Figure 4

Physical factors regulating lineage commitment of MSCs. MSCs physically interact with various components in the tissue microenvironment in vivo. The physical factors including cell shape, external mechanical forces, extracellular matrix, and geometric structures are involved in stem cell fate decision. By regulating RhoA-ROCK signaling pathway, spread cells tend to differentiate into osteoblasts while round cells tend to become adipocytes (a). Different physical forces can also direct MSCs to differentiate into different lineages via controlling myosin II activity (b). Meanwhile, components of extracellular matrix, such as osteopontin and fibronectin, can regulate the adipo-osteogenic balance of MSCs through binding to integrin receptors (c). In addition, geometric cues such as nanoscale changes can also effectively dictate the differentiation of MSCs (d)