Physicochemical Control of Adult Stem Cell Differentiation: Shedding Light on Potential Molecular Mechanisms

Figure 5

Schematic for an integrative model that depicts coupling mechanisms mediating the effects of physicochemical cues. In addition to effects induced by the soluble factors, an external physical stimulus induces an increase in the cytosolic calcium concentration, which depolymerizes the F-actins and decrease the cell elasticity. The physical stimuli can also cause depletion of intracellular ATP, for example, by ATP release that, in turn, leads to inhibition of the ERM protein linkers’ binding properties and their dissociation from the membrane and actin cytoskeleton. A separation of the cell membrane from the cytoskeleton occurs and effectively decreases the membrane tension, attributable both to down-regulation of active ERM proteins and actin depolymerization. Altered calcium dynamics along with cytoskeletal remodeling may not simply be consequences of stem cell differentiation but rather important key factors regulating it.