Surface curvature and basal hydraulic stress induce spatial bias in cell extrusion

Abstract

Epithelial cell extrusion is employed in maintaining a healthy epithelium. It remains unclear how environmental conditions specific to various epithelial tissues, such as geometry and fluid osmolarity, affect cell extrusions. We found that, over curved surfaces, epithelial monolayers exhibited higher extrusion rates in concave regions than convex ones. This difference, and overall extrusions, decreased when osmotically induced basal hydraulic stress was reduced by increasing media osmolarity or by culturing monolayers on hydrogels. Mechanistically, basal fluid accumulation antagonized cell-substrate adhesions and the subsequent FAK-Akt survival pathway, leading to apoptotic cell death. Convex surfaces induced cellular forces that acted against osmosis, thereby promoting adhesions and lowering apoptosis. This effect was reversed in concave regions, and together, resulted in the curvature induced spatial bias in cell extrusions. Curvature induces forces in cell-sheets that act against/with osmosis to reduce/elevate fluid stress driven cell extrusions.

Gel-Shrink Softlithography: Enabling 3D Tissue Culture Microstructure Miniaturization and Tacky Super-Soft Material Molding

“…In a recent study, our research team devised a versatile microfabrication methodology designed to generate hemi-cylindrical wave structures (13) . These structures feature half-period dimensions spanning from conventional cell sizes to dimensions exceeding several hundred microns.…”