Fig. 6

Matrix stiffening modulates fibroblast activation involving upregulating SNAI2 expression. a Schematic illustration of the generation of normal-like stiffness (~1kpa) and tumor-like stiffness (~100 kpa) using the PAA gel substrate. b Representative images of the MRC5 cells growing on substrate with variant matrix stiffness (1~100 kpa), with a plastic plate being a positive control for cell spreading. c–e Representative images and quantification of the cellular cytoskeleton by F-actin staining in the MRC5 cells (c), the primary NFs (d) and the CAFs (e) grown on a soft or stiff matrix. f Western blot showing the protein expression of ACTA2, YAP1, SNAI2 and SNAI1 in the MRC5 cells and the primary CAFs grown on a soft or stiff matrix. g Immunoblotting showing the protein expression of ACTA2, YAP1, SNAI2 and SNAI1 in the MRC5 cells and the primary CAFs grown on soft or stiff matrix, in the presence or absence of a scramble siRNA or an siRNA specifically targeting YAP1, SNAI2 or SNAI1. h Representative images of the MRC5 cells and the primary CAFs grown on a soft or stiff substrate and in the presence or absence of an siRNA specifically targeting SNAI2. i Representative images and quantification of the cellular cytoskeleton by F-actin staining in MRC5 cells and in primary CAFs grown on a soft or stiff substrate and in the presence or absence of an siRNA specifically targeting SNAI2