Wavy Cells Control Nuclear Morphology through Actin Network

Many tissues are composed of aligned collagen fibers in the body, the cell and nucleus in this structure exhibit wavy morphology. Our study, along with previous studies, show that wavy structures control cell gene expression and nuclear morphology may regulate gene expression. To investigate how wavy structure affect cell and nucleus, we used micro-contact printing to fabricate PDMS microgroove substrates with straight and wavy structures and then seeded human mesenchymal stem cells (MSCs) on the patterns. Cells and nuclei conformed to different pattern shapes, we further infer that nuclear morphology is regulated by cell cytoskeleton. The results of cytoskeleton inhibition show that without actin fibers the nuclear curvature increased, and actin substructures could lead to different nuclear deformation. Actin inhibition or disruption generates actin fragments, termed actin clusters here, which deforms the malleable nucleus. During cell adhesion and spreading, the developing actin cytoskeleton would control nucleus depending on cell morphology. These results indicate the actin controls nuclear morphology. Future study would be exploring contributions to nuclear deformation and cell phenotype by actin substructures and LINC complex.