Expression of proteins involved in fibroblast contraction. Cell extracts from centrally and distally derived fibroblasts from control subjects and COPD patients were immunoblotted using antibodies against ROCK1 (A), α-SMA (B), RhoA (C), and GAPDH. Blotted bands were quantified with morphometry and values are presented as the intensity of each band relative to the intensity of the loading control: GAPDH. Photos show representative bands. ** P < 0.01 and *** < 0.001.