Figure 2
From: Extracellular matrix stiffness dictates Wnt expression through integrin pathway
ECM stiffness regulated β-catenin accumulation independently with Wnt signals.
Results from primary chondrocytes 48 hr after seeding on stiff (100 kPa) or soft (0.5–1 kPa) ECM. (a) Wnt1 and (b) β-catenin levels in the presence of WIF-1 (1 μg/ml) or solvent were analyzed by western blotting. (c) Total β-catenin and wnt1 levels in the presence of sFRP1 (1 μg/ml) or solvent were analyzed by western blotting. (d) Total β-catenin and (e) phosphorylated GSK3β levels in the presence of Wnt1 (100 ng/ml) or solvent were analyzed by western blotting. (f) Phosphorylated GSK3β levels in the presence of sFRP1 (1 μg/ml) or solvent were analyzed by western blotting. (g) β-catenin and (h) Wnt1 levels in chondrocytes treated with 10 μM Cardamonin or DMSO were analyzed by western blotting. (i) β-catenin and Wnt1 levels in chondrocytes transfected by β−catenin siRNA or scrambled siRNA on normal plates and (j) on stiff or soft ECM. (k) Wnt1 mRNA levels in chondrocytes treated with NaCl or LiCl (20 mmol/L) were analyzed by Real-time PCR. (l)Wnt1 levels in chondrocytes treated with NaCl or LiCl (20 mmol/L) were analyzed by western blotting. Western results were from 3 independent experiments (except 5 in b and i, 6 in j), with blots exemplifying one experiment and the bar graphs showing the combined results of 5 experiments as percentages (mean ± SEM) of the corresponding results on soft matrix. GAPDH was used to normalize for equal loading in western blotting. *P < 0.05, **P < 0.01, n.s. stands for not statistically significant.
