Eosinophil-Derived Cationic Proteins Activate the Synthesis of Remodeling Factors by Airway Epithelial Cells

Abstract

Eosinophil cationic proteins influence several biological functions of the respiratory epithelium, yet their direct contribution to airway remodeling has not been established. We show that incubation of the human bronchial epithelial cell line, BEAS-2B, or primary cultured human bronchial epithelial cells, normal human bronchial epithelial cells, with subcytotoxic concentrations (0.1, 0.3, and 1 μM) of major basic protein (MBP), or eosinophil peroxidase (EPO), augmented the transcripts of endothelin-1, TGF-α, TGF-β1, platelet-derived growth factor (PDGF)-β, epidermal growth factor receptor, metalloproteinase (MMP)-9, fibronectin, and tenascin. A down-regulation of MMP-1 gene expression was observed exclusively in BEAS-2B cells. Cationic protein-induced transcriptional effects were followed by the release of endothelin-1, PDGF-AB in the supernatants by ELISA, and by a down- and up-regulation, respectively, in the levels of MMP-1 and MMP-9 in cell lysates, by Western blot. Cell stimulation with the synthetic polycation, poly-l-arginine, reproduced some but not all effects of MBP and EPO. Finally, simultaneous cell incubation with the polyanion molecules, poly-l-glutamic acid or heparin, restored MMP-1 gene expression but incompletely inhibited MBP- and EPO-induced transcriptional effects as well as endothelin-1 and PDGF-AB release, suggesting that cationic proteins act partially through their cationic charge. We conclude that eosinophil-derived cationic proteins are able to stimulate bronchial epithelium to synthesize factors that influence the number and behavior of structural cells and modify extracellular matrix composition and turnover.

Expression Levels of Eosinophil Granule Protein mRNAs in Induced Sputum Reflect Airway Hyperresponsiveness and Airflow Limitation

“…The level of sputum eosinophil plays an important role in airway remodeling in asthma (Pegorier et al 2006). Furthermore, eosinophil has been known to play a key role in the natural exacerbation caused by viral and non-viral agents in asthma (Hogan et al 2008).…”

“…Both the ECP and EPO reflect the disease activity in AR, and a study reported that the ECP and EPO were predictors of the development of asthma in AR patients (Nielsen et al 2009). One study has reported that the MBP and EPO were associated with the activation of the airway remodeling factor (Pegorier et al 2006).…”

“…Other studies have reported that eosinophil granule proteins in induced sputum or serum are higher in allergic diseases such as asthma or AR than in normal subjects (Sohn et al 2008;Hogan et al 2008) and were reflective of disease activities in AR or asthma (Nielsen et al 2009). Some investigators have suggested that eosinophil granule proteins are associated with the airway remodeling associated with these diseases (Pegorier et al 2006;Hogan et al 2008) and that they contribute to bronchoconstriction and airway hyperresponsiveness in asthma (Gundel et al 1991;Coyle et al 1993;Uchida et al 1993).…”

“…Many researchers have investigated the proportion of eosinophils and the expression of eosinophil granule proteins in the aforementioned eosinophilic airway diseases (Koh et al 2003;Badar et al 2004;Pegorier et al 2006;Sohn et al 2008;Hogan et al 2008). However, none of them investigated which is more important in the identification of the disease and disease activity: the extent of eosinophil activity, as reflected by the eosinophil granule protein concentration in induced sputum, the eosinophil cell count in serum or the proportion of eosinophils among the cells obtained from induced sputum.…”

Lung Chitinolytic Activity and Chitotriosidase Are Elevated in Chronic Obstructive Pulmonary Disease and Contribute to Lung Inflammation

“…The levels of the transcripts encoding ChTRase were assessed by quantitative real-time PCR (Mx 3000P apparatus, Stratagene Europe, Amsterdam, The Netherlands), and their expression was normalized to that of ubiquitin C, using GeNorm software. 17 Primers (ChTRase, GenBank Identifier NM_003465, sense 5Ј-CTGCATCATGGTGCG-GTC-3Ј, antisense, 5Ј-GTGCTCAGCTGGTGGTTG-3Ј; ubiquitin C (GenBank Idenfier NM_004168), sense, 5Ј-CACTTGGTCCTGCGCTTGA-3Ј, antisense, 5Ј-TTTTGG-GAATGCAACAACTTT-3Ј) were designed using Primer Express 2 Software (Applied Biosystems, Framingham, MA) and were synthesized by Genosys (Sigma). Their sequences were blasted against Basic Local Alignment Search Tool database (http://www.ncbi.nlm.nih.gov/ BLAST).…”