Intrinsic biochemical and functional differences in bronchial epithelial cells of children with asthma

Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, 6001, Western Australia, Australia.
American Journal of Respiratory and Critical Care Medicine (Impact Factor: 11.99). 12/2006; 174(10):1110-8. DOI: 10.1164/rccm.200603-392OC
Source: PubMed

ABSTRACT Convincing evidence of epithelial damage and aberrant repair exists in adult asthmatic airways, even in the absence of inflammation. However, comparable studies in children have been limited by access and availability of clinical samples.
To determine whether bronchial epithelial cells from children with asthma are inherently distinct from those obtained from children without asthma.
Epithelial cells were obtained by nonbronchoscopic bronchial brushing of children with mild asthma (n = 7), atopic children without asthma (n = 9), and healthy children (n = 12). Cells were subject to morphologic, biochemical, molecular, and functional assessment. Responses were also compared with commercially available epithelial cultures and the transformed cell line 16HBE140.
All epithelial cells exhibited a "cobblestone" morphology, which was maintained throughout culture and repeated passage. Expression of cytokeratin 19 varied, with disease phenotype being greatest in healthy nonatopics and lowest in asthmatics. In contrast, expression of cytokeratin 5/14 was greatest in asthmatic samples and least in healthy nonatopic samples. Asthmatic epithelial cells also spontaneously produced significantly greater amounts of interleukin (IL)-6, prostaglandin E2, and epidermal growth factor, and equivalent amounts of IL-1beta and soluble intracellular adhesion molecule-1, but significantly lower amounts of transforming growth factor beta1. This profile was maintained through successive passages. Asthmatic epithelial cells also exhibited greater rates of proliferation than nonasthmatic cells.
This study has shown that epithelial cells from children with mild asthma are intrinsically different both biochemically and functionally compared with epithelial cells from children without asthma. Importantly, these differences are maintained over successive passages, suggesting that they are not dependent on an in vivo environment.

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    • "The described differences between these two could be explained by the preliminary data of altered cytokeratin expression. We have previously described a similar cytokeratin profile in asthmatic pAEC [12], suggesting that pAEC CF may also be less well differentiated compared to healthy cells. We are currently exploring this further in order to assess if this is intrinsic or a result of constant injury. "
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    ABSTRACT: ABSTRACT Aim of the study: The bronchial brushing technique presents an opportunity to establish a gold standard in vitro model of Cystic Fibrosis (CF) airway disease. However, unique obstacles exist when establishing CF airway epithelial cells (pAECCF). We aimed to identify determinants of culture success through retrospective analysis of a program of routinely brushing children with CF. Materials and methods: Anaesthetised children (CF and non-CF) had airway samples taken which were immediately processed for cell culture. Airway data for the CF cohort was obtained from clinical records and the AREST CF database. Results: Of 260 brushings processed for culture, 114 (43.8%) pAECCF successfully cultured to passage one (P1) and 63 (24.2% of total) progressed to passage two (P2). However, >80% of non-CF specimens (pAECnon-CF) cultured to P2 from similar cell numbers. Within the CF cohort, specimens successfully cultured to P2 had a higher initial cell count and lower proportion of severe CF mutation phenotype than those that did not proliferate beyond initial seeding. Elevated airway IL-8 concentration was also negatively associated with culture establishment. Contamination by opportunistic pathogens was observed in 81 (31.2% of total) cultures and brushings from children with lower respiratory tract infections were more likely to co-culture contaminating flora. Conclusions: Lower passage rates of pAECCF cultures uniquely contrasts with pAECnon-CF despite similar cell numbers. An equivalent establishment rate of CF nasal epithelium reported elsewhere, significant associations to CFTR mutation phenotype, elevated airway IL-8 and opportunistic pathogens all suggest this is likely related to the CF disease milieu.
    Experimental Lung Research 09/2014; 40(9). DOI:10.3109/01902148.2014.946631 · 1.75 Impact Factor
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