Matrix Metalloproteinases in a Gerbil Cholesteatoma Model

OBJECTIVE: The goal of this study was to determine whether expression of matrix metalloproteinases (MMP) and tumor necrosis factor-α (TNF-α) occurs in a gerbil cholesteatoma model, which may be involved early in the pathogenesis of cholesteatoma. STUDY DESIGN: Atelectasis was induced by transpalatal, bilateral Eustachian tube obstruction on gerbil ears (n = 60). Tympanic membranes were removed at days 0, 3, 7, 14, 28, 56, and 84, and quantitative analysis of TNF-α and MMPs was performed. RESULTS: Atelectasis and middle ear inflammation increased with time. TNF-α and MMP levels increased (P < 0.0083) with time, inflammation, and atelectatic stage with some variability seen between different MMPs. CONCLUSION: Elevation of TNF-α and MMPs associated with progressive tympanic membrane atelectasis suggests a possible role for these inflammatory mediators in the pathogenesis of cholesteatoma. (Otolaryngol Head Neck Surg 2003;129:402–7.)