0000000000888402
AUTHOR
Sarah M. Puddicombe
Asthmatic Bronchial Epithelium Is More Susceptible to Oxidant-Induced Apoptosis
Abnormal apoptotic mechanisms are associated with disease pathogenesis. Because the asthmatic bronchial epithelium is characteristically damaged with loss of columnar epithelial cells, we postulated that this is due to unscheduled apoptosis. Using an antibody directed toward the caspase cleavage product of poly(ADP-ribose) polymerase, immunohistochemistry applied to endobronchial biopsies showed higher levels of staining in the bronchial epithelium of subjects with asthma as compared with normal control subjects (% epithelial staining [median (range) = 10.5 (1.4-24.5) versus 0.4 (0.0-9.7)]; P < 0.001). Because we were unable to determine whether this difference was due to ongoing inflammati…
Epithelial-mesenchymal communication in the pathogenesis of chronic asthma.
Although Th-2-mediated inflammation is a key therapeutic target in asthma, its relationship to altered structure and functions of the airways is largely unknown. In addition to inflammation, asthma is a disorder involving the airway epithelium that is more vulnerable to environmental injury and responds to this by impaired healing. This establishes a chronic wound scenario that is capable of sustaining chronic inflammation as well as remodeling. This response occurs as a consequence of activation of the epithelial-mesenchymal unit, involving reciprocal activities of growth factors belonging to the fibroblast growth factor, epidermal growth factor, and transforming growth factor-beta familie…
Asthmatic bronchial epithelial cells have a deficient innate immune response to infection with rhinovirus
Rhinoviruses are the major trigger of acute asthma exacerbations and asthmatic subjects are more susceptible to these infections. To investigate the underlying mechanisms of this increased susceptibility, we examined virus replication and innate responses to rhinovirus (RV)-16 infection of primary bronchial epithelial cells from asthmatic and healthy control subjects.Viral RNA expression and late virus release into supernatant was increased 50- and 7-fold, respectively in asthmatic cells compared with healthy controls. Virus infection induced late cell lysis in asthmatic cells but not in normal cells. Examination of the early cellular response to infection revealed impairment of virus induc…