In order to better understand the cause of hereditary hearing impairment, we have performed a proteomic analysis of the inner ear proteins using two-dimensional gel electrophoresis. In the process of analysis, we have found very unique properties of the bovine homologue of the human COCH gene product. The COCH gene is responsible for one of the hereditary hearing impairments, DFNA9, and was recently suggested to be a possible genetic factor contributing to Ménière's disease. The Coch protein constitutes 70% of bovine inner ear proteins and is composed of 16 different protein spots, with charge and size heterogeneity. Heterogeneity of this protein suggests that the Coch gene is processed in several ways, at the transcriptional and/or posttranslational level. Much knowledge has accumulated about the hereditary hearing impairment genes; however, little research has been done regarding the protein products of those genes. This is the first report to characterize the Coch protein. Study of the Coch protein might provide more information on the mechanism of hearing and vestibular disorders.

PurposeNasal polyposis is a chronic inflammatory disease of the upper airways often associated with asthma and characterized by markedly increased numbers of eosinophils, Th2 type lymphocytes, fibroblasts, goblet cells and mast cells. Previous studies have shown elevated levels of thymic stromal lymphopoietin (TSLP) in atopic diseases like asthma, atopic dermatitis and mainly in animal models of allergic rhinitis (AR). Here, we investigated the expression of TSLP in nasal polyps from atopics and non-atopics in comparison with the nasal mucosa and its potential role in nasal polyposis.MethodsMessenger RNA expression for TSLP, thymus and activation-regulated chemokine (TARC) and macrophage derived chemokine (MDC) in nasal polyps and nasal mucosa of atopics and non-atopics was analyzed by real time PCR. Immunoreactivity for TSLP in nasal polyps and in the nasal mucosa of patients with AR and non-allergic rhinitis (NAR) was analyzed by immunohistochemistry. Eosinophil counts was analyzed by Wright-Giemsa staining and nasal polyp tissue IgE, by ELISA.ResultsMessenger RNA expression for TSLP,TARC and MDC was markedly higher in nasal polyps as compared to the allergic nasal mucosa. Immunoreactivity for TSLP was detected in epithelial cells, endothelial cells, fibroblasts and inflammatory cells of the nasal mucosa and nasal polyps. The number of TSLP+ cells was significantly greater in the nasal mucosa of AR than NAR patients. The number of TSLP+ cells in nasal polyps from atopics was significantly greater than that of non-atopics and that in the allergic nasal mucosa. The number of TSLP+ cells correlated well with the number of eosinophils and the levels of IgE in nasal polyps.ConclusionsThe high expression of TSLP in nasal polyps and its strong correlation to eosinophils and IgE suggest a potential role for TSLP in the pathogenesis of nasal polyps by regulating the Th2 type and eosinophilic inflammation.

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The molecular and cellular factors resulting in the pathologic features of acquired and congenital cholesteatomas are not completely known. Recently, proinflammatory cytokines like interleukin-1α (IL-1α) and tumor necrosis factor-alpha (TNF-α) have been shown to induce bone resorption, in vitro. To elucidate the key molecules involved in bone resorption and cell infiltration associated with cholesteatoma, we examined the in vivo levels of IL-1α and TNF-α, intercellular adhesion molecule-1 (ICAM-1) and lymphocyte functional antigen-1 (LFA-1) in acquired and congenital cholesteatomas, by reverse transcriptase-polymerase chain reaction, immunohistochemistry, and ELISA. Increased levels of IL-1 and TNF-α were detected in both types of cholesteatomas as compared to normal skin. Increased ICAM-1 expression and LFA-1+ cells were detected in acquired but not congenital cholesteatoma. Strong correlation was detected between TNF-α and bone resorption in both types of cholesteatoma, and between TNF-α and ICAM, TNF-α and severity of infection, or cell infiltration in acquired cholesteatoma. No correlation existed between various parameters and IL-1α. These results suggest that TNF-α may play a crucial role in the pathogenesis of both acquired and congenital cholesteatomas by regulating bone resorption and cell infiltration.

Eosinophil infiltration of tissue is a hallmark of nasal polyposis and asthma in both atopic and nonatopic patients. Structural cells like airway fibroblasts are a rich source of cytokines and inflammatory mediators. In order to verify whether airway fibroblasts play a role in eosinophilic infiltration, we investigated the release of eosinophil chemotactic and activating factors from airway fibroblasts when stimulated with nonallergenic exogenous agents such as endotoxin (lipopolysaccharide; LPS). Using a number of primary human airway tissue–derived fibroblast lines, we demonstrated that LPS could induce the gene expression and production of RANTES (regulated and normal T cell expressed and presumably secreted) and granulocyte/macrophage colony–stimulating factor (GM–CSF) only in nasal but not in pharyngeal, tracheal, bronchial, and lung fibroblasts. This selective responsiveness of nasal fibroblasts to LPS was time and dose dependent. These findings suggest that nasal fibroblasts may play an important role in the recruitment and activation of eosinophils into nasal polyps through the release of RANTES and GM–CSF.