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Beaune G, Stirbat TV, Khalifat N, Cochet-Escartin O, Garcia S, Gurchenkov VV, Murrell MP, Dufour S, Cuvelier D, Brochard-Wyart F. How cells flow in the spreading of cellular aggregates. Proc Natl Acad Sci U S A 2014; 111:8055-60. [PMID: 24835175 PMCID: PMC4050549 DOI: 10.1073/pnas.1323788111] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Like liquid droplets, cellular aggregates, also called "living droplets," spread onto adhesive surfaces. When deposited onto fibronectin-coated glass or polyacrylamide gels, they adhere and spread by protruding a cellular monolayer (precursor film) that expands around the droplet. The dynamics of spreading results from a balance between the pulling forces exerted by the highly motile cells at the periphery of the film, and friction forces associated with two types of cellular flows: (i) permeation, corresponding to the entry of the cells from the aggregates into the film; and (ii) slippage as the film expands. We characterize these flow fields within a spreading aggregate by using fluorescent tracking of individual cells and particle imaging velocimetry of cell populations. We find that permeation is limited to a narrow ring of width ξ (approximately a few cells) at the edge of the aggregate and regulates the dynamics of spreading. Furthermore, we find that the subsequent spreading of the monolayer depends heavily on the substrate rigidity. On rigid substrates, the migration of the cells in the monolayer is similar to the flow of a viscous liquid. By contrast, as the substrate gets softer, the film under tension becomes unstable with nucleation and growth of holes, flows are irregular, and cohesion decreases. Our results demonstrate that the mechanical properties of the environment influence the balance of forces that modulate collective cell migration, and therefore have important implications for the spreading behavior of tissues in both early development and cancer.
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Affiliation(s)
- Grégory Beaune
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 168, Institut Curie, 75248 Paris Cedex 05, France
| | - Tomita Vasilica Stirbat
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 168, Institut Curie, 75248 Paris Cedex 05, France
| | - Nada Khalifat
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 168, Institut Curie, 75248 Paris Cedex 05, France
| | - Olivier Cochet-Escartin
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 168, Institut Curie, 75248 Paris Cedex 05, France
| | - Simon Garcia
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 168, Institut Curie, 75248 Paris Cedex 05, France
| | - Vasily Valérïévitch Gurchenkov
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 144, Institut Curie, 75248 Paris Cedex 05, France
| | - Michael P Murrell
- Departments of Biomedical Engineering and Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706; and
| | - Sylvie Dufour
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 144, Institut Curie, 75248 Paris Cedex 05, France
| | - Damien Cuvelier
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 168, Institut Curie, 75248 Paris Cedex 05, France
| | - Françoise Brochard-Wyart
- University Pierre and Marie Curie, University of Paris, Institut Curie, 75248 Paris Cedex 05, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Unité Mixte de Recherche 168, Institut Curie, 75248 Paris Cedex 05, France;
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