RhoA signalling directly influences cyclin D1 mRNA and protein expression in lung fibroblasts. Fig 3a. Human lung fibroblasts (3 IPF fibroblast lines and normal equivalents) were transfected with RhoA T19N (dominant negative) and RhoA G14V (constitutively active) constructs. Cells were serum deprived for 48 hours post transfection before incubation with TGF-β1 (5 ng/ml) for 8 hours. Data shown demonstrates analysis from LL97a and CCD8LU fibroblasts. Data are representative of transfection performed in triplicate from three independent experiments. Data are expressed as mean fold change in cyclin D1 transcript ± SEM. * = p < 0.05 relative to control, † = p < 0.05 relative to normal lung fibroblasts, †† = p < 0.05 relative to TGF-β1 treated fibroblasts. Fig 3b. Human lung fibroblasts (normal CCD8LU and IPF-derived HIPF, LL29 and LL97a) were treated with 0.5 μg/ml and 5 μg/ml of C3 exotoxin with or without subsequent TGF-β1 (5 ng/ml) stimulation. The control shown represents fibroblasts not exposed to C3 exotoxin and/or TGF-β1. Cyclin D1 protein levels found in 25 μg of total protein was determined by western blotting. Data shown demonstrates analysis from LL97a and CCD8LU fibroblasts. Data is representative of westerns performed in triplicate and shown as mean density ± SEM, * = p < 0.05.