The laminin-keratin link shields the nucleus from mechanical deformation and signalling

Nat Mater. 2023 Nov;22(11):1409-1420. doi: 10.1038/s41563-023-01657-3. Epub 2023 Sep 14.

Abstract

The mechanical properties of the extracellular matrix dictate tissue behaviour. In epithelial tissues, laminin is a very abundant extracellular matrix component and a key supporting element. Here we show that laminin hinders the mechanoresponses of breast epithelial cells by shielding the nucleus from mechanical deformation. Coating substrates with laminin-111-unlike fibronectin or collagen I-impairs cell response to substrate rigidity and YAP nuclear localization. Blocking the laminin-specific integrin β4 increases nuclear YAP ratios in a rigidity-dependent manner without affecting the cell forces or focal adhesions. By combining mechanical perturbations and mathematical modelling, we show that β4 integrins establish a mechanical linkage between the substrate and keratin cytoskeleton, which stiffens the network and shields the nucleus from actomyosin-mediated mechanical deformation. In turn, this affects the nuclear YAP mechanoresponses, chromatin methylation and cell invasion in three dimensions. Our results demonstrate a mechanism by which tissues can regulate their sensitivity to mechanical signals.

MeSH terms

  • Cell Adhesion
  • Cytoskeleton / metabolism
  • Extracellular Matrix / metabolism
  • Fibronectins / metabolism
  • Integrins / metabolism
  • Keratins*
  • Laminin* / metabolism

Substances

  • Laminin
  • Keratins
  • Fibronectins
  • Integrins