title: Measuring mechanodynamics in an unsupported epithelial monolayer grown at an air-water interface.
abstract: Actomyosin contraction and relaxation in a monolayer is a fundamental biophysical process in development and homeostasis. Current methods used to characterize the mechanodynamics of monolayers often involve cells grown on solid supports such as glass or gels. The results of these studies are fundamentally influenced by these supporting structures. Here we describe a new method for measuring the mechanodynamics of epithelial monolayers by culturing cells at an air-liquid interface. These model monolayers are grown in the absence of any supporting structures, removing cell-substrate effects. This method's potential was evaluated by observing and quantifying the generation and release of internal stresses upon actomyosin contraction (800 ± 100 Pa) and relaxation (600 ± 100 Pa) in response to chemical treatments. Although unsupported monolayers exhibited clear major and minor strain axes, they were not correlated with nuclear alignment as observed when the monolayers were grown on soft deformable gels. It was also observed that both gels and glass substrates led to the promotion of long-range cell nuclei alignment not seen in the hanging-drop model. This new approach provides us with a picture of basal actomyosin mechanodynamics in a simplified system, allowing us to infer how the presence of a substrate affects contractility and long-range multicellular organization and dynamics.
authors.affiliation: Centre for Interdisciplinary NanoPhysics, Department of Physics, University of Ottawa, Ottawa, ON K1N5N5, Canada.
authors.forename: Corinne
authors.initials: C
authors.lastname: Gullekson
authors.affiliation: Department of Biology, University of Ottawa, Ottawa, ON K1N5N5, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Walker
authors.affiliation: Centre for Interdisciplinary NanoPhysics, Department of Physics, University of Ottawa, Ottawa, ON K1N5N5, Canada.|Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N5N5, Canada.
authors.forename: James L
authors.initials: JL
authors.lastname: Harden
authors.affiliation: Centre for Interdisciplinary NanoPhysics, Department of Physics, University of Ottawa, Ottawa, ON K1N5N5, Canada a@pellinglab.net.|Department of Biology, University of Ottawa, Ottawa, ON K1N5N5, Canada.|Institute for Science Society and Policy, University of Ottawa, Ottawa, ON K1N5N5, Canada.|SymbioticA, School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA 6009, Australia.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Pelling
mesh_terms: D000205:Actomyosin / Q000378:metabolism / Q000502:physiology; D000388:Air; D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology*; D055592:Biophysical Phenomena; D018929:Cell Culture Techniques / Q000379:methods*; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology*; D005782:Gels; D061985:Madin Darby Canine Kidney Cells; D055595:Mechanical Phenomena; D008954:Models, Biological; D013499:Surface Properties; D014867:Water
chemical_list: D005782:Gels; D014867:Water; D000205:Actomyosin