SUN2 and Hutchinson-Gilford progeria syndrome: By applying cyclic mechanical stretch to mesenchymal stromal cells (MSCs) of WT and Zmpset24−/− mice (Z24−/−, a model for HGPS), we observed much increased nuclear damage in Z24−/− MSCs, which also featured elevated Sun2 expression, RhoA activation, F-actin polymerization and nuclear stiffness, indicating the compromised nuclear decoupling capacity.