Opening the Gate to the Serism Project: From Earth to Space and Back

In the context of Space Medicine, the aim of “SERiSM” (Role of the Endocannabinoid System in Reprogramming human pluripotent Stem cells under Microgravity) project, selected by the Italian Space Agency, was to study the involvement of the endocannabinoid system (ECS) in the osteogenic differentiation under real microgravity. An innovative and easily accessible stem cell model derived from human blood (human blood-derived stem cells, hBDSCs) was used to this purpose. This model is autologous and possesses a remarkable proliferative and differentiative capacity underground gravity conditions, with high therapeutic potential for bone degenerative diseases. ECS is a fine network of proteins that interact to regulate the endogenous levels of lipid mediators, collectively termed endocannabinoids (eCBs), which in turn are involved in cell communication and in the mechanisms governing the switch between cell life and death. In the frame of the VITA mission, led by European Space Agency (ESA) astronaut Paolo Nespoli, we analyzed the differentiation process also under microgravity condition and evaluated the expression of ECS proteins through immunoassay methods. Our results demonstrate that some elements of the ECS are modulated during the differentiation process and in microgravity, supporting the idea that increased levels of anandamide are indeed need to stimulate type-1 cannabinoid receptor. In conclusion, microgravity could drive endocannabinoid signalling in the former stages of hBDSCs differentiation.