Expression Of MUC5AC In Human Nasal Polyp And Inferior Turbinate Epithelium

The epithelial surface of the respiratory tract is coated with mucus which serve as the selective physical barrier between the extracellular milieu and the cell membrane and play important roles in humidification, lubrication, insulation, entrapment of microorganisms and particulates, and other host defense functions. This secretory blanket consists of two layers: the surface mucus layer and the deeper serous layer in which the cilia function. Airway mucus is composed of water, ions, lung secretions, serum protein transudates, and mucin glycoproteins (mucins). When this mucus blanket is altered in amount or composition, rhinorrhea, nasal obstruction, polyposis, and sinusitis may develop. Mucins are large, heterogeneous, and highly glycosylated proteins which produced by goblet cells in the surface epitheliam and by mucous and serous cells in the submucosal glands. They are the major glycoprotein components of the mucus layer, and play an essential role in the defense of the epithelium against invading pathogens. To date, 12 human mucin genes (MUC1-4, MUC5AC, MUC5B, MUC6-8, MUC9, MUCII, and MUC12) have been identified. Among them, MUC2, MUC5AC, MUC5B, MUC6, and MUC7 are known to be secretory mucin genes in the human lower airway, and MUC1, MUC3, MUC4, and MUC12 are thought to be membrane bounded, others are not classified. The molecular analysis, structure and function of mucin have caused extensive and deep investigation since the first cDNA clone had been identified in 1988.In recent years, the research about mucin in oversea E.N.T.department had increased, however, little had been reported in our country. With immunohistochemistry ABC and HE dyeing , polyps and chronic hypertrophy rhinitis inferior turbinates epithelium were applied to this study. ObjectTo examine the expression of MUC5AC in human nasal polyp and inferior turbinate epithelium, to evaluate the relationship between MUC5AC and the increased mucous secretions in polyps and chronic hypertrophy rhinitis. Method27 polyp tissues were obtained from the patients( males 15, females 12; age range 13-56 years, average age 35.5 years ) who were subjected to nasal polypectomy in our department. 19 chronic hypertrophy rhinitis inferior turbinates tissues were obtained from the patients (males 12, females 7; age range 18-48 years, average age 29 years ) who were subjected to inferior turbinectomy in our department. Inferior turbinate mucosa as control group were from 9 patients ( all male, age range 31-46 years, average age 37 years) with rhino-genesis snoring. All cases have not the history of asthma, allergy, aspirin intolerance and not receiving steroids before two weeks. All specimens were fixed with 4% paraformaldehyde, paraffin-embeded and make sections at 5 m thick. The slides were detected with HE staining for routine histopathologic examination, immuno-histochemical staining was performed for observing the expression of- - 6 - -1.27 Nasal polyps tissue is morphologically characterized by oedema, goblet cell hyperplasia of the epithelium, is extreme edema and gland proliferation. There are a lot of inflammatory cells in nasal polyp tissues by HE. 19 Inferior turbinates tissues is morphologically characterized by oedema, goblet cell hyperplasia of the epithelium, is edema in lamina propria mucosae, there are lymphocytes and plasmacytes in them.2. The number of MUC5AC expressing cells in nasal polyps and chronic hypertrophy rhinitis was significantly higner than in normal inferior turbinates(P<0.05), and the expression of MUC5AC cells are mainly concentrate on the goblet cells. DiscussionMucins are large, heterogeneous, and highly glycosylated proteins which produced by goblet cells in the surface epitheliam and by mucous and serous cells in the submucosal glands. They are the major glycoprotein components of the mucus, they give mucus its viscous and elastic characteristics that enable it to be transported by cilia. The regulations of expression, transcription and post-transcription and the correlation between mucins can affect the quali...