S. Jamil et al., ABNORMAL MUCOUS CELL PHENOTYPE INDUCED BY NEUTROPHIL ELASTASE IN HAMSTER BRONCHI, Experimental lung research, 23(4), 1997, pp. 285-295
Bronchial mucous cell metaplasia (MCM) is a histologic component of ch
ronic mucus hypersecretion. The hamster model of elastase-induced MCM
appears to involve an irreversible conversion of Clara cells to mucous
cells. The present study questioned whether the mucous cells seen in
hamster bronchi exposed to neutrophil elastase produce and maintain a
form of glycoconjugate secretory product different from that normally
found in mucous cells or Clara cells. Ultrastructural cytochemistry us
ing the gold-labeled lectin HPA revealed a difference in the cell surf
ace and stared secretory granules of elastase-derived mucous cells com
pared to normal mucous cells and Clara cells at 3 weeks and 4 months f
ollowing exposure. The results suggest that elastase irreversibly alte
rs the glycoconjugate character of the Clara cells normally present so
that they produce an abnormal form of mucus. Because secreted glycoco
njugates can affect the rate of mucociliary clearance and receptor med
iated binding of microorganisms, this change in phenotype may be invol
ved in the pathogenesis of diseases associated with chronic mucus hype
rsecretion in humans.