Mucus glycoproteins and pulmonary surfactant pathways

The mucus glycoproteins and pulmonary surfactant pathways are essential components of the respiratory system's defense and mechanical stability. Mucus glycoproteins, primarily the gel-forming mucins MUC5AC and MUC5B, create a viscoelastic barrier that traps inhaled particles and pathogens, which are then cleared from the airways by ciliary action [3, 5]. Pulmonary surfactants, consisting of phospholipids and proteins (SP-A, SP-B, SP-C, and SP-D), are critical for reducing surface tension at the alveolar air-liquid interface, preventing alveolar collapse during expiration, and modulating local immune responses [13]. Abnormalities in these pathways, such as the hypersecretion of thick mucus or the depletion of functional surfactant, are hallmark features of diseases like chronic obstructive pulmonary disease (COPD), cystic fibrosis, and acute respiratory distress syndrome (ARDS) [10, 14]. Pharmacological management includes the use of mucolytics to thin secretions, surfactant replacement therapies to restore lung compliance, and mucokinetic agents to improve clearance [7, 10]. These therapies aim to restore the balance of the airway surface liquid and improve gas exchange in compromised lungs [9, 12].

Other names

Mucociliary clearance and surfactant systemAirway surface liquid pathwaysRespiratory mucus and surfactant proteinsASL pathways

Reduction of mucus viscosity via disulfide bond disruption; depolymerization of extracellular DNA; reduction of alveolar surface tension; enhancement of mucociliary clearance