Effects of Proinflammatory Cytokines and Natural Products on Mucin Release from Cultured Hamster Tracheal Surface Epithelial Cells

In this study, we investigated whether TNF-alpha, IL-1beta, CTMA (carboxymethyl trimethylammonium) and LPD (Lup-20[29]-ene-3beta,28-diol) affect mucin release from airway goblet cells and compared the activities of these agents with the inhibitory action of PLL and the stimulatory action of ATP on mucin release. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with $^3H-glucosamine$ for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on $^3H-mucin$ release. The results were as follows: TNF-alpha, CTMA and LPD increased mucin release at the highest concentration, but IL-1beta did not. We conclude that CTMA and LPD can stimulate mucin release by directly acting on airway mucin-secreting cells, and suggest that these agents should be further investigated for the possible use as mild expectorants during the treatment of chronic airway diseases.