Association between human beta defensin expression and cholesteatoma formation

Area of Science:

• Otorhinolaryngology
• Immunology
• Microbiology

Background:

• Cholesteatoma is a destructive эпителиальное образование in the middle ear.
• Human beta defensins (hBDs) are antimicrobial peptides with roles in innate immunity.
• The role of hBDs in cholesteatoma pathogenesis is not fully understood.

Purpose of the Study:

• To investigate the association between human beta defensin (hBD) expression and cholesteatoma formation.
• To analyze hBD-1 and hBD-2 mRNA and protein expression in cholesteatoma and middle ear tissues.
• To evaluate the utility of an external acoustic meatus skin organ culture model for studying bacterial stimulation.

Main Methods:

• hBD-2 mRNA expression was assessed in Pseudomonas aeruginosa-stimulated and non-stimulated external acoustic meatus skin organ cultures.
• hBD-1 and hBD-2 protein production was visualized using immunohistochemistry.
• hBD-1 and hBD-2 mRNA expression was analyzed in samples of external acoustic meatus skin, cholesteatoma, and control tissues.

Main Results:

• Non-stimulated meatal tissue did not express hBD-2, but P. aeruginosa stimulation induced hBD-2 expression.
• hBD-1 mRNA was detected in cholesteatoma (14/17), meatal skin, and middle ear mucosa (11/18).
• hBD-2 mRNA was found in eight cholesteatoma (28.5%) and three middle ear mucosa samples (37.5%).

Conclusions:

• Data suggest constitutive hBD-1 and inducible hBD-2 expression in chronic middle ear infection and cholesteatoma.
• A failure in hBD-1 and hBD-2 expression may predispose individuals to cholesteatoma exacerbation.
• The external acoustic meatus skin organ culture model is effective for evaluating germ stimulation experiments.