Regulation of mucociliary clearance in health and disease

Airway secretions are cleared by mucociliary clearance (MCC), in addition to other mechanisms such as cough, peristalsis, two-phase gas-liquid flow and alveolar clearance. MCC comprises the cephalad movement of mucus caused by the cilia lining the conducting airways until it can be swallowed or expectorated. MCC is a very complex process in which many variables are involved, all of which may modify the final outcome. The structure, number, movement and co-ordination of the cilia present in the airways as well as the amount, composition and rheological properties of the periciliary and mucus layers are determinants of MCC. Physiological factors such as age, sex, posture, sleep and exercise are reported to influence MCC due to a change in the cilia, the mucus or the periciliary layer, or a combination of these. Environmental pollution is suspected to have a depressant effect on MCC dependent on different factors such as pollutant concentration and the duration of exposure. Most studies focus on sulphur dioxide, sulphuric acid, nitrogen dioxide and ozone. Tobacco smoke and hairspray have been noted to have a negative influence on MCC. Some diseases are known to affect MCC, mostly negatively. The underlying mechanism differs from one illness to another. Immotile cilia syndrome, asthma, bronchiectasis, chronic bronchitis, cystic fibrosis and some acute respiratory tract infections are among the most frequently reported. The present paper reviews normal mucociliary clearance and the effects of diseases on this process.

This article has been cited by other articles:

				J. Fernandes, I. M. Lorenzo, Y. N. Andrade, A. Garcia-Elias, S. A. Serra, J. M. Fernandez-Fernandez, and M. A. Valverde IP3 sensitizes TRPV4 channel to the mechano- and osmotransducing messenger 5'-6'-epoxyeicosatrienoic acid J. Cell Biol., April 3, 2008; 181(1): 143 - 155. [Abstract] [Full Text] [PDF]

				L. J. van der Giessen, R. Gosselink, W. C. J. Hop, and H. A. W. M. Tiddens Recombinant human DNase nebulisation in children with cystic fibrosis: before bedtime or after waking up? Eur. Respir. J., October 1, 2007; 30(4): 763 - 768. [Abstract] [Full Text] [PDF]

				M. P Purdue, L. Gold, B. Jarvholm, M. C R Alavanja, M. H Ward, and R. Vermeulen Impaired lung function and lung cancer incidence in a cohort of Swedish construction workers Thorax, January 1, 2007; 62(1): 51 - 56. [Abstract] [Full Text] [PDF]

				J. L. Koff, M. X. G. Shao, S. Kim, I. F. Ueki, and J. A. Nadel Pseudomonas Lipopolysaccharide Accelerates Wound Repair via Activation of a Novel Epithelial Cell Signaling Cascade J. Immunol., December 15, 2006; 177(12): 8693 - 8700. [Abstract] [Full Text] [PDF]

				D. Elad, S. Naftali, M. Rosenfeld, and M. Wolf Physical stresses at the air-wall interface of the human nasal cavity during breathing J Appl Physiol, March 1, 2006; 100(3): 1003 - 1010. [Abstract] [Full Text] [PDF]

				W. Moller, K. Haussinger, R. Winkler-Heil, W. Stahlhofen, T. Meyer, W. Hofmann, and J. Heyder Mucociliary and long-term particle clearance in the airways of healthy nonsmoker subjects J Appl Physiol, December 1, 2004; 97(6): 2200 - 2206. [Abstract] [Full Text] [PDF]

				A. J. Hirsh, J. R. Sabater, A. Zamurs, R. T. Smith, A. M. Paradiso, S. Hopkins, W. M. Abraham, and R. C. Boucher Evaluation of Second Generation Amiloride Analogs as Therapy for Cystic Fibrosis Lung Disease J. Pharmacol. Exp. Ther., December 1, 2004; 311(3): 929 - 938. [Abstract] [Full Text] [PDF]

				X. Zhan, D. Li, and R. A. Johns Expression of Endothelial Nitric Oxide Synthase in Ciliated Epithelia of Rats J. Histochem. Cytochem., January 1, 2003; 51(1): 81 - 87. [Abstract] [Full Text] [PDF]

				J. C. HO, K. N. CHAN, W. H. HU, W. K. LAM, L. ZHENG, G. L. TIPOE, J. SUN, R. LEUNG, and K. W. TSANG The Effect of Aging on Nasal Mucociliary Clearance, Beat Frequency, and Ultrastructure of Respiratory Cilia Am. J. Respir. Crit. Care Med., March 15, 2001; 163(4): 983 - 988. [Abstract] [Full Text]