Expression of matrix metalloproteinases in bronchoalveolar cells in COPD and in COPD phenotypes

Abstract

Background: Matrix metalloproteinases (MMP) are a group of proteases involved in the pathogenesis of COPD. Objectives: To assess expression of mRNA for certain MMPs and their inhibitors (TIMP) in bronchoalveolar cells in COPD and to compare the expression of mRNA for MMPs and TIMP in COPD and controls and between certain COPD phenotypes. Methods: A total of 31 COPD patients and 33 controls were included in the study. All subjects underwent flexible bronchoscopy and bronchoalveolar lavage, cytological examination of the bronchoalveolar fluid and determination of relative expression of mRNA for MMP-2, MMP-9 and TIMP-1 in bronchoalveolar cells. In the subsequent 2 years, all COPD patients were followed for frequency of exacerbations and symptoms and divided according to their phenotypes. Results: The COPD group comprised 16 patients with bronchitic phenotype,15 without bronchitic phenotype,11 frequent exacerbators (≥2 exacerbations/year) and 20 non-frequent exacerbators. The COPD patients had higher expression of mRNA for MMP-9 (0.036 vs.0.017,p=0.026),MMP-2 (0.043 vs.0.021,p=0.016) and TIMP-1 (2.30 vs.0.82,p=0.014) than control group. The bronchitic phenotype patients had lower expression of mRNA for MMP-9 (0.000 vs.0.082,p=0,038),MMP-2 (0.015 vs.0.068,p=0,149) and higher expression of mRNA for TIMP-1 (3.24 vs.2.16,p=0,12) than non-bronchitic phenotype patients. Frequent exacerbators had lower expression of mRNA for MMP-9 (0.008 vs.0.069,p=0.012),MMP-2 (0.011 vs.0.051,p=0.086) and TIMP-1 (0.97 vs.2.36,p=0.048) than non-frequent exacerbators. Conclusions: Expression of mRNA for MMP-9, MMP-2 and TIMP-1 is elevated in COPD and different in various COPD phenotypes.Supported by IGA MZ CR NT/13560.