Dose-dependence of inhibition of collagen I and ASMA expression and MEK/ERK activation in fibroblasts by CSD and its subdomains. NLF and SLF were cultured as described in Figure 8 with 0, 1, 3, or 5 μM of the indicated peptides. Collagen I in the medium and pERK, ph-MEK, ASMA and actin (loading control) in the cell layer were detected by Western blotting. Blots were quantified densitometrically. The levels of collagen I, pERK, pMEK, and ASMA in cells treated with no peptide (divided by the level of actin) were set to 100 arbitrary units. The data presented are the average of the densitometric quantification of three independent experiments.