Role of mechanical factors in fate decisions of stem cells.

Stem cells derived from adult tissues or from the inner cell mass of blastocyst-stage embryos can self-renew in culture and have the remarkable potential to undergo lineage-specific differentiation. Extensive studies have been devoted to achieving a better understanding of the soluble factors and the mechanism(s) by which they regulate the fate decisions of these cells, but it is only recently that a critical role has been revealed for physical and mechanical factors in controlling self-renewal and lineage specification. This review summarizes selected aspects of current work on stem cell mechanics with an emphasis on the influence of matrix stiffness, surface topography, cell shape and mechanical forces on the fate determination of mesenchymal stem cells and embryonic stem cells.