IBEC-led study finds stretched epithelia rebuild keratin networks and uncage nuclei

Researchers led by the Institute for Bioengineering of Catalonia report in Nature Physics that epithelial cells under hours-long stretch rebuild their keratin cytoskeleton across groups of cells and gradually force the nucleus out of its keratin cage. The team grew engineered epithelial tissues in a microfluidic stretcher and tracked live-cell changes with computer models. Over several hours, fine keratin filaments assembled into thick, star-shaped bundles that crossed cell boundaries and distributed stress. Modeling and imaging showed the same process thins the mesh around the nucleus until it separates almost completely, a response the authors call nuclear uncaging. Actin restrained how quickly keratin reorganized: weakening actin-keratin links made bundles form almost three times faster. Co-lead Xavier Trepat said it remains open whether uncaging protects the nucleus from a stressed network or leaves it more exposed. The paper lists DOI 10.1038/s41567-026-03371-8.