Fig. 1.

A Astronaut Kimiya Yui (Jaxa) extracts the ENDO EUs from KUBIK, at the end of the experiment in the Columbus module of ISS (photo with permission by ESA). Samples aligned against the incubator walls were exposed to μg, while those in the centrifuge (object with circular section in red at the center) were exposed to 1g. B KISS facility hosted in the home laboratory in Pisa, within a thermal incubator. The electronic control of culture procedures allowed running the same protocol, at the same time points, both on ground and on the ISS. C Workflow of the 'Endothelial Cells' study. Of 40 EUs prepared at Baykonur, 24 flew to the ISS. Set inside KUBIC (framed in blue), 16 of them remained in microgravity (SF-μg), and 8 were set in the centrifuge within (circled in red) that can accommodate 8 EUs maximum (SF-1g). The other 16 EUs remained on Earth (GC). Red boxes: half of all EUs were prepared for nucleic acid extraction and fixed with RNAprotect Cell Reagent (Qiagen, USA). Three EUs exposed to μg and two kept in the centrifuge at 1g were used for RNA extraction. Green boxes: half of all EUs were prepared for cell imaging analysis, and fixed with NOTOXHisto (EarthSafe Industries, USA). All coverslips were used up for IF. Coverslips were cut in parts to increase numerosity. For technical replicas, each antibody was hybridized on at least three different parts originated from different coverslips. Diagonal stripes: SF-1g samples. D Timing of the ENDO experiment, including pre-launch (L) and post-L activities in hours, with relevant temperature values, in °C, under the blue arrows