Altering the Cellular Morphology Results in the Mechanical Regulation of Nuclear Shape and Functions by Central Actin Filaments

Abstract

Growing evidence suggests that cytoplasmic actin filaments are essential players in the modulation of nuclear shape and functions. However, the mechanistic understanding of the internal orchestration between cell and nuclear shape is still lacking. In this communication, we shape-engineered single endothelial cells to quantitatively and non-invasively assess the nuclear morphology and the intracellular force balance in response to large-scale cell elongations. Our study reveals for the first time that nuclear orientation and deformation are regulated by lateral compressive forces driven by tension in central actomyosin stress fibers. We show that tension in central stress fibers is gradually generated by anisotropic force contraction dipoles as the cell elongates and strongly dependent on the cell spreading area. Our findings indicate that large-scale cell shape changes induce a chromatin condensation and dramatically affect cell proliferation. On the basis of these findings, we propose a simple mechanical model that quantitatively accounts for our experimental data and provides a conceptual framework for the mechanistic coordination between cell and nuclear shape.View Large Image | View Hi-Res Image | Download PowerPoint Slide