Rhinovirus (RV), which causes exacerbation in patients with chronic airway diseases, readily infects injured airway epithelium and has been reported to delay wound closure. In this study, we examined the effects of RV on cell repolarization and differentiation in a model of injured/regenerating airway epithelium (polarized, undifferentiated cells). RV causes only a transient barrier disruption in a model of normal (mucociliary-differentiated) airway epithelium.
View Article and Find Full Text PDFUnlabelled: Barrier dysfunction of airway epithelium may increase the risk for acquiring secondary infections or allergen sensitization. Both rhinovirus (RV) and polyinosinic-polycytidilic acid [poly(I·C)], a double-stranded RNA (dsRNA) mimetic, cause airway epithelial barrier dysfunction, which is reactive oxygen species (ROS) dependent, implying that dsRNA generated during RV replication is sufficient for disrupting barrier function. We also demonstrated that RV or poly(I·C)-stimulated NADPH oxidase 1 (NOX-1) partially accounts for RV-induced ROS generation.
View Article and Find Full Text PDFBacterial infections following rhinovirus (RV), a common cold virus, are well documented, but pathogenic mechanisms are poorly understood. We developed animal and cell culture models to examine the effects of RV on subsequent infection with non-typeable Hemophilus influenzae (NTHi). We focused on NTHI-induced neutrophil chemoattractants expression that is essential for bacterial clearance.
View Article and Find Full Text PDFRhinovirus (RV), which is responsible for the majority of common colds, also causes exacerbations in patients with asthma and chronic obstructive pulmonary disease. So far, there are no drugs available for treatment of rhinovirus infection. We examined the effect of quercetin, a plant flavanol on RV infection in vitro and in vivo.
View Article and Find Full Text PDFNontypeable Haemophilus influenzae (NTHi) is an important bacterial pathogen associated with lower respiratory tract colonization and with acute exacerbations and disease progression in chronic obstructive pulmonary disease (COPD). Why the immune system fails to eliminate NTHi and the exact contribution of the organism to COPD progression are not well understood, in part because we lack an animal model that mimics all aspects of COPD. For this study, we used an established murine model that exhibits typical features of COPD.
View Article and Find Full Text PDFPreviously, we showed that rhinovirus (RV), which is responsible for the majority of common colds, disrupts airway epithelial barrier function, as evidenced by reduced transepithelial resistance (R(T)), dissociation of zona occludins 1 (ZO-1) from the tight junction complex, and bacterial transmigration across polarized cells. We also showed that RV replication is required for barrier function disruption. However, the underlying biochemical mechanisms are not known.
View Article and Find Full Text PDFBackground: Chronic obstructive pulmonary disease (COPD) is characterized by chronic bronchitis, emphysema and irreversible airflow limitation. These changes are thought to be due to oxidative stress and an imbalance of proteases and antiproteases. Quercetin, a plant flavonoid, is a potent antioxidant and anti-inflammatory agent.
View Article and Find Full Text PDFRecently, estrogens have been reported to have protective effects against experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS). Although the molecular mechanism for such a protective effect is currently incomplete, we hypothesized that estradiol may reduce the release of ATP from erythrocytes (ERYs), thereby lowering the production of nitric oxide (NO) by endothelial cells. Here, we report on the use of a microfluidic device to investigate the direct effects of the estrogen estradiol on endothelial cell nitric oxide production.
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