Fig. 1

a Normal lung fibroblasts were cultured on polyacrylamide substrates with Young’s moduli of 400 Pa or 6400 Pa for 24 h in serum-free media prior to treatment with/without the Fas-activating antibody (Fas-Ab, 250 ng/ml) for 16 h, and apoptosis was assessed using ELISA detection of histone-associated DNA-fragments. The figure represents pooled data from five independent experiments with 3 technical replicates included in each experiment, with the data for each independent experiment normalized to 400 Pa controls to allow comparisons. *** p < 0.001 compared to untreated cells on 400 Pa. Comparisons were made using one-way ANOVA with Tukey’s multiple comparison test. b Fas mRNA in normal fibroblasts cultured for 24 h on 400 or 6400 Pa substrates was assessed by quantitative real-time RT-PCR. n = 3 independent experiments with two technical replicates per experiment, with data normalized to the average expression in cells on the 6400 Pa substrates. * p < 0.05 using unpaired T-test. c Fas protein in cell lysates was measured by ELISA. Data pooled from 3 independent experiments. Fas concentration was determined as pg Fas/μg protein collected and was then normalized to the average concentration of 6400 Pa substrates to allow direct comparisons between experimental replicates. * p < 0.05 using unpaired T-test