Expression of beta-defensins in the tubotympanum of experimental otitis media.

CONCLUSION

Since the expression levels of beta-defensins 2-4 were up-regulated in experimental otitis media, they may play a protective role in the pathogenesis of otitis media.

OBJECTIVES

Defensins are antimicrobial peptides that play a major role in innate immunity. The goal of this study was to identify the expression of defensins in experimental otitis media of the mouse.

MATERIALS AND METHODS

The expression of three alpha-defensins (cryptdins, cryptdin-related sequences 1-C (CRS1-C), and CRS4-C) and four beta-defensins (mBD1, mBD2, mBD3, and mBD4) was investigated in the tubotympanum of experimental otitis media in mice by a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and the expression levels of three beta-defensins (mBD2, mBD3, mBD4) were evaluated by Western blotting.

RESULTS

The alpha-defensins were not expressed in the tubotympanum. mBD1 was expressed constitutively in normal middle ear mucosa and Eustachian tube mucosa, but up-regulated expression of mBD2, mBD3, and mBD4 was observed with RT-PCR and Western blotting in the tubotympanums in experimental otitis media, while the normal tubotympanums did not express them.