title: A periciliary brush promotes the lung health by separating the mucus layer from airway epithelia.
abstract: Mucus clearance is the primary defense mechanism that protects airways from inhaled infectious and toxic agents. In the current gel-on-liquid mucus clearance model, a mucus gel is propelled on top of a "watery" periciliary layer surrounding the cilia. However, this model fails to explain the formation of a distinct mucus layer in health or why mucus clearance fails in disease. We propose a gel-on-brush model in which the periciliary layer is occupied by membrane-spanning mucins and mucopolysaccharides densely tethered to the airway surface. This brush prevents mucus penetration into the periciliary space and causes mucus to form a distinct layer. The relative osmotic moduli of the mucus and periciliary brush layers explain both the stability of mucus clearance in health and its failure in airway disease.
authors.affiliation: Cystic Fibrosis Research and Treatment Center, University of North Carolina, Chapel Hill, NC 27599-7248, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Button
authors.forename: Li-Heng
authors.initials: LH
authors.lastname: Cai
authors.forename: Camille
authors.initials: C
authors.lastname: Ehre
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kesimer
authors.forename: David B
authors.initials: DB
authors.lastname: Hill
authors.forename: John K
authors.initials: JK
authors.lastname: Sheehan
authors.forename: Richard C
authors.initials: RC
authors.lastname: Boucher
authors.forename: Michael
authors.initials: M
authors.lastname: Rubinstein
mesh_terms: D002478:Cells, Cultured; D002923:Cilia / Q000502:physiology* / Q000648:ultrastructure; D005782:Gels; D006025:Glycosaminoglycans / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000502:physiology*; D008171:Lung Diseases / Q000503:physiopathology; D008954:Models, Biological; D009077:Mucins / Q000502:physiology*; D009079:Mucociliary Clearance; D009093:Mucus / Q000502:physiology*; D009997:Osmotic Pressure; D020545:Respiratory Mucosa / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D005782:Gels; D006025:Glycosaminoglycans; D009077:Mucins