tiotropium-bromide and Metaplasia

It has been shown that acetylcholine is both a neurotransmitter and acts as a local mediator, produced by airway cells including epithelial cells. In vivo studies have demonstrated an indirect role for acetylcholine in epithelial cell differentiation. Here, we aimed to investigate direct effects of endogenous non-neuronal acetylcholine on epithelial cell differentiation.. Human airway epithelial cells from healthy donors were cultured at an air-liquid interface (ALI). Cells were exposed to the muscarinic antagonist tiotropium (10 nM), interleukin (IL)-13 (1, 2 and 5 ng/mL), or a combination of IL-13 and tiotropium, during or after differentiation at the ALI.. Human airway epithelial cells expressed all components of the non-neuronal cholinergic system, suggesting acetylcholine production. Tiotropium had no effects on epithelial cell differentiation after air exposure. Differentiation into goblet cells was barely induced after air exposure. Therefore, IL-13 (1 ng/mL) was used to induce goblet cell metaplasia. IL-13 induced MUC5AC-positive cells (5-fold) and goblet cells (14-fold), as assessed by histochemistry, and MUC5AC gene expression (105-fold). These effects were partly prevented by tiotropium (47-92%). Goblet cell metaplasia was induced by IL-13 in a dose-dependent manner, which was inhibited by tiotropium. In addition, tiotropium reversed goblet cell metaplasia induced by 2 weeks of IL-13 exposure. IL-13 decreased forkhead box protein A2 (FoxA2) expression (1.6-fold) and increased FoxA3 (3.6-fold) and SAM-pointed domain-containing ETS transcription factor (SPDEF) (5.2-fold) expression. Tiotropium prevented the effects on FoxA2 and FoxA3, but not on SPDEF.. We demonstrate that tiotropium has no effects on epithelial cell differentiation after air exposure, but inhibits and reverses IL-13-induced goblet cell metaplasia, possibly via FoxA2 and FoxA3. This indicates that non-neuronal acetylcholine contributes to goblet cell differentiation by a direct effect on epithelial cells.

Topics: Acetylcholine; Cell Differentiation; Cells, Cultured; Cholinergic Antagonists; Dose-Response Relationship, Drug; Epithelial Cells; Gene Expression Regulation; Goblet Cells; Humans; Interleukin-13; Metaplasia; Mucin 5AC; Respiratory Mucosa; Scopolamine Derivatives; Tiotropium Bromide; Transcription Factors

Airway occlusion by mucus in chronic obstructive disease (COPD) is associated with a poor prognosis. We hypothesised that tiotropium has the ability to inhibit neutrophil elastase (NE)-induced goblet cell metaplasia in mice and mucin production in vitro. On days 1, 4, and 7, tiotropium or vehicle was administered to C57BL/6 mice by inhalation and they were allowed to intranasally aspirate human NE. Bronchoalveolar lavage fluid (BALF) and lung sections were analysed on days 8, 11 and 14. The effect of late administration of tiotropium on the goblet cell metaplasia by NE aspiration was also assessed. NE-induced MUC5AC production by NCI-H292 cells was measured with ELISA. Repeated NE aspiration induced marked goblet cell metaplasia. The grading of goblet cell metaplasia, neutrophil count and eosinophil count in BALF, keratinocyte-derived chemokine level and leukotriene B(4) level in BALF, and M(3) receptor expression by immunohistochemistry, were lower in the tiotropium group than in the vehicle group. Late administration of tiotropium inhibited the established goblet cell metaplasia. Tiotropium inhibited NE-induced MUC5AC production. Tiotropium inhibited NE-induced goblet cell metaplasia and mucin production, probably mediated by suppression of inflammation and a direct action on epithelial cells. This result suggests that tiotropium may be useful for the treatment of mucus overproduction in COPD.

Topics: Administration, Inhalation; Animals; Bronchoalveolar Lavage Fluid; Cells, Cultured; Goblet Cells; Humans; Leukocyte Elastase; Male; Metaplasia; Mice; Mice, Inbred C57BL; Mucin 5AC; Respiratory Mucosa; Scopolamine Derivatives; Tiotropium Bromide