SCD – Stem Cell Differentiation on board the International Space Station [miRNA-seq on miRNAs from exosomes]. Homo sapiens

The bone loss observed in astronauts and animal models after spaceflight is attributable to alterations in the bone tissue formation that depends from the continuous remodeling through the activities of bone-resorbing osteoclasts of hematopoietic lineage and bone-forming osteoblasts of mesenchymal origin. This disease is frequent in aged people, but develops much more rapidly in space. Our experiment, selected by ESA (European Space Agency), aimed to determine how human bone marrow mesenchymal stem cells (hBMSCs) react and differentiate in real microgravity, on board the International Space Station, in approx. 2 weeks time. Overall design: Increased formation of exosomes/macrovescicle was observed in samples on board the ISS. To further investigate cell-cell communication through miRNAs secreted into the medium, exosomes were purified from spent growth media