“…Binding of integrins to matrix proteins promotes the bundling of F-actin at the cell-matrix adhesion and the subsequent maturation of both the focal adhesion and the actin stress fiber (Zaidel-Bar et al, 2003;Wolfenson et al, 2009Wolfenson et al, , 2011 to generate the tension required for cell adherence, migration, and tissue homeostasis. Exposure to microgravity reduces the formation, number, and total area of focal adhesions per cell (Guignandon et al, 2003;Tan et al, 2018) consequently affecting cellular adherence, migration capacity, and viability (Plett et al, 2004;Nabavi et al, 2011;Shi et al, 2015;Ahn et al, 2019;Dietz et al, 2019), albeit with contradictory results. Mechanical unloading has been shown to significantly reduce gene expression of a number of focal adhesion proteins, including FAK, DOCK1, and PTEN, while caveolin and p130Cas expression were shown to be increased (Grenon et al, 2013;Ratushnyy and Buravkova, 2017).…”