The LINC complex is required for endothelial cell adhesion and adaptation to shear stress and cyclic stretch

Abstract

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex is a structure consisting of nesprin, SUN, and lamin proteins. A principal function of the LINC complex is anchoring the nucleus to the actin, microtubule, and intermediate filament cytoskeletons. The LINC complex is present in nearly all cell types, including endothelial cells. Endothelial cells line the innermost surfaces of blood vessels and are critical for blood vessel barrier function. In addition, endothelial cells have specialized functions, including adaptation to the mechanical forces of blood flow. Previous studies have shown that depletion of individual nesprin isoforms results in impaired endothelial cell function. To further investigate the role of the LINC complex in endothelial cells we utilized dominant negative KASH (DN-KASH), a dominant negative protein that displaces endogenous nesprins from the nuclear envelope and disrupts nuclear-cytoskeletal connections. Endothelial cells expressing DN-KASH had altered cell-cell adhesion and barrier function, as well as altered cell-matrix adhesion and focal adhesion dynamics. In addition, cells expressing DN-KASH failed to properly adapt to shear stress or cyclic stretch. DN-KASH-expressing cells exhibited impaired collective cell migration in wound healing and angiogenesis assays. Our results demonstrate the importance of an intact LINC complex in endothelial cell function and homeostasis.