Airway mucus mucin network

The airway mucus mucin network is a complex, viscoelastic hydrogel that serves as the primary physical defense of the respiratory tract against inhaled pathogens and environmental particulates [Fahy & Dickey, 2010, NEJM]. It is predominantly composed of two large, gel-forming glycoproteins, MUC5AC and MUC5B, which are organized into a three-dimensional scaffold through covalent disulfide bonds and non-covalent interactions [Ma et al., 2018, JCI Insight]. In healthy lungs, this network is efficiently cleared by ciliary action, but in chronic diseases such as cystic fibrosis, COPD, and asthma, the network becomes pathologically altered through hypersecretion and dehydration [Boucher, 2019, JCI]. These changes lead to increased mucus viscosity and impaired clearance, resulting in airway obstruction and chronic infection. Therapeutic interventions target the network by chemically reducing disulfide cross-links (mucolytics), improving hydration (osmotic agents), or regulating mucin production (mucoregulators) [Rubin, 2007, Chest]. Effective management of the mucin network is critical for restoring lung function and preventing exacerbations in patients with obstructive pulmonary disorders.

Other names

Respiratory mucusTracheobronchial mucusMucin gelAirway surface liquid

Mucolytics reduce viscosity by cleaving disulfide bonds between mucin polymers; mucokinetics enhance clearance by increasing ciliary activity; mucoregulators inhibit mucin hypersecretion; osmotic agents hydrate the network to improve transportability.