Environmental pollutants damage airway epithelial cell cilia: Implications for the prevention of obstructive lung diseases

Abstract

Mucociliary epithelium lining the upper and lower respiratory tract constitutes the first line of defense of the airway and lungs against inhaled pollutants and pathogens. The concerted beating of multiciliated cells drives mucociliary clearance. Abnormalities in both the structure and function of airway cilia have been implicated in obstructive lung diseases. Emerging evidence reveals a close correlation between lung diseases and environmental stimuli such as sulfur dioxide and tobacco particles. However, the underlying mechanism remains to be described. In this review, we emphasize the importance of airway cilia in mucociliary clearance and discuss how environmental pollutants affect the structure and function of airway cilia, thus shedding light on the function of airway cilia in preventing obstructive lung diseases and revealing the negative effects of environmental pollutants on human health.

Keywords: Airway epithelium; environmental pollutant; lung disease; mucociliary clearance.

Figure 1

Secretory cells and ciliated epithelial cells constitute the first line of lung defense. Secretory cells produce gel‐forming mucins to entrap inhaled particles and ciliated epithelial cells transport them out of the lung through cilia beating. Reversely, some environmental pollutants, including particles, NO, NO₂, SO₂, and O₃, can lead to impaired structure and function of airway cilia, thus resulting in inadequate MCC and consequently leading to various lung diseases.