  The shape that stem cells reach at the end of adhesion process influences
their differentiation. Rearrangement of cytoskeleton and modification of
intracellular tension may activate mechanotransduction pathways controlling
cell commitment. In the present study, the mechanical signals involved in cell
adhesion were computed in in vitro stem cells of different shapes using a
single cell model, the so-called Cytoskeleton Divided Medium (CDM) model. In
the CDM model, the filamentous cytoskeleton and nucleoskeleton networks were
represented as a mechanical system of multiple tensile and compressive
interactions between the nodes of a divided medium. The results showed that
intracellular tonus, focal adhesion forces as well as nuclear deformation
increased with cell spreading. The cell model was also implemented to simulate
the adhesion process of a cell that spreads on protein-coated substrate by
emitting filopodia and creating new distant focal adhesion points. As a result,
the cell model predicted cytoskeleton reorganisation and reinforcement during
cell spreading. The present model quantitatively computed the evolution of
certain elements of mechanotransduction and may be a powerful tool for
understanding cell mechanobiology and designing biomaterials with specific
surface properties to control cell adhesion and differentiation.
