Nesprin-2G knockout fibroblasts exhibit reduced migration, changes in focal adhesion composition, and reduced ability to generate traction forces.

The nuclear envelope protein nesprin-2G is a component of the LINC (linker of nucleoskeleton and cytoskeleton) complex and is responsible for mechanical and signaling crosstalk between the nucleus and cytoskeleton. A prior study has demonstrated that nesprin-2G knockout mice show delayed wound healing. Our goal was to elucidate the mechanism underlying the delayed wound closure in this mouse model. We isolated primary fibroblasts from wildtype and knockout neonatal mice. Knockout cells exhibited decreased focal adhesion (FA) size, number, and intensity. Consistent with this result, FA protein expression levels were decreased in knockout cells. Additionally, knockout fibroblasts displayed an abnormal actin cytoskeleton, as evidenced by loss of TAN line formation and both cytoplasmic and peri-nuclear actin staining. Using collective and single cell motility assays, we found that knockout cells exhibited a reduction in both speed and directed migration. Traction force microscopy revealed that knockout fibroblasts generated fewer traction forces compared to WT fibroblasts. In summary, our data indicate that changes in actin organization and defects in FAs result in a reduced ability of knockout fibroblasts to generate traction forces needed for efficient motility. This article is protected by copyright. All rights reserved.