RATIONALE: Defective efferocytosis (phagocytic clearance of apoptotic cells) in the airway may perpetuate inflammation via secondary necrosis in chronic obstructive pulmonary disease (COPD). We have previously reported that low-dose azithromycin improved alveolar macrophage (AM) phagocytic function in vitro. OBJECTIVES: We investigated collectins (mannose-binding lectin [MBL] and surfactant protein [SP]-D) and mannose receptor (MR) in COPD and their possible role in the azithromycin-mediated improvement in phagocytosis. METHODS: In vitro effects of azithromycin on AM expression of MR were investigated. MBL, SP-D, and MR were measured in patients with COPD and control subjects. Azithromycin (250 mg orally daily for 5 d then twice weekly for 12 wk) was administered to 11 patients with COPD. Assessments included AM phagocytic ability and expression of MR, MBL, SP-D, bronchial epithelial cell apoptosis, pulmonary function, C-reactive protein, blood/BAL leukocyte counts, cytokine production, and T-cell markers of activation and phenotype. MEASUREMENTS AND MAIN RESULTS: Azithomycin (500 ng/ml) increased MR expression by 50% in vitro. AM MR expression and levels of MBL and SP-D were significantly reduced in patients with COPD compared with control subjects. In patients with COPD, after azithromycin therapy, we observed significantly improved AM phagocytic ability (pre: 9.9%; post: 15.1%), reduced bronchial epithelial cell apoptosis (pre: 30.0%; post: 19.7%), and increased MR and reduced inflammatory markers in the peripheral blood. These findings implicate the MR in the defective phagocytic function of AMs in COPD and as a target for the azithromycin-mediated improvement in phagocytic ability. CONCLUSIONS: Our findings indicate a novel approach to supplement existing therapies in COPD.
RATIONALE: Defective efferocytosis (phagocytic clearance of apoptotic cells) in the airway may perpetuate inflammation via secondary necrosis in chronic obstructive pulmonary disease (COPD). We have previously reported that low-dose azithromycin improved alveolar macrophage (AM) phagocytic function in vitro. OBJECTIVES: We investigated collectins (mannose-binding lectin [MBL] and surfactant protein [SP]-D) and mannose receptor (MR) in COPD and their possible role in the azithromycin-mediated improvement in phagocytosis. METHODS: In vitro effects of azithromycin on AM expression of MR were investigated. MBL, SP-D, and MR were measured in patients with COPD and control subjects. Azithromycin (250 mg orally daily for 5 d then twice weekly for 12 wk) was administered to 11 patients with COPD. Assessments included AM phagocytic ability and expression of MR, MBL, SP-D, bronchial epithelial cell apoptosis, pulmonary function, C-reactive protein, blood/BAL leukocyte counts, cytokine production, and T-cell markers of activation and phenotype. MEASUREMENTS AND MAIN RESULTS:Azithomycin (500 ng/ml) increased MR expression by 50% in vitro. AM MR expression and levels of MBL and SP-D were significantly reduced in patients with COPD compared with control subjects. In patients with COPD, after azithromycin therapy, we observed significantly improved AM phagocytic ability (pre: 9.9%; post: 15.1%), reduced bronchial epithelial cell apoptosis (pre: 30.0%; post: 19.7%), and increased MR and reduced inflammatory markers in the peripheral blood. These findings implicate the MR in the defective phagocytic function of AMs in COPD and as a target for the azithromycin-mediated improvement in phagocytic ability. CONCLUSIONS: Our findings indicate a novel approach to supplement existing therapies in COPD.
Authors: Mark T Kearns; Samay Dalal; Sarah A Horstmann; Tiffany R Richens; Takeshi Tanaka; Jenna M Doe; Darren M Boe; Norbert F Voelkel; Laimute Taraseviciene-Stewart; William J Janssen; Chun G Lee; Jack A Elias; Donna Bratton; Rubin M Tuder; Peter M Henson; R William Vandivier Journal: Am J Physiol Lung Cell Mol Physiol Date: 2012-02-03 Impact factor: 5.464
Authors: M Vrančić; M Banjanac; K Nujić; M Bosnar; T Murati; V Munić; D Stupin Polančec; D Belamarić; M J Parnham; V Eraković Haber Journal: Br J Pharmacol Date: 2012-03 Impact factor: 8.739
Authors: Yudong Wen; David W Reid; Dongcheng Zhang; Chris Ward; Richard Wood-Baker; E Haydn Walters Journal: Int J Chron Obstruct Pulmon Dis Date: 2010-10-05