title: Hydraulic fracture during epithelial stretching.
abstract: The origin of fracture in epithelial cell sheets subject to stretch is commonly attributed to excess tension in the cells' cytoskeleton, in the plasma membrane, or in cell-cell contacts. Here, we demonstrate that for a variety of synthetic and physiological hydrogel substrates the formation of epithelial cracks is caused by tissue stretching independently of epithelial tension. We show that the origin of the cracks is hydraulic; they result from a transient pressure build-up in the substrate during stretch and compression manoeuvres. After pressure equilibration, cracks heal readily through actomyosin-dependent mechanisms. The observed phenomenology is captured by the theory of poroelasticity, which predicts the size and healing dynamics of epithelial cracks as a function of the stiffness, geometry and composition of the hydrogel substrate. Our findings demonstrate that epithelial integrity is determined in a tension-independent manner by the coupling between tissue stretching and matrix hydraulics.
authors: Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain.
authors: Laura
authors: L
authors: Casares
authors: Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain.
authors: Romaric
authors: R
authors: Vincent
authors: Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain.
authors: Dobryna
authors: D
authors: Zalvidea
authors: 1] Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain [2] Unitat de Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, and CIBERES, 08036 Barcelona, Spain.
authors: Noelia
authors: N
authors: Campillo
authors: 1] Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain [2] Unitat de Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, and CIBERES, 08036 Barcelona, Spain.
authors: Daniel
authors: D
authors: Navajas
authors: Universitat Politècnica de Catalunya-BarcelonaTech, 08034 Barcelona, Spain.
authors: Marino
authors: M
authors: Arroyo
authors: 1] Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain [2] Unitat de Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, and CIBERES, 08036 Barcelona, Spain [3] Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain.
authors: Xavier
authors: X
authors: Trepat
mesh_terms: D000818:Animals; D004285:Dogs; D004847:Epithelial Cells / Q000737:chemistry* / Q000502:physiology*; D057446:Hydrodynamics; D061985:Madin Darby Canine Kidney Cells; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D008846:Micromanipulation; D008954:Models, Biological; D011312:Pressure; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength / Q000502:physiology