Intranasal steroids decrease eosinophils but not mucin expression in nasal polyps

Abstract

Increased mucin expression is a feature of nasal polyposis. Corticosteroids reduce polyp size and symptoms, but their effect on mucin production remains unknown. In this study, the effects of intranasal corticosteroids on MUC5AC mucin expression, nasal resistance, eosinophil and neutrophil infiltration, epidermal growth factor receptor (EGFR), interleukin (IL)-8, and tumour necrosis factor (TNF)-a expression was assessed in nasal polyps.In nine subjects, one nasal polyp was removed surgically before treatment and another was removed after 8 weeks of intranasal fluticasone (400 mg?day -1 ). Tissues were processed for in situ hybridisation and immunohistochemical staining. Described effects of fluticasone on nasal polyps (reduction in nasal resistance and in eosinophil infiltration) were evaluated. Morphometric analysis was performed to assess the effect of fluticasone on epithelial-, MUC5AC-, EGFR-and IL-8-stained areas, TNF-astained cells, and neutrophil numbers.Treatment with fluticasone decreased nasal resistance and intra-epithelial eosinophils. The MUC5AC-stained area in the epithelium was unchanged by treatment; MUC5AC mRNA expression was unaffected by treatment. EGFR-stained area, intraepithelial neutrophil numbers, IL-8 and TNF-a expression were also unchanged by therapy.Intranasal fluticasone was effective in decreasing nasal airflow resistance and intraepithelial eosinophils but had no effect on mucin or epidermal growth factor receptor expression or on neutrophil recruitment.

Roles of epidermal growth factor receptor activation in epithelial cell repair and mucin production in airway epithelium

“…In a recent study we assessed the effects of an intranasal corticosteroid on mucus production in nasal polyps. 49 One nasal polyp was removed surgically before treatment and another was removed after 8 weeks of treatment with intranasal fluticasone (400 mg/day) in nine subjects. The polyp tissues were examined morphometrically.…”

Pseudomonas aeruginosa eradicates Staphylococcus aureus by manipulating the host immunity

“…Immunohistochemical staining was performed on 5 mm paraffin-embedded sections. The sections were deparaffinized, rehydrated and treated with 0.3% H 2 O 2 in methyl alcohol 69 . The primary antibody (Ab) raised against sPLA2-IIA was a rabbit polyclonal Ab (4 mg ml À 1 , Cat.…”

Pseudomonas aeruginosa induces vascular endothelial growth factor synthesis in airway epithelium in vitro and in vivo

“…5-mm paraffin sections were prepared and stained as described previously [17]. The following primary Abs were used: a polyclonal rabbit Ab raised against the N-terminus of VEGF-A (A-20, dilution 1:200; Santa Cruz Biotechnology, Santa Cruz, CA, USA); a polyclonal goat Ab raised against the phosphorylated (activated) EGFR (dilution 1:50, sc-16803; Santa Cruz Biotechnology); and a polyclonal rabbit Ab raised against the endothelial marker von Willebrand factor (vWF; Dako, Glostrup, Denmark) to identify peribronchial blood vessels.…”