hBD-2-gene expression in nasal mucosa.

Chronic sinusitis is one of the frequent inflammatory diseases and has a co mplex pathogenesis. A substantial factor seems to be recurrent bacterial in fections. Pseudomonas aeruginosa (PA) frequently can be found in nasal smea rs of patients with persistent sinus symptoms after sinus surgery. Lately a new antimicrobial peptide of epithelial origin, human Beta-Defensin-2 (hBD -2), with a strong antibacterial effect against PA could be identified with in lesional skin scales of patients suffering psoriasis. Aim of this study was to investigate hBD-2-mRNA expression in nasal cells and tissue. Methods : Total RNA was extracted from nasal polyps and turbinates following TRIzol (TM) protocol. Epithelial cells and fibroblasts of nasal human tissue were isolated and cultivated. The cells were stimulated with PA using different time points and different concentrations. Total RNA was isolated as mention ed above, reverse transcribed and amplified in a Semiquantitative Reverse T ranscriptase PCR (SQRT-PCR) with gene-specific hBD-2 primers. Results: PA i nduces time- and dose-dependently hBD-2 gene expression in nasal epithelial cells. Unstimulated epithelial nasal cells were able to express hBD-2 mRNA constitutively, whereas nasal fibroblasts showed no hBD-2 mRNA expression. Nasal polyps showed a comparable less hBD-2 gene expression then nasal tur binates. Conclusions: hBD-2 possibly mediates a specific, early starting an timicrobial defense strategy of the nasal mucosa. This hypothesis would exp lain persistent infections with PA through diminished hBD-2 gene expression .