploration, and solidly establishes Earth’s gravity as a major shaper of human life through promoting tissue regenerative health. Additionally, as microgravity is thought to cause accelerated aging and onset of age-based disease phenotypes, including osteoarthritis, cardiovascular disease, and fibrotic liver disease, this research has broad applications to debilitating disease progression both in space and on Earth.