The effect of formoterol on airway goblet cell hyperplasia and protein Muc5ac expression in asthmatic mice.

OBJECTIVES: Aim for this study was to investigate the effect of long-acting beta2-adrenoceptor agonist formoterol on airway goblet cell hyperplasia and protein Muc5ac expression in asthmatic mice.

MATERIALS AND METHODS: Forty female BABL/c mice were randomly divided into four groups with 10 mice in each. Mice in group A were treated with saline as control, and mice in group B, group C and group D were sensitized by intraperitoneal injection of 10 microg alum precipitated chicken egg ovalbumin (OVA) to establish asthmatic model, but group C were pretreated with formoterol and group D were pretreated with dexamethasone. All mice were killed 24 hours after the final OVA challenging. The left lung tissue sections were stained with periodic acid Schiff (PAS) for identification of goblet cell hyperplasia. Immunohistochemistry was used to identify the protein of Muc5ac. The right lung was isolated for detecting Muc5ac mRNA by the method of real-time fluorescence quantitative reverse transcription Polymerase Chain Reaction (real-time qRT-PCR).

RESULTS: The number of the goblet cells, the percentage of goblet cell to total cell, the transcription and the expression of Muc5ac were significantly higher in group B than those in group A [(163.63 +/- 16.68) vs. (0.46 +/- 0.16), (77.36 +/- 5.05) % vs. (0.03 +/- 0.01) % (10.31 +/- 0.73) vs. (1.00 +/- 0.13), (0.64 +/- 0.03) vs. (0.19 +/- 0.03) respectively, all P < 0.05]. The number of the goblet cells, the percentage of goblet cell to total cell, the transcription and the expression of Muc5ac were significantly lower in group C than those in group B [(52.04 +/- 4.60) vs (163.63 +/- 16.68), (30.05 +/-3.72) % vs. (77.36 +/- 5.05) %, (1.64 +/- 0.14) vs. (10.31 +/- 0.73), (0.26 +/- 0.01) vs (0.64 +/- 0.03) respectively, all P < 0.05] The number of the goblet cells, the percentage of goblet cell to total cell, the transcription and the expression of Muc5ac were significantly lower in group D than those in group B [(63.41 +/- 6.39) vs. (163.63 +/- 16.68), (38.52 +/- 3.83)% vs. (77.36 +/- 5.05) %, (1.72 +/- 0.10) vs. (10.31 +/- 0.73), (0.31 +/- 0.01) vs. (0.64 +/- 0.03) respectively, all P < 0.05]. For mentioned above, no significant differences were found between group C and group D [(52.04 +/- 4.60) vs. (63.41 +/- 6.39), (30.05 +/- 3.72) % vs. (38.52 +/- 3.83) %, (1.64 +/- 0.14) vs. (1.72 +/- 0.10), (0.26 +/- 0.01) vs. (0.31 +/- 0.01) respectively, all P < 0.05].

CONCLUSIONS: This study demonstrates that the long-acting beta2-receptor agonist formoterol may inhibit airway goblet cell hyperplasia and protein Muc5ac expression in asthmatic mice.