• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.94-94
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• 1997

The objective of this study was to generate and characterize monoclonal antibodies against rat airway mucins, and therefore, should serve as a useful tool in studying the regulation of airway mucins using various in vivo rat models that are currently available. As an antigen, we used a high molecular mass mucin preparation purified from the spent media of rat tracheal surface epithelial cells in primary culture. Seven hybridomas were obtained which secrete monoclonal antibodies against the rat mucin among which mAbRT03 showed the highest immunoreactivity against the mucin based on ELISA. All of the antibodies secreted by these hybridomas recognized carbohydrate epitopes but not sialic acid residues since their immunoreactivity was completely abolished by treatment of the mucin with 20 mM periodate but not with neuraminidase. Further characterization of mAbRT03 showed that: (1) it belongs to the IgM type, (2) it binds to high molecular mass mucins based on both Western blot analysis and indirect immunoprecipitation, (3) it binds to the luminal side of tracheal epithelium as well as some goblet cells based on immunohistochemistry, and (4) it also recognizes in vive airway mucins from rats but not from human nor hamsters which have been purified from the airway lavage fluids. This is the first anti-rat airway mucin monoclonal antibody which has been developed against purified rat airway mucins. Therefore, mAbRT03 should be able to serve as an invaluable tool in studying the regulation of airway mucins using various intact rat models that are currently available.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.770-780
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• 2002

The airway surface liquid (ASL), often referred to as mucus, is a thin layer of fluid covering the luminal surface of the airway. The major function of mucus is to protect the lung through mucociliary clearance against foreign particles and chemicals entering the lung. The mucus is comprised of water, ions, and various kinds of macromolecules some of which possess the protective functions such as anti-microbial, anti-protease, and anti-oxidant activity. Mucus glycoproteins or mucins are mainly responsible for the viscoelastic property of mucus, which is crucial for the effective mucociliary clearance. There are at least eight mucin genes identified in the human airways, which will potentially generate various kinds of mucin molecules. At present, neither the exact structures of mucin proteins nor their regulation are understood although it seems likely that different types of mucins are involved in different functions and might also be associated with certain airway diseases. The fact that mucins are tightly associated with various macromolecules present in ASL seems to suggest that the defensive role of ASL is determined not only by these individual components but rather by a combination of these components. Collectively, mucins in ASL may be compared to aircraft carriers carrying various types of weapons in defense of airborne enemies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.387-395
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• 1994

The effect of vitamin C on th egramoxone toxicity in the duodenal globlet cells of rats were investigated suing histochemical methods. Rats in control, gramoxone and gramoxone+vitmain C (Vt.C) group, aged 6 to 7 weeks, were fed 18% casein diet. In th egramoxone group, neutral and acid mucins of the globlet cells in villi and crypts of duodenum tended to decrease as compared with the control group. And the globle cells secreting nonsuphated mucins tended to increase in number, being usually accompanied by a decrease of the globlet cells secreting suphated mucins which are prominent in the duodenal mucosa of control group. However, the goblet cells secreting nonsuphated mucins tended to increase in the gramoxone + Vt.C group. Morphological changes of the globlet cells in the gramoxone group were noted vacuolation and demolition of globlet cells, while those changes were not significant in the gramoxone +Vt. C group. It seems to be that Vt. C has alleviating effects on the gramoxone toxicity in secretion and production of the duodenal goblet cells.

• The Korean Journal of Zoology
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• v.17 no.1
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• pp.43-50
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• 1974

This study was performed in order to know the histochemical changes of mucosubstances in mucous glands under normal and dry conditions. The frogs, Rana nigromaculata Hallowell, were collected near Seoul area in mid-August. The experimental group was retained under dry conditions for 12, 24, 30 and 36 hrs to make a comparison to normal group. The results obtained were as follows: 1. Mucosubstances in mucous glands of the frog skin contain neutral mucin and sulfated and non-sulfated mucins. Mucosubstances in the cells of the gland neck are neutral mucin, while the gland body is composed of neutral, sulfated and non-sulfated mucins. 2. Mucosubstances in mucous gland of the frog skin decreased distinctively under dry conditions, as is evident from the hitochemical properties, te neutral mucins were influenced more clearly than acid mucins. 3. Histochemical compositions of the mucosubstances in the cell of the mucous gland (the gland neck and the gland body) were not changed. 4. The phenomena were considered as a general adaptation syndrome to keep homeostasis.

• BMB Reports
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• v.54 no.7
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• pp.344-355
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• 2021

Mucins are high molecular-weight epithelial glycoproteins and are implicated in many physiological processes, including epithelial cell protection, signaling transduction, and tissue homeostasis. Abnormality of mucus expression and structure contributes to biological properties related to human cancer progression. Tumor growth sites induce inhospitable conditions. Many kinds of research suggest that mucins provide a microenvironment to avoid hypoxia, acidic, and other biological conditions that promote cancer progression. Given that the mucus layer captures growth factors or cytokines, we propose that mucin helps to ameliorate inhospitable conditions in tumor-growing sites. Additionally, the composition and structure of mucins enable them to mimic the surface of normal epithelial cells, allowing tumor cells to escape from immune surveillance. Indeed, human cancers such as mucinous carcinoma, show a higher incidence of invasion to adjacent organs and lymph node metastasis than do non-mucinous carcinoma. In this mini-review, we discuss how mucin provides a tumor-friendly environment and contributes to increased cancer malignancy in mucinous carcinoma.

• Journal of Oral Medicine and Pain
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• v.33 no.3
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• pp.229-240
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• 2008

Animal mucins have structural characteristics similar to human salivary mucins. Animal mucins have been regarded as suitable substances for saliva substitutes. Since animal mucin molecules in saliva substitutes and host-derived antimicrobial salivary molecules exist simultaneously in whole saliva and the pellicles of patients with dry mouth, interactions may occur between these molecules. The purpose of this study was to investigate the influence of animal mucins on peroxidase activity in solution and on the surface of hydroxyapatite(HA) surfaces. The effects of animal mucins on peroxidase activity were examined by incubating porcine gastric mucin(PGM) or bovine submaxillary mucin (BSM) with either bovine lactoperoxidase(bLPO) or saliva samples. For solid-phase assays, immobilized animal mucins or peroxidase on three different HA surfaces(HA beads, HA disc, and bovine tooth) were used. Peroxidase activity was determined with an NbsSCN assay. The obtained results were as follows: 1. PGM enhanced the enzymatic activity of bLPO in solution phase. PGM did not affect the enzymatic activity of peroxidase in saliva sample(POS). 2. BSM did not affect the enzymatic activities of both bLPO and POS in solution phase. 3. HA-adsorbed PGM increased subsequent bLPO adsorption in all three HA phases. The activity of POS was increased on both the HA beads and bovine tooth. 4. The peroxidase activities on the HA beads and disc were increased when the HA surfaces were exposed to a mixture of bLPO and PGM. 5. The binding affinity of bLPO to PGM was greater than that of bLPO to BSM. Collectively, our results suggest that animal mucins affects the enzymatic activity of peroxidase on the HA surfaces as well as in solution. Saliva substitutes containing animal mucins may affect the function of antimicrobial components in natural saliva and saliva substitutes.

• Journal of Oral Medicine and Pain
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• v.24 no.3
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• pp.261-267
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• 1999

The present investigation was carried out to identify salivary components of mucosal pellicle and to explore the difference of mucosal pellicle components according to the location of oral mucosa. By using antisera and immunoblotting, high-(MG1) and low-(MG2) molecular-mass salivary mucins, amylase, IgA, proline-rich proteins(PRPs) were detected in mucosal pellicle in vivo. In addition, the data indicated that mucins, IgA and proline-rich proteins could be cleaved into lower-molecular-mass products, whereas the IgA, proline-rich proteins could also be cross-linked into higher-molecular-mass complexes. Mucosal pellicles from buccal, labial and palatal mucosa showed similar pattern in immunoblotting experiments using anti-MG2 and anti-PRPs antisera. The data from this study suggest that during mucosal pellicle formation multiple components of saliva adsorb to oral mucosal epithelial cell surfaces, and selected components can be proteolytically cleaved into smaller fragments and/or cross-linked into higher-molecular products.

• Journal of Oral Medicine and Pain
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• v.48 no.2
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• pp.39-44
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• 2023

Primary Sjögren's syndrome (pSS) is an autoimmune progressive disease characterized by dysfunction and inflammation of the salivary glands. The underlying mechanisms of salivary gland involvement in pSS remain unclear, and researchers have primarily focused on immunological phenomena, making it difficult to distinguish between the cause and effect of the disease. Consequently, our research aims to directly investigate changes in homeostasis occurring in acinar cells, specifically in the context of muscarinic signaling, mucins, aquaporins, and forkhead box protein O1, to elucidate the initial step of pSS. We compare the disease-related phenomena observed in salivary gland acinar cells in pSS with the overall process of salivary secretion.

• Korean Journal of Ichthyology
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• v.13 no.4
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• pp.254-260
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• 2001

In the goby Micropercops swinhonis, the follicular layer of full-grown oocytes consists of an outer layer (theca cell) and an inner layer (granulosa cell). As the oocyte grows, columnar cells of inner granulosa layer secrete mucin to their cytoplasm and then surround the oocyte. Such granulosa cells appear to be cuboidal cells in the early vitellogenesis, yolk vesicle stage, to be replaced by columnar cell secreting mucins (adhesive materials) in the middle vitellogenesis, yolk granule stage. The enveloping layer of the oocyte has a muco- follicle layer filled with mucins. The mucins are an amorphous and electron-dense substance. Interestingly, the oocyte enveloping layer becomes thickened towards the animal pole as vitelogenesis proceeds. A zona radiata of about $7.8{\sim}11.5\;{\mu}m$ thick is present below the muco-follicle layer. The zona radiata is composed of an one-layered electron-dense externa and a three to five-layered electron-less interna.

• The Korean Journal of Cytopathology
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• v.8 no.1
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• pp.83-86
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• 1997

Signet ring cell carcinoma is a variant of adenocarcinoma and has been rarely reported in the lung as a primary site. Recently, we experienced two cases of primary signet ring cell carcinoma in the lung without any other extrapulmonary lesion. Sputum cytology was performed and the tumor cells which have eccentrically located nuclei and abundnat mucinous cytoplasm were dispersed in diffuse sheets. On resected specimen, the signet ring cells occupied about $50{\sim}80%$ of all tumor cell nests. Histochemical staining revealed that the mucin produced by tumor cells was mostly carboxylated acid mucins. Ultrastructurally, the tumor cells contained variable sized membrane-bound mucin granules with weak central osmilophilic density and showed numerous surface microvilli, which represented that tumor cells arose from bronchial epithelial cells. In general, this tumor has diffusely infiltrative nature and the prognosis is fatal due to widespread metastasis before clinical discovery.