Respiratory tract epithelium and mucus

The respiratory tract epithelium and the overlying mucus layer serve as the primary defense mechanism and physical barrier of the pulmonary system. This complex tissue is composed of various specialized cells, including ciliated cells that facilitate the movement of debris and goblet cells that secrete mucins like MUC5AC and MUC5B to trap pathogens (Fahy & Dickey, 2010). The mucus layer provides a hydrated environment that supports innate immune functions and protects the underlying cells from dehydration and environmental insults (Whitsett, 2018). In pathological conditions such as cystic fibrosis, asthma, and chronic obstructive pulmonary disease (COPD), the balance of mucus production and clearance is disrupted, leading to airway obstruction and chronic inflammation (Boucher, 2019). Drugs targeting this system include mucolytics, which chemically alter mucus consistency, and ion channel modulators that adjust the hydration of the airway surface liquid (Rogers, 2007). Understanding the interaction between the epithelial cells and the mucus layer is critical for developing therapies that restore normal lung function and prevent infection-related damage (Ganesan et al., 2013).

Other names

Airway mucosaTracheobronchial epitheliumRespiratory liningAirway surface liquid

Therapeutic intervention involves the reduction of mucus viscosity through the cleavage of disulfide bonds in mucin polymers, the regulation of airway surface liquid via ion channel modulation (e.g., CFTR activation or ENaC inhibition), and the suppression of inflammatory pathways that drive goblet cell hyperplasia and hypersecretion.