title: Substrate rigidity regulates the formation and maintenance of tissues.
abstract: The ability of cells to form tissues represents one of the most fundamental issues in biology. However, it is unclear what triggers cells to adhere to one another in tissues and to migrate once a piece of tissue is planted on culture surfaces. Using substrates of identical chemical composition but different flexibility, we show that this process is controlled by substrate rigidity: on stiff substrates, cells migrate away from one another and spread on surfaces, whereas on soft substrates they merge to form tissue-like structures. Similar behavior was observed not only with fibroblastic and epithelial cell lines but also explants from neonatal rat hearts. Cell compaction on soft substrates involves a combination of weakened adhesions to the substrate and myosin II-dependent contractile forces that drive cells toward one another. Our results suggest that tissue formation and maintenance is regulated by differential mechanical signals between cell-cell and cell-substrate interactions, which in turn elicit differential contractile forces and adhesions to determine the preferred direction of cell migration and association.
authors.affiliation: Department of Physiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.
authors.forename: Wei-hui
authors.initials: WH
authors.lastname: Guo
authors.forename: Margo T
authors.initials: MT
authors.lastname: Frey
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Burnham
authors.forename: Yu-li
authors.initials: YL
authors.lastname: Wang
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002449:Cell Aggregation / Q000502:physiology*; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology*; D004548:Elasticity; D004847:Epithelial Cells / Q000166:cytology* / Q000502:physiology*; D051379:Mice; D020409:Molecular Motor Proteins / Q000502:physiology*; D024462:Myosin Type II / Q000502:physiology*
chemical_list: D020409:Molecular Motor Proteins; D024462:Myosin Type II