Benoit Vianay1, Fabrice Senger2, Simon Alamos3, Maya Anjur-Dietrich3, Elizabeth Bearce3, Bevan Cheeseman3, Lisa Lee3, Manuel Théry1,2. 1. University of Paris Diderot, INSERM, CEA, Hôpital Saint Louis, Institut Universitaire d'Hematologie, UMRS1160, CytoMorpho Lab, 75010, Paris, France. 2. University of Grenoble-Alpes, CEA, CNRS, INRA, Biosciences & Biotechnology Institute of Grenoble, Laboratoire de Phyiologie Cellulaire & Végétale, CytoMorpho Lab, 38054, Grenoble, France. 3. Physiology Course, Marine Biology Laboratory, Woods Hole, MA, USA.
Abstract
BACKGROUND INFORMATION: Tissue morphogenesis results from the interplay between cell growth and mechanical forces. While the impact of geometrical confinement and mechanical forces on cell proliferation has been fairly well characterised, the inverse relationship is much less understood. Here, we investigated how traction forces vary during cell cycle progression. RESULTS: Cell shape was constrained on micropatterned substrates in order to distinguish variations in cell contractility from cell size increase. We performed traction force measurements of asynchronously dividing cells expressing a cell-cycle reporter, to obtain measurements of contractile forces generated during cell division. We found that forces tend to increase as cells progress through G1, before reaching a plateau in S phase, and then decline during G2. CONCLUSIONS: While cell size increases regularly during cell cycle progression, traction forces follow a biphasic behaviour based on specific and opposite regulation of cell contractility during early and late growth phases. SIGNIFICANCE: These results highlight the key role of cellular signalling in the regulation of cell contractility, independently of cell size and shape. Non-monotonous variations of cell contractility during cell cycle progression are likely to impact the mechanical regulation of tissue homoeostasis in a complex and non-linear manner.
BACKGROUND INFORMATION: Tissue morphogenesis results from the interplay between cell growth and mechanical forces. While the impact of geometrical confinement and mechanical forces on cell proliferation has been fairly well characterised, the inverse relationship is much less understood. Here, we investigated how traction forces vary during cell cycle progression. RESULTS: Cell shape was constrained on micropatterned substrates in order to distinguish variations in cell contractility from cell size increase. We performed traction force measurements of asynchronously dividing cells expressing a cell-cycle reporter, to obtain measurements of contractile forces generated during cell division. We found that forces tend to increase as cells progress through G1, before reaching a plateau in S phase, and then decline during G2. CONCLUSIONS: While cell size increases regularly during cell cycle progression, traction forces follow a biphasic behaviour based on specific and opposite regulation of cell contractility during early and late growth phases. SIGNIFICANCE: These results highlight the key role of cellular signalling in the regulation of cell contractility, independently of cell size and shape. Non-monotonous variations of cell contractility during cell cycle progression are likely to impact the mechanical regulation of tissue homoeostasis in a complex and non-linear manner.