Mechanism of bone resorption in middle ear cholesteatoma in the light of epithelial barrier function

2015 Fiscal Year Final Research Report

• Project/Area Number: 25462656
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: University of Occupational and Environmental Health, Japan
• Principal Investigator: SUZUKI Hideaki 産業医科大学, 医学部, 教授 (20187751)
• Co-Investigator(Kenkyū-buntansha): HASHIDA Koichi 産業医科大学, 医学部, 講師 (90389461) ; WAKASUGI Tetsuro 産業医科大学, 医学部, 助教 (20461569) ; OHBUCHI Toyoaki 産業医科大学, 医学部, 助教 (00412651) ; KOIZUMI Hiroki 産業医科大学, 医学部, 助教 (70461572)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 中耳真珠腫 / 骨吸収 / pH / 上皮バリア / 透過性 / 破骨細胞

Outline of Final Research Achievements

Middle ear cholesteatoma is an epidermal cyst with keratin debris accumulating inside that has acidic pH. Generally speaking, the surface of normal epidermis is maintained acidic, however, barrier function of the horny and granular layers protects subepidermal tissues from the acidic environment. On the other hand, barrier function of the cholesteatoma epithelium is impaired, resulting in an increased permeability. Impaired barrier function is explained by an decease in the expressions of filaggrin and corneodesmosin in the horny layer and claudin-1, claudin-3 and tricellulin in the granulara layer. These lines of evidence supports the acid lysis theory that the cholesteatoma epithelium has impaired barrier function and leaks the acidity of its contents, leading to the resorption of the underlying bone.

Free Research Field

炎症性上気道疾患の病態