Collective cell migration plays a vital role in a wide range of physiological and pathological processes. Typically, cells collectively move not in a free space, but in a confined space from nonmotile cells or microenvironments. It has been experimentally reported that many types of cells confined in circular islands can perform coherent angular rotation. However, the biophysical origins underlying the coherent motion are still unclear. By proposing a dynamic biomechanical model, a deep investigation of spatiotemporal evolutions of small cell clusters in confined circular space is conducted. This model reveals that cell chirality is crucial in coherent angular rotations: a pair of cells coordinately rotate when they have identical chiral orientation.
The cover image for the May 17 issue of Biophysical Journal illustrates that a pair of cells confined in the circular island (gray) perform coherent angular rotation in a “yin-yang” pattern. Both cells are described by their membranes (green bilayer membranes), microtubules (red cytoskeletal fibers), and nuclei (dark gold spheres). Both cells form counterclockwise chirality, and, interestingly, this two-cell cluster rotates in a clockwise direction, which is opposite from each cell’s chiral orientation.
The cover image was inspired by the presented dynamic model, which captures the essential mechanical characteristics of cell deformations. This study draws a few conclusions. First, for a pair of cells confined in a circular island, the two cells perform coherent angular rotation when they have identical chiral orientation. Second, during the persistent rotation, each cell not only revolves around the island center, but also rotates around its own centroid, as with tidal locking in astronomy. Third, for a few more cells, the coherent angular rotation also appears, and the emergence of a central cell can accelerate the cluster rotation.
More details of coherent angular rotation of small cell clusters confined in circular islands can be found in the paper. This work sheds light on collective cell migration in life processes and provides an in-depth understanding of the spatiotemporal dynamics of active matter. The findings also hold promise for potential applications in regulating coherent motion of confined cell groups.
To view more research from the authors, please visit the following website: https://www.researchgate.net/profile/Guangkui_Xu.
- Bi-Cong Wang and Guang-Kui Xu