[Molecular cloning of human respiratory tract mucin and studies of mucin gene expression in tracheobronchial epithelium of the rat].

Mucus hypersecretion is an important symptom of chronic airway diseases such as Chronic Bronchitis, Asthma, and Cystic Fibrosis. The cellular and molecular pathogenesis of hypersecretion is poorly understood. Airway mucin is a marker of chronic hypersecretion. By characterising an airway mucin cDNA, we were able to show that human airway epithelium and the intestine express the same mucin gene MUC2. It is also expressed in Cystic Fibrosis tracheobronchial epithelium. In an animal model of hypersecretion, viral infection and sulfur dioxide exposition lead to a dramatic accumulation of mucin mRNA in the airway epithelium. This could represent an important initial step in the pathogenesis of tracheobronchial hypersecretion.