Bone destruction in chronic otitis media is not mediated by the RANKL pathway or estrogen receptor-alpha

BACKGROUND: Chronic otitis media with or without cholesteatoma progresses with various degrees of bone resorption and remodeling. Estrogen mediates osteoprotective effects through the receptor activator of NF-κB ligand (RANKL) pathway, which is mainly mediated by estrogen receptor-alpha (ER-α). OBJECTIVES: The present study investigated the expression patterns of receptor activator of NF-κB (RANK), osteoprotegerin (OPG), RANKL, and ER-α in pathological tissue from patients with chronic otitis media to determine the roles of those factors in osteolytic mechanisms underlying the pathogenesis of chronic otitis media. METHODS: Normal and pathological specimens from 18 patients with chronic otitis media were examined. RESULTS: There were no significant differences in RANK, OPG, RANKL, or ER-α mRNA expression between normal and pathological specimens of epithelial tissue. CONCLUSIONS: Our findings suggested that RANK, OPG, RANKL, and ER-α are not associated with the bone destruction in chronic otitis media; other cytokines may directly activate the osteoclasts in chronic otitis media.