Significance and expression of transforming growth factor beta in human nasal polyp tissue]

OBJECTIVE: To explore the pathogenesis of nasal polyposis and the expression of transforming growth factor beta (TGF-beta) in human inflammatory nasal polyps. METHODS: TGF-beta 1-3 in nasal polyp tissues and inferior turbinate mucosa of twenty-five polyposis patients were detected with immunohistochemistry alkaline phosphatase and anti-alkaline phosphatase (APAAP) method. The inferior turbinate mucosa of eight healthy volunteers were selected as control. Six polyp tissues were estimated with double immunolabeling and Western-blot analysis to compare the characterization of the TGF-beta isoforms expression and the proportion of macrophages and eosinophils in nasal polyp tissues. RESULTS: The expression of TGF-beta 1-3 in nasal polyps was significantly higher than that in nasal mucosa and indetecable in nasal mucosa from healthy volunteers; TGF-beta 1 was the main isoform detected in nasal polyps; TGF-beta positively was accompanied by numerous macrophage and eosinophil infiltration. CONCLUSIONS: TGF-beta mainly TGF-beta 1 is strongly expressed in nasal polyps and its mucosa, where it could be produced by macrophages and eosinophils. TGF-beta could induce modification of epithelium and connective tissue and therefore be involved in the pathogenesis of nasal polyposis.