Figure 1.

Model of the ECM mediating cell fate of MSCs via interactions with mechanosensors and by modulating the bioavailability of hormones, such as TGFβ. Matrix stiffness and cell shape activates ROCK signaling cascade causing actin polymerization and formation of stress fibers (right). Stress fiber formation drives nuclear translocation of MRTFA and YAP/TAZ and transcriptional expression of SMA and osteogenic genes, which drives commitment to osteoblast and smooth muscle-like cell lineages. BMPs and MMPs decrease ROCK activity, causing actin disruption and preventing nuclear translocation of actin-bound MRTFA and phosphorylated YAP/TAZ, which facilitate white and beige adipogenic lineage commitment (left).