Expressions of isopeptide bonds and corneodesmosin in middle ear cholesteatoma.

OBJECTIVE: Isopeptide bonds form cross-links between constituent proteins in the horny layer of the epidermis. Corneodesmosin (CDSN) is a major component of corneodesmosomes, which bind corneocytes together. Both play important roles in maintaining epidermal barrier functions. In the present study, we investigated the expressions of isopeptide bonds, CDSN, and related enzymes in middle ear cholesteatoma in comparison with the skin. DESIGN: Prospective case series of patients with middle ear cholesteatoma. SETTING: Tertiary medical institute. PARTICIPANTS: Cholesteatoma and normal postauricular skin were collected from patients with acquired middle ear cholesteatoma during tympanomastoidectomy. MAIN OUTCOME MEASURES: Expression of e-(g-glutamyl)lysine isopeptide bonds was examined by immunohistochemistry; Expressions of transglutaminase (TGase)1, TGase2, TGase3, and TGase5 by immunohistochemistry and quantitative RT-PCR (qRT-PCR); expression of CDSN by immunohistochemistry, qRT-PCR, and Western blot; and expressions of tissue kallikrein-related peptidase (KLK)5, KLK7, KLK14, and serine peptidase inhibitor Kazal type 5 (SPINK5) by qRT-PCR. RESULTS: TGase2 was higher (P=0.0046) and TGase5 was lower (P=0.0008) in cholesteatoma than in the postauricular skin. Immunoreactivity for isopeptide bonds was localized in the granular and horny layers, and was not different between the two tissues. Immunoreactivity for CDSN was localized in the granular layer, and was lower in cholesteatoma than in the skin (P=0.0090). Western blot and qRT-PCR confirmed that the expression of CDSN was lower in cholesteatoma than in the skin. Expressions of KLK5, KLK7, KLK14, or SPINK5 were not different between the two tissues. CONCLUSIONS: These results indicate that the production of CDSN is likely to be suppressed in cholesteatoma, which would account, at least in part, for the mechanical fragility and increased permeability of the cholesteatoma epithelium.

Expression of epidermal growth factors and a tight junction protein in the nasal mucosa of patients with chronic hypertrophic rhinitis

Background: ErbB family receptors and tight junction proteins participate in the pathologic process including tissue remodelling of inflammatory diseases in the upper and lower respiratory tracts. This study aimed at investigating the expressions of erbB1, 2, 3, 4, and a tight junction protein, claudin-1, in the nasal mucosa of patients with chronic hypertrophic rhinitis. Methods: Inferior turbinates were collected from 10 turbinectomised patients with allergic and non-allergic chronic hypertrophic rhinitis. The expressions of erbB1, 2, 3, 4, and claudin-1 were examined by fluorescence immunohistochemistry and by quantitative real-time transcription-polymerase chain reaction (qRT-PCR). Results: All erbB1-4 and claudin-1 were detected, and mainly localised in the epithelial cells and nasal gland cells. The immunoreactivity for claudin-1 was positively correlated with the expressions of erbB1, 2 and 4, but negatively correlated with that of erbB3. The mRNA expressions of erbB1, 2 and 4 were positively correlated with one another, whereas the expression of erbB3 showed negative correlation with the immunoreactivity for erbB2 and 4. Conclusions: These results suggest a possible participation of erbBs and claudin-1 in tissue remodelling in chronic hypertrophic rhinitis (AU)

Expression of epidermal growth factors and a tight junction protein in the nasal mucosa of patients with chronic hypertrophic rhinitis.

BACKGROUND: ErbB family receptors and tight junction proteins participate in the pathologic process including tissue remodelling of inflammatory diseases in the upper and lower respiratory tracts. This study aimed at investigating the expressions of erbB1, 2, 3, 4, and a tight junction protein, claudin-1, in the nasal mucosa of patients with chronic hypertrophic rhinitis. METHODS: Inferior turbinates were collected from 10 turbinectomised patients with allergic and non-allergic chronic hypertrophic rhinitis. The expressions of erbB1, 2, 3, 4, and claudin-1 were examined by fluorescence immunohistochemistry and by quantitative real-time transcription-polymerase chain reaction (qRT-PCR). RESULTS: All erbB1-4 and claudin-1 were detected, and mainly localised in the epithelial cells and nasal gland cells. The immunoreactivity for claudin-1 was positively correlated with the expressions of erbB1, 2 and 4, but negatively correlated with that of erbB3. The mRNA expressions of erbB1, 2 and 4 were positively correlated with one another, whereas the expression of erbB3 showed negative correlation with the immunoreactivity for erbB2 and 4. CONCLUSIONS: These results suggest a possible participation of erbBs and claudin-1 in tissue remodelling in chronic hypertrophic rhinitis.