Ebselen abolishes vascular dysfunction in influenza A virus-induced
exacerbations of cigarette smoke-induced lung inflammation in mice
Abstract
Background and Purpose: People with COPD are susceptible to respiratory
infections which exacerbate pulmonary and/or cardiovascular
complications, increasing their likelihood of death. The mechanisms
driving these complications remain unknown but increased oxidative
stress has been implicated. Here we investigated whether influenza A
virus (IAV) infection, following chronic cigarette smoke (CS) exposure,
worsens vascular function and if so, whether the antioxidant ebselen
alleviates this vascular dysfunction. Experimental Approach: Male BALB/c
mice were exposed to either room air or CS for 8 weeks followed by
inoculation with IAV (Mem71, 1 x 104.5 pfu)). Mice were treated with
ebselen (10 mg/kg) or vehicle (5% w/v CM-cellulose in water) daily.
Mice were culled 3- and 10-days post-infection, and their lungs lavaged
to assess inflammation. The thoracic aorta was excised to investigate
endothelial and smooth muscle dilator responses, expression of key
vasodilatory and oxidative stress modulators and infiltrating immune
cells. Key Results: CS increased lung inflammation and caused
significant vascular endothelial dysfunction, which was worsened by IAV
infection. CS-driven increases in vascular oxidative stress and
suppression of eNOS were not affected by IAV infection. CS and IAV
infection significantly enhanced T-cell recruitment into the aortic
wall. Ebselen abolished the exaggerated lung inflammation, vascular
dysfunction and increased aortic T-cell infiltration in CS and
IAV-infected mice. Conclusion and Implications: Ebselen abolished
vascular dysfunction in IAV-induced exacerbations of cigarette
smoke-induced lung inflammation indicating it may have potential for the
treatment of cardiovascular comorbidities seen in acute exacerbations of
COPD.