Here, using muscle‐derived mesenchymal stromal/stem cells (MSCs) from the Zmpste24−/− (Z24−/−) mouse (a model for HGPS) and human HGPS fibroblasts, we investigated the mechanical mechanism of progerin‐induced cellular senescence, involving the role and interaction of mechanical sensors RhoA and Sun1/2 in regulating F‐actin cytoskeleton stiffness, nuclear blebbing, micronuclei formation, and the innate immune response. Here, SUN1 is linked to Hutchinson-Gilford progeria syndrome.