Stress-shape misalignment in confluent cell layers

• Published in: Nature communications 2024-04, Vol.15 (1), p.3628-3628, Article 3628
• Main Authors: Nejad, Mehrana R., Ruske, Liam J., McCord, Molly, Zhang, Jun, Zhang, Guanming, Notbohm, Jacob, Yeomans, Julia M.
• Format: Article
• Language: English
• Subjects: 631/114/2397; 631/57/343/1361; 631/80/79/2066; 639/766/747; Animals; Biomechanical Phenomena; Cell body; Cell Shape; Cell size; Cells; Continuum modeling; Contractility; Dogs; Epithelial Cells; Epithelium; Experiments; Humanities and Social Sciences; Madin Darby Canine Kidney Cells; Misalignment; Models, Biological; Monolayers; multidisciplinary; Physics; Science; Science (multidisciplinary); Stress, Mechanical; Stresses
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-47702-w

In tissue formation and repair, the epithelium undergoes complex patterns of motion driven by the active forces produced by each cell. Although the principles governing how the forces evolve in time are not yet clear, it is often assumed that the contractile stresses within the cell layer align with the axis defined by the body of each cell. Here, we simultaneously measured the orientations of the cell shape and the cell-generated contractile stresses, observing correlated, dynamic domains in which the stresses were systematically misaligned with the cell body. We developed a continuum model that decouples the orientations of contractile stress and cell body. The model recovered the spatial and temporal dynamics of the regions of misalignment in the experiments. These findings reveal that the cell controls its contractile forces independently from its shape, suggesting that the physical rules relating cell forces and cell shape are more flexible than previously thought. When studying nematic ordering of cells in a monolayer, it is commonly assumed that the principal stress and cell shape axes are tightly coupled. Here, the authors measure cell shape and cell-generated contractile stresses and show that cells in monolayers form correlated, dynamic domains in which the stresses are systematically misaligned with the cell bodies.