Chronic Aspergillus fumigatus exposure upregulates the expression of mucin 5AC in the airways of asthmatic rats.

Background: Airway mucus hypersecretion is associated with increased morbidity and mortality in patients with asthma. Chronic Aspergillus fumigatus (A. fumigatus) exposure leads to aggravation of airway inflammation and remodeling, including goblet cell hyperplasia (GCH) and mucus hypersecretion in a rat model of asthma. The effects of chronic A. fumigatus exposure on the expression of airway mucin 5AC (MUC5AC) are unknown. Methods: The rat model of chronic asthma was set up by systemic sensitization and repeated challenge to ovalbumin (OVA). The asthmatic rats were exposed to chronic intranasal inhalation of A. fumigatus spores. The changes of MUC5AC expression, the extent of GCH, and airway hyperreactivity (AHR) were measured after exposure to the fungus. Results and Conclusions: Chronic exposure to A. fumigatus upregulates the expression of MUC5AC, and induces GCH in the airways of asthma rats, and the remodeling changes of the airway epithelium was positively correlated with AHR. Upregulation of MUC5AC and induction of GCH may be mechanisms by which chronic A. fumigatus exposure promotes the progression of asthma.