Signaling through rho gtpases in microgravity (rho signaling) on iss (soyuz tma-1) belgian soyuz mission “odissea”

Rho GTPases, RhoA, Rac1 and Cdc42, are molecular switches in the intracellular signaling pathways, that relay the information collected by receptors to soluble mediators and insoluble extracellular matrix environment. The objective of this experiment was to investigate the impact of microgravity on cellular processes depending on Rho GTPases activity, i.e.cytoskeleton and focal adhesions organization, GTPases translocation to the membrane, nuclear translocation of signaling molecules and gene expression. WI26 fibroblasts were stably transfected by the constitutively active form of each of the Rho GTPase. Selected clone of the engineered cells and the wild-type cells were used during the belgian ODISSEA Soyuz mission to investigate the alterations of the mechanical and phenotypic expression of the cells induced by microgravity and their rescue by the engineered Rho GTPases. A failure in the time schedule, a disconnection of the experiment containers before the automatic activation of the fixation procedure, was responsible for the loss of the biological samples.