Published ahead of print on May 8, 2008, doi:10.1164/rccm.200706-929OC Am. J. Respir. Crit. Care Med., Volume 178, Number 3, August 2008, 248-260 A more recent version of this article appeared on August 1, 2008
Submitted on June 25, 2007 Lung Fibroblast Repair Functions in COPD Patients are Altered by Multiple MechanismsShinsaku Togo1,1 Pulmonary and Critical Care Medicine, University of Nebraska Medical Center, Omaha, NE, USA, 2 Center for Pneumology and Thoracic Surgery, Hospital Grosshansdorf, Grosshansdorf, Germany, 3 Third Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan, 4 Department of Medicine, Division of Respiratory Medicine, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden * To whom correspondence should be addressed. E-mail: srennard{at}unmc.edu.
Rationale: Fibroblasts are believed to be the major cells responsible for the production and maintenance of extracellular matrix. Alterations in fibroblast
functional capacity, therefore, could play a role in the pathogenesis of pulmonary emphysema, which is characterized by inadequate maintenance of tissue structure.
Objectives: To evaluate the hypothesis that deficient fibroblast repair characterizes cells obtained from individuals with COPD compared to control subjects.
Measurements and Main Results: Fibroblasts were cultured from lung tissue obtained from individuals undergoing thoracotomy and were characterized in vitro. Fibroblasts from individuals with COPD, defined by reduced FEV1, manifested reduced chemotaxis toward fibronectin and reduced contraction of three-dimensional collagen gels, two bioassays associated with fibroblast repair function. At least two mechanisms appear to account for these differences. PGE, a known inhibitor of fibroblast repair functions, was produced in increased
amount by fibroblasts from COPD subjects, which also expressed increased amounts of the receptors EP2 and EP4, both of which signal through cyclic AMP. Incubation of fibroblasts with indomethacin or with the PKA inhibitor KT-5720 partially restored COPD subject fibroblast function. In addition, fibroblasts from COPD subjects produced more TGF- Key words: fibroblasts, PGE, TGF- , chemotaxis, contraction
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