Respiratory mucus mucoproteins and extracellular DNA

Respiratory mucus is a complex hydrogel primarily composed of water, gel-forming mucoproteins (mucins), and, in pathological states, high concentrations of extracellular DNA (Source: PubMed, PMID: 25108218). Mucins like MUC5AC and MUC5B provide the structural framework through disulfide cross-linking, while extracellular DNA released from infiltrating neutrophils significantly increases the viscosity and elasticity of the mucus (Source: NIH, StatPearls). In chronic respiratory diseases such as cystic fibrosis and chronic obstructive pulmonary disease (COPD), the accumulation of thick, tenacious mucus impairs mucociliary clearance, leading to airway obstruction and recurrent infections (Source: PubMed, PMID: 30243718). Therapeutic strategies target these components to reduce mucus viscosity; for instance, mucolytics like N-acetylcysteine disrupt mucin disulfide bonds, while dornase alfa enzymatically digests the DNA polymers (Source: FDA, Pulmozyme Label). Modulating the physical properties of respiratory mucus is a critical approach to improving lung function and reducing the frequency of pulmonary exacerbations (Source: PubMed, PMID: 29107110).

Other names

Airway mucusSputum componentsMucus glycoproteinsExtracellular DNA (eDNA)

The mechanism involves the chemical reduction of disulfide bridges between mucin monomers to liquefy mucus, and the enzymatic cleavage of long-chain extracellular DNA into smaller fragments to reduce the viscoelasticity of purulent sputum (Source: StatPearls; PubMed, PMID: 15191020).