Enhanced ROCK1 dependent contractility in fibroblast from chronic obstructive pulmonary disease patients.
BACKGROUND
During wound healing processes fibroblasts account for wound closure by adopting a contractile phenotype. One disease manifestation of COPD is emphysema which is characterized by destruction of alveolar walls and our hypothesis is that fibroblasts in the COPD lungs differentiate into a more contractile phenotype as a response to the deteriorating environment.


METHODS
Bronchial (central) and parenchymal (distal) fibroblasts were isolated from lung explants from COPD patients (n = 9) (GOLD stage IV) and from biopsies from control subjects and from donor lungs (n = 12). Tissue-derived fibroblasts were assessed for expression of proteins involved in fibroblast contraction by western blotting whereas contraction capacity was measured in three-dimensional collagen gels.


RESULTS
The basal expression of rho-associated coiled-coil protein kinase 1 (ROCK1) was increased in both centrally and distally derived fibroblasts from COPD patients compared to fibroblasts from control subjects (p < 0.001) and (p < 0.01), respectively. Distally derived fibroblasts from COPD patients had increased contractile capacity compared to control fibroblasts (p < 0.01). The contraction was dependent on ROCK1 activity as the ROCK inhibitor Y27632 dose-dependently blocked contraction in fibroblasts from COPD patients. ROCK1-positive fibroblasts were also identified by immunohistochemistry in the alveolar parenchyma in lung tissue sections from COPD patients.


CONCLUSIONS
Distally derived fibroblasts from COPD patients have an enhanced contractile phenotype that is dependent on ROCK1 activity. This feature may be of importance for the elastic dynamics of small airways and the parenchyma in late stages of COPD.
Department of Experimental Medical Science, BMC D12, Lund University, Lund, Sweden. oskar.hallgren@med.lu.se
Oskar
O
Hallgren
Sara
S
Rolandsson
Annika
A
Andersson-Sjöland
Kristian
K
Nihlberg
Elisabet
E
Wieslander
Martina
M
Kvist-Reimer
Magnus
M
Dahlbäck
Leif
L
Eriksson
Leif
L
Bjermer
Jonas S
JS
Erjefält
Claes-Göran
CG
Löfdahl
Gunilla
G
Westergren-Thorsson
D000328:Adult; D015153:Blotting, Western; D005260:Female; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000201:enzymology*; D054460:rho-Associated Kinases / Q000502:physiology*
C515851:ROCK1 protein, human; D054460:rho-Associated Kinases