Airway mucus: its components and function

  title={Airway mucus: its components and function},
  author={Erik. P. Lillehoj and K. Chul Kim},
  journal={Archives of Pharmacal Research},
The airway surface liquid (ASL), often referred to as mucus, is a thin layer of fluid covering the luminal surface of the airway. The major function of mucus is to protect the lung through mucociliary clearance against foreign particles and chemicals entering the lung. The mucus is comprised of water, ions, and various kinds of macromolecules some of which possess the protective functions such as anti-microbial, anti-protease, and anti-oxidant activity. Mucus glycoproteins or mucins are mainly… 
Role of Epithelial Cells in Chronic Inflammatory Lung Disease
Airborne pathogens entering the lungs first encounter the mucus layer overlaying epithelial cells as a first line of host defense as well as proinflammatory cytokines and chemokines that initiate and amplify host defensive responses to these toxic agents.
MUC5B Secretion is Up-Regulated in Sinusitis Compared with Controls
Estimation of secretion of sinus mucus mucins in healthy individuals and CRS and correlate them with mucus biophysical properties showed MUC5B secretion is significantly up-regulated in CRS compared with control subjects, likely to have important implications for future therapies in C RS.
Differential Muc 2 and Muc 5 ac secretion by stimulated guinea pig tracheal epithelial cells in vitro
The antibodies used in this study can recognize specific mucin subtypes in guinea pig airway epithelium and in proteins from GPTE cells, and this finding contrasts with expression patterns in the airways of a variety of mammalian species in which only Muc5ac predominates.
Cis-acting polymorphism of MUC gene expression.
Significant correlations were detected between MUC5B and allergy and wheeze history, although the significance of these correlations is unclear and could reflect differences in M UC5B properties rather than expression, or might have arisen from multiple testing.
Ionic composition of rat airway surface liquid determined by X‐ray microanalysis
X‐ray microanalysis is a suitable method to determine the ionic composition of ASL, and results from both frozen‐hydrated specimens and from the dextran beads showed that ASL from rat trachea is hypotonic.
Effects of dexamethasone on Muc5ac mucin production by primary airway goblet cells.
Mucus hypersecretion associated with airway inflammation is reduced by glucocorticoids. Two mechanisms of glucocorticoid-mediated inhibition of mucus production have been proposed, direct inhibition
The role of airway epithelium and blood neutrophils in the inflammatory response in cystic fibrosis.
Collectins and Cationic Antimicrobial Peptides of the Respiratory Epithelia
The purpose of this review is to discuss antimicrobial innate immune elements within the respiratory tract of healthy and pneumonic lung with emphasis on hydrophilic surfactant proteins and β-defensins.


Rôle of lipids in airway function.
Although much airway lipid may travel up from the alveoli, there is evidence that the larger airways can secrete their own lipids, and these functions may include a modification of mucus rheology, an effect on ciliary beat and mucociliary clearance, and a lessening of the tendency to collapse of small airways due to the surface activity of the lipids.
Lipids in airway secretions.
Radioactive precursors 14C acetate and 14C palmitate were incorporated into lipids secreted "in vitro" by canine tracheal explants indicating that they are synthesised by the airway.
Heterogeneity of airways mucus: variations in the amounts and glycoforms of the major oligomeric mucins MUC5AC and MUC5B.
The findings indicate that M UC5AC and MUC5B are the major oligomeric mucins and that airways mucus contains variable amounts of these glycoproteins, and can be altered significantly in diseased airways with, for instance, an increase in the low-charge form of the Muc5B mucin in CF and COPD mucus.
Hyaluronan serves a novel role in airway mucosal host defense
It is shown that enzymes are retained at the apical surface of the airway epithelium by binding to surface‐associated hya‐luronan, providing an apical enzyme pool ‘ready for use’ and protected from ciliary clearance.
Most of the lipid in purulent sputum is bound to mucus glycoprotein.
The results of this study indicate that most of the lipids in purulent sputum are associated with mucin.
The lactoperoxidase system functions in bacterial clearance of airways.
The data suggest that the LPO system is a major contributor to airway defenses, and may have significant implications for chronic airway colonization seen in respiratory diseases such as cystic fibrosis.
Heterogeneity of the composition and thickness of tracheal mucus in rats.
A nonaqueous fixative is used that retains mucus (epiphase) over a lucent layer (hypophase) of osmium tetroxide dissolved in a perfluorocarbon to preserve airway mucus in situ for refined study of developmental, physiological, and pathological alterations to the airway coat.
Functions of proteins and lipids in airway secretions.
Airway secretory proteins, such as secretory immunoglobulin A, transferrin and lysozyme, participate in the airway antibacterial defence and other biochemical components found in secretions contribute significantly to the protection of the underlying epithelium.
Inhibition of neutrophil elastase by mucus glycoprotein.
Results indicate that inhibition of HLE by mucin involves binding of the positively charged HLE molecules to the negatively charged sulfated carbohydrates in the mucin, indicating that mucin is a rapid-acting inhibitor.
Structural organization and classification of the human mucin genes.
The study of the mucins structure as well as the relationship between structure and function show that mucins also possess other important functions, such as growth, direct implication in the fetal development, the epithelial renewal and differentiation,The epithelial integrity, carcinogenesis, and metastasis.