Curvature-dependent contraints drive remodeling of epithelia

Data from paper under submission to Journal of Cell Science

Epithelial tissues function as barriers that separate the organism from the environment. They usually have highly curved shapes, such as tubules or cysts. However, interplays between the environment and cell mechanical properties to set the shape are not known. In this study, we encapsulated two epithelial cell lines, MDCK and J3B1A, into hollow alginate tubes and grew them under cylindrical confinement. Once formed, the MDCK layer detached from the alginate shell, while J3B1A layer remained attached longer. Detachment resulted from contractile forces within cell layers that pulled cells away from the shell. We concluded that J3B1A cells have lower contractility than MDCK cells. As the pulling forces depend on the tube radius, we induced detachment of J3B1A cells by reducing the size of the hollow tube. Moreover, in curved tubes, detachment was more pronounced on the outer side of the turn, while extrusion occurred in the inner side, further highlighting the coupling between curvature and cell contractility.