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Sample records for mucin muc7 binding

  1. Absence of capsule reveals glycan-mediated binding and recognition of salivary mucin MUC7 by Streptococcus pneumoniae.

    PubMed

    Thamadilok, S; Roche-Håkansson, H; Håkansson, A P; Ruhl, S

    2016-04-01

    Salivary proteins modulate bacterial colonization in the oral cavity and interact with systemic pathogens that pass through the oropharynx. An interesting example is the opportunistic respiratory pathogen Streptococcus pneumoniae that normally resides in the nasopharynx, but belongs to the greater Mitis group of streptococci, most of which colonize the oral cavity. Streptococcus pneumoniae also expresses a serine-rich repeat (SRR) adhesin, PsrP, which is a homologue to oral Mitis group SRR adhesins, such as Hsa of Streptococcus gordonii and SrpA of Streptococcus sanguinis. As the latter bind to salivary glycoproteins through recognition of terminal sialic acids, we wanted to determine whether S. pneumoniae also binds to salivary proteins through possibly the same mechanism. We found that only a capsule-free mutant of S. pneumoniae TIGR4 binds to salivary proteins, most prominently to mucin MUC7, but that this binding was not mediated through PsrP or recognition of sialic acid. We also found, however, that PsrP is involved in agglutination of human red blood cells (RBCs). After removal of PsrP, an additional previously masked lectin-like adhesin activity mediating agglutination of sialidase-treated RBCs becomes revealed. Using a custom-spotted glycoprotein and neoglycoprotein dot blot array, we identify candidate glycan motifs recognized by PsrP and by the putative S. pneumoniae adhesin that could perhaps be responsible for pneumococcal binding to salivary MUC7 and glycoproteins on RBCs. PMID:26172471

  2. Recent evolution of the salivary mucin MUC7

    PubMed Central

    Xu, Duo; Pavlidis, Pavlos; Thamadilok, Supaporn; Redwood, Emilie; Fox, Sara; Blekhman, Ran; Ruhl, Stefan; Gokcumen, Omer

    2016-01-01

    Genomic structural variants constitute the majority of variable base pairs in primate genomes and affect gene function in multiple ways. While whole gene duplications and deletions are relatively well-studied, the biology of subexonic (i.e., within coding exon sequences), copy number variation remains elusive. The salivary MUC7 gene provides an opportunity for studying such variation, as it harbors copy number variable subexonic repeat sequences that encode for densely O-glycosylated domains (PTS-repeats) with microbe-binding properties. To understand the evolution of this gene, we analyzed mammalian and primate genomes within a comparative framework. Our analyses revealed that (i) MUC7 has emerged in the placental mammal ancestor and rapidly gained multiple sites for O-glycosylation; (ii) MUC7 has retained its extracellular activity in saliva in placental mammals; (iii) the anti-fungal domain of the protein was remodified under positive selection in the primate lineage; and (iv) MUC7 PTS-repeats have evolved recurrently and under adaptive constraints. Our results establish MUC7 as a major player in salivary adaptation, likely as a response to diverse pathogenic exposure in primates. On a broader scale, our study highlights variable subexonic repeats as a primary source for modular evolutionary innovation that lead to rapid functional adaptation. PMID:27558399

  3. Recent evolution of the salivary mucin MUC7.

    PubMed

    Xu, Duo; Pavlidis, Pavlos; Thamadilok, Supaporn; Redwood, Emilie; Fox, Sara; Blekhman, Ran; Ruhl, Stefan; Gokcumen, Omer

    2016-01-01

    Genomic structural variants constitute the majority of variable base pairs in primate genomes and affect gene function in multiple ways. While whole gene duplications and deletions are relatively well-studied, the biology of subexonic (i.e., within coding exon sequences), copy number variation remains elusive. The salivary MUC7 gene provides an opportunity for studying such variation, as it harbors copy number variable subexonic repeat sequences that encode for densely O-glycosylated domains (PTS-repeats) with microbe-binding properties. To understand the evolution of this gene, we analyzed mammalian and primate genomes within a comparative framework. Our analyses revealed that (i) MUC7 has emerged in the placental mammal ancestor and rapidly gained multiple sites for O-glycosylation; (ii) MUC7 has retained its extracellular activity in saliva in placental mammals; (iii) the anti-fungal domain of the protein was remodified under positive selection in the primate lineage; and (iv) MUC7 PTS-repeats have evolved recurrently and under adaptive constraints. Our results establish MUC7 as a major player in salivary adaptation, likely as a response to diverse pathogenic exposure in primates. On a broader scale, our study highlights variable subexonic repeats as a primary source for modular evolutionary innovation that lead to rapid functional adaptation. PMID:27558399

  4. Factors affecting antimicrobial activity of MUC7 12-mer, a human salivary mucin-derived peptide

    PubMed Central

    Wei, Guo-Xian; Campagna, Alexander N; Bobek, Libuse A

    2007-01-01

    Background MUC7 12-mer (RKSYKCLHKRCR), a cationic antimicrobial peptide derived from the human low-molecular-weight salivary mucin MUC7, possesses potent antimicrobial activity in vitro. In order to evaluate the potential therapeutic application of the MUC7 12-mer, we examined the effects of mono- and divalent cations, EDTA, pH, and temperature on its antimicrobial activity. Methods Minimal Inhibitory Concentrations (MICs) were determined using a liquid growth inhibition assay in 96-well microtiter plates. MUC7 12-mer was added at concentrations of 1.56–50 μM. MICs were determined at three endpoints: MIC-0, MIC-1, and MIC-2 (the lowest drug concentration showing 10%, 25% and 50% of growth, respectively). To examine the effect of salts or EDTA, a checkerboard microdilution technique was used. Fractional inhibitory concentration index (FICi) was calculated on the basis of MIC-0. The viability of microbial cells treated with MUC7 12-mer in the presence of sodium or potassium was also determined by killing assay or flow cytometry. Results The MICs of MUC7 12-mer against organisms tested ranged from 6.25–50 μM. For C. albicans, antagonism (FICi 4.5) was observed for the combination of MUC7 12-mer and calcium; however, there was synergism (FICi 0.22) between MUC7 12-mer and EDTA, and the synergism was retained in the presence of calcium at its physiological concentration (1–2 mM). No antagonism but additivity or indifference (FICi 0.55–2.5) was observed for the combination of MUC7 12-mer and each K+, Na+, Mg2+, or Zn2+. MUC7 12-mer peptide (at 25 μM) also exerted killing activity in the presence of NaCl, (up to 25 mM for C. albicans and up to 150 mM for E. coli, a physiological concentration of sodium in the oral cavity and serum, respectively) and retained candidacidal activity in the presence of KCl (up to 40 mM). The peptide exhibited higher inhibitory activity against C. albicans at pH 7, 8, and 9 than at pH 5 and 6, and temperature up to 60°C did not

  5. Reduced Mucin-7 (Muc7) Sialylation and Altered Saliva Rheology in Sjögren's Syndrome Associated Oral Dryness.

    PubMed

    Chaudhury, Nayab M A; Proctor, Gordon B; Karlsson, Niclas G; Carpenter, Guy H; Flowers, Sarah A

    2016-03-01

    Sjögren's syndrome is a chronic autoimmune disorder characterized by lymphocytic infiltration and hypofunction of salivary and lacrimal glands. This loss of salivary function leads to oral dryness, impaired swallowing and speech, and increased infection and is associated with other autoimmune diseases and an increased risk of certain cancers. Despite the implications of this prevalent disease, diagnosis currently takes years, partly due to the diversity in patient presentation. Saliva is a complicated biological fluid with major constituents, including heavily glycosylated mucins MUC5B and MUC7, important for its viscoelastic and hydrating and lubricating properties. This study investigated Sjögren's patient's perception of dryness (bother index questionnaires) along with the rheological, protein composition, and glycan analysis of whole mouth saliva and the saliva on the mucosal surface (residual mucosal saliva) to understand the properties that most affect patient wellbeing. Sjögren's patients exhibited a statistically significant reduction in residual mucosal saliva, salivary flow rate, and extensional rheology, spinnbarkeit (stringiness). Although the concentration of mucins MUC5B and MUC7 were similar between patients and controls, a comparison of protein Western blotting and glycan staining identified a reduction in mucin glycosylation in Sjögren's, particularly on MUC7. LC-MS/MS analysis of O-glycans released from MUC7 by β-elimination revealed that although patients had an increase in core 1 sulfation, the even larger reduction in sialylation resulted in a global decline of charged glycans. This was primarily due to the loss of the extended core 2 disialylated structure, with and without fucosylation. A decrease in the extended, fucosylated core 2 disialylated structure on MUC7, residual mucosal wetness, and whole mouth saliva flow rate appeared to have a negative and cumulative effect on the perception of oral dryness. The observed changes in MUC7

  6. Anti-HIV-1 activity of salivary MUC5B and MUC7 mucins from HIV patients with different CD4 counts

    PubMed Central

    2010-01-01

    Background We have previously shown that MUC5B and MUC7 mucins from saliva of HIV negative individuals inhibit HIV-1 activity by 100% in an in vitro assay. The purpose of this subsequent study was to investigate whether MUC5B and MUC7 from saliva of HIV patients or with full blown AIDS had a similar inhibitory activity against the virus. Methods Salivary MUC5B and MUC7 from HIV patients with different CD4 counts (< 200, 200-400 and > 400) were incubated with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells). Cells were then cultured and viral replication was measured by a qualitative p24 antigen assay. The size, charge and immunoreactivity of mucins from HIV negative and positive individuals was also analysed by SDS-PAGE, Western blot and ELISA respectively. Results It was shown that irrespective of their CD4 counts both MUC5B and MUC7 from HIV patients, unlike the MUC5B and MUC7 from HIV negative individuals, did not inhibit HIV-1 activity. Size, charge and immunoreactivity differences between the mucins from HIV negative and positive individuals and among the mucins from HIV patients of different CD4 count was observed by SDS-PAGE, Western blot and ELISA. Conclusions Purified salivary mucins from HIV positive patients do not inhibit the AIDS virus in an in vitro assay. Although the reason for the inability of mucins from infected individuals to inhibit the virus is not known, it is likely that there is an alteration of the glycosylation pattern, and therefore of charge of mucin, in HIV positive patients. The ability to inhibit the virus by aggregation by sugar chains is thus diminished. PMID:20946627

  7. The role of crude human saliva and purified salivary MUC5B and MUC7 mucins in the inhibition of Human Immunodeficiency Virus type 1 in an inhibition assay

    PubMed Central

    Habte, Habtom H; Mall, Anwar S; de Beer, Corena; Lotz, Zoë E; Kahn, Delawir

    2006-01-01

    Background Despite the continuous shedding of HIV infected blood into the oral cavity and the detectable presence of the AIDS virus at a high frequency, human saliva is reported to inhibit oral transmission of HIV through kissing, dental treatment, biting, and aerosolization. The purpose of this study was to purify salivary MUC5B and MUC7 mucins from crude saliva and determine their anti-HIV-1 activities. Methods Following Sepharose CL-4B column chromatography and caesium chloride isopycnic density-gradient ultra-centrifugation, the purity and identity of the mucins was determined by SDS-PAGE and Western blotting analysis respectively. Subsequently an HIV-1 inhibition assay was carried out to determine the anti-HIV-1 activity of the crude saliva and purified salivary mucins by incubating them with subtype D HIV-1 prior to infection of the CD4+ CEM SS cells. Results Western blotting analysis confirmed that the mucin in the void volume is MUC5B and the mucin in the included volume is MUC7. The HIV inhibition assay revealed that both the crude saliva and salivary MUC5B and MUC7 mucins inhibited HIV-1 activity by 100%. Conclusion Although the mechanism of action is not clear the carbohydrate moieties of the salivary mucins may trap or aggregate the virus and prevent host cell entry. PMID:17125499

  8. Mucin Binding Reduces Colistin Antimicrobial Activity

    PubMed Central

    Huang, Johnny X.; Blaskovich, Mark A. T.; Pelingon, Ruby; Ramu, Soumya; Kavanagh, Angela; Elliott, Alysha G.; Butler, Mark S.

    2015-01-01

    Colistin has found increasing use in treating drug-resistant bacterial lung infections, but potential interactions with pulmonary biomolecules have not been investigated. We postulated that colistin, like aminoglycoside antibiotics, may bind to secretory mucin in sputum or epithelial mucin that lines airways, reducing free drug levels. To test this hypothesis, we measured binding of colistin and other antibiotics to porcine mucin, a family of densely glycosylated proteins used as a surrogate for human sputum and airway mucin. Antibiotics were incubated in dialysis tubing with or without mucin, and concentrations of unbound antibiotics able to penetrate the dialysis tubing were measured over time using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The percentage of antibiotic measured in the dialysate after 4 h in the presence of mucin, relative to the amount without mucin, was 15% for colistin, 16% for polymyxin B, 19% for tobramycin, 52% for ciprofloxacin, and 78% for daptomycin. Antibiotics with the strongest mucin binding had an overall polybasic positive charge, whereas those with comparatively little binding were less basic. When comparing MICs measured with or without added mucin, colistin and polymyxin B showed >100-fold increases in MICs for multiple Gram-negative bacteria. Preclinical evaluation of mucin binding should become a standard procedure when considering the potential pulmonary use of new or existing antibiotics, particularly those with a polybasic overall charge. In the airways, mucin binding may reduce the antibacterial efficacy of inhaled or intravenously administered colistin, and the presence of sub-MIC effective antibiotic concentrations could result in the development of antibiotic resistance. PMID:26169405

  9. Rat and human colonic mucins bind to and inhibit adherence lectin of Entamoeba histolytica.

    PubMed Central

    Chadee, K; Petri, W A; Innes, D J; Ravdin, J I

    1987-01-01

    Establishment of adherence by Entamoeba histolytica is mediated by a 170-kD Gal/GalNAc inhibitable lectin and is required for cytolysis and phagocytosis of mammalian target cells. We studied the biochemical mechanisms of the in vitro interaction between rat and human colonic mucins and axenic E. histolytica trophozoites. Crude mucus prevented amebic adherence to Chinese hamster ovary (CHO) cells by up to 70%. Purification of the colonic mucins by Sepharose 4B chromatography, nuclease digestion, and cesium chloride gradient centrifugation resulted in a 1,000-fold enrichment of the inhibitory mucins. Purified rat mucin inhibited amebic adherence to and cytolysis of homologous rat colonic epithelial cells. Oxidation and enzymatic cleavage of rat mucin Gal and GalNAc residues completely abrogated mucin inhibition of amebic adherence. The binding of rat 125I-mucin to amebae was galactose specific, saturable, reversible, and pH dependent. A monoclonal antibody specific for the 170-kD amebic Gal/GalNAc lectin completely inhibited the binding of rat 125I-mucin. Rat mucin bound to Affigel affinity purified the amebic lectin from conditioned medium. Colonic mucin glycoproteins act as an important host defense by binding to the parasite's adherence lectin, thus preventing amebic attachment to and cytolysis of host epithelial cells. Images PMID:2890655

  10. Adhesion properties of Lactobacillus rhamnosus mucus-binding factor to mucin and extracellular matrix proteins.

    PubMed

    Nishiyama, Keita; Nakamata, Koichi; Ueno, Shintaro; Terao, Akari; Aryantini, Ni Putu Desy; Sujaya, I Nengah; Fukuda, Kenji; Urashima, Tadasu; Yamamoto, Yuji; Mukai, Takao

    2015-01-01

    We previously described potential probiotic Lactobacillus rhamnosus strains, isolated from fermented mare milk produced in Sumbawa Island, Indonesia, which showed high adhesion to porcine colonic mucin (PCM) and extracellular matrix (ECM) proteins. Recently, mucus-binding factor (MBF) was found in the GG strain of L. rhamnosus as a mucin-binding protein. In this study, we assessed the ability of recombinant MBF protein from the FSMM22 strain, one of the isolates of L. rhamnosus from fermented Sumbawa mare milk, to adhere to PCM and ECM proteins by overlay dot blot and Biacore assays. MBF bound to PCM, laminin, collagen IV, and fibronectin with submicromolar dissociation constants. Adhesion of the FSMM22 mbf mutant strain to PCM and ECM proteins was significantly less than that of the wild-type strain. Collectively, these results suggested that MBF contribute to L. rhamnosus host colonization via mucin and ECM protein binding. PMID:25351253

  11. Characterization of Binding of Candida albicans to Small Intestinal Mucin and Its Role in Adherence to Mucosal Epithelial Cells

    PubMed Central

    de Repentigny, Louis; Aumont, Francine; Bernard, Karine; Belhumeur, Pierre

    2000-01-01

    In order to approximate and adhere to mucosal epithelial cells, Candida must traverse the overlying mucus layer. Interactions of Candida species with mucin and human buccal epithelial cells (BECs) were thus investigated in vitro. Binding of the Candida species to purified small intestinal mucin showed a close correlation with their hierarchy of virulence. Significant differences (P < 0.05) were found among three categories of Candida species adhering highly (C. dubliniensis, C. tropicalis, and C. albicans), moderately (C. parapsilosis and C. lusitaniae) or weakly (C. krusei and C. glabrata) to mucin. Adherence of C. albicans to BECs was quantitatively inhibited by graded concentrations of mucin. However, inhibition of adherence was reversed by pretreatment of mucin with pronase or C. albicans secretory aspartyl proteinase Sap2p but not with sodium periodate. Saturable concentration- and time-dependent binding of mucin to C. albicans was abrogated by pronase or Sap2p treatment of mucin but was unaffected by β-mercaptoethanol, sodium periodate, neuraminidase, lectins, or potentially inhibitory sugars. Probing of membrane blots of the mucin with C. albicans revealed binding of the yeast to the 66-kDa cleavage product of the 118-kDa C-terminal glycopeptide of mucin. Although no evidence was found for the participation of C. albicans cell surface mannoproteins in specific receptor-ligand binding to mucin, inhibition of binding by p-nitrophenol (1 mM) and tetramethylurea (0.36 M) revealed that hydrophobic interactions are involved in adherence of C. albicans to mucin. These results suggest that C. albicans may both adhere to and enzymatically degrade mucins by the action of Saps, and that both properties may act to modulate Candida populations in the oral cavity and gastrointestinal tract. PMID:10816460

  12. The levels of Brachyspira hyodysenteriae binding to porcine colonic mucins differ between individuals, and binding is increased to mucins from infected pigs with de novo MUC5AC synthesis.

    PubMed

    Quintana-Hayashi, Macarena P; Mahu, Maxime; De Pauw, Nele; Boyen, Filip; Pasmans, Frank; Martel, An; Premaratne, Pushpa; Fernandez, Harvey R; Teymournejad, Omid; Vande Maele, Lien; Haesebrouck, Freddy; Lindén, Sara K

    2015-04-01

    Brachyspira hyodysenteriae colonizes the pig colon, resulting in mucohemorrhagic diarrhea and growth retardation. Fecal mucus is a characteristic feature of swine dysentery; therefore, we investigated how the mucin environment changes in the colon during infection with B. hyodysenteriae and how these changes affect this bacterium's interaction with mucins. We isolated and characterized mucins, the main component of mucus, from the colon of experimentally inoculated and control pigs and investigated B. hyodysenteriae binding to these mucins. Fluorescence microscopy revealed a massive mucus induction and disorganized mucus structure in the colon of pigs with swine dysentery. Quantitative PCR (qPCR) and antibody detection demonstrated that the mucus composition of pigs with swine dysentery was characterized by de novo expression of MUC5AC and increased expression of MUC2 in the colon. Mucins from the colon of inoculated and control pigs were isolated by two steps of isopycnic density gradient centrifugation. The mucin densities of control and inoculated pigs were similar, whereas the mucin quantity was 5-fold higher during infection. The level of B. hyodysenteriae binding to mucins differed between pigs, and there was increased binding to soluble mucins isolated from pigs with swine dysentery. The ability of B. hyodysenteriae to bind, measured in relation to the total mucin contents of mucus in sick versus healthy pigs, increased 7-fold during infection. Together, the results indicate that B. hyodysenteriae binds to carbohydrate structures on the mucins as these differ between individuals. Furthermore, B. hyodysenteriae infection induces changes to the mucus niche which substantially increase the amount of B. hyodysenteriae binding sites in the mucus. PMID:25644008

  13. Aeromonas salmonicida binds differentially to mucins isolated from skin and intestinal regions of Atlantic salmon in an N-acetylneuraminic acid-dependent manner.

    PubMed

    Padra, János T; Sundh, Henrik; Jin, Chunsheng; Karlsson, Niclas G; Sundell, Kristina; Lindén, Sara K

    2014-12-01

    Aeromonas salmonicida subsp. salmonicida infection, also known as furunculosis disease, is associated with high morbidity and mortality in salmonid aquaculture. The first line of defense the pathogen encounters is the mucus layer, which is predominantly comprised of secreted mucins. Here we isolated and characterized mucins from the skin and intestinal tract of healthy Atlantic salmon and studied how A. salmonicida bound to them. The mucins from the skin, pyloric ceca, and proximal and distal intestine mainly consisted of mucins soluble in chaotropic agents. The mucin density and mucin glycan chain length from the skin were lower than were seen with mucin from the intestinal tract. A. salmonicida bound to the mucins isolated from the intestinal tract to a greater extent than to the skin mucins. The mucins from the intestinal regions had higher levels of sialylation than the skin mucins. Desialylating intestinal mucins decreased A. salmonicida binding, whereas desialylation of skin mucins resulted in complete loss of binding. In line with this, A. salmonicida also bound better to mammalian mucins with high levels of sialylation, and N-acetylneuraminic acid appeared to be the sialic acid whose presence was imperative for binding. Thus, sialylated structures are important for A. salmonicida binding, suggesting a pivotal role for sialylation in mucosal defense. The marked differences in sialylation as well as A. salmonicida binding between the skin and intestinal tract suggest interorgan differences in the host-pathogen interaction and in the mucin defense against A. salmonicida. PMID:25287918

  14. Group A Streptococci Bind to Mucin and Human Pharyngeal Cells through Sialic Acid-Containing Receptors

    PubMed Central

    Ryan, Patricia A.; Pancholi, Vijaykumar; Fischetti, Vincent A.

    2001-01-01

    The first step in the colonization of group A streptococci (Streptococcus pyogenes) is adherence to pharyngeal epithelial cells. Prior to adherence to their target tissue, the first barrier that the streptococci encounter is the mucous layer of the respiratory tract. The present study was undertaken to characterize the interaction between mucin, the major glycoprotein component of mucus, and streptococci. We report here that S. pyogenes is able to bind to bovine submaxillary mucin in solid-phase microtiter plate assays. Western blots probed with 125I-labeled mucin and a panel of monoclonal antibodies revealed that the streptococcal M protein is one of two cell wall-associated proteins responsible for this binding. The binding was further localized to the N-terminal portion of the M molecule. Further analysis revealed that the M protein binds to the sialic acid moieties on mucin, and this interaction seems to be based on M-protein conformation rather than specific amino acid sequences. We found that sialic acid also plays a critical role in the adherence of an M6 streptococcal strain to the Detroit 562 human pharyngeal cell line and have identified α2-6-linked sialic acid as an important sialylated linkage for M-protein recognition. Western blot analysis of extracted pharyngeal cell membrane proteins identified three potential sialic acid-containing receptors for the M protein. The results are the first to show that sialic acid not only is involved in the binding of the streptococci to mucin but also plays an important role in adherence of group A streptococci to the pharyngeal cell surface. PMID:11705914

  15. A Preliminary Study Examining the Binding Capacity of Akkermansia muciniphila and Desulfovibrio spp., to Colonic Mucin in Health and Ulcerative Colitis

    PubMed Central

    Joshi, Lokesh; Carrington, Stephen; Martin, Sean T.; Coffey, J. Calvin; Winter, Desmond C.; O’Connell, P. Ronan

    2015-01-01

    Background Akkermansia muciniphila and Desulfovibrio spp. are commensal microbes colonising the mucus gel layer of the colon. Both species have the capacity to utilise colonic mucin as a substrate. A. muciniphila degrades colonic mucin, while Desulfovibrio spp. metabolise the sulfate moiety of sulfated mucins. Altered abundances of these microorganisms have been reported in ulcerative colitis (UC). However their capacity to bind to human colonic mucin, and whether this binding capacity is affected by changes in mucin associated with UC, remain to be defined. Methods Mucin was isolated from resected colon from control patients undergoing resection for colonic cancer (n = 7) and patients undergoing resection for UC (n = 5). Isolated mucin was purified and printed onto mucin microarrays. Binding of reference strains and three clinical isolates of A. muciniphila and Desulfovibrio spp. to purified mucin was investigated. Results Both A. muciniphila and Desulfovibro spp. bound to mucin. The reference strain and all clinical isolates of A. muciniphila showed increased binding capacity for UC mucin (p < .005). The Desulfovibrio reference strain showed increased affinity for UC mucin. The mucin binding profiles of clinical isolates of Desulfovibrio spp. were specific to each isolate. Two isolates showed no difference in binding. One UC isolate bound with increased affinity to UC mucin (p < .005). Conclusion These preliminary data suggest that differences exist in the mucin binding capacity of isolates of A. muciniphila and Desulfovibrio spp. This study highlights the mucin microarray platform as a means of studying the ability of bacteria to interact with colonic mucin in health and disease. PMID:26491870

  16. Ocular Surface Membrane-Associated Mucins.

    PubMed

    Ablamowicz, Anna F; Nichols, Jason J

    2016-07-01

    Ocular surface epithelial cells produce and secrete mucins that form a hydrophilic barrier for protection and lubrication of the eye. This barrier, the glycocalyx, is formed by high molecular weight heavily glycosylated membrane-associated mucins (MAMs) that include MUC1, MUC4, and MUC16. These mucins extend into the tear film from the anterior surfaces of the conjunctiva and cornea, and, through interactions with galectin-3, prevent penetrance of pathogens into the eye. Due primarily to the glycosylation of the mucins, the glycocalyx also creates less friction during blinking and enables the tear film to maintain wetting of the eye. The secretory mucins include soluble MUC7 and gel-forming MUC5AC. These mucins, particularly MUC5AC, assist with removal of debris from the tear film and contribute to the hydrophilicity of the tear film. While new methodologies and cell culture models have expanded our understanding of mucin structure and function on the ocular surface, there is still a paucity of studies characterizing the glycosylation of MAMs on a normal ocular surface and a diseased ocular surface. Although studies have shown alterations in mucin production and expression in dry eye diseases, the relationship between changes in mucins and functional consequences is unclear. This review focuses on comparing what is known about MAMs in wet-surfaced epithelia of the body to what has been studied on the eye. PMID:27154035

  17. T Cell Immunoglobulin Mucin-3 Crystal Structure Reveals a Galectin-9-Independent Ligand-Binding Surface

    SciTech Connect

    Cao,E.; Zang, X.; Ramagopal, U.; Mukhopadhaya, A.; Fedorov, A.; Fedorov, E.; Zencheck, W.; Lary, J.; Cole, J.; et al.

    2007-01-01

    The T cell immunoglobulin mucin (Tim) family of receptors regulates effector CD4+ T cell functions and is implicated in autoimmune and allergic diseases. Tim-3 induces immunological tolerance, and engagement of the Tim-3 immunoglobulin variable (IgV) domain by galectin-9 is important for appropriate termination of T helper 1-immune responses. The 2 {angstrom} crystal structure of the Tim-3 IgV domain demonstrated that four cysteines, which are invariant within the Tim family, form two noncanonical disulfide bonds, resulting in a surface not present in other immunoglobulin superfamily members. Biochemical and biophysical studies demonstrated that this unique structural feature mediates a previously unidentified galectin-9-independent binding process and suggested that this structural feature is conserved within the entire Tim family. The current work provided a graphic example of the relationship between sequence, structure, and function and suggested that the interplay between multiple Tim-3-binding activities contributes to the regulated assembly of signaling complexes required for effective Th1-mediated immunity.

  18. Cloning, expression and characterization of a mucin-binding GAPDH from Lactobacillus acidophilus.

    PubMed

    Patel, Dhaval K; Shah, Kunal R; Pappachan, Anju; Gupta, Sarita; Singh, Desh Deepak

    2016-10-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a ubiquitous enzyme involved in glycolysis. It is also referred to as a moonlighting protein as it has many diverse functions like regulation of apoptosis, iron homeostasis, cell-matrix interactions, adherence to human colon etc. apart from its principal role in glycolysis. Lactobacilli are lactic acid bacteria which colonize the human gut and confer various health benefits to humans. In the present study, we have cloned, expressed and purified the GAPDH from Lactobacillus acidophilus to get a recombinant product (r-LaGAPDH) and characterized it. Size exclusion chromatography shows that r-LaGAPDH exists as a tetramer in solution and have a mucin binding and hemagglutination activity indicating carbohydrate like binding adhesion mechanism. Fluorescence spectroscopy studies showed an interaction of r-LaGAPDH with mannose, galactose, N-acetylgalactosamine and N-acetylglucosamine with a Kd of 3.6±0.7×10(-3)M, 4.34±0.09×10(-3)M, 4±0.87×10(-3)M and 3.7±0.28×10(-3)M respectively. We hope that this preliminary data will generate more interest in further elucidation of the roles of GAPDH in the adhesion processes of the bacteria. PMID:27180300

  19. Carbohydrate-binding specificities of potential probiotic Lactobacillus strains in porcine jejunal (IPEC-J2) cells and porcine mucin.

    PubMed

    Valeriano, Valerie Diane; Bagon, Bernadette B; Balolong, Marilen P; Kang, Dae-Kyung

    2016-07-01

    Bacterial lectins are carbohydrate-binding adhesins that recognize glycoreceptors in the gut mucus and epithelium of hosts. In this study, the contribution of lectin-like activities to adhesion of Lactobacillus mucosae LM1 and Lactobacillus johnsonii PF01, which were isolated from swine intestine, were compared to those of the commercial probiotic Lactobacillus rhamnosus GG. Both LM1 and PF01 strains have been reported to have good adhesion ability to crude intestinal mucus of pigs. To confirm this, we quantified their adhesion to porcine gastric mucin and intestinal porcine enterocytes isolated from the jejunum of piglets (IPEC-J2). In addition, we examined their carbohydrate-binding specificities by suspending bacterial cells in carbohydrate solutions prior to adhesion assays. We found that the selected carbohydrates affected the adherences of LM1 to IPEC-J2 cells and of LGG to mucin. In addition, compared to adhesion to IPEC-J2 cells, adhesion to mucin by both LM1 and LGG was characterized by enhanced specific recognition of glycoreceptor components such as galactose, mannose, and N-acetylglucosamine. Hydrophobic interactions might make a greater contribution to adhesion of PF01. A similar adhesin profile between a probiotic and a pathogen, suggest a correlation between shared pathogen-probiotic glycoreceptor recognition and the ability to exclude enteropathogens such as Escherichia coli K88 and Salmonella Typhimurium KCCM 40253. These findings extend our understanding of the mechanisms of the intestinal adhesion and pathogen-inhibition abilities of probiotic Lactobacillus strains. PMID:27350617

  20. Muc5ac gastric mucin glycosylation is shaped by FUT2 activity and functionally impacts Helicobacter pylori binding

    PubMed Central

    Magalhães, Ana; Rossez, Yannick; Robbe-Masselot, Catherine; Maes, Emmanuel; Gomes, Joana; Shevtsova, Anna; Bugaytsova, Jeanna; Borén, Thomas; Reis, Celso A.

    2016-01-01

    The gastrointestinal tract is lined by a thick and complex layer of mucus that protects the mucosal epithelium from biochemical and mechanical aggressions. This mucus barrier confers protection against pathogens but also serves as a binding site that supports a sheltered niche of microbial adherence. The carcinogenic bacteria Helicobacter pylori colonize the stomach through binding to host glycans present in the glycocalyx of epithelial cells and extracellular mucus. The secreted MUC5AC mucin is the main component of the gastric mucus layer, and BabA-mediated binding of H. pylori to MUC5AC confers increased risk for overt disease. In this study we unraveled the O-glycosylation profile of Muc5ac from glycoengineered mice models lacking the FUT2 enzyme and therefore mimicking a non-secretor human phenotype. Our results demonstrated that the FUT2 determines the O-glycosylation pattern of Muc5ac, with Fut2 knock-out leading to a marked decrease in α1,2-fucosylated structures and increased expression of the terminal type 1 glycan structure Lewis-a. Importantly, for the first time, we structurally validated the expression of Lewis-a in murine gastric mucosa. Finally, we demonstrated that loss of mucin FUT2-mediated fucosylation impairs gastric mucosal binding of H. pylori BabA adhesin, which is a recognized feature of pathogenicity. PMID:27161092

  1. Pseudomonas aeruginosa pyocyanin modulates mucin glycosylation with sialyl-Lewis(x) to increase binding to airway epithelial cells.

    PubMed

    Jeffries, J L; Jia, J; Choi, W; Choe, S; Miao, J; Xu, Y; Powell, R; Lin, J; Kuang, Z; Gaskins, H R; Lau, G W

    2016-07-01

    Cystic fibrosis (CF) patients battle life-long pulmonary infections with the respiratory pathogen Pseudomonas aeruginosa (PA). An overabundance of mucus in CF airways provides a favorable niche for PA growth. When compared with that of non-CF individuals, mucus of CF airways is enriched in sialyl-Lewis(x), a preferred binding receptor for PA. Notably, the levels of sialyl-Lewis(x) directly correlate with infection severity in CF patients. However, the mechanism by which PA causes increased sialylation remains uncharacterized. In this study, we examined the ability of PA virulence factors to modulate sialyl-Lewis(x) modification in airway mucins. We found pyocyanin (PCN) to be a potent inducer of sialyl-Lewis(x) in both mouse airways and in primary and immortalized CF and non-CF human airway epithelial cells. PCN increased the expression of C2/4GnT and ST3Gal-IV, two of the glycosyltransferases responsible for the stepwise biosynthesis of sialyl-Lewis(x), through a tumor necrosis factor (TNF)-α-mediated phosphoinositol-specific phospholipase C (PI-PLC)-dependent pathway. Furthermore, PA bound more efficiently to airway epithelial cells pre-exposed to PCN in a flagellar cap-dependent manner. Importantly, antibodies against sialyl-Lewis(x) and anti-TNF-α attenuated PA binding. These results indicate that PA secretes PCN to induce a favorable environment for chronic colonization of CF lungs by increasing the glycosylation of airway mucins with sialyl-Lewis(x). PMID:26555707

  2. Pseudomonas aeruginosa pyocyanin modulates mucin glycosylation with sialyl-Lewisx to increase binding to airway epithelial cells

    PubMed Central

    Choi, Woosuk; Choe, Shawn; Miao, Jinfeng; Xu, Ying; Powell, Rebecca; Lin, Jingjun; Kuang, Zhizhou; Gaskins, H Rex; Lau, Gee W.

    2015-01-01

    Cystic fibrosis (CF) patients battle life-long pulmonary infections with the respiratory pathogen Pseudomonas aeruginosa (PA). An overabundance of mucus in CF airways provides a favorable niche for PA growth. When compared to that of non-CF individuals, mucus of CF airways is enriched in sialyl-Lewisx, a preferred binding receptor for PA. Notably, the levels of sialyl-Lewisx directly correlate with infection severity in CF patients. However, the mechanism by which PA causes increased sialylation remains uncharacterized. In this study, we examined the ability of PA virulence factors to modulate sialyl-Lewisx modification in airway mucins. We found pyocyanin (PCN) to be a potent inducer of sialyl-Lewisx in both mouse airways and in primary and immortalized CF and non-CF human airway epithelial cells. PCN increased the expression of C2/4GnT and ST3Gal-IV, two of the glycosyltransferases responsible for the stepwise biosynthesis of sialyl-Lewisx, through a TNF-α-mediated phosphoinositol-specific phospholipase C (PI-PLC) dependent pathway. Furthermore, PA bound more efficiently to airway epithelial cells pre-exposed to PCN through a flagellar cap-dependent manner. Importantly, antibodies against sialyl-Lewisx and anti-TNF-α attenuated PA binding. These results indicate that PCN secretes PCN to induce a favorable environment for chronic colonization of CF lungs by increasing the glycosylation of airway mucins with sialyl-Lewisx. PMID:26555707

  3. Cold-inducible RNA binding protein regulates mucin expression induced by cold temperatures in human airway epithelial cells.

    PubMed

    Ran, DanHua; Chen, LingXiu; Xie, WenYue; Xu, Qing; Han, Zhong; Huang, HuaPing; Zhou, XiangDong

    2016-08-01

    Mucus overproduction is an important manifestation of chronic airway inflammatory diseases, however, the mechanisms underlying the association between cold air and mucus overproduction remain unknown. We found that the expression of the cold-inducible RNA binding protein (CIRP) was increased in patients with chronic obstructive pulmonary disease (COPD). In the present study, we tested whether CIRP was involved in inflammatory factors and mucin5AC (MUC5AC) expression after cold stimulation and investigated the potential signaling pathways involved in this process. We found that CIRP was highly expressed in the bronchi of COPD patients. The expression of CIRP, interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) were increased, and the CIRP was localized in cytoplasm after cold stimulation. MUC5AC mRNA and protein expression levels were elevated in a temperature- and time-dependent manner after cold stimulation and were associated with the phosphorylation of ERK and NF-κB, which reflected their activation. These responses were suppressed by knockdown of CIRP with a specific siRNA or the ERK and NF-κB inhibitors. These results demonstrated that CIRP was expressed in the bronchi of human COPD patients and was involved in inflammatory factors and MUC5AC expression after cold stimulation through the ERK and NF-κB pathways. PMID:27184164

  4. Reorganisation of the salivary mucin network by dietary components: insights from green tea polyphenols.

    PubMed

    Davies, Heather S; Pudney, Paul D A; Georgiades, Pantelis; Waigh, Thomas A; Hodson, Nigel W; Ridley, Caroline E; Blanch, Ewan W; Thornton, David J

    2014-01-01

    The salivary mucins that include MUC5B (gel-forming) and MUC7 (non-gel-forming) are major contributors to the protective mucus barrier in the oral cavity, and it is possible that dietary components may influence barrier properties. We show how one dietary compound, the green tea polyphenol epigallocatechin gallate (EGCG), can substantially alter the properties of both the polymeric MUC5B network and monomeric MUC7. Using rate-zonal centrifugation, MUC5B in human whole saliva and MUC5B purified from saliva sedimented faster in the presence of EGCG. The faster sedimentation by EGCG was shown to be greater with increasing MUC5B concentration. Particle tracking microrheology was employed to determine the viscosity of purified MUC5B solutions and showed that for MUC5B solutions of 200-1600 µg/mL, EGCG caused a significant increase in mucin viscosity, which was greater at higher MUC5B concentrations. Visualisation of the changes to the MUC5B network by EGCG was performed using atomic force microscopy, which demonstrated increased aggregation of MUC5B in a heterogeneous manner by EGCG. Using trypsin-resistant, high-molecular weight oligosaccharide-rich regions of MUC5B and recombinant N-terminal and C-terminal MUC5B proteins, we showed that EGCG causes aggregation at the protein domains of MUC5B, but not at the oligosaccharide-rich regions of the mucin. We also demonstrated that EGCG caused the majority of MUC7 in human whole saliva to aggregate. Furthermore, purified MUC7 also underwent a large increase in sedimentation rate in the presence of EGCG. In contrast, the green tea polyphenol epicatechin caused no change in the sedimentation rate of either MUC5B or MUC7 in human whole saliva. These findings have demonstrated how the properties of the mucin barrier can be influenced by dietary components. In the case of EGCG, these interactions may alter the function of MUC5B as a lubricant, contributing to the astringency (dry puckering sensation) of green tea. PMID:25264771

  5. Human Trefoil Factor 2 Is a Lectin That Binds α-GlcNAc-capped Mucin Glycans with Antibiotic Activity against Helicobacter pylori*

    PubMed Central

    Hanisch, Franz-Georg; Bonar, David; Schloerer, Nils; Schroten, Horst

    2014-01-01

    Helicobacter pylori infection is the major cause of gastric cancer and remains an important health care challenge. The trefoil factor peptides are a family of small highly conserved proteins that are claimed to play essential roles in cytoprotection and epithelial repair within the gastrointestinal tract. H. pylori colocalizes with MUC5AC at the gastric surface epithelium, but not with MUC6 secreted in concert with TFF2 by deep gastric glands. Both components of the gastric gland secretome associate non-covalently and show increased expression upon H. pylori infection. Although blood group active O-glycans of the Lewis-type form the basis of H. pylori adhesion to the surface mucin layer and to epithelial cells, α1,4-GlcNAc-capped O-glycans on gastric mucins were proposed to inhibit H. pylori growth as a natural antibiotic. We show here that the gastric glycoform of TFF2 is a calcium-independent lectin, which binds with high specificity to O-linked α1,4-GlcNAc-capped hexasaccharides on human and porcine stomach mucin. The structural assignments of two hexasaccharide isomers and the binding active glycotope were based on mass spectrometry, linkage analysis, 1H nuclear magnetic resonance spectroscopy, glycan inhibition, and lectin competition of TFF2-mucin binding. Neoglycolipids derived from the C3/C6-linked branches of the two isomers revealed highly specific TFF2 binding to the 6-linked trisaccharide in GlcNAcα1-4Galβ1-4GlcNAcβ1-6(Fucα1-2Galβ1-3)GalNAc-ol(Structure 1). Supposedly, lectin TFF2 is involved in protection of gastric epithelia via a functional relationship to defense against H. pylori launched by antibiotic α1,4-GlcNAc-capped mucin glycans. Lectin-carbohydrate interaction may have also an impact on more general functional aspects of TFF members by mediating their binding to cell signaling receptors. PMID:25124036

  6. Evaluation of the Porcine Gastric Mucin Binding Assay for High-Pressure-Inactivation Studies Using Murine Norovirus and Tulane Virus

    PubMed Central

    Li, Xinhui

    2014-01-01

    We compared the results of high-hydrostatic-pressure (HHP) inactivation of murine norovirus type 1 (MNV-1) and Tulane virus (TV) obtained by a porcine gastric mucin binding assay followed by quantitative reverse transcription-PCR (referred to here as the PGM-MB/PCR assay) and a plaque assay and evaluated HHP inactivation of a human norovirus (HuNoV) genogroup I genotype 1 (GI.1) strain and a HuNoV GII.4 strain by using the PGM-MB/PCR assay. Viruses were treated at different pressure levels for 2 min at 4 or 21°C in culture medium of neutral pH and in culture medium of pH 4 at 21°C. The log reductions of infectious MNV-1 and TV particles caused by HHP were assessed using the PGM-MB/PCR and plaque assays, while the log reductions of HuNoVs were assessed by the PGM-MB/PCR assay only. For TV and MNV-1, the two pressure inactivation curves obtained using the plaque and PGM-MB/PCR assays were almost identical at ≤2-log-reduction levels regardless of the treatment temperature and pH. Further increasing the pressure over the 2-log-reduction level resulted in higher log reductions of TV and MNV-1, as assessed by the plaque assay, but did not increase the log reductions, as assessed by the PGM-MB/PCR assay. HHP treatments could achieve maximum reductions of ∼3 and 3.5 log units for GI.1 and GII.4, respectively, as assessed by the PGM-MB/PCR assay. On the basis of these results, it can reasonably be concluded that the PGM-MB/PCR assay would very likely be able to estimate HHP inactivation of HuNoV at ≤2-log-reduction levels. It would also likely conservatively quantify HHP inactivation of the GI.1 strain at 2- to 3-log-reduction levels and the GII.4 strain at 2- to 3.5-log-reduction levels. PMID:25362063

  7. A Panel of Recombinant Mucins Carrying a Repertoire of Sialylated O-Glycans Based on Different Core Chains for Studies of Glycan Binding Proteins.

    PubMed

    Cherian, Reeja Maria; Jin, Chunsheng; Liu, Jining; Karlsson, Niclas G; Holgersson, Jan

    2015-01-01

    Sialylated glycans serve as key elements of receptors for many viruses, bacteria, and bacterial toxins. The microbial recognition and their binding specificity can be affected by the linkage of the terminal sugar residue, types of underlying sugar chains, and the nature of the entire glycoconjugate. Owing to the pathobiological significance of sialylated glycans, we have engineered Chinese hamster ovary (CHO) cells to secrete mucin-type immunoglobulin-fused proteins carrying terminal α2,3- or α2,6-linked sialic acid on defined O-glycan core saccharide chains. Besides stably expressing P-selectin glycoprotein ligand-1/mouse immunoglobulin G2b cDNA (PSGL-1/mIgG2b), CHO cells were stably transfected with plasmids encoding glycosyltransferases to synthesize core 2 (GCNT1), core 3 (B3GNT6), core 4 (GCNT1 and B3GNT6), or extended core 1 (B3GNT3) chains with or without the type 1 chain-encoding enzyme B3GALT5 and ST6GAL1. Western blot and liquid chromatography-mass spectrometry analysis confirmed the presence of core 1, 2, 3, 4, and extended core 1 chains carrying either type 1 (Galb3GlcNAc) or type 2 (Galb4GlcNAc) outer chains with or without α2,6-linked sialic acids. This panel of recombinant mucins carrying a repertoire of sialylated O-glycans will be important tools in studies aiming at determining the fine O-glycan binding specificity of sialic acid-specific microbial adhesins and mammalian lectins. PMID:26274979

  8. A Panel of Recombinant Mucins Carrying a Repertoire of Sialylated O-Glycans Based on Different Core Chains for Studies of Glycan Binding Proteins

    PubMed Central

    Maria Cherian, Reeja; Jin, Chunsheng; Liu, Jining; Karlsson, Niclas G.; Holgersson, Jan

    2015-01-01

    Sialylated glycans serve as key elements of receptors for many viruses, bacteria, and bacterial toxins. The microbial recognition and their binding specificity can be affected by the linkage of the terminal sugar residue, types of underlying sugar chains, and the nature of the entire glycoconjugate. Owing to the pathobiological significance of sialylated glycans, we have engineered Chinese hamster ovary (CHO) cells to secrete mucin-type immunoglobulin-fused proteins carrying terminal α2,3- or α2,6-linked sialic acid on defined O-glycan core saccharide chains. Besides stably expressing P-selectin glycoprotein ligand-1/mouse immunoglobulin G2b cDNA (PSGL-1/mIgG2b), CHO cells were stably transfected with plasmids encoding glycosyltransferases to synthesize core 2 (GCNT1), core 3 (B3GNT6), core 4 (GCNT1 and B3GNT6), or extended core 1 (B3GNT3) chains with or without the type 1 chain-encoding enzyme B3GALT5 and ST6GAL1. Western blot and liquid chromatography-mass spectrometry analysis confirmed the presence of core 1, 2, 3, 4, and extended core 1 chains carrying either type 1 (Galβ3GlcNAc) or type 2 (Galβ4GlcNAc) outer chains with or without α2,6-linked sialic acids. This panel of recombinant mucins carrying a repertoire of sialylated O-glycans will be important tools in studies aiming at determining the fine O-glycan binding specificity of sialic acid-specific microbial adhesins and mammalian lectins. PMID:26274979

  9. Salivary Mucin 19 Glycoproteins

    PubMed Central

    Culp, David J.; Robinson, Bently; Cash, Melanie N.; Bhattacharyya, Indraneel; Stewart, Carol; Cuadra-Saenz, Giancarlo

    2015-01-01

    Saliva functions in innate immunity of the oral cavity, protecting against demineralization of teeth (i.e. dental caries), a highly prevalent infectious disease associated with Streptococcus mutans, a pathogen also linked to endocarditis and atheromatous plaques. Gel-forming mucins are a major constituent of saliva. Because Muc19 is the dominant salivary gel-forming mucin in mice, we studied Muc19−/− mice for changes in innate immune functions of saliva in interactions with S. mutans. When challenged with S. mutans and a cariogenic diet, total smooth and sulcal surface lesions are more than 2- and 1.6-fold higher in Muc19−/− mice compared with wild type, whereas the severity of lesions are up to 6- and 10-fold higher, respectively. Furthermore, the oral microbiota of Muc19−/− mice display higher levels of indigenous streptococci. Results emphasize the importance of a single salivary constituent in the innate immune functions of saliva. In vitro studies of S. mutans and Muc19 interactions (i.e. adherence, aggregation, and biofilm formation) demonstrate Muc19 poorly aggregates S. mutans. Nonetheless, aggregation is enhanced upon adding Muc19 to saliva from Muc19−/− mice, indicating Muc19 assists in bacterial clearance through formation of heterotypic complexes with salivary constituents that bind S. mutans, thus representing a novel innate immune function for salivary gel-forming mucins. In humans, expression of salivary MUC19 is unclear. We find MUC19 transcripts in salivary glands of seven subjects and demonstrate MUC19 glycoproteins in glandular mucous cells and saliva. Similarities and differences between mice and humans in the expression and functions of salivary gel-forming mucins are discussed. PMID:25512380

  10. Changes in Saliva Rheological Properties and Mucin Glycosylation in Dry Mouth.

    PubMed

    Chaudhury, N M A; Shirlaw, P; Pramanik, R; Carpenter, G H; Proctor, G B

    2015-12-01

    Saliva is vital for the maintenance of normal oral physiology and mucosal health. The loss of salivary function can have far-reaching consequences, as observed with dry mouth, which is associated with increased orodental disease, speech impairment, dysphagia, and a significant negative effect on quality of life. The timely diagnosis of oral dryness is vital for the management of orodental disease and any associated often-undiagnosed systemic disease (e.g., Sjögren syndrome). Our aim was to investigate differences in mucin glycoproteins and saliva rheological properties between sufferers and nonsufferers of dry mouth in order to understand the relationship between saliva composition, rheological properties, and dryness perception and provide additional potential diagnostic markers. All patients exhibited objective and subjective oral dryness, irrespective of etiology. Over half of the patients (n = 20, 58.8%) had a saliva secretion rate above the gland dysfunction cutoff of 0.1 mL/min. Mucin (MUC5B and MUC7) concentrations were generally similar or higher in patients. Despite the abundance of these moisture-retaining proteins, patients exhibited reduced mucosal hydration (wetness) and significantly lower saliva spinnbarkeit (stringiness), suggesting a loss of the lubricating and retention/adhesion properties of saliva, which, at least partially, are associated with mucin glycoproteins. Over 90% of patients with dry mouth (DMPs) consistently had unstimulated whole mouth saliva (UWMS) spinnbarkeit below the proposed normal cutoff (10 mm). Further analysis of mucins revealed the reduced glycosylation of mucins in DMPs compared to healthy controls. Our data indicate that UWMS mucin concentrations are not reduced in dry mouth but that the mucin structure (glycosylation) is altered. UWMS from DMPs had reduced spinnbarkeit, the assessment of which, in conjunction with sialometry, could improve sensitivity for the diagnosis of dry mouth. Additionally, it may be useful to

  11. Structural insights into bacterial recognition of intestinal mucins.

    PubMed

    Etzold, Sabrina; Juge, Nathalie

    2014-10-01

    The mucosal layer covering our gut epithelium represents the first line of host defenses against the luminal content, while enabling contacts between the resident microbiota and the host. Mucus is mainly composed of mucins, large glycoproteins containing a protein core and a high number of O-linked oligosaccharides. Mucin glycans act as binding sites or carbon sources for the intestinal microbes, thereby functioning as a host-specific determinant affecting the microbiota composition and human health. Reflecting the structural diversity of mucin glycans and their prime location, commensal and pathogenic microbes have evolved a range of adhesins allowing their interaction with the host. However, despite the recognised importance of mucin glycans in modulating intestinal homeostasis, information on carbohydrate-binding proteins from gut bacteria is disparate. This review is focussed on recent structural insights into host-microbe interactions mediated by mucins. PMID:25106027

  12. Primary Retroperitoneal Mucinous Cystadenoma

    PubMed Central

    Han, Weon Cheol

    2016-01-01

    Mucinous cystadenomas and cystadenocarcinomas of the ovary are clinically and histopathologically well-established common tumors. However, primary retroperitoneal mucinous cystic tumors are extremely rare, and although their histopathogenesis is still uncertain, several theories have been proposed. Most authors suggest that they develop through mucinous metaplasia in a preexisting mesothelium-lined cyst. An accurate preoperative diagnosis of these tumors is difficult because no effective diagnostic measures have been established. Delay in diagnosis and treatment of this tumor may be fatal for the patient because of complications such as rupture, infection, and malignant transformation. We describe the case of a 31-year-old woman with abdominal pain and a palpable mass. Computed tomography of the abdomen revealed a retroperitoneal cystic mass, which was resected successfully through laparoscopy. Histopathological examination of the resected mass confirmed the diagnosis of a primary retroperitoneal mucinous cystadenoma. The patient was discharged on postoperative day 5 without any complications. PMID:26962534

  13. Chemical modification of carbohydrates in tissue sections may unmask mucin antigens.

    PubMed

    Kirkeby, S

    2013-01-01

    Expression of mucins in cells and tissues is of great diagnostic and prognostic importance, and immunohistochemistry frequently is used to detect them. Reports concerning mucin localization in sections sometimes are conflicting, however, partly because immunogenic regions of the mucin molecule may be masked and thus not available for binding to an antibody. We modified carbohydrates in tissue sections chemically to enhance the binding of monoclonal mucin antibodies and of the lectin, Vicia villosa B4, to human tissue. The immunohistochemical localization of MUC1 and the simple mucin-type antigens, Tn and sialyl-Tn, was influenced by oxidation with periodic acid and by β-elimination before incubation. In some epithelial cells the staining was prevented by these procedures while in other cells it was evident. It appears that chemical modification can either destroy some antigen binding sites or unmask cryptic antigen binding sites in the mucin molecule and thereby make them accessible for immunohistochemical detection. PMID:22998734

  14. Analysis of Candida albicans adhesion to salivary mucin.

    PubMed Central

    Hoffman, M P; Haidaris, C G

    1993-01-01

    Clearance of Candida albicans from the oral cavity is thought to be mediated via specific receptor-ligand interactions between salivary constituents and the fungus. Since surfaces in the oral cavity are normally coated with a saliva-derived pellicle, specific interactions between salivary constituents and C. albicans may also contribute to adhesion of C. albicans to the oral mucosa and dental prostheses. Therefore, the purpose of this study was to identify salivary constituents to which C. albicans is capable of binding. A solid-phase overlay assay was used in which electrophoretically separated rat and human salivary constituents bound to membrane filters were incubated with radiolabelled C. albicans cells. C. albicans adhered to a single salivary component from each host. Correlation of cell-binding activity with specific monoclonal antibody (MAb)-binding activity indicated that the constituent bound by C. albicans in human saliva was low-molecular-weight mucin (MG2) and that in rat saliva was rat submandibular gland (RSMG) mucin. Further studies showed an identical cell hybridization signal and MAb colocalization by using RSMG ductal saliva and an aqueous RSMG extract in the solid-phase overlay assay. Analysis of cell binding to the aqueous extract of RSMG fractionated by anion-exchange chromatography demonstrated that C. albicans binding was restricted to an acidic subfraction of the RSMG extract, which also bound the RSMG mucin-specific MAb. The Candida-binding fraction contained predominantly RSMG mucin glycoprotein and also a noncovalently associated, chloroform-extractable material. Furthermore, we identified two strains of C. albicans which differed severalfold in the ability to bind RSMG mucin in the overlay assay. These results suggest that C. albicans binds to only a specific subfraction of RSMG mucin and that the two C. albicans strains tested differ in the ability to bind RSMG mucin subfractions. Images PMID:8478083

  15. Aggregation of mucin by chromium(III) complexes as revealed by electrokinetic and rheological studies: influence on the tryptic and O-glycanase digestion of mucin.

    PubMed

    Shrivastava, H Yamini; Sreeram, K J; Nair, Balachandran Unni

    2004-04-01

    In the present study, the impact of chromium(III) complexes ([Cr(salen)(H2O)2](+) (1), [Cr(en)3]3+ (2) and [Cr(EDTA)(H2O)]- (3)) on the biophysical properties of mucin like specific viscosity, zeta potential and particle size has been investigated. It is evident from the present investigation that the nature of the coordinated ligand has a major role to play in bringing about the changes in the physical characteristics of the glycoprotein. It was observed that (1) and (3) because of their coordinate mode of binding lead to decrease in the specific viscosity of mucin, whereas (2) on the other hand was found to bring about drastic increase in the mucin viscosity due to sol-gel transition in the mucin conformation. Complex (2) was found to gradually lower the zeta potential value of mucin (particle size=51.5 nm) from -24.8 +/- 1.31 mV to -0.58 +/- 0.30 mV, which reveals aggregation (particle size=216 nm) and subsequent sedimentation of mucin with an increase in the average diameter of mucin particles. The binding of (2) to mucin was found to impart resistance to mucin against both tryptic and O-glycanase digestion, suggesting that, the aggregation of mucin causes conformational as well as configurational changes in the glycoprotein; thus perturbing the location of carbohydrate domains. PMID:14769060

  16. Tear Film Mucins: Front Line Defenders of the Ocular Surface; Comparison with Airway and Gastrointestinal Tract Mucins

    PubMed Central

    Hodges, Robin R.; Dartt, Darlene A.

    2014-01-01

    The ocular surface including the cornea and conjunctiva and its overlying tear film are the first tissues of the eye to interact with the external environment. The tear film is complex containing multiple layers secreted by different glands and tissues. Each layer contains specific molecules and proteins that not only maintain the health of the cells on the ocular surface by providing nourishment and removal of waste products but also protect these cells from environment. A major protective mechanism that the corneal and conjunctival cells have developed is secretion of the innermost layer of the tear film, the mucous layer. Both the cornea and conjunctiva express membrane spanning mucins, whereas the conjunctiva also produces soluble mucins. The mucins present in the tear film serve to maintain the hydration of the ocular surface and to provide lubrication and anti-adhesive properties between the cells of the ocular surface and conjunctiva during the blink. A third function is to contribute to the epithelial barrier to prevent pathogens from binding to the ocular surface. This review will focus on the different types of mucins produced by the corneal and conjunctival epithelia. Also included in this review will be a presentation of the structure of mucins, regulation of mucin production, role of mucins in ocular surface diseases, and the differences in mucin production by the ocular surface, airways and gastrointestinal tract. PMID:23954166

  17. Mucin-Based Vaccines

    NASA Astrophysics Data System (ADS)

    Richardson, Jonathan P.; MacMillan, Derek

    Mucins are heavily O-glycosylated cell surface and secreted glycoproteins . In addition to orchestrating cell-extracellular matrix and cell-cell interactions in healthy organisms mucins are also the major carriers of altered glycosylation in carcinomas. Tumor-associated antigens displayed by cancer cells comprise oligosaccharide and glycopeptide motifs not encountered in the same locale or at the same frequency in healthy cells, and potentially confer a selective advantage to the tumor. Frequently tumor-associated antigens are under-glycosylated and prematurely sialylated, and it is these relatively simple saccharide and glycopeptide structures that have been targeted to serve as drug candidates in most cases. A major goal is to assemble glycopeptide vaccine candidates based on partial mucin sequences and displaying tumor-associated antigens that can mount a potent immunological tumor-specific response when, in reality, the tumor has already coerced the immune system into a state of co-existence.

  18. Macromolecular properties and polymeric structure of canine tracheal mucins.

    PubMed Central

    Shankar, V; Virmani, A K; Naziruddin, B; Sachdev, G P

    1991-01-01

    Two high-Mr mucus glycoproteins (mucins), CTM-A and CTM-B, were highly purified from canine tracheal pouch secretions, and their macromolecular properties as well as polymeric structure were investigated. On SDS/composite-gel electrophoresis, a diffuse band was observed for each mucin. Polyacrylamide-gel electrophoresis using 6% gels also showed the absence of low-Mr contaminants in the mucins. Comparison of chemical and amino acid compositions revealed significant differences between the two mucins. Using a static-laser-light-scattering technique, CTM-A and CTM-B were found to have weight-average Mr values of about 11.0 x 10(6) and 1.4 x 10(6) respectively. Both mucins showed concentration-dependent aggregation in buffer containing 6 M-guanidine hydrochloride. Under similar experimental conditions, reduced-alkylated CTM-A had an Mr of 5.48 x 10(6) and showed no concentration-dependent aggregation. Hydrophobic properties of the mucins, investigated by the fluorescent probe technique using mansylphenylalanine as the probe, showed the presence of a large number of low-affinity (KD approx. 10(5) M) binding sites. These sites appeared to be located on the non-glycosylated regions of the protein core, since Pronase digestion of the mucins almost completely eliminated probe binding. Reduction of disulphide bonds of CTM-A and CTM-B did not significantly alter the probe-binding properties. Also, addition of increasing NaCl concentrations (0.03-1.0 M) to the buffer caused only a small change in the hydrophobic properties of native and reduced-alkylated mucins. CTM-A was deglycosylated, without notable in the hydrophobic properties of native and reduced-alkylated mucins. CTM-A was deglycosylated, without notable degradation, using a combination of chemical and enzymic methods. On SDS/PAGE the protein core was estimated to have an Mr of approx. 60,000. On the basis of the protein and carbohydrate contents of the major mucin CTM-A, the mucin monomer was calculated to have an

  19. A Primary Retroperitoneal Mucinous Tumor

    PubMed Central

    Heelan Gladden, Alicia A.; Wohlauer, Max; McManus, Martine C.; Gajdos, Csaba

    2015-01-01

    A twenty-five-year-old female presented with a large retroperitoneal mass. Workup included history and physical exam, imaging, biopsy, colonoscopy, and gynecologic exam. After surgical resection, the mass was determined to be a primary retroperitoneal mucinous tumor (PRMT). Clinically and histologically, these tumors are similar pancreatic and ovarian mucinous neoplasms. PRMTs are rare and few case reports have been published. PRMTs are divided into mucinous cystadenomas, mucinous borderline tumors of low malignant potential, and mucinous carcinoma. These tumors have malignant potential so resection is indicated and in some cases adjuvant chemotherapy and/or surveillance imaging. PMID:25874152

  20. Mucin-drugs interaction: The case of theophylline, prednisolone and cephalexin.

    PubMed

    Pontremoli, Carlotta; Barbero, Nadia; Viscardi, Guido; Visentin, Sonja

    2015-10-15

    The binding of mucin with three commercially available drugs (theophylline, cephalexin and prednisolone) belonging to different pharmaceutical classes was investigated. The studied drugs are normally used to treat the symptomatology of cystic fibrosis. The interaction between drugs and mucin has been investigated using fluorescence and UV-Vis absorption spectroscopy; quenching mechanism, binding constants, binding sites, thermodynamic parameters and binding distance of the interaction were obtained. PMID:26422788

  1. Detecting, visualising, and quantifying mucins.

    PubMed

    Harrop, Ceri A; Thornton, David J; McGuckin, Michael A

    2012-01-01

    The extreme size, extensive glycosylation, and gel-forming nature of mucins make them a challenge to work with, and methodologies for the detection of mucins must take into consideration these features to ensure that one obtains both accurate and meaningful results. In understanding and appreciating the nature of mucins, this affords the researcher a valuable toolkit which can be used to full advantage in detecting, quantifying, and visualising mucins. The employment of a combinatorial approach to mucin detection, using antibody, chemical, and lectin detection methods, allows important information to be gleaned regarding the size, extent of glycosylation, specific mucin species, and distribution of mucins within a given sample. In this chapter, the researcher is guided through considerations into the structure of mucins and how this both affects the detection of mucins and can be used to full advantage. Techniques including ELISA, dot/slot blotting, and Western blotting, use of lectins and antibodies in mucin detection on membranes as well as immunohistochemistry and immunofluorescence on both tissues and cells grown on Transwell™ inserts are described. Notes along with each section advice the researcher on best practice and describe any associated limitations of a particular technique from which the researcher can further develop a particular protocol. PMID:22259129

  2. Characterization of pig colonic mucins.

    PubMed Central

    Fogg, F J; Hutton, D A; Jumel, K; Pearson, J P; Harding, S E; Allen, A

    1996-01-01

    Pig colonic mucins isolated from the adherent mucus gel in the presence of proteinase inhibitors were solubilized by homogenization and the component mucins fractionated by CsC1 density-gradient centrifugation. Polymeric and reduced pig colonic mucin were both largely excluded on Sepharose CL-2B, papain-digested colonic mucin was included. The M(r) values of polymeric, reduced and digested mucins were 5.5 x 10(6), 2.1 x 10(6) and 0.6 x 10(6) respectively. This suggests that pig colonic mucin is comprised of 2-3 subunits, each subunit containing 3-4 glycosylated regions. The intrinsic viscosities of polymeric, reduced and digested mucin were 240 ml.g-1, 100 ml.g-1 and 20 ml.g-1 respectively. Polymeric pig colonic mucin comprised 16% protein per mg of glycoprotein and was rich in serine, threonine and proline (43% of total amino acids). There were approx. 150 disulphide bridges and 53 free thiol groups per mucin polymer. A seventh of the protein content was lost on reduction. This protein was particularly rich in proline and the hydrophobic amino acids. Papain-digested pig colonic mucin contained 11% protein per mg of glycoprotein and was rich in serine, threonine, glutamate and aspartate. All types of amino acids with the exception of aspartate were lost on digestion. The amino acid analysis of the proteolytically digested regions of pig colonic mucin are markedly different to the tandem repeat regions of the human mucin genes shown to be expressed in the colon. PMID:8670173

  3. Human milk mucin inhibits rotavirus replication and prevents experimental gastroenteritis.

    PubMed Central

    Yolken, R H; Peterson, J A; Vonderfecht, S L; Fouts, E T; Midthun, K; Newburg, D S

    1992-01-01

    Acute gastrointestinal infections due to rotaviruses and other enteric pathogens are major causes of morbidity and mortality in infants and young children throughout the world. Breast-feeding can reduce the rate of serious gastroenteritis in infants; however, the degrees of protection offered against rotavirus infection vary in different populations. The mechanisms associated with milk-mediated protection against viral gastroenteritis have not been fully elucidated. We have isolated a macromolecular component of human milk that inhibits the replication of rotaviruses in tissue culture and prevents the development of gastroenteritis in an animal model system. Purification of the component indicates that the antiviral activity is associated with an acidic fraction (pI = 4.0-4.6), which is free of detectable immunoglobulins. Furthermore, high levels of antiviral activity are associated with an affinity-purified complex of human milk mucin. Deglycosylation of the mucin complex results in the loss of antiviral activity. Further purification indicated that rotavirus specifically binds to the milk mucin complex as well as to the 46-kD glycoprotein component of the complex. Binding to the 46-kD component was substantially reduced after chemical hydrolysis of sialic acid. We have documented that human milk mucin can bind to rotavirus and inhibit viral replication in vitro and in vivo. Variations in milk mucin glycoproteins may be associated with different levels of protection against infection with gastrointestinal pathogens. Images PMID:1331178

  4. Mining the “glycocode”—exploring the spatial distribution of glycans in gastrointestinal mucin using force spectroscopy

    PubMed Central

    Gunning, A. Patrick; Kirby, Andrew R.; Fuell, Christine; Pin, Carmen; Tailford, Louise E.; Juge, Nathalie

    2013-01-01

    Mucins are the main components of the gastrointestinal mucus layer. Mucin glycosylation is critical to most intermolecular and intercellular interactions. However, due to the highly complex and heterogeneous mucin glycan structures, the encoded biological information remains largely encrypted. Here we have developed a methodology based on force spectroscopy to identify biologically accessible glycoepitopes in purified porcine gastric mucin (pPGM) and purified porcine jejunal mucin (pPJM). The binding specificity of lectins Ricinus communis agglutinin I (RCA), peanut (Arachis hypogaea) agglutinin (PNA), Maackia amurensis lectin II (MALII), and Ulex europaeus agglutinin I (UEA) was utilized in force spectroscopy measurements to quantify the affinity and spatial distribution of their cognate sugars at the molecular scale. Binding energy of 4, 1.6, and 26 aJ was determined on pPGM for RCA, PNA, and UEA. Binding was abolished by competition with free ligands, demonstrating the validity of the affinity data. The distributions of the nearest binding site separations estimated the number of binding sites in a 200-nm mucin segment to be 4 for RCA, PNA, and UEA, and 1.8 for MALII. Binding site separations were affected by partial defucosylation of pPGM. Furthermore, we showed that this new approach can resolve differences between gastric and jejunum mucins.—Gunning, A. P., Kirby, A. R., Fuell, C., Pin, C., Tailford L. E., Juge, N. Mining the “glycocode”—exploring the spatial distribution of glycans in gastrointestinal mucin using force spectroscopy. PMID:23493619

  5. Age-related changes in mucins from human whole saliva.

    PubMed

    Denny, P C; Denny, P A; Klauser, D K; Hong, S H; Navazesh, M; Tabak, L A

    1991-10-01

    The predominant mucins in human whole saliva, MG1 and MG2, serve to protect and to lubricate the oral cavity. In this study, both unstimulated and stimulated whole salivas were collected from two groups of subjects: young (18-35 years of age) and aged (65-83 years of age). The subjects were in apparent good health. Saliva samples from each subject were analyzed by SDS-PAGE. The gels were stained with Stains-all, and both MG1 and MG2 were quantitated by video-image densitometry. The protocol gave reproducible values for each mucin. The stimulated and unstimulated salivas from aged subjects showed significant reductions in concentrations of both MG1 and MG2, as quantitated in mucin dye-binding units. Possible associations of these reductions with the aging process are discussed. PMID:1719051

  6. Density variant glycan microarray for evaluating cross-linking of mucin-like glycoconjugates by lectins.

    PubMed

    Godula, Kamil; Bertozzi, Carolyn R

    2012-09-26

    Interactions of mucin glycoproteins with cognate receptors are dictated by the structures and spatial organization of glycans that decorate the mucin polypeptide backbone. The glycan-binding proteins, or lectins, that interact with mucins are often oligomeric receptors with multiple ligand binding domains. In this work, we employed a microarray platform comprising synthetic glycopolymers that emulate natural mucins arrayed at different surface densities to evaluate how glycan valency and spatial separation affect the preferential binding mode of a particular lectin. We evaluated a panel of four lectins (Soybean agglutinin (SBA), Wisteria floribunda lectin (WFL), Vicia villosa-B-4 agglutinin (VVA), and Helix pomatia agglutin (HPA)) with specificity for α-N-acetylgalactosamine (α-GalNAc), an epitope displayed on mucins overexpressed in many adenocarcinomas. While these lectins possess the ability to agglutinate A(1)-blood cells carrying the α-GalNAc epitope and cross-link low valency glycoconjugates, only SBA showed a tendency to form intermolecular cross-links among the arrayed polyvalent mucin mimetics. These results suggest that glycopolymer microarrays can reveal discrete higher-order binding preferences beyond the recognition of individual glycan epitopes. Our findings indicate that glycan valency can set thresholds for cross-linking by lectins. More broadly, well-defined synthetic glycopolymers enable the integration of glycoconjugate structural and spatial diversity in a single microarray screening platform. PMID:22967056

  7. Transmembrane mucins as novel therapeutic targets

    PubMed Central

    Constantinou, Pamela E; Danysh, Brian P; Dharmaraj, Neeraja; Carson, Daniel D

    2011-01-01

    Membrane-tethered mucin glycoproteins are abundantly expressed at the apical surfaces of simple epithelia, where they play important roles in lubricating and protecting tissues from pathogens and enzymatic attack. Notable examples of these mucins are MUC1, MUC4 and MUC16 (also known as cancer antigen 125). In adenocarcinomas, apical mucin restriction is lost and overall expression is often highly increased. High-level mucin expression protects tumors from killing by the host immune system, as well as by chemotherapeutic agents, and affords protection from apoptosis. Mucin expression can increase as the result of gene duplication and/or in response to hormones, cytokines and growth factors prevalent in the tumor milieu. Rises in the normally low levels of mucin fragments in serum have been used as markers of disease, such as tumor burden, for many years. Currently, several approaches are being examined that target mucins for immunization or nanomedicine using mucin-specific antibodies. PMID:22201009

  8. Intestinal Goblet Cells and Mucins in Health and Disease: Recent Insights and Progress

    PubMed Central

    Ho, Samuel B.

    2010-01-01

    The mucus layer coating the gastrointestinal tract is the front line of innate host defense, largely because of the secretory products of intestinal goblet cells. Goblet cells synthesize secretory mucin glycoproteins (MUC2) and bioactive molecules such as epithelial membrane-bound mucins (MUC1, MUC3, MUC17), trefoil factor peptides (TFF), resistin-like molecule β (RELMβ), and Fc-γ binding protein (Fcgbp). The MUC2 mucin protein forms trimers by disulfide bonding in cysteine-rich amino terminal von Willebrand factor (vWF) domains, coupled with crosslinking provided by TFF and Fcgbp proteins with MUC2 vWF domains, resulting in a highly viscous extracellular layer. Colonization by commensal intestinal microbiota is limited to an outer “loose” mucus layer, and interacts with the diverse oligosaccharides of mucin glycoproteins, whereas an “inner” adherent mucus layer is largely devoid of bacteria. Defective mucus layers resulting from lack of MUC2 mucin, mutated Muc2 mucin vWF domains, or from deletion of core mucin glycosyltransferase enzymes in mice result in increased bacterial adhesion to the surface epithelium, increased intestinal permeability, and enhanced susceptibility to colitis caused by dextran sodium sulfate. Changes in mucin gene expression and mucin glycan structures occur in cancers of the intestine, contributing to diverse biologic properties involved in the development and progression of cancer. Further research is needed on identification and functional significance of various components of mucus layers and the complex interactions among mucus layers, microbiota, epithelial cells, and the underlying innate and adaptive immunity. Further elucidation of the regulatory mechanisms involved in mucin changes in cancer and inflammation may lead to the development of novel therapeutic approaches. PMID:20703838

  9. Mucin overproduction in chronic inflammatory lung disease

    PubMed Central

    Hauber, Hans-Peter; Foley, Susan C; Hamid, Qutayba

    2006-01-01

    Mucus overproduction and hypersecretion are commonly observed in chronic inflammatory lung disease. Mucins are gel-forming glycoproteins that can be stimulated by a variety of mediators. The present review addresses the mechanisms involved in the upregulation of secreted mucins. Mucin induction by neutrophil elastase, bacteria, cytokines, growth factors, smoke and cystic fibrosis transmembrane conductance regulator malfunction are also discussed. PMID:16983448

  10. Heterogeneity of airways mucus: variations in the amounts and glycoforms of the major oligomeric mucins MUC5AC and MUC5B.

    PubMed Central

    Kirkham, Sara; Sheehan, John K; Knight, David; Richardson, Paul S; Thornton, David J

    2002-01-01

    Respiratory mucus contains a mixture of gel-forming mucins but the functional significance of these different mucin species is unknown. To help gain a better understanding of mucus in airways we therefore need to ascertain the concentration of each of the gel-forming mucins within respiratory secretions. Thus the aim of this study was to determine the amounts of specific gel-forming mucins directly from solubilized secretions of the airways and purified mucin preparations. We investigated the feasibility of using direct-binding ELISA employing mucin-specific antisera but were unable to obtain reliable data owing to interference with the immobilization of the mucins on the assay surface by 6 M urea and high levels of non-mucin proteins. We therefore developed an alternative approach based on quantitative Western blotting after agarose-gel electrophoresis, which was not subject to these problems. Here we demonstrate that this procedure provides reliable and reproducible data and have employed it to determine the amounts of the MUC2, MUC5AC and MUC5B mucins in saline-induced sputa from healthy airways and spontaneous sputa from asthmatic airways. Additionally we have used this procedure to analyse these glycoproteins in mucin preparations purified from cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) mucus. Our findings indicate that MUC5AC and MUC5B are the major oligomeric mucins and that airways mucus contains variable amounts of these glycoproteins. By contrast, the MUC2 mucin comprised, at most, only 2.5% of the weight of the gel-forming mucins, indicating that MUC2 is a minor component in sputum. Finally, we show that the amounts and glycosylated variants of the MUC5AC and MUC5B mucins can be altered significantly in diseased airways with, for instance, an increase in the low-charge form of the MUC5B mucin in CF and COPD mucus. PMID:11802783

  11. Structure and interactions of human respiratory mucin

    NASA Astrophysics Data System (ADS)

    Purdy, Kirstin; Sheehan, John; Rubinstein, Michael; Wong, Gerard

    2006-03-01

    Human respiratory mucin plays a crucial role in the pathology of Cystic Fibrosis lung infections. Mucin is a flexible, linear polyelectrolyte, characterized by its many charged oligo-carbohydrate side chains that give it its bottle-brush structure. The macroscopic properties of a mucin suspension are known to change drastically with changes in ion concentration and solution pH, but little is known about the effect of these variables on individual mucin structure. We present preliminary results on the structural response of individual human respiratory mucin molecules to variations in concentration of ions of different valences via small angle x-ray diffraction.

  12. Subcellular localization of KL-6 mucin in intraductal papillary mucinous neoplasm of the pancreas.

    PubMed

    Inagaki, Yoshinori; Seyama, Yasuji; Hasegawa, Kiyoshi; Tang, Wei; Kokudo, Norihiro

    2014-08-01

    This study aimed to clarify the expression profile of KL-6 mucin in intraductal papillary mucinous neoplasm (IPMN) and its relation to tumor malignancy. Expression of KL-6 mucin in 38 IPMNs (intraductal papillary mucinous adenoma (IPMA), 24 cases; minimally invasive intraductal papillary mucinous carcinoma (MI-IPMC), 8 cases; invasive carcinoma originating from IPMC (IC-IPMC), 6 cases) and 66 pancreatic ductal adenocarcinomas (PDACs) was evaluated immunohistochemically. IC-IPMCs and MI-IPMCs had positive staining of KL-6 mucin whereas 58% of IPMAs tested negative. Subcellular localization of KL-6 mucin varied among IPMNs whereas all of the PDAC had positive expression in the circumferential membrane and cytoplasm of cancer cells. IC-IPMCs and MI-IPMCs had a higher frequency of circumferential membrane and cytoplasmic localization of KL-6 mucin than did IPMAs. These results suggest that localization of KL-6 mucin could be used to predict the malignancy of IPMN. PMID:25047009

  13. Surface structure of human mucin using X-ray photoelectron spectroscopy.

    PubMed

    Russell, B G; Moddeman, W E; Birkbeck, J C; Wright, S E; Millington, D S; Stevens, R D; Dombrowski, K E

    1998-01-01

    X-ray photoelectron spectroscopy (XPS) is a surface sensitive analytical technique that measures the binding energy of electrons in atoms and molecules on the surface of a material. XPS was used to determine the distribution of the oligosaccharide side chains in the glycoprotein, MUC1 mucin. Low-resolution XPS spectra provided elemental composition of MUC1 mucin (fully glycosylated), mucin polypeptide (nonglycosylated), and carbohydrates found in mucin. The nitrogen content of MUC1 mucin was determined to be intermediate between the mucin polypeptide and the carbohydrates. Assuming a uniform distribution of carbohydrate on MUC1 mucin, the average thickness of the carbohydrate layer was calculated to be 4.9 nm using the low-resolution N 1s signals. High-resolution XPS spectra give detailed information about the chemical bonding of the surface molecules. Calculations based on the high-resolution O 1s spectra showed a carbohydrate thickness of 6.6 nm. These experimentally determined values agree reasonably well with an estimated 5 nm of carbohydrate thickness from a simple model which assume that the core protein is a rodlike molecule approximately 5 nm in diameter. Although the carbohydrate coating on the MUC1 mucin appears to be thick enough to cover the core protein entirely, fully glycosylated breast milk MUC1 mucin is susceptible to proteolytic digestion without removal of any oligosaccharide side chain, suggesting areas of exposed core protein. A possible explanation is that the oligosaccharide side chains may form patches of carbohydrate along the core protein with regions of exposed core protein. PMID:9706384

  14. Complete sequence of the human mucin MUC4: a putative cell membrane-associated mucin.

    PubMed Central

    Moniaux, N; Nollet, S; Porchet, N; Degand, P; Laine, A; Aubert, J P

    1999-01-01

    The MUC4 gene, which encodes a human epithelial mucin, is expressed in various epithelial tissues, just as well in adult as in poorly differentiated cells in the embryo and fetus. Its N-terminus and central sequences have previously been reported as comprising a 27-residue peptide signal, followed by a large domain varying in length from 3285 to 7285 amino acid residues. The present study establishes the whole coding sequence of MUC4 in which the C-terminus is 1156 amino acid residues long and shares a high degree of similarity with the rat sialomucin complex (SMC). SMC is a heterodimeric glycoprotein complex composed of mucin (ascites sialoglycoprotein 1, ASGP-1) and transmembrane (ASGP-2) subunits. The same organization is found in MUC4, where the presence of a GlyAspProHis proteolytic site may cleave the large precursor into two subunits, MUC4alpha and MUC4beta. Like ASGP-2, which binds the receptor tyrosine kinase p185(neu), MUC4beta possesses two epidermal growth factor-like domains, a transmembrane sequence and a potential phosphorylated site. MUC4, the human homologue of rat SMC, may be a heterodimeric bifunctional cell-surface glycoprotein of 2.12 micrometers. These results confer a new biological role for MUC4 as a ligand for ErbB2 in cell signalling. PMID:10024507

  15. Design and expression of a synthetic mucin gene fragment in Escherichia coli.

    PubMed

    Dolby, N; Dombrowski, K E; Wright, S E

    1999-02-01

    Adenocarcinomas of glandular tissues produce a hypoglycosylated form of a normal glycoprotein (mucin) that elicits an immune response. A tumor-specific epitope of mucin occurs in a 20-amino-acid, tandemly repeated domain of human MUC1 mucin. A synthetic gene encoding five tandem repeats of the tumor-specific epitope of human mucin (m5tr) was designed for efficient cloning and expression in Escherichia coli for subsequent use in preparing reagent quantities of the mucin 5 tandem repeat (mtr5) polypeptide. The synthetic gene was cloned in the correct reading frame into the maltose-binding protein (MBP) fusion expression vector pMAL-p2. Bacterial clones containing the mucin synthetic gene (m5tr) were shown to produce the intended recombinant fusion protein, MBP-mtr5. The fusion protein represents a significant fraction of the cell protein, 50% or more of which is secreted into the periplasm. The MBP-mtr5 protein is largely intact and easily prepared in sufficient quantity and purity for preliminary structure-function studies. PMID:10024481

  16. Secretory glycoconjugates of a mucin-synthesizing human colonic adenocarcinoma cell line. Analysis using double labeling with lectins.

    PubMed

    Phillips, T E; Frisch, E B

    1990-01-01

    Lectins were used to characterize mucin glycoproteins and other secretory glycoconjugates synthesized by a human colon adenocarcinoma-derived cell line which expresses a goblet cell phenotype. Despite being clonally derived, HT29-18N2 (N2) cells, like normal goblet cells in situ were heterogeneous in their glycosylation of mucin. Only wheat-germ agglutinin, which recognizes N-acetylglucosamine and sialic acid residues, and succinylated wheatgerm agglutinin, which binds N-acetylglucosamine, stained the contents of all secretory granules in all N2 goblet cells. The N-acetylgalactosamine binding lectins Dolichos biflorus and Glycine max stained 20% and 21% of N2 goblet cells respectively. Ricinus communis I, a galactose-binding lectin, stained 67% of N2 goblet cells although staining by another galactose-binding lectin, Bandeiraea simplicifolia I, was limited to 19%. Peanut agglutinin, a lectin whose Gal(beta 1-3)GalNAc binding site is not present on mucins produced in the normal colon but which is found on most mucins of cancerous colonic epithelia, stained 68% of the cells. Ulex europeus I, a fucose-binding lectin, did not stain any N2 goblet cells. Four lectins (Lens culinaris, Pisum sativum, Phaseolus vulgaris E, Phaseolus vulgaris L) which recognize sugars normally present only in N-linked oligosaccharides stained up to 38% of N2 goblet cells. The binding of these lectins indicates either both O-linked and N-linked oligosaccharide chains are present on the mucin protein backbone or the co-existence of non-mucin N-linked glycoproteins and O-linked mucins within the goblet cell secretory granule. PMID:2312359

  17. Mucin Dynamics in Intestinal Bacterial Infection

    PubMed Central

    Lindén, Sara K.; Florin, Timothy H. J.; McGuckin, Michael A.

    2008-01-01

    Background Bacterial gastroenteritis causes morbidity and mortality in humans worldwide. Murine Citrobacter rodentium infection is a model for gastroenteritis caused by the human pathogens enteropathogenic Escherichia coli and enterohaemorrhagic E. coli. Mucin glycoproteins are the main component of the first barrier that bacteria encounter in the intestinal tract. Methodology/Principal Findings Using Immunohistochemistry, we investigated intestinal expression of mucins (Alcian blue/PAS, Muc1, Muc2, Muc4, Muc5AC, Muc13 and Muc3/17) in healthy and C. rodentium infected mice. The majority of the C. rodentium infected mice developed systemic infection and colitis in the mid and distal colon by day 12. C. rodentium bound to the major secreted mucin, Muc2, in vitro, and high numbers of bacteria were found in secreted MUC2 in infected animals in vivo, indicating that mucins may limit bacterial access to the epithelial surface. In the small intestine, caecum and proximal colon, the mucin expression was similar in infected and non-infected animals. In the distal colonic epithelium, all secreted and cell surface mucins decreased with the exception of the Muc1 cell surface mucin which increased after infection (p<0.05). Similarly, during human infection Salmonella St Paul, Campylobacter jejuni and Clostridium difficile induced MUC1 in the colon. Conclusion Major changes in both the cell-surface and secreted mucins occur in response to intestinal infection. PMID:19088856

  18. An improved lectin-based method for the detection of mucin-type O-glycans in biological samples.

    PubMed

    Lee, Cheng-Siang; Muthusamy, Arivalagan; Abdul-Rahman, Puteri Shafinaz; Bhavanandan, Veer P; Hashim, Onn Haji

    2013-06-21

    Mucins and mucin-type glycoproteins, collectively referred to as mucin-type O-glycans, are implicated in many important biological functions and pathological conditions, including malignancy. Presently, there is no reliable method to measure the total mucin-type O-glycans of a sample, which may contain one or more of these macromolecules of unknown structures. We report the development of an improved microassay that is based on the binding of lectins to the unique and constant GalNAc-Ser/Thr structural feature of mucin-type O-glycans. Since the sugar-amino acid linkage in the mucin-type O-glycans is invariably cryptic, we first chemically removed the heterogeneous peripheral and core saccharides of model glycoconjugates before examining for their interactions using an enzyme-linked lectin assay (ELLA). Desialylation of the model glycoconjugates led to maximal binding of the lectins but additional treatments such as Smith degradation did not result in increased binding. Of the lectins tested for their ability to probe the desialylated O-glycans, jacalin showed the highest sensitivity followed by champedak galactose binding (CGB) lectin and Vicia villosa agglutinin. Further improvement in the sensitivity of ELLA was achieved by using microtiter plates that were pre-coated with the CGB lectin, which increased the specificity of the assay to mucin-type O-glycans. Finally, the applicability of the developed sandwich ELLA to crude samples was demonstrated by estimating trace quantities of the mucin-type O-glycans in the human serum. PMID:23665615

  19. Regulation of Airway Mucin Gene Expression

    PubMed Central

    Thai, Philip; Loukoianov, Artem; Wachi, Shinichiro; Wu, Reen

    2015-01-01

    Mucins are important components that exert a variety of functions in cell-cell interaction, epidermal growth factor receptor signaling, and airways protection. In the conducting airways of the lungs, mucins are the major contributor to the viscoelastic property of mucous secretion, which is the major barrier to trapping inhaled microbial organism, particulates, and oxidative pollutants. The homeostasis of mucin production is an important feature in conducting airways for the maintenance of mucociliary function. Aberrant mucin secretion and accumulation in airway lumen are clinical hallmarks associated with various lung diseases, such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, emphysema, and lung cancer. Among 20 known mucin genes identified, 11 of them have been verified at either the mRNA and/or protein level in airways. The regulation of mucin genes is complicated, as are the mediators and signaling pathways. This review summarizes the current view on the mediators, the signaling pathways, and the transcriptional units that are involved in the regulation of airway mucin gene expression. In addition, we also point out essential features of epigenetic mechanisms for the regulation of these genes. PMID:17961085

  20. Mucins in pancreatic cancer and its microenvironment

    PubMed Central

    Kaur, Sukhwinder; Kumar, Sushil; Momi, Navneet; Sasson, Aaron R.; Batra, Surinder K.

    2014-01-01

    Pancreatic cancer remains a lethal malignancy with poor prognosis owing to therapeutic resistance, frequent recurrence and the absence of treatment strategies that specifically target the tumour and its supporting stroma. Deregulated cell-surface proteins drive neoplastic transformations and are envisioned to mediate crosstalk between the tumour and its microenvironment. Emerging studies have elaborated on the role of mucins in diverse biological functions, including enhanced tumorigenicity, invasiveness, metastasis and drug resistance through their characteristic O-linked and N-linked oligosaccharides (glycans), extended structures and unique domains. Multiple mucin domains differentially interact and regulate different components of the tumour microenvironment. This Review discusses: the expression pattern of various mucins in the pancreas under healthy, inflammatory, and cancerous conditions; the context-dependent attributes of mucins that differ under healthy and pathological conditions; the contribution of the tumour microenvironment in pancreatic cancer development and/or progression; diagnostic and/or prognostic efficacy of mucins; and mucin-based therapeutic strategies. Overall, this information should help to delineate the intricacies of pancreatic cancer by exploring the family of mucins, which, through various mechanisms in both tumour cells and the microenvironment, worsen disease outcome. PMID:23856888

  1. Cervical Mucins Carry α(1,2)Fucosylated Glycans that Partly Protect from Experimental Vaginal Candidiasis

    PubMed Central

    Domino, Steven E.; Hurd, Elizabeth A.; Thomsson, Kristina A.; Karnak, David M.; Holmén Larsson, Jessica M.; Thomsson, Elisabeth; Bäckström, Malin; Hansson, Gunnar C.

    2009-01-01

    Cervical mucins are glycosylated proteins that form a protective cervical mucus. To understand the role of mucin glycans in Candida albicans infection, oligosaccharides from mouse cervical mucins were analyzed by liquid chromatography-mass spectrometry. Cervical mucins carry multiple α(1,2)fucosylated glycans, but α(1,2)fucosyltransferase Fut2-null mice are devoid of these epitopes. Epithelial cells in vaginal lavages from Fut2-null mice lacked Ulex europaeus agglutinin-1 (UEA-I) staining for α(1,2)fucosylated glycans. Hysterectomy to remove cervical mucus eliminated UEA-I and acid mucin staining in vaginal epithelial cells from wild type mice indicating the cervix as the source of UEA-I positive epithelial cells. To assess binding of α(1,2) fucosylated glycans on C. albicans infection, an in vitro adhesion assay was performed with vaginal epithelial cells from wild type and Fut2-null mice. Vaginal epithelial cells from Fut2-null mice were found to bind increased numbers of C. albicans compared to vaginal epithelial cells obtained from wild type mice. Hysterectomy lessened the difference between Fut2-null and wild type mice in binding of C. ablicans in vitro and susceptibility to experimental C. albicans vaginitis in vivo. We generated a recombinant fucosylated MUC1 glycanpolymer to test whether the relative protection of wild type mice compared to Fut2-null mice could be mimicked with exogenous mucin. While a small portion of the recombinant MUC1 epitopes displayed α(1,2)fucosylated glycans, the predominant epitopes were sialylated due to endogenous sialyltransferases in the cultured cells. Intravaginal instillation of recombinant MUC1 glycanpolymer partially reduced experimental yeast vaginitis suggesting that a large glycanpolymer, with different glycan epitopes, may affect fungal burden. PMID:19326211

  2. Cervical mucins carry alpha(1,2)fucosylated glycans that partly protect from experimental vaginal candidiasis.

    PubMed

    Domino, Steven E; Hurd, Elizabeth A; Thomsson, Kristina A; Karnak, David M; Holmén Larsson, Jessica M; Thomsson, Elisabeth; Bäckström, Malin; Hansson, Gunnar C

    2009-12-01

    Cervical mucins are glycosylated proteins that form a protective cervical mucus. To understand the role of mucin glycans in Candida albicans infection, oligosaccharides from mouse cervical mucins were analyzed by liquid chromatography-mass spectrometry. Cervical mucins carry multiple alpha(1-2)fucosylated glycans, but alpha(1,2)fucosyltransferase Fut2-null mice are devoid of these epitopes. Epithelial cells in vaginal lavages from Fut2-null mice lacked Ulex europaeus agglutinin-1 (UEA-I) staining for alpha(1-2)fucosylated glycans. Hysterectomy to remove cervical mucus eliminated UEA-I and acid mucin staining in vaginal epithelial cells from wild type mice indicating the cervix as the source of UEA-I positive epithelial cells. To assess binding of alpha(1-2) fucosylated glycans on C. albicans infection, an in vitro adhesion assay was performed with vaginal epithelial cells from wild type and Fut2-null mice. Vaginal epithelial cells from Fut2-null mice were found to bind increased numbers of C. albicans compared to vaginal epithelial cells obtained from wild type mice. Hysterectomy lessened the difference between Fut2-null and wild type mice in binding of C. ablicans in vitro and susceptibility to experimental C. albicans vaginitis in vivo. We generated a recombinant fucosylated MUC1 glycanpolymer to test whether the relative protection of wild type mice compared to Fut2-null mice could be mimicked with exogenous mucin. While a small portion of the recombinant MUC1 epitopes displayed alpha(1-2)fucosylated glycans, the predominant epitopes were sialylated due to endogenous sialyltransferases in the cultured cells. Intravaginal instillation of recombinant MUC1 glycanpolymer partially reduced experimental yeast vaginitis suggesting that a large glycanpolymer, with different glycan epitopes, may affect fungal burden. PMID:19326211

  3. Biomimetic oral mucin from polymer micelle networks

    NASA Astrophysics Data System (ADS)

    Authimoolam, Sundar Prasanth

    Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated using affinity-based interactions on synthetic and biological surfaces. Unlike conventional polyelectrolyte-based LBL methods, pre-assembled biotin-functionalized filamentous (worm-like) micelles was utilized as the network building block, which from complementary additions of streptavidin generated synthetic networks of desired thickness. The biomimetic nature in those synthetic networks are studied by evaluating its structural and bio-functional properties. Structurally, synthetic networks formed a nanoporous mesh. The networks demonstrated excellent surface hydration property and were able capable of microbial capture. Those functional properties are akin to that of natural mucin networks. Further, the role of synthetic mucin as a drug delivery vehicle, capable of providing localized and tunable release was demonstrated. By incorporating antibacterial curcumin drug loading within synthetic networks, bacterial growth inhibition was also demonstrated. Thus, such bioactive interfaces can serve as a model for independently characterizing mucin network properties and through its role as a drug carrier vehicle it presents exciting future opportunities for localized drug delivery, in regenerative applications and as bio

  4. Identification of Differentially Expressed miRNAs in Appendiceal Mucinous Cystadenocarcinoma from Mucinous Cystadenoma

    PubMed Central

    Wu, Richard Licheng; Ali, Shadan; Sarkar, Fazlul H; Beydoun, Rafic

    2016-01-01

    Objective Mucinous cystadenocarcinoma of appendix is a rare entity. Differentiating mucinous cystadenocarcinoma from mucinous cystadenoma is very challenging and depends on establishing the presence of malignant cells in the appendix wall. The invasion may be very difficult to assess in some cases, especially in early stages of the disease, which could have devastating prognostic effects on patients. Therefore, it is necessary to develop an ancillary test that can differentiate the mucinous cystadenocarcinoma from mucinous cystadenoma. So far, there is no report available about the role of differentially expressed miRNAs in the diagnosis of appendiceal mucinous cystadenocarcinoma. Materials and Methods Six confirmed mucinous appendiceal cystadenocarcinoma and twelve mucinous appendiceal cystadenoma cases were selected. The total RNAs were extracted from the formalin-fixed paraffin-embedded specimen of these cases. The comprehensive miRNA microarray expression profiling from pooled aliquots of RNA samples from these two entities were analyzed to detect the differentially expressed miRNAs in mucinous cystadenocarcinoma. The best seven differentially expressed miRNAs were validated in individual cases by quantitative reverse transcriptase PCR (qRT-PCR). Results The microarray miRNA expression profiling analysis revealed 646 miRNAs that were differentially expressed in the mucinous cystadenocarcinoma. Among these differentially expressed miRNAs, the expression of 80 miRNAs showed statistical difference (p<0.01). The quantitative RT-PCR validated that the expression of miR-1, miR-4328 was significantly down regulated in mucinous cystadenocarcinoma compared to the mucinous cystadenoma (p<0.05). On the other hand, the expression of miR-200b, miR-200c, miR-451, miR-223 and miR-21 were significantly upregulated in mucinous cystadenocarcinoma (p<0.05). Conclusion The expression levels of miRNAs tested were significantly altered in the appendiceal mucinous cystadenocarcinoma

  5. Mucins and Their Sugars. Critical Mediators of Hyperreactivity and Inflammation.

    PubMed

    Raclawska, Dorota S; Ttofali, Fani; Fletcher, Ashley A; Harper, Daniel N; Bochner, Bruce S; Janssen, William J; Evans, Christopher M

    2016-03-01

    Excessive mucus causes severe airflow obstruction in fatal asthma. It is also present in mild to moderate disease, but is poorly understood and treated. Mucus overproduction is associated with dysregulated expression of the mucins MUC5AC and MUC5B. Whereas increased MUC5AC is a consistent finding, MUC5B varies-remaining stably produced in some patients but strongly repressed in others (>90%). Patients with lower MUC5B display worsened asthma phenotypes including airway hyperreactivity (AHR) to methacholine (MCh) and eosinophilic inflammation. To better understand the roles of mucins in asthma, we generated Muc5ac and Muc5b knockout ((-/-)) mice. AHR to MCh was abolished in antigen-challenged Muc5ac(-/-) mice, due to prevention of heterogeneous mucous plugging that occurred in allergic wild-type mice during MCh-induced bronchoconstriction. Thus, in addition to the established role of smooth muscle-mediated airway narrowing, Muc5ac is an essential noncontractile AHR component. We also found that, unlike Muc5ac(-/-) mice, Muc5b-deficient mice were not protected from asthma phenotypes. Furthermore, whereas inflammation was unaffected by Muc5ac deficiency, it was exaggerated in the absence of Muc5b. On the basis of these differential effects, we are now determining how asthma phenotypes are regulated by mucin isoform specificity. Glycosylation is dramatically different: Muc5ac is heavily fucosylated whereas Muc5b is mainly sialylated. Fucosylation increases mucus viscoelasticity, and FUT2, the enzyme that catalyzes mucin α1,2-fucosylation, is associated with severe asthma exacerbation risk. Sialylation is required for binding to siglec (sialic acid-binding immunoglobulin-like lectin) receptors on leukocytes. Eosinophils express Siglec-F (mouse) or Siglec-8 (human). Engagement by sialoside ligands induces eosinophil apoptosis, and Muc5b via sialylated termini that require the α2,3-sialyltransferase ST3Gal3 for synthesis binds Siglec-F and induces apoptosis in mouse

  6. Mucinous Urothelial Carcinoma of the Renal Pelvis

    PubMed Central

    Behzatğlu, Kemal; Boyaci, Ceren; Okçu, Oğuzhan; Hacihasanoğlu, Ezgi; Çakir, Yasemin; Darakçi, Seher

    2014-01-01

    Urothelial carcinoma with abundant myxoid stroma is a newly-described and extremely rare entity. Since only very few cases have been reported, there is no consensus on its nomenclature. Microscopic examination revealed invasive urothelial carcinoma with widespread low-grade noninvasive areas. There were focal invasive areas in the neighborhood of the renal parenchyma. Malignant urothelial tumor/cell groups localized in the stroma had abundant myxoid/mucinous background in the invasive areas. The cytoplasm of the tumoral cells was more eosinophilic in these areas and the cells formed small groups and cords. Histochemically, PAS and Alcian Blue were positive in the cytoplasm of the tumoral cells and in the stroma while negative in the non-mucinous areas. Immunohistochemically, the tumoral cells of the mucinous invasive areas diffusely expressed MUC1 and MUC2. We discuss the origin of the mucinous/myxoid stroma, the tumor’s nature and its nomenclature with histochemical and immunohistochemical features. PMID:25568745

  7. Mouse gastric mucin: cloning and chromosomal localization.

    PubMed Central

    Shekels, L L; Lyftogt, C; Kieliszewski, M; Filie, J D; Kozak, C A; Ho, S B

    1995-01-01

    Mucins protect gastric epithelium by maintaining a favourable pH gradient and preventing autodigestion. The purpose of this study was to clone a mouse gastric mucin which would provide a foundation for analysis of mucin gene regulation. Mucin was purified from the glandular portion of gastric specimens and deglycosylated by HF solvolysis. Antibodies against native and deglycosylated mouse gastric mucin (MGM) were raised in chickens. Screening of a mouse stomach cDNA library with the anti-(deglycosylated MGM) antibody yielded partial clones containing a 48 bp tandem repeat and 768 bp of non-repetitive sequence. The 16-amino-acid tandem repeat has a consensus sequence of QTSSPNTGKTSTISTT with 25% serine and 38% threonine. The MGM tandem repeat sequence bears no similarity to previously identified mucins. The MGM non-repetitive region shares sequence similarity with human MUC5AC and, to a lesser extent, human MUC2 and rat intestinal mucin. Northern blot analysis reveals a polydisperse message beginning at 13.5 kb in mouse stomach with no expression in oesophagus, trachea, small intestine, large intestine, caecum, lung or kidney. Immunoreactivity of antibodies against deglycosylated MGM and against a synthetic MGM tandem repeat peptide was restricted to superficial mucous cells, antral glands and Brunner's glands in the pyloric-duodenal region. DNA analysis shows that MGM recognizes mouse and rat DNA but not hamster, rabbit or human DNA. The MGM gene maps to a site on mouse chromosome 7 homologous to the location of a human secretory mucin gene cluster on human chromosome 11p15. Due to sequence similarity and predominant expression in the stomach, the MGM gene may be considered a MUC5AC homologue and named Muc5ac. Images Figure 1 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:7487932

  8. Direct demonstration of increased expression of Thomsen-Friedenreich (TF) antigen in colonic adenocarcinoma and ulcerative colitis mucin and its concealment in normal mucin.

    PubMed Central

    Campbell, B J; Finnie, I A; Hounsell, E F; Rhodes, J M

    1995-01-01

    Increased binding of the lectin peanut agglutinin is a common feature in epithelial malignancy and hyperplasia. This may have considerable functional importance in the intestine by allowing interaction between the epithelium and mitogenic lectins of dietary or microbial origin. Peanut agglutinin binds the disaccharide Thomsen-Friedenreich (TF, T or core 1) blood group antigen, Gal beta (1-3) GalNAc alpha-, but is not totally specific for this site. Consequently, there has been controversy about the presence of this structure in colon cancer; studies with anti-TF monoclonal antibodies have failed to detect it. We have examined the presence of TF antigen in colonic mucus glycoprotein (mucin) using endo-alpha-N-acetylgalactosaminidase (O-Glycanase), which specifically catalyzes the hydrolysis of TF antigen from glycoconjugates. Samples of adenocarcinoma, inflammatory bowel disease (ulcerative colitis), and normal mucin were treated with O-glycanase, the liberated disaccharide was separated from the glycoprotein and analyzed using dual CarboPac PA-100 column high performance anion-exchange chromatography coupled with pulsed amperometric detection. O-Glycanase treatment released increased amounts of TF antigen from both colonic adenocarcinoma (8.0 +/- 3.9 ng/micrograms protein, n = 11; P < 0.0001 ANOVA) and ulcerative colitis mucin (3.3 +/- 0.3 ng/micrograms protein, n = 5; P = 0.04) compared with mucin samples from histologically normal mucosa distant from carcinoma (1.5 +/- 1.1 ng/micrograms protein, n = 9). However, after mild acid treatment to remove sialic acids and fucose, releasable TF antigen was increased in all nine of these histologically normal mucin samples (5.5 +/- 2.6 ng/micrograms protein, P < 0.0002). We conclude that TF antigen is an oncofetal antigen which is expressed in colon cancer, but is concealed by further glycosylation (sialylation and/or fucosylation) in the normal colonic mucosa. PMID:7860740

  9. Physical Properties of the Glycoprotein Mucin

    NASA Astrophysics Data System (ADS)

    Matthews, Garrett; Davis, William; Superfine, Richard; Boucher, Richard

    2003-03-01

    Epithelial cell surfaces are covered by a protective gel known as mucus. The physiological function of this gel depends on its rheological properties, and these properties are largely derived from the secreted glycoprotein mucin. The genetic disease Cystic Fibrosis (CF) is characterized by the adhesion of thick, viscous mucus on these tissues. In the lungs, this results in the interruption of mucus transport thus compromising the first line of defense against pathogens in these tissues. In order to restore the flow of tracheobronchial mucus out of the body, knowledge of the molecular and physical properties of mucin and mucin solutions would be greatly beneficial. The present model for these molecules is that of a long linear strand consisting of highly glycosylated regions linked by cystein-rich globular regions. It is thought that the globular regions may interact either through intermolecular disulfide bonds or through hydrophobic interactions. It has also been speculated that the glycosylated regions may have lectin-like interactions. In the present work, single mucin molecules were imaged at high resolution using atomic force microscopy (AFM). Phase mode imaging was used to map the interactions between functionalized AFM tips and the molecular topography. Additionally, using force-distance curves with the AFM, the adhesion between mucin bound tips and cell surface glycocalyx and glycocalyx-like model surfaces, was measured. And, finally, the viscoelastic properties of mucin solutions were measured using the recently developed technique, single particle tracking microrheology. A model is being developed that will incorporate the properties of mucins beginning at the single molecule and ending with the bulk viscoelastic properties.

  10. Bovine gall-bladder mucin contains two distinct tandem repeating sequences: evidence for scavenger receptor cysteine-rich repeats.

    PubMed Central

    Nunes, D P; Keates, A C; Afdhal, N H; Offner, G D

    1995-01-01

    Gall-bladder mucin is a densely glycosylated macromolecule which is the primary secretory product of the gall-bladder epithelium. It has been shown to bind cholesterol and other biliary lipids and to promote cholesterol crystal nucleation in vitro. In order to understand the molecular basis for mucin-lipid interactions, bovine gall-bladder mucin cDNAs were identified by expression cloning and were isolated and sequenced. The nucleotide sequences of these cDNAs revealed two distinct tandem repeating domains. One of these domains contained a 20-amino acid tandem repeating sequence enriched in threonine, serine and proline. This sequence was similar to, but not identical with, the short tandem repeating sequences identified previously in other mammalian mucins. The other domain contained a 127-amino acid tandem repeating sequence enriched in cysteine and glycine. This repeat displayed considerable sequence similarity to a family of receptor- and ligand-binding proteins containing scavenger receptor cysteine-rich repeats. By analogy with other proteins containing these cysteine-rich repeats, it is possible that, in gall-bladder mucin, this domain serves as a binding site for hydrophobic ligands such as bilirubin, cholesterol and other biliary lipids. Images Figure 4 Figure 5 Figure 6 PMID:7646470

  11. Regulated Mucin Secretion from Airway Epithelial Cells

    PubMed Central

    Adler, Kenneth B.; Tuvim, Michael J.; Dickey, Burton F.

    2013-01-01

    Secretory epithelial cells of the proximal airways synthesize and secrete gel-forming polymeric mucins. The secreted mucins adsorb water to form mucus that is propelled by neighboring ciliated cells, providing a mobile barrier which removes inhaled particles and pathogens from the lungs. Several features of the intracellular trafficking of mucins make the airway secretory cell an interesting comparator for the cell biology of regulated exocytosis. Polymeric mucins are exceedingly large molecules (up to 3 × 106 Da per monomer) whose folding and initial polymerization in the ER requires the protein disulfide isomerase Agr2. In the Golgi, mucins further polymerize to form chains and possibly branched networks comprising more than 20 monomers. The large size of mucin polymers imposes constraints on their packaging into transport vesicles along the secretory pathway. Sugar side chains account for >70% of the mass of mucins, and their attachment to the protein core by O-glycosylation occurs in the Golgi. Mature polymeric mucins are stored in large secretory granules ∼1 μm in diameter. These are translocated to the apical membrane to be positioned for exocytosis by cooperative interactions among myristoylated alanine-rich C kinase substrate, cysteine string protein, heat shock protein 70, and the cytoskeleton. Mucin granules undergo exocytic fusion with the plasma membrane at a low basal rate and a high stimulated rate. Both rates are mediated by a regulated exocytic mechanism as indicated by phenotypes in both basal and stimulated secretion in mice lacking Munc13-2, a sensor of the second messengers calcium and diacylglycerol (DAG). Basal secretion is induced by low levels of activation of P2Y2 purinergic and A3 adenosine receptors by extracellular ATP released in paracrine fashion and its metabolite adenosine. Stimulated secretion is induced by high levels of the same ligands, and possibly by inflammatory mediators as well. Activated receptors are coupled to

  12. Cross-species immunoreactivity of airway mucin as revealed by monoclonal antibodies directed against mucins from human, hamster, and rat.

    PubMed

    Shin, C Y; Lee, W J; Kim, D J; Park, C S; Choi, E Y; Ko, K H

    2000-10-01

    Airway mucin plays crucial role in host-defense and has been implicated in pathophysiology of various airway diseases including asthma and cystic fibrosis. The analysis of airway mucin has been hampered mostly by the lack of specific and efficient methods for the detection of mucin. Recent production of antibodies against airway mucin from several species and also the development of immunoassay procedures make it more efficient to study the airway mucin. However, the cross-species immunoreactivity of antibodies against airway mucin has not been clearly demonstrated and this prompted us to investigate the cross-species immunoreactivity of monoclonal antibodies against human (HM02), hamster (HTA), and rat airway mucin (RT03), which is three most widely used species in the study of mucin. All the monoclonal antibodies (MAbs) used in this study is IgM isotype and recognizes N-acetyl-galactosamine-linked carbohydrate core or backbone portion of airway mucin. In enzyme-linked immunoadsorbent assay (ELISA), Western blot, immunoprecipitation, and immunohistochemical staining experiments, it was demonstrated that human and hamster airway mucin showed strong cross-species immunoreactivity. However, rat airway mucin did not show any cross-species immunoreactivity against human and hamster airway mucin. Endotoxin-induced secretory cell metaplasia and hence the increase in mucin release from hamster airway mucin could be detected with antibodies against hamster and human airway mucin in vivo and in vitro. However, the same increase from rat airway could only be detected with antibody against rat airway mucin but not with antibodies against human and hamster airway mucin. In addition, the increase in mucin release from asthmatic patients could be detected with antibodies against human and hamster airway mucin but not with the antibody against rat airway mucin. The data from the present study implicates that the carbohydrate chain of human and hamster airway mucin, but not that

  13. Mucinous borderline ovarian tumor with ascites.

    PubMed

    Batool, Tahira; Ullah, Nasreen Rehmat

    2014-11-01

    Borderline mucinous tumors are epithelial ovarian tumors with low rate of growth and low potential to invade or metastasize and associated with significantly better prognosis and excellent disease-free survival after surgical removal than other epithelial ovarian cancers. The accepted initial treatment is surgical removal of the tumor. Fertility-sparing surgery may suffice in young patients with tumors confined to the ovary. Radical surgery is recommended in patients with advanced disease and advanced age. Long-term surveillance is recommended to document and treat late recurrences. We report a case of a 59 years old postmenopausal patient with complex ovarian mucinous tumor and gross ascites; she had received three lines of chemotherapeutic agents pre-operatively, without any favorable outcome. Then, she went for staging laparotomy and histopathology showed borderline ovarian mucinous tumor required no further treatment and is fine till date. PMID:25518783

  14. Mucin 1 Regulates Cox-2 Gene in Pancreatic Cancer

    PubMed Central

    Nath, Sritama; Roy, Lopamudra Das; Grover, Priyanka; Rao, Shanti; Mukherjee, Pinku

    2015-01-01

    Objective Eighty percent of pancreatic ductal adenocarcinomas (PDAs) overexpress mucin 1 (MUC1), a transmembrane mucin glycoprotein. MUC1high PDA patients also express high levels of cyclooxygenase 2 (COX-2) and show poor prognosis. The cytoplasmic tail of MUC1 (MUC1-CT) partakes in oncogenic signaling, resulting in accelerated cancer progression. Our aim was to understand the regulation of Cox-2 expression by MUC1. Methods Levels of COX-2 and MUC1 were determined in MUC1−/−, MUC1low, and MUC1high PDA cells and tumors using reverse transcriptase–polymerase chain reaction, Western blot, and immunohistochemistry. Proliferative and invasive potential was assessed using MTT and Boyden chamber assays. Chromatin immunoprecipitation was performed to evaluate binding of MUC1-CT to the promoter of COX-2 gene. Results Significantly higher levels of COX-2 mRNA and protein were detected in MUC1high versus MUC1low/null cells, which were recapitulated in vivo. In addition, deletion of MUC1 gene and transient knockdown of MUC1 led to decreased COX-2 level. Also, MUC1-CT associated with the COX-2 promoter at ∼1000 base pairs upstream of the transcription start site, the same gene locus where nuclear factor κB p65 associates with the COX-2 promoter. Conclusions Data supports a novel regulation of COX-2 gene by MUC1 in PDA, the intervention of which may lead to a better therapeutic targeting in PDA patients. PMID:26035123

  15. In vitro utilization of mucin by Bacteroides fragilis.

    PubMed Central

    Roberton, A M; Stanley, R A

    1982-01-01

    A method for isolating pig colon mucin in a soluble high-molecular-weight form, suitable for addition to bacterial growth media, is described. This preparation was utilized as a sole carbohydrate energy source by two strains of Bacteroides fragilis. The extent of degradation was compared with that of commercial pig gastric mucin by the same strains. Gas-liquid chromatographic analysis of the mucin carbohydrates and gel chromatography of the preparations were carried out before and after in vitro degradation. The mucin carbohydrates were utilized only to a very limited extent, colon mucin being more resistant to degradation than gastric mucin. Both mucins chromatographed at or near the excluded volume on Sepharose 4B, and only in the case of ATCC 25285 grown on gastric mucin was a significant degradation peak detected. If mucins are degraded in vivo by the sequential action of several bacteria, a pure culture in vitro might be expected to degrade mucins to a limited extent only. Techniques previously used to examine mucin utilization by pure cultures may have overlooked limited mucin degradation demonstrated by the methods used in this work. PMID:6174077

  16. The role of disulphide bonds in human intestinal mucin

    PubMed Central

    Forstner, Janet F.; Jabbal, Inderjit; Qureshi, Rauf; Kells, David I. C.; Forstner, Gordon G.

    1979-01-01

    Goblet-cell mucin (mucin 1) was isolated and purified from human small-intestinal scrapings. After application of mucin 1 to DEAE-Bio-Gel (A) columns, most of the glycoprotein (76–94% of hexoses) was eluted in the first peak (designated mucin 2). Minor amounts of acidic glycoproteins were eluted with 0.2m- and 0.4m-NaCl in later peaks. Analyses of mucin 1 and mucin 2 revealed mucin 2 to be a monodisperse highly glycosylated glycoprotein containing 6.3% by wt. of protein, N-acetylgalactosamine, N-acetylglucosamine, galactose and fucose. Mucin 1 was similar in composition, but was polydisperse and contained more protein (12.3% by wt.) as well as N-acetylneuraminic acid. Analytical CsCl-gradient ultracentrifugation showed both mucin 1 and mucin 2 to have a major component with an average buoyant density of 1.47000g/ml. Mucin 1 also contained a slightly less-dense minor glycoprotein component. After exhaustive reduction and alkylation mucin 1 retained its major component, but partly dissociated into two lighter glycoprotein components. Mucin 2, in contrast, did not change its density distribution after reduction. Band ultracentrifugation in 2H2O-containing iso-osmotic buffers showed that mucin 1 contained a major fast-sedimenting component (so=37±2S), and a minor amount of a slower-sedimenting component. After reduction there was an increased quantity of the latter component, for which an so value of 14.5S was calculated. In contrast, mucin 2 was unaltered by reduction (so=33±2S). These findings indicate that the major component of goblet-cell mucin (mucin 2) does not dissociate after S–S-bond reduction, and thus does not apparently rely for its polymeric structure on the association of subunits through covalent disulphide bonds. However, the effects of reduction on mucin 1 suggest that in the native mucin intramolecular disulphide bonds in the minor glycoproteins may stabilize their structure, permitting secondary non-covalent interactions to develop with the

  17. Assessment of Intracellular Mucin Content In Vivo

    PubMed Central

    Piccotti, Lucia; Dickey, Burton F.

    2013-01-01

    Airway mucus presents a first line of defense against inhaled materials. It also, however, is a significant pathological contributor to chronic lung diseases such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease. Thus, gaining a better understanding of the mechanisms of mucus production and secretion is an important goal for improving respiratory health. Mucins, the chief glycoprotein components of airway mucus, are very large polymeric glycoproteins, and measuring their production and secretion in experimental animals present significant technical challenges. Over the past several years, we have developed assays for accurately quantifying mucin production and secretion using histological and biochemical assays. These methods are described here. PMID:22259143

  18. Identification of O-glycan Structures from Chicken Intestinal Mucins Provides Insight into Campylobactor jejuni Pathogenicity*

    PubMed Central

    Struwe, Weston B.; Gough, Ronan; Gallagher, Mary E.; Kenny, Diarmuid T.; Carrington, Stephen D.; Karlsson, Niclas G.; Rudd, Pauline M.

    2015-01-01

    The Gram-negative bacteria Campylobactor jejuni is the primary bacteria responsible for food poisoning in industrialized countries, and acute diarrheal illness is a leading cause of mortality among children in developing countries. C. jejuni are commensal in chickens. They are particularly abundant in the caecal crypts, and poultry products are commonly infected as a result of cross-contamination during processing. The interactions between C. jejuni and chicken intestinal tissues as well as the pathogenic molecular mechanisms of colonization in humans are unknown, but identifying these factors could provide potential targets to reduce the incidence of campylobacteriosis. Recently, purified chicken intestinal mucin was shown to attenuate adherence and invasion of C. jejuni in the human colorectal adenocarcinoma cell line HCT-8 in vitro, and this effect was attributed to mucin O-glycosylation. Mucins from different regions of the chicken intestine inhibited C. jejuni binding and internalization differentially, with large intestine>small intestine>caecum. Here, we use LC-MS to perform a detailed structural analysis of O-glycans released from mucins purified from chicken large intestine, small intestine, and caecum. The O-glycans identified were abundantly sulfated compared with the human intestines, and sulfate moieties were present throughout the chicken intestinal tract. Interestingly, alpha 1–2 linked fucose residues, which have a high binding affinity to C. jejuni, were identified in the small and large intestines. Additionally, N-glycolylneuraminic/N-acetylneuraminic acid containing structures present as Sda-like epitopes were identified in large intestine samples but not small intestine or caecum. O-glycan structural characterization of chicken intestinal mucins provides insights into adherence and invasion properties of C. jejuni, and may offer prospective candidate molecules aimed at reducing the incidence of infection. PMID:25776888

  19. Salivary mucins in host defense and disease prevention.

    PubMed

    Frenkel, Erica Shapiro; Ribbeck, Katharina

    2015-01-01

    Mucus forms a protective coating on wet epithelial surfaces throughout the body that houses the microbiota and plays a key role in host defense. Mucins, the primary structural components of mucus that creates its viscoelastic properties, are critical components of the gel layer that protect against invading pathogens. Altered mucin production has been implicated in diseases such as ulcerative colitis, asthma, and cystic fibrosis, which highlights the importance of mucins in maintaining homeostasis. Different types of mucins exist throughout the body in various locations such as the gastrointestinal tract, lungs, and female genital tract, but this review will focus on mucins in the oral cavity. Salivary mucin structure, localization within the oral cavity, and defense mechanisms will be discussed. These concepts will then be applied to present what is known about the protective function of mucins in oral diseases such as HIV/AIDS, oral candidiasis, and dental caries. PMID:26701274

  20. Mucins in lung cancer: diagnostic, prognostic, and therapeutic implications.

    PubMed

    Lakshmanan, Imayavaramban; Ponnusamy, Moorthy P; Macha, Muzafar A; Haridas, Dhanya; Majhi, Prabin Dhangada; Kaur, Sukhwinder; Jain, Maneesh; Batra, Surinder K; Ganti, Apar Kishor

    2015-01-01

    Aberrant expression of mucins is associated with cancer development and metastasis. An overexpression of few mucins contributes to oncogenesis by enhancing cancer cell growth and providing constitutive survival signals. This review focuses on the importance of mucins both in the normal bronchial epithelial cells and the malignant tumors of the lung and their contribution in the diagnosis and prognosis of lung cancer patients. During lung cancer progression, mucins either alone or through their interaction with many receptor tyrosine kinases mediate cell signals for growth and survival of cancer cells. Also, stage-specific expression of certain mucins, like MUC1, is associated with poor prognosis from lung cancer. Thus, mucins are emerging as attractive targets for developing novel therapeutic approaches for lung cancer. Several strategies targeting mucin expression and function are currently being investigated to control lung cancer progression. PMID:25319180

  1. Salivary mucins in host defense and disease prevention

    PubMed Central

    Frenkel, Erica Shapiro; Ribbeck, Katharina

    2015-01-01

    Mucus forms a protective coating on wet epithelial surfaces throughout the body that houses the microbiota and plays a key role in host defense. Mucins, the primary structural components of mucus that creates its viscoelastic properties, are critical components of the gel layer that protect against invading pathogens. Altered mucin production has been implicated in diseases such as ulcerative colitis, asthma, and cystic fibrosis, which highlights the importance of mucins in maintaining homeostasis. Different types of mucins exist throughout the body in various locations such as the gastrointestinal tract, lungs, and female genital tract, but this review will focus on mucins in the oral cavity. Salivary mucin structure, localization within the oral cavity, and defense mechanisms will be discussed. These concepts will then be applied to present what is known about the protective function of mucins in oral diseases such as HIV/AIDS, oral candidiasis, and dental caries. PMID:26701274

  2. Quantitative microscopic evaluation of mucin areas and its percentage in mucinous carcinoma of the breast using tissue histological images.

    PubMed

    Saha, Monjoy; Arun, Indu; Basak, Bijan; Agarwal, Sanjit; Ahmed, Rosina; Chatterjee, Sanjoy; Bhargava, Rohit; Chakraborty, Chandan

    2016-06-01

    Mucinous carcinoma (MC) of the breast is very rare (∼1-7% of all breast cancers), invasive ductal carcinoma. Presence of pools of extracellular mucin is one of the most important histological features for MC. This paper aims at developing a quantitative computer-aided methodology for automated identification of mucin areas and its percentage using tissue histological images. The proposed method includes pre-processing (i.e., colour space transformation and colour normalization), mucin regions segmentation, post-processing, and performance evaluation. The proposed algorithm achieved 97.74% segmentation accuracy in comparison to ground truths. In addition, the percentage of mucin present in the tissue regions is calculated by the mucin index (MI) for grading MC (pure, moderately, minimally mucinous). PMID:26971129

  3. Small-Molecule Inhibition of GCNT3 Disrupts Mucin Biosynthesis and Malignant Cellular Behaviors in Pancreatic Cancer.

    PubMed

    Rao, Chinthalapally V; Janakiram, Naveena B; Madka, Venkateshwar; Kumar, Gaurav; Scott, Edgar J; Pathuri, Gopal; Bryant, Taylor; Kutche, Hannah; Zhang, Yuting; Biddick, Laura; Gali, Hariprasad; Zhao, Yan D; Lightfoot, Stan; Mohammed, Altaf

    2016-04-01

    Pancreatic cancer is an aggressive neoplasm with almost uniform lethality and a 5-year survival rate of 7%. Several overexpressed mucins that impede drug delivery to pancreatic tumors have been therapeutically targeted, but enzymes involved in mucin biosynthesis have yet to be preclinically evaluated as potential targets. We used survival data from human patients with pancreatic cancer, next-generation sequencing of genetically engineered Kras-driven mouse pancreatic tumors and human pancreatic cancer cells to identify the novel core mucin-synthesizing enzyme GCNT3 (core 2 β-1,6 N-acetylglucosaminyltransferase). In mouse pancreatic cancer tumors, GCNT3 upregulation (103-fold; P < 0.0001) was correlated with increased expression of mucins (5 to 87-fold; P < 0.04-0.0003). Aberrant GCNT3 expression was also associated with increased mucin production, aggressive tumorigenesis, and reduced patient survival, and CRISPR-mediated knockout of GCNT3 in pancreatic cancer cells reduced proliferation and spheroid formation. Using in silico small molecular docking simulation approaches, we identified talniflumate as a novel inhibitor that selectively binds to GCNT3. In particular, docking predictions suggested that three notable hydrogen bonds between talniflumate and GCNT3 contribute to a docking affinity of -8.3 kcal/mol. Furthermore, talniflumate alone and in combination with low-dose gefitinib reduced GCNT3 expression, leading to the disrupted production of mucins in vivo and in vitro Collectively, our findings suggest that targeting mucin biosynthesis through GCNT3 may improve drug responsiveness, warranting further development and investigation in preclinical models of pancreatic tumorigenesis. Cancer Res; 76(7); 1965-74. ©2016 AACR. PMID:26880801

  4. Differentiation of F4 receptor profiles in pigs based on their mucin 4 polymorphism, responsiveness to oral F4 immunization and in vitro binding of F4 to villi.

    PubMed

    Nguyen, V U; Goetstouwers, T; Coddens, A; Van Poucke, M; Peelman, L; Deforce, D; Melkebeek, V; Cox, E

    2013-03-15

    F4(+) enterotoxigenic Escherichia coli (F4(+) ETEC) are an important cause of diarrhoea and mortality in piglets. F4(+) ETEC use their F4 fimbriae to adhere to specific receptors (F4Rs) on small intestinal brush borders, resulting in colonization of the small intestine. To prevent pigs from post-weaning diarrhoea, pigs should be vaccinated during the suckling period. Previously, we demonstrated that F4acR(+), but not F4acR(-) piglets could be orally immunized with purified F4 fimbriae resulting in a protective immunity against F4(+) ETEC infections, indicating that this immune response was F4R dependent. Recently, aminopeptidase N has been identified as a glycoprotein receptor important for this oral immune response. However, in some oral immunization experiments, a few F4acR(+) piglets did not show an antibody response upon oral immunization, suggesting additional receptors. Therefore, the binding profile of F4 to brush border membrane (glyco)proteins was determined for pigs differing in F4-specific antibody response upon oral immunization, in in vitro adhesion of F4(+)E. coli to small intestinal villi, and in Muc4 genotype. Six groups of pigs could be identified. Only two groups positive in all three assays showed two high molecular weight (MW) glycoprotein bands (>250kDa) suggesting that these high MW bands are linked to the MUC4 susceptible genotype. The fact that these bands were absent in the MUC4 resistant group which showed a positive immune response against F4 and was positive in the adhesion test confirm that at least one or perhaps more other F4Rs exist. Interestingly, two pigs that were positive in the villous adhesion assay did not show an immune response against F4 fimbriae. This suggests that a third receptor category might exist which allows the bacteria to adhere but does not allow effective immunization with soluble F4 fimbriae. Future research will be necessary to confirm or reveal the identity of these receptors. PMID:23084626

  5. Mucin Characteristics of Human Corneal-Limbal Epithelial Cells that Exclude the Rose Bengal Anionic Dye

    PubMed Central

    Argüeso, Pablo; Tisdale, Ann; Spurr-Michaud, Sandra; Sumiyoshi, Mika; Gipson, Ilene K.

    2005-01-01

    Purpose Rose bengal is an organic anionic dye used to assess damage of the ocular surface epithelium in ocular surface disease. It has been proposed that mucins have a protective role, preventing rose bengal staining of normal ocular surface epithelial cells. The current study was undertaken to evaluate rose bengal staining in a human corneal-limbal epithelial (HCLE) cell line known to produce and glycosylate membrane-associated mucins. Methods HCLE cells were grown to confluence in serum-free medium and switched to DMEM/F12 with 10% serum to promote differentiation. Immunolocalization of the membrane-associated mucins MUC1 and MUC16 and the T-antigen carbohydrate epitope was performed with the monoclonal antibodies HMFG-2 and OC125 and jacalin lectin, respectively. To assess dye uptake, cultures were incubated for 5 minutes with 0.1% rose bengal and photographed. To determine whether exclusion of negatively charged rose bengal requires a negative charge at the cell surface, cells were incubated with fluoresceinated cationized ferritin. The effect of hyperosmotic stress on rose bengal staining in vitro was evaluated by increasing the ion concentration (Ca+2 and Mg+2) in the rose bengal uptake assay. Results The cytoplasm and nucleus of confluent HCLE cells cultured in media without serum, lacking the expression of MUC16 but not MUC1, as well as human corneal fibroblasts, which do not express mucins, stained with rose bengal. Culture of HCLE cells in medium containing serum resulted in the formation of islands of stratified cells that excluded rose bengal. Apical cells of the stratified islands produced MUC16 and the T-antigen carbohydrate epitope on their apical surfaces. Colocalization experiments demonstrated that fluoresceinated cationized ferritin did not bind to these stratified cells, indicating that rose bengal is excluded from cells that lack negative charges. Increasing the amounts of divalent cations in the media reduced the cellular area protected

  6. Mucinous ovarian cancer: A therapeutic review.

    PubMed

    Xu, Wen; Rush, Jack; Rickett, Kirsty; Coward, Jermaine I G

    2016-06-01

    Mucinous ovarian cancer represents approximately 3% of epithelial ovarian cancers (EOC). Despite this seemingly low prevalence, it remains a diagnostic and therapeutic conundrum that has resulted in numerous attempts to adopt novel strategies in managing this disease. Anecdotally, there has been a prevailing notion that established gold standard systemic regimens should be substituted for those utilised in cancers such as gastrointestinal (GI) malignancies; tumours that share more biological similarities than other EOC subtypes. This review summarises the plethora of small studies which have adopted this philosophy and influenced the design of the multinational GOG142 study, which was ultimately terminated due to poor accrual. To date, there is a paucity of evidence to support delivering 'GI style' chemotherapy for mucinous ovarian cancer over and above carboplatin-paclitaxel doublet therapy. Hence there is an urge to develop studies focused on targeted therapeutic agents driven by refined mutational analysis and conducted within the context of harmonised international collaborations. PMID:27083591

  7. Folding and Aggregation of Mucin Domains.

    NASA Astrophysics Data System (ADS)

    Urbanc, Brigita; Bansil, Rama; Turner, Bradley

    2007-03-01

    Mucin glycoproteins consist of tandem repeating glycosylated regions flanked by non-repetitive protein domains with little glycosylation. These non-repetitive domains are involved in polymerization of mucin via disulfide bonds and play an important role in the pH dependent gelation of gastric mucin, which is essential to protecting the stomach from autodigestion. We have examined the folding and aggregation of the non-repetitive sequence of von Willebrand factor vWF-C1 domain (67 amino acids) and PGM 2X (242 amino acids) using Discrete Molecular Dynamics (four-bead protein model with hydrogen bonding and amino acid-specific hydrophobic/hydrophilic and electrostatic interactions of side chains). Simulations of vWF C1 show 4-6 β-strands separated by turns/loops with more loops at lower pH. A simulation of several vWF C1 proteins at low pH shows aggregates still with a high content of β-strands and enhanced turn/loop regions. For the PGM 2X simulation the contact map shows several salt bridges enclosing hairpin turns. The implications of these simulations for describing the aggregation/gelation of PGM will be discussed.

  8. Mucin-producing tumors of the ovary: MR imaging appearance.

    PubMed

    Laurent, P-E; Thomassin-Piana, J; Jalaguier-Coudray, A

    2015-11-01

    Mucin-producing tumors of the ovary can be either primary epithelial mucin-producing tumors or ovarian metastases from a remote adenocarcinoma usually originating from the gastrointestinal tract. The purpose of this pictorial review is to describe the main types of primary or secondary mucin-producing tumors of the ovary and to provide MR imaging diagnostic criteria in order to guide further therapy. PMID:25753545

  9. Expression of REG4 in ovarian mucinous tumors.

    PubMed

    Huang, Qiong; Chen, Xiaoduan; Lu, Weiguo; Lai, Maode; Lu, Bingjian

    2014-04-01

    Regenerating islet-deprived gene family, number 4 (REG4), is a novel marker for intestinal differentiation. We performed immunohistochemical studies on REG4, cytokeratin (CK)7, CK20, and caudal type homeobox 2 (CDX2) in 291 ovarian mucinous tumors. There were 226 primary tumors and 65 metastatic tumors. The primary tumors comprised 69/226 mucinous cystadenomas, 79/226 mucinous borderline tumors (64/79 intestinal-type and 15/79 endocervical-like tumors), and 78/226 mucinous carcinomas. We found that REG4 expression was significantly higher in mucinous borderline tumors (30/79, 38.0%) and primary mucinous carcinomas (26/78, 33.3%) than in mucinous cystadenomas (4/69, 5.8%; P<0.05). However, REG4 expression was more commonly associated with intestinal-type, borderline, mucinous tumors rather than the endocervical-like type (30/64 vs. 0/15, P<0.001). There was a significant correlation between the REG4 and CDX2 expression profiles in primary ovarian mucinous tumors (r=0.772, P<0.001). REG4, CDX2, and diffuse CK20 had higher expression frequencies in metastatic lower gastrointestinal adenocarcinoma than in primary mucinous tumors (P<0.01). The CK7/REG4 coordinate expression profile was comparable in diagnostic value to CK7/CK20 or CK7/CDX2 profile. We conclude that REG4 expression is common in mucinous borderline tumors of the intestinal type as it is absent in the endocervical-like form in this series. Expression of CK7/REG4 may contribute to the differential diagnosis between primary and metastatic ovarian mucinous tumors. PMID:23958547

  10. Interaction of extravillous trophoblast galectin-1 and mucin(s)-Is there a functional relevance?

    PubMed

    Bojić-Trbojević, Žanka; Jovanović Krivokuća, Milica; Kolundžić, Nikola; Kadoya, Toshihiko; Radojčić, Ljiljana; Vićovac, Ljiljana

    2016-03-01

    In the course of embryo implantation extensive interaction of the trophoblast with uterine tissue is crucial for adequate trophoblast invasion. This interaction is highly controlled, and it has been pointed out that a specific glycocode and changes in glycosylation may be important for successful implantation and maintenance of pregnancy. Both uterine and trophoblast cells have been shown to express cell surface glycoconjugates and sugar binding proteins, such as mucins (MUC) and galectins (gals). An increasing number of studies have investigated potential candidates interacting in this process. However, knowledge about the biochemical nature of the interactions and their importance for trophoblast cell function, and, consequently, for pregnancy outcome are still lacking. This review is aimed at deliberating the possibility that mucins, as heavily glycosylated proteins, might be among the functionally relevant galectin ligands in human trophoblast, based on both published data and our original research. PMID:26418067

  11. Interaction of cellulose-based cationic polyelectrolytes with mucin.

    PubMed

    Mazoniene, Edita; Joceviciute, Simona; Kazlauske, Jurgita; Niemeyer, Bernd; Liesiene, Jolanta

    2011-03-01

    Mucoadhesivity of water-soluble polymers is an important factor, when testing their suitability for controlled drug delivery systems. For this purpose, the interaction of new cationic cellulose polyelectrolytes with lyophilized mucin was investigated by means of turbidimetric titration, microscopy and measurement of zeta potential and particle size changes in the system. Results show that the cellulose derivatives interact with mucin. This interaction became stronger if cellulose macromolecules contained positively charged groups and an electrostatic interaction with the negatively charged mucin particles occurred. Under certain conditions flocculation of mucin particles by the cellulose polyelectrolyte was observed. PMID:21134731

  12. Pyocyanin-induced mucin production is associated with redox modification of FOXA2

    PubMed Central

    2013-01-01

    Background The redox-active pyocyanin (PCN) is a toxic, secondary metabolite secreted by the respiratory pathogen Pseudomonas aeruginosa (PA). Previously, we have shown that mouse lungs chronically exposed to PCN develop goblet cell hyperplasia and metaplasia (GCHM) and mucus hypersecretion, fibrosis and emphysema. These pathological features are commonly found in the airways of several chronic lung diseases, including cystic fibrosis (CF), as well as in mouse airways deficient in the forkhead box A2 (FOXA2), a transcriptional repressor of goblet GCHM and mucus biosynthesis. Furthermore, PCN inhibits FOXA2 by activating the pro-GCHM signaling pathways Stat6 and EGFR. However, it is not known whether PCN-generated reactive oxygen (ROS) and nitrogen (RNS) species posttranslationally modify and inactivate FOXA2. Methods We examined the posttranslational modifications of FOXA2 by PCN using specific antibodies against oxidation, nitrosylation, acetylation and ubiquitination. Electrophoretic mobility shift assay (EMSA) was used to examine the ability of modified FOXA2 to bind the promoter of MUC5B mucin gene. In addition, we used quantitative real time PCR, ELISA, immunofluorescence and mouse lung infection to assess whether the loss of FOXA2 function caused GCHM and mucin overexpression. Finally, we examined the restoration of FOXA2 function by the antioxidant glutathione (GSH). Results We found that PCN-generated ROS/RNS caused nitrosylation, acetylation, ubiquitination and degradation of FOXA2. Modified FOXA2 had reduced ability to bind the promoter of the MUC5B gene. The antioxidant GSH alleviated the modification of FOXA2 by PCN, and inhibited the overexpression of MUC5AC and MUC5B mucins. Conclusion These results suggest that PCN-mediated posttranslational modifications of FOXA2 are positively correlated with GCHM and overexpression of airway mucins. Furthermore, antioxidant treatment restores the function of FOXA2 to attenuate GCHM and mucus hypersecretion. PMID

  13. FTIR Study On The Secondary Structure Of Mucin From Mucinous Cystadenoma Of The Ovary

    NASA Astrophysics Data System (ADS)

    Shen, Keng; Wu, Paochen; Zhou, Weij in; Liu, Fuan; Guo, Hai; Wu, Jinguang

    1989-12-01

    The mucinous cystadenoma, a common benign neoplasm of the ovary, may sometime bring about a fatal outcome known as pseudomyxoma peritonei which is characterized by massive accumulation of mucinous substance in the peritoneal cavity, resulting in extensive adhesions, chronic progressive intestinal obstruction and finally death of the patient. Surgical approach to this condition proves to be a palliative procedure. Repeated operation can only remove part of the geletinous material and reaccumulation of mucus within 1-2 years after the initial surgery is almost a rule. In view of the benign histologic nature of the disease, chemotherapy, either systemic or intraperitoneal, and radiotherapy are generally ineffective in arresting the progression of the pathologic process and preventing the reaccumulation of mucus. Therefore, the only hope lies on the introduction into the peritoneal cavity some agents which may dissolve the accumulated mucin, relieve the intestinal obstruction, and consequently, prolong and even save the life f the patient. Based on this conception, sporadic articles by a few authors(1,2)ap-peared in the literature reporting their clinical experience with different mucolytic agents. However, some blindness would inevitably be involved in such investigations due to the lack of a comprehensive understanding of the chemical structures of the substance. The purpose of the present paper is to report our preliminary results of study of the secondary structures of mucin secreted by this special type of tumor.

  14. Frequent GNAS mutations in low-grade appendiceal mucinous neoplasms

    PubMed Central

    Nishikawa, G; Sekine, S; Ogawa, R; Matsubara, A; Mori, T; Taniguchi, H; Kushima, R; Hiraoka, N; Tsuta, K; Tsuda, H; Kanai, Y

    2013-01-01

    Background: The molecular basis for the development of appendiceal mucinous tumours, which can be a cause of pseudomyxoma peritonei, remains largely unknown. Methods: Thirty-five appendiceal mucinous neoplasms were analysed for GNAS and KRAS mutations. A functional analysis of mutant GNAS was performed using a colorectal cancer cell line. Results: A mutational analysis identified activating GNAS mutations in 16 of 32 low-grade appendiceal mucinous neoplasms (LAMNs) but in none of three mucinous adenocarcinomas (MACs). KRAS mutations were found in 30 LAMNs and in all MACs. We additionally analysed a total of 186 extra-appendiceal mucinous tumours and found that GNAS mutations were highly prevalent in intraductal papillary mucinous tumours of the pancreas (88%) but were rare or absent in mucinous tumours of the colorectum, ovary, lung and breast (0–9%). The prevalence of KRAS mutations was quite variable among the tumours. The introduction of the mutant GNAS into a colorectal cancer cell line markedly induced MUC2 and MUC5AC expression, but did not promote cell growth either in vitro or in vivo. Conclusion: Activating GNAS mutations are a frequent and characteristic genetic abnormality of LAMN. Mutant GNAS might play a direct role in the prominent mucin production that is a hallmark of LAMN. PMID:23403822

  15. Heterogeneity and persistence length in human ocular mucins.

    PubMed Central

    Round, A N; Berry, M; McMaster, T J; Stoll, S; Gowers, D; Corfield, A P; Miles, M J

    2002-01-01

    Atomic force microscopy (AFM) has been used to investigate the heterogeneity and flexibility of human ocular mucins and their subunits. We have paid particular attention, in terms of theory and experiment, to the problem of inducing the polymers to assume equilibrium conformations at a surface. Mucins deposited from a buffer containing Ni(2+) ions adopt extended conformations on mica akin to those observed for DNA under similar conditions. The heterogeneity of the intracellular native mucins is evident from a histogram of contour lengths, reflecting, in part, the diversity of mucin gene products expressed. Reduction of the native mucin with dithiothreitol, thereby breaking the S==S bonds between cysteine residues, causes a marked reduction in polymer length. These results reflect the modes of transport and assembly of newly synthesized mucins in vivo. By modifying the worm-like chain model for applicability to two dimensions, we have confirmed that under the conditions employed mucin adsorbs to mica in an equilibrated conformation. The determined persistence length of the native mucin, 36 nm, is consistent with that of an extended, flexible polymer; such characteristics will influence the properties of the gels formed in vivo. PMID:12202389

  16. Intestinal mucins from normal subjects and patients with cystic fibrosis. Variable contents of the disulphide-bound 118 kDa glycoprotein and different reactivities with an anti-(118 kDa glycoprotein) antibody.

    PubMed Central

    Mantle, M; Stewart, G

    1989-01-01

    1. A specific antibody was developed against the disulphide-bound 118 kDa glycoprotein of human intestinal mucin and used to establish an e.l.i.s.a. Fourteen purified mucins [eight normal (N) and six cystic fibrosis (CF)] had the same affinity for the antibody in the e.l.i.s.a., but their relative immunoreactivities varied widely (approx. 100,000-fold). In general, CF mucins were more antigenic than N mucins. 2. Variations (approx. 10-fold) were detected in the 118 kDa glycoprotein content of both N and CF mucins (assessed from Coomassie Blue-stained polyacrylamide gels), but these did not appear to be responsible for the differences in mucin immunoreactivity. 3. Variations (approx. 6-fold) were also observed in the size of the 118 kDa peak produced by N and CF mucins on Western blots. These were mostly due to differences in the 118 kDa glycoprotein content of mucins, although a small proportion resulted from changes in the number of antigenic determinants within individual 118 kDa glycoproteins. 4. After concanavalin A affinity chromatography of four reduced mucins (two N and two CF), purified 118 kDa glycoprotein was recovered in the bound fractions from the column, specifically eluted by methyl alpha-mannoside. 5. The amounts of 118 kDa glycoprotein isolated from the four mucins varied as predicted from the size of their 118 kDa bands on Coomassie Blue-stained gels. 6. Three 118 kDa glycoproteins (one N and two CF) showed almost identical reactivity in the e.l.i.s.a.; the fourth had fewer antigenic determinants. 7. Since differences in 118 kDa glycoprotein content and in the number of antigenic determinants within the 118 kDa glycoprotein did not account for variations in the reactivity of native mucins in the e.l.i.s.a., it appeared that accessibility of the 118 kDa glycoprotein to antibody binding may be critical in determining mucin immunoreactivity. This suggests that the three-dimensional conformation of CF mucins may differ from that of N mucins, leading

  17. Altered Mucins (MUC) Trafficking in Benign and Malignant Conditions

    PubMed Central

    Joshi, Suhasini; Kumar, Sushil; Choudhury, Amit; Ponnusamy, Moorthy P.; Batra, Surinder K.

    2014-01-01

    Mucins are high molecular weight O-glycoproteins that are predominantly expressed at the apical surface of epithelial cells and have wide range of functions. The functional diversity is attributed to their structure that comprises of a peptide chain with unique domains and multiple carbohydrate moieties added during posttranslational modifications. Tumor cells aberrantly overexpress mucins, and thereby promote proliferation, differentiation, motility, invasion and metastasis. Along with their aberrant expression, accumulating evidence suggest the critical role of altered subcellular localization of mucins under pathological conditions due to altered endocytic processes. The mislocalization of mucins and their interactions result in change in the density and activity of important cell membrane proteins (like, receptor tyrosine kinases) to facilitate various signaling, which help cancer cells to proliferate, survive and progress to more aggressive phenotype. In this review article, we summarize studies on mucins trafficking and provide a perspective on its importance to pathological conditions and to answer critical questions including its use for therapeutic interventions. PMID:25261375

  18. Caenorhabditis elegans Bacterial Pathogen Resistant bus-4 Mutants Produce Altered Mucins

    PubMed Central

    Parsons, Lisa M.; Mizanur, Rahman M.; Jankowska, Ewa; Hodgkin, Jonathan; O′Rourke, Delia; Stroud, Dave; Ghosh, Salil; Cipollo, John F.

    2014-01-01

    Caenorabditis elegans bus-4 glycosyltransferase mutants are resistant to infection by Microbacterium nematophilum, Yersinia pestis and Yersinia pseudotuberculosis and have altered susceptibility to two Leucobacter species Verde1 and Verde2. Our objective in this study was to define the glycosylation changes leading to this phenotype to better understand how these changes lead to pathogen resistance. We performed MALDI-TOF MS, tandem MS and GC/MS experiments to reveal fine structural detail for the bus-4 N- and O-glycan pools. We observed dramatic changes in O-glycans and moderate ones in N-glycan pools compared to the parent strain. Ce core-I glycans, the nematode's mucin glycan equivalent, were doubled in abundance, halved in charge and bore shifts in terminal substitutions. The fucosyl O-glycans, Ce core-II and neutral fucosyl forms, were also increased in abundance as were fucosyl N-glycans. Quantitative expression analysis revealed that two mucins, let-653 and osm-8, were upregulated nearly 40 fold and also revealed was a dramatic increase in GDP-Man 4,6 dehydratease expression. We performed detailed lectin binding studies that showed changes in glycoconjugates in the surface coat, cuticle surface and intestine. The combined changes in cell surface glycoconjugate distribution, increased abundance and altered properties of mucin provide an environment where likely the above pathogens are not exposed to normal glycoconjugate dependent cues leading to barriers to these bacterial infections. PMID:25296196

  19. FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection.

    PubMed

    Kerr, Sheena C; Fischer, Gregory J; Sinha, Meenal; McCabe, Orla; Palmer, Jonathan M; Choera, Tsokyi; Lim, Fang Yun; Wimmerova, Michaela; Carrington, Stephen D; Yuan, Shaopeng; Lowell, Clifford A; Oscarson, Stefan; Keller, Nancy P; Fahy, John V

    2016-04-01

    The immune mechanisms that recognize inhaled Aspergillus fumigatus conidia to promote their elimination from the lungs are incompletely understood. FleA is a lectin expressed by Aspergillus fumigatus that has twelve binding sites for fucosylated structures that are abundant in the glycan coats of multiple plant and animal proteins. The role of FleA is unknown: it could bind fucose in decomposed plant matter to allow Aspergillus fumigatus to thrive in soil, or it may be a virulence factor that binds fucose in lung glycoproteins to cause Aspergillus fumigatus pneumonia. Our studies show that FleA protein and Aspergillus fumigatus conidia bind avidly to purified lung mucin glycoproteins in a fucose-dependent manner. In addition, FleA binds strongly to macrophage cell surface proteins, and macrophages bind and phagocytose fleA-deficient (∆fleA) conidia much less efficiently than wild type (WT) conidia. Furthermore, a potent fucopyranoside glycomimetic inhibitor of FleA inhibits binding and phagocytosis of WT conidia by macrophages, confirming the specific role of fucose binding in macrophage recognition of WT conidia. Finally, mice infected with ΔfleA conidia had more severe pneumonia and invasive aspergillosis than mice infected with WT conidia. These findings demonstrate that FleA is not a virulence factor for Aspergillus fumigatus. Instead, host recognition of FleA is a critical step in mechanisms of mucin binding, mucociliary clearance, and macrophage killing that prevent Aspergillus fumigatus pneumonia. PMID:27058347

  20. FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection

    PubMed Central

    Sinha, Meenal; McCabe, Orla; Palmer, Jonathan M.; Choera, Tsokyi; Yun Lim, Fang; Wimmerova, Michaela; Carrington, Stephen D.; Yuan, Shaopeng; Lowell, Clifford A.; Oscarson, Stefan; Keller, Nancy P.; Fahy, John V.

    2016-01-01

    The immune mechanisms that recognize inhaled Aspergillus fumigatus conidia to promote their elimination from the lungs are incompletely understood. FleA is a lectin expressed by Aspergillus fumigatus that has twelve binding sites for fucosylated structures that are abundant in the glycan coats of multiple plant and animal proteins. The role of FleA is unknown: it could bind fucose in decomposed plant matter to allow Aspergillus fumigatus to thrive in soil, or it may be a virulence factor that binds fucose in lung glycoproteins to cause Aspergillus fumigatus pneumonia. Our studies show that FleA protein and Aspergillus fumigatus conidia bind avidly to purified lung mucin glycoproteins in a fucose-dependent manner. In addition, FleA binds strongly to macrophage cell surface proteins, and macrophages bind and phagocytose fleA-deficient (∆fleA) conidia much less efficiently than wild type (WT) conidia. Furthermore, a potent fucopyranoside glycomimetic inhibitor of FleA inhibits binding and phagocytosis of WT conidia by macrophages, confirming the specific role of fucose binding in macrophage recognition of WT conidia. Finally, mice infected with ΔfleA conidia had more severe pneumonia and invasive aspergillosis than mice infected with WT conidia. These findings demonstrate that FleA is not a virulence factor for Aspergillus fumigatus. Instead, host recognition of FleA is a critical step in mechanisms of mucin binding, mucociliary clearance, and macrophage killing that prevent Aspergillus fumigatus pneumonia. PMID:27058347

  1. Bovine submaxillary mucin contains multiple domains and tandemly repeated non-identical sequences.

    PubMed Central

    Jiang, W; Woitach, J T; Keil, R L; Bhavanandan, V P

    1998-01-01

    A number of cDNA fragments coding for bovine submaxillary mucin (BSM) were cloned, and the nucleotide sequence of the largest clone, BSM421, was determined. Two peptide sequences determined from the purified apoBSM were found near the N-terminus of the mucin-coding region of BSM421. This clone does not contain a start or stop codon, but its 3' end overlaps with the 5' end of a previously isolated clone, lambdaBSM10. The composite sequence of 1589 amino acid residues consists of five distinct protein domains, which are numbered from the C-terminus. The cysteine-rich domain I can be further divided into a von Willebrand factor type C repeat and a cystine knot. Domains III and V consist of similar repeated peptide sequences with an average of 47 residues. Domains II and IV do not contain such sequences but are similar to domains III and V in being rich in serine and threonine, many of which are predicted to be potential O-glycosylation sites. Domain III also contains two sequences that match the ATP/GTP-binding site motif A (P-loop). Only beta-strands and no alpha-helices are predicted for the partial deduced amino acid sequence. Northern analysis of submaxillary gland RNA with the BSM421 probe detected multiple messages of BSM with sizes from 1.1 to over 10 kb. The tandemly repeated, non-identical peptide sequences of approx. 47 residues in domains III and V of BSM differ from the tandemly repeated, identical 81-residue sequences of pig submaxillary mucin (PSM), although both BSM and PSM contain similar C-terminal domains. In contrast, two peptide sequences of ovine submaxillary mucin are highly similar (86% and 65% identical respectively) to the corresponding sequences in domain V of BSM. PMID:9512479

  2. Penile mucinous carcinoma: A case report

    PubMed Central

    ÖZTÜRK, HAKAN

    2015-01-01

    Penile cancer is an extremely rare form of urological cancer that usually originates in the epithelium of the inner preputium or glans. Major etiological factors include phimosis, poor penile hygiene and smoking. Nearly 95% of penile cancers are squamous cell carcinomas and usually occur in the sixth decade of life. The disease exhibits two variants, namely metastatic and atypical disease. Squamous differentiation may also present with mucinous metaplasia. An extremely limited number of case reports on penile cancer are available in the literature. The present study reports the case of a 39-year-old patient with penile mucinous adenocarcinoma who was admitted with the complaint of perineal discharge, which is, to the best of our knowledge, the first case in the literature. The patient underwent total penectomy and inguinal lymph node dissection. The tumor was staged as T4N1M0, according to the European Association of Urology’s tumor-node-metastasis classification system. The patient was treated with pelvic radiotherapy and six cycles of systemic neoadjuvant chemotherapy with cisplatin and paclitaxel simultaneously, over a period of four months. After nine months of follow-up the patient succumbed to the disease due to widespread metastases. PMID:25663900

  3. Mucins Suppress Virulence Traits of Candida albicans

    PubMed Central

    Kavanaugh, Nicole L.; Zhang, Angela Q.; Nobile, Clarissa J.; Johnson, Alexander D.

    2014-01-01

    ABSTRACT Candida albicans is the most prevalent fungal pathogen of humans, causing a variety of diseases ranging from superficial mucosal infections to deep-seated systemic invasions. Mucus, the gel that coats all wet epithelial surfaces, accommodates C. albicans as part of the normal microbiota, where C. albicans resides asymptomatically in healthy humans. Through a series of in vitro experiments combined with gene expression analysis, we show that mucin biopolymers, the main gel-forming constituents of mucus, induce a new oval-shaped morphology in C. albicans in which a range of genes related to adhesion, filamentation, and biofilm formation are downregulated. We also show that corresponding traits are suppressed, rendering C. albicans impaired in forming biofilms on a range of different synthetic surfaces and human epithelial cells. Our data suggest that mucins can manipulate C. albicans physiology, and we hypothesize that they are key environmental signals for retaining C. albicans in the host-compatible, commensal state. PMID:25389175

  4. Trypanosoma cruzi TcSMUG L-surface Mucins Promote Development and Infectivity in the Triatomine Vector Rhodnius prolixus

    PubMed Central

    Gonzalez, Marcelo S.; Souza, Marcela S.; Garcia, Eloi S.; Nogueira, Nadir F. S.; Mello, Cícero B.; Cánepa, Gaspar E.; Bertotti, Santiago; Durante, Ignacio M.; Azambuja, Patrícia; Buscaglia, Carlos A.

    2013-01-01

    Background TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector. Methodology and Principal Findings Here, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy. Conclusion and Significance Together, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus. PMID:24244781

  5. Two-log increase in sensitivity for detection of Norovirus in complex samples using porcine gastric mucin capture and immunomagnetic separation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human histo-blood group antigens (HBGA) have been identified previously as candidate receptors for human norovirus (NOR). Type A, type H1, Lewis HBGAs have been identified major HBGA for NOR binding. We have identified that pig stomach mucin (PGM) contains group A, type H1, and Lewis b type HBGAs...

  6. The physicochemical characterisation of pepsin degraded pig gastric mucin.

    PubMed

    Abodinar, Atiga; Tømmeraas, Kristoffer; Ronander, Elena; Smith, Alan M; Morris, Gordon A

    2016-06-01

    Mucins are the main macromolecular components of the mucus secretions that cover the oral cavity, gastrointestinal and urogenital tracts of animals. The properties of the mucus secretions are therefore directly correlated with the physicochemical properties of mucin glycoproteins. In this study, mucins were obtained from pig gastric mucous after digestion with pepsin at 37°C for 4h, these mucins were characterised in terms of compositional and hydrodynamic properties. Compositional analysis showed that this mucin contains protein (15%), carbohydrates (55%) of which the constituents are: fucose (4%), galactose (9%), glucosamine (55%), glucosamine (33%) and sialic acid (2%). The latter component gives the mucin polymer a pH-dependant negative charge, with a ζ-potential of -3mV at pH 1.2 up to -11mV at pH 7.4. The weight average molar mass was ∼1×10(6)g/mol and intrinsic viscosity was ∼0.42dL/g although there was a small pH dependency due to the polyelectrolyte behavior of the polymer. The measurements of viscosity versus shear rate showed shear thinning behavior and the critical overlap concentration was determined to be 10-11% w/v indicating a compact structure. Knowledge of these properties is fundamental to the understanding interactions of mucins, with for example, novel drug delivery systems. PMID:26944659

  7. Ovarian mucinous tumor with malignant mural nodules: dedifferentiation or collision?

    PubMed

    Desouki, Mohamed M; Khabele, Dineo; Crispens, Marta A; Fadare, Oluwole

    2015-01-01

    Ovarian mucinous tumors with mural nodules are rare surface epithelial-stromal tumors. The mural nodules are divergent neoplasms that may be benign or malignant. The latter may be in the form of a sarcoma, carcinosarcoma, anaplastic carcinoma, or a variety of other recognized histotypes of carcinoma, which raises the question of whether malignant mural nodules represent a form of dedifferentiation in ovarian mucinous tumors or whether they represent collision tumors. We recently reported the K-RAS gene mutation status in a case of ovarian mucinous adenocarcinoma with mural nodule of high-grade sarcoma. The mucinous and sarcomatous components revealed a mutation in codon 12 of the K-RAS gene of a different nucleotide substitution, indicating that these 2 tumor components were different clones of the same tumor. Herein, we are reporting another case of a 20-yr-old woman who presented with 22 cm pelvic mass, omental caking, and ascites. A diagnosis of invasive mucinous carcinoma with mural nodules of anaplastic carcinoma was rendered. K-RAS gene mutation studies revealed p.G12V, c.35G>T mutation in the 2 components of the tumor, which is the most common mutation reported in mucinous tumors of the ovary. The fact that sarcomatous or anaplastic carcinomatous mural nodules in ovarian mucinous tumors display the same K-RAS mutations as their underlying mucinous neoplasms provides supportive evidence that at least some malignant mural nodules represent a form of dedifferentiation in ovarian mucinous tumors, rather than a collision of 2 divergent tumor types. PMID:25473748

  8. Mucin glycan foraging in the human gut microbiome.

    PubMed

    Tailford, Louise E; Crost, Emmanuelle H; Kavanaugh, Devon; Juge, Nathalie

    2015-01-01

    The availability of host and dietary carbohydrates in the gastrointestinal (GI) tract plays a key role in shaping the structure-function of the microbiota. In particular, some gut bacteria have the ability to forage on glycans provided by the mucus layer covering the GI tract. The O-glycan structures present in mucin are diverse and complex, consisting predominantly of core 1-4 mucin-type O-glycans containing α- and β- linked N-acetyl-galactosamine, galactose and N-acetyl-glucosamine. These core structures are further elongated and frequently modified by fucose and sialic acid sugar residues via α1,2/3/4 and α2,3/6 linkages, respectively. The ability to metabolize these mucin O-linked oligosaccharides is likely to be a key factor in determining which bacterial species colonize the mucosal surface. Due to their proximity to the immune system, mucin-degrading bacteria are in a prime location to influence the host response. However, despite the growing number of bacterial genome sequences available from mucin degraders, our knowledge on the structural requirements for mucin degradation by gut bacteria remains fragmented. This is largely due to the limited number of functionally characterized enzymes and the lack of studies correlating the specificity of these enzymes with the ability of the strain to degrade and utilize mucin and mucin glycans. This review focuses on recent findings unraveling the molecular strategies used by mucin-degrading bacteria to utilize host glycans, adapt to the mucosal environment, and influence human health. PMID:25852737

  9. Mucin glycan foraging in the human gut microbiome

    PubMed Central

    Tailford, Louise E.; Crost, Emmanuelle H.; Kavanaugh, Devon; Juge, Nathalie

    2015-01-01

    The availability of host and dietary carbohydrates in the gastrointestinal (GI) tract plays a key role in shaping the structure-function of the microbiota. In particular, some gut bacteria have the ability to forage on glycans provided by the mucus layer covering the GI tract. The O-glycan structures present in mucin are diverse and complex, consisting predominantly of core 1-4 mucin-type O-glycans containing α- and β- linked N-acetyl-galactosamine, galactose and N-acetyl-glucosamine. These core structures are further elongated and frequently modified by fucose and sialic acid sugar residues via α1,2/3/4 and α2,3/6 linkages, respectively. The ability to metabolize these mucin O-linked oligosaccharides is likely to be a key factor in determining which bacterial species colonize the mucosal surface. Due to their proximity to the immune system, mucin-degrading bacteria are in a prime location to influence the host response. However, despite the growing number of bacterial genome sequences available from mucin degraders, our knowledge on the structural requirements for mucin degradation by gut bacteria remains fragmented. This is largely due to the limited number of functionally characterized enzymes and the lack of studies correlating the specificity of these enzymes with the ability of the strain to degrade and utilize mucin and mucin glycans. This review focuses on recent findings unraveling the molecular strategies used by mucin-degrading bacteria to utilize host glycans, adapt to the mucosal environment, and influence human health. PMID:25852737

  10. Expression profile of mucins in ovarian mucinous tumors: distinguishing primary ovarian from metastatic tumors.

    PubMed

    Wang, Jayson; El-Bahrawy, Mona A

    2014-03-01

    Ovarian mucinous tumors (OMTs) of the intestinal type share morphologic features with primary tumors of other sites, and it can often be difficult to distinguish primary ovarian from metastatic mucinous tumors. MUC1, MUC2, MUC5AC, and MUC6 expressions were studied by immunohistochemistry in 36 OMTs of intestinal type (17 malignant, 19 borderline), 18 pancreatic, 12 biliary, 15 esophageal, 9 gastric, and 7 colorectal/appendiceal adenocarcinomas. All samples were from primary sites, except for colorectal tumors which were from ovarian metastases. Borderline and malignant OMTs show similar mucin immunoprofile, being strongly and uniformly positive for MUC5AC (97.2% of cases), whereas only focally positive for MUC1 (19.4%), MUC2 (38.9%), and MUC6 (22.2%). The positive frequencies of pancreatic adenocarcinomas for MUC1, MUC2, MUC5AC, and MUC6, respectively, were 100%, 16.7%, 94.4%, and 61.1%; for biliary (cholangiocarcinomas) were 91.7%, 0%, 16.7%, and 8.3%; for esophageal carcinomas were 73.3%, 33.3%, 53.3%, and 26.7%; for gastric carcinomas were 44.4%, 44.4%, 44.4%, and 0% and for lower gastrointestinal tract cancers were 28.6%, 85.7%, 42.9%, and 0%. Our study shows that OMTs are usually MUC5AC+/MUC1-, which is different from pancreatic, biliary, esophageal, gastric, and colorectal/appendiceal carcinomas. We recommend that these mucin stains be added to the panel of immunostains to differentiate metastatic tumors to the ovary from primary OMTs. PMID:24487472

  11. [Physiological role of mucins in the colonic barrier integrity].

    PubMed

    Gaudier, Estelle; Hoebler, Christine

    2006-01-01

    Colonic mucus is a key element of colonic barrier as it is located at the frontier between luminal microflora and colonic mucosa itself. Colonic mucus is mainly composed of high molecular weight glycoproteins called mucins that can be either secreted or membrane-linked. The expression of various colonic mucins is altered in colorectal cancers or inflammations. The aim of this review is to highlight the crucial role played by colonic mucins in the maintenance of colonic barrier integrity, both because they are part of the protective mucus layer, and because they individually exert specific functions involved in epithelial barrier, like cell growth and differentiation, immunomodulation, signal transduction or cell adhesion. PMID:17075443

  12. Mucinous ovarian tumors associated with mucinous adenocarcinomas of the cervix. A clinicopathological analysis of 16 cases.

    PubMed

    Young, R H; Scully, R E

    1988-01-01

    Sixteen cases of mucinous adenocarcinoma of the cervix that were associated with a mucinous tumor of one or both ovaries are reported. The patients ranged from 25 to 70 (average, 44) years of age; two of them had the Peutz-Jeghers syndrome. Eight patients complained of abdominal swelling; most of the remainder had symptoms of uterine origin. Twelve patients had bilateral and four had unilateral ovarian tumors, which were typically large and cystic. Microscopic examination of most of the ovarian tumors revealed various combinations of benign-appearing, borderline, and carcinomatous mucinous epithelium within the same specimen. Most of the cervical tumors were deeply invasive; 10 of them were of the adenoma malignum type. Although there were varying degrees of uncertainty in individual cases, consideration of several features including the extent and distribution of disease in the abdomen, the comparative histology of the tumors, and the pattern of ovarian involvement suggested that 10 of the ovarian tumors were independent primary tumors, three were metastatic from the cervix, and in three cases the ovaries contained both primary and metastatic tumors. PMID:2840404

  13. Role of Extracellular Transaldolase from Bifidobacterium bifidum in Mucin Adhesion and Aggregation

    PubMed Central

    González-Rodríguez, Irene; Sánchez, Borja; Ruiz, Lorena; Turroni, Francesca; Ventura, Marco; Ruas-Madiedo, Patricia; Gueimonde, Miguel

    2012-01-01

    The ability of bifidobacteria to establish in the intestine of mammals is among the main factors considered to be important for achieving probiotic effects. The role of surface molecules from Bifidobacterium bifidum taxon in mucin adhesion capability and the aggregation phenotype of this bacterial species was analyzed. Adhesion to the human intestinal cell line HT29 was determined for a collection of 12 B. bifidum strains. In four of them—B. bifidum LMG13195, DSM20456, DSM20239, and A8—the involvement of surface-exposed macromolecules in the aggregation phenomenon was determined. The aggregation of B. bifidum A8 and DSM20456 was abolished after treatment with proteinase K, this effect being more pronounced for the strain A8. Furthermore, a mucin binding assay of B. bifidum A8 surface proteins showed a high adhesive capability for its transaldolase (Tal). The localization of this enzyme on the surface of B. bifidum A8 was unequivocally demonstrated by immunogold electron microscopy experiments. The gene encoding Tal from B. bifidum A8 was expressed in Lactococcus lactis, and the protein was purified to homogeneity. The pure protein was able to restore the autoaggregation phenotype of proteinase K-treated B. bifidum A8 cells. A recombinant L. lactis strain, engineered to secrete Tal, displayed a mucin- binding level more than three times higher than the strain not producing the transaldolase. These findings suggest that Tal, when exposed on the cell surface of B. bifidum, could act as an important colonization factor favoring its establishment in the gut. PMID:22447584

  14. Mucin-Type O-Glycosylation in Gastric Carcinogenesis.

    PubMed

    Duarte, Henrique O; Freitas, Daniela; Gomes, Catarina; Gomes, Joana; Magalhães, Ana; Reis, Celso A

    2016-01-01

    Mucin-type O-glycosylation plays a crucial role in several physiological and pathological processes of the gastric tissue. Modifications in enzymes responsible for key glycosylation steps and the consequent abnormal biosynthesis and expression of their glycan products constitute well-established molecular hallmarks of disease state. This review addresses the major role played by mucins and associated O-glycan structures in Helicobacter pylori adhesion to the gastric mucosa and the subsequent establishment of a chronic infection, with concomitant drastic alterations of the gastric epithelium glycophenotype. Furthermore, alterations of mucin expression pattern and glycan signatures occurring in preneoplastic lesions and in gastric carcinoma are also described, as well as their impact throughout the gastric carcinogenesis cascade and in cancer progression. Altogether, mucin-type O-glycosylation alterations may represent promising biomarkers with potential screening and prognostic applications, as well as predictors of cancer patients' response to therapy. PMID:27409642

  15. Respiratory mucins: identification of core proteins and glycoforms.

    PubMed

    Thornton, D J; Carlstedt, I; Howard, M; Devine, P L; Price, M R; Sheehan, J K

    1996-06-15

    At least eight mucin apoproteins are expressed by the tracheobronchial epithelium, but it is not known which, if any, of these are major constituents of the respiratory secretions responsible for the formation of the mucus gel. To address this we have isolated mucins from normal, asthmatic and chronic bronchitic secretions. The asthmatic mucin reduced subunits were fractionated into four populations (I-IV) by anion-exchange HPLC. Amino acid and monosaccharide compositional analysis, as well as M(r) and size measurements, indicate that two of these populations (I and II) are glycoforms of the same or related apoprotein(s) and that the other populations contain two different apoproteins. A panel of antibodies and antisera recognizing the variable number tandem repeat (VNTR) of specific mucin apoproteins did not, as predicted, react with the glycosylated molecules, but after deglycosylation the majority of these probes (with the exception of those to MUC2, which were negative) reacted at a low level with each of the subunit populations. In contrast, an antiserum against a non-VNTR sequence of MUC5AC identified one of the populations (III) as the MUC5AC mucin. The MUC5AC reduced subunit had an M(r) of 2.2 x 10(6) and an RG (radius of gyration) of 57 nm. The genetic identities of the major mucin (populations I and II) and a minor component (population IV) were not established. The MUC5AC mucin was also identified as a major component in the pooled normal secretions from 20 individuals, whereas in a chronic bronchitic sample it was only a minor constituent. Furthermore, in all these different respiratory secretions the MUC5AC mucin appears as a similar biochemical entity, as assessed by Mono Q chromatography and agarose electrophoresis, suggesting that it may have a well-defined pattern of glycosylation in the respiratory tract. PMID:8670177

  16. Antiviral activity of purified human breast milk mucin.

    PubMed

    Habte, Habtom H; Kotwal, Girish J; Lotz, Zoë E; Tyler, Marilyn G; Abrahams, Melissa; Rodriques, Jerry; Kahn, Delawir; Mall, Anwar S

    2007-01-01

    Human breast milk is known to contain numerous biologically active components which protect breast fed infants against microbes, viruses, and toxins. The purpose of this study was to purify and characterize the breast milk mucin and determine its anti-poxvirus activity. In this study human milk mucin, free of contaminant protein and of sufficient quantity for further analysis, was isolated and purified by Sepharose CL-4B gel filtration and cesiumchloride density-gradient centrifugation. Based on the criteria of size and appearance of the bands and their electrophoretic mobility on sodium dodecyl sulfate polyacrylamide-gel electrophoresis, Western blotting together with the amino acid analysis, it is very likely that the human breast milk mucin is MUC1. It was shown that this breast milk mucin inhibits poxvirus activity by 100% using an inhibition assay with a viral concentration of 2.4 million plaque-forming units/ml. As the milk mucin seems to aggregate poxviruses prior to their entry into host cells, it is possible that this mucin may also inhibit other enveloped viruses such as HIV from entry into host cells. PMID:17361093

  17. Effects of calcium on intestinal mucin: implications for cystic fibrosis.

    PubMed

    Forstner, J F; Forstner, G G

    1976-06-01

    A major feature of the disease cystic fibrosis is the excessive concentration of mucus within ducts and glands of mucous-producing organs. Some mucous secretions also show an elevation in calcium concentration. Using purified rat intestinal goblet cell mucin as a model mucin, we have investigated the effect of millimolar additions (1-25 mM) of CaCl2 on the physical properties of the mucin. Isotonicity of incubation media was preserved in order to mimic in vivo conditions. CaCl2 (8-15mM) caused a 15-33% decrease in viscosity, no change in electrophoretic mobility in acrylamide gels, and a 20-30% decrease in solubility of the mucin. Solubility changes were reversed by the addition of EDTA (20 mM) to incubations. Insolubility was also produced in incubations of mucin with a mixture of soluble intestinal contents (NaCl washings). These findings strongly suggest that the mucin became smaller and more dense as calcium was added, a process most probably achieved by loss of intramolecular water. PMID:1272637

  18. Chemically tunable mucin chimeras assembled on living cells

    PubMed Central

    Kramer, Jessica R.; Onoa, Bibiana; Bustamante, Carlos; Bertozzi, Carolyn R.

    2015-01-01

    Mucins are a family of secreted and transmembrane glycoproteins characterized by a massive domain of dense O-glycosylation on serine and threonine residues. Mucins are intimately involved in immunity and cancer, yet elucidation of the biological roles of their glycodomains has been complicated by their massive size, domain polymorphisms, and variable glycosylation patterns. Here we developed a synthetic route to a library of compositionally defined, high-molecular weight, dual end-functionalized mucin glycodomain constructs via N-carboxyanhydride polymerization. These glycopolypeptides are the first synthetic analogs to our knowledge to feature the native α-GalNAc linkage to serine with molecular weights similar to native mucins, solving a nearly 50-year synthetic challenge. Physical characterization of the mimics revealed insights into the structure and properties of mucins. The synthetic glycodomains were end-functionalized with an optical probe and a tetrazine moiety, which allowed site-specific bioorthogonal conjugation to an engineered membrane protein on live mammalian cells. This strategy in protein engineering will open avenues to explore the biological roles of cell surface mucins. PMID:26420872

  19. Regulation of mucin secretion from in vitro cellular models.

    PubMed

    Davis, C William

    2002-01-01

    Conceptually, in vitro models for airway mucin secretion may provide useful information pertinent to many aspects of goblet cell biology/physiology. Such models may be especially useful in identifying potential secretagogues, probing the distribution of receptors between goblet cell apical and basolateral membrane domains, and revealing intracellular messenger pathways underlying receptor activation. We have focused most recently on human bronchial epithelial cell cultures grown as tracheal xenografts and SPOC1 cell cultures. These two models are remarkably similar with respect to the regulation of mucin secretion: luminal challenges with the P2Y2 purinoceptor agonists ATP or UTP elicit mucin secretion with EC50s of about 3 microM and archetypal agonists to other purinoceptors test negative. P2Y2 purinoceptors typically couple via Gq to phospholipase C, suggesting that intracellular Ca2+ and protein kinase C (PKC) are important in activating intracellular pathways leading to goblet cell mucin release. Consistent with this notion, phorbol myristate acetate and ionomycin elicit mucin secretion from SPOC1 cells and HBE xenografts, whereas cyclic nucleotides do not. Delineation of the molecules comprising these receptor/messenger interactions and their supporting pathways remains an important challenge for the development of drugs effective in therapeutic interventions in mucin hypersecretory airway diseases; with these models we have initiated the process. PMID:12568491

  20. Mucinous adenocarcinoma of the renal pelvis with pseudomyxoma peritonei.

    PubMed

    Shah, Vinaya B; Amonkar, Gayathri P; Deshpande, Jaya R; Bhalekar, Hemant

    2008-01-01

    Mucinous adenocarcinoma of the renal pelvis is an extremely rare tumor with very few case reports in literature. Pseudomyxoma peritonei is an uncommon condition characterized by the presence of mucinous gelatinous material in the peritoneal cavity. It occurs secondary to primary mucinous neoplasms of particularly the appendix and the ovary. We present a case of a 35-year-old female who had a history of dull aching pain in the right flank since one and a half years. Upon ultrasonography (USG) and computerized tomography (CT) scan, there was a large cystic mass measuring 15x15x12 cm, extending into the right lumbar region. Grossly, the entire kidney was converted into a cystic mass measuring 15x15x12 cm containing gelatinous mucinous material weighing 1 kg. Histologically, the tumor was composed of simple and complex glandular acini together with a superficial resemblance to colonic mucosa with abundant extracellular mucin. Thus, a diagnosis of mucinous adenocarcinoma of the renal pelvis leading to pseudomyxoma peritonei was made. PMID:19008588

  1. Mucin function in inflammatory bowel disease: an update.

    PubMed

    Boltin, Doron; Perets, Tsachi T; Vilkin, Alex; Niv, Yaron

    2013-02-01

    MUC2 is the primary component of the mucin barrier that separates the intestinal microbiota and the intestinal epithelium. This mucous barrier is affected by both luminal/microbial factors and host/immune factors, both of which have genetic and environmental determinants. The complex interactions between these players in health and disease states are not fully understood. Inflammatory bowel disease (IBD) has both genetic and environmental etiologies that lead to the breakdown of the epithelial barrier. In this review, we explore the up-to-date evidence that implicates mucin in the pathogenesis of IBD. In IBD, quantitative changes in mucin secretion occur, as well as structural changes in mucin's glycoprotein core and the sulfation and sialylation of mucin's oligosaccharide residues. These changes are associated with a diminished functionality of the mucous barrier. We identify the various genetic mutations associated with these changes and outline the animal models that have enhanced the current understanding of the genetic basis for IBD. Further study is needed to better characterize the immune and genetic influences on mucin expression and secretion and role of endoplasmic reticulum stress and a defective unfolded protein response in mediating these changes. PMID:23164684

  2. Appendiceal mucinous neoplasms: a clinicopathologic analysis of 107 cases.

    PubMed

    Misdraji, Joseph; Yantiss, Rhonda K; Graeme-Cook, Fiona M; Balis, Ulysses J; Young, Robert H

    2003-08-01

    The classification of appendiceal mucinous tumors is controversial and terminology used for them inconsistent, particularly when they lack overtly malignant features but are associated with extra-appendiceal spread. We reviewed 107 appendiceal mucinous neoplasms and classified them as low-grade appendiceal mucinous neoplasm (LAMN) (n = 88), mucinous adenocarcinomas (MACAs) (n = 16), or discordant (n = 3) based on architectural and cytologic features. LAMNs were characterized by a villous or flat proliferation of mucinous epithelium with low-grade atypia. Thirty-nine tumors were confined to the appendix, but 49 had extra-appendiceal tumor spread, including 39 with peritoneal tumor characterized by mucin pools harboring low-grade mucinous epithelium, usually dissecting in a hyalinized stroma. Eight of the 16 MACAs lacked destructive invasion of the appendiceal wall and eight showed an infiltrative pattern of invasion. Extra-appendiceal tumor spread was present in 12 MACAs (four peritoneum, seven peritoneum and ovaries; one ovaries only). In MACAs with an infiltrative pattern, peritoneal tumor consisted of glands and single cells in a desmoplastic stroma. The peritoneal tumor in the remaining cases consisted of mucin pools that contained mucinous epithelium with high-grade atypia and, in some cases, increased cellularity compared with that seen in peritoneal spread in cases of LAMN. Three cases were classified as discordant because the appendiceal tumors were LAMNs but the peritoneal tumors were high-grade. Follow-up was available for 49 LAMNs, 15 MACAs, and 2 discordant cases. None of the patients with LAMNs confined to the appendix experienced recurrence (median follow-up 6 years). LAMNs with extra-appendiceal spread were associated with 3-, 5-, and 10-year survival rates of 100%, 86%, and 45%, respectively. Patients with MACA had 3- and 5-year survival rates of 90% and 44%, respectively (p = 0.04). The bulk of peritoneal disease correlated with prognosis among

  3. Evidence for mucin-like glycoproteins that tether sporozoites of Cryptosporidium parvum to the inner surface of the oocyst wall.

    PubMed

    Chatterjee, Anirban; Banerjee, Sulagna; Steffen, Martin; O'Connor, Roberta M; Ward, Honorine D; Robbins, Phillips W; Samuelson, John

    2010-01-01

    Cryptosporidium parvum oocysts, which are spread by the fecal-oral route, have a single, multilayered wall that surrounds four sporozoites, the invasive form. The C. parvum oocyst wall is labeled by the Maclura pomifera agglutinin (MPA), which binds GalNAc, and the C. parvum wall contains at least two unique proteins (Cryptosporidium oocyst wall protein 1 [COWP1] and COWP8) identified by monoclonal antibodies. C. parvum sporozoites have on their surface multiple mucin-like glycoproteins with Ser- and Thr-rich repeats (e.g., gp40 and gp900). Here we used ruthenium red staining and electron microscopy to demonstrate fibrils, which appear to attach or tether sporozoites to the inner surface of the C. parvum oocyst wall. When disconnected from the sporozoites, some of these fibrillar tethers appear to collapse into globules on the inner surface of oocyst walls. The most abundant proteins of purified oocyst walls, which are missing the tethers and outer veil, were COWP1, COWP6, and COWP8, while COWP2, COWP3, and COWP4 were present in trace amounts. In contrast, MPA affinity-purified glycoproteins from C. parvum oocysts, which are composed of walls and sporozoites, included previously identified mucin-like glycoproteins, a GalNAc-binding lectin, a Ser protease inhibitor, and several novel glycoproteins (C. parvum MPA affinity-purified glycoprotein 1 [CpMPA1] to CpMPA4). By immunoelectron microscopy (immuno-EM), we localized mucin-like glycoproteins (gp40 and gp900) to the ruthenium red-stained fibrils on the inner surface wall of oocysts, while antibodies to the O-linked GalNAc on glycoproteins were localized to the globules. These results suggest that mucin-like glycoproteins, which are associated with the sporozoite surface, may contribute to fibrils and/or globules that tether sporozoites to the inner surface of oocyst walls. PMID:19949049

  4. Mucin Promotes Rapid Surface Motility in Pseudomonas aeruginosa

    PubMed Central

    Yeung, Amy T. Y.; Parayno, Alicia; Hancock, Robert E. W.

    2012-01-01

    ABSTRACT An important environmental factor that determines the mode of motility adopted by Pseudomonas aeruginosa is the viscosity of the medium, often provided by adjusting agar concentrations in vitro. However, the viscous gel-like property of the mucus layer that overlays epithelial surfaces is largely due to the glycoprotein mucin. P. aeruginosa is known to swim within 0.3% (wt/vol) agar and swarm on the surface at 0.5% (wt/vol) agar with amino acids as a weak nitrogen source. When physiological concentrations or as little as 0.05% (wt/vol) mucin was added to the swimming agar, in addition to swimming, P. aeruginosa was observed to undergo highly accelerated motility on the surface of the agar. The surface motility colonies in the presence of mucin appeared to be circular, with a bright green center surrounded by a thicker white edge. While intact flagella were required for the surface motility in the presence of mucin, type IV pili and rhamnolipid production were not. Replacement of mucin with other wetting agents indicated that the lubricant properties of mucin might contribute to the surface motility. Based on studies with mutants, the quorum-sensing systems (las and rhl) and the orphan autoinducer receptor QscR played important roles in this form of surface motility. Transcriptional analysis of cells taken from the motility zone revealed the upregulation of genes involved in virulence and resistance. Based on these results, we suggest that mucin may be promoting a new or highly modified form of surface motility, which we propose should be termed “surfing.” PMID:22550036

  5. CYSTIC FIBROSIS: AN INHERITED DISEASE AFFECTING MUCIN-PRODUCING ORGANS

    PubMed Central

    Ehre, Camille; Ridley, Caroline; Thornton, David J

    2014-01-01

    Our current understanding of cystic fibrosis (CF) has revealed that the biophysical properties of mucus play a considerable role in the pathogenesis of the disease in view of the fact that most mucus-producing organs are affected in CF patients. In this review, we discuss the potential causal relationship between altered cystic fibrosis transmembrane conductance regulator (CFTR) function and the production of mucus with abnormal biophysical properties in the intestine and lungs, highlighting what has been learned from cell cultures and animal models that mimic CF pathogenesis. A similar cascade of events, including mucus obstruction, infection and inflammation, is common to all epithelia affected by impaired surface hydration. Hence, the main structural components of mucus, namely the polymeric, gel-forming mucins, are critical to the onset of the disease. Defective CFTR leads to epithelial surface dehydration, altered pH/electrolyte composition and mucin concentration. Further, it can influence mucin transition from the intracellular to extracellular environment, potentially resulting in aberrant mucus gel formation. While defective HCO3− production has long been identified as a feature of CF, it has only recently been considered as a key player in the transition phase of mucins. We conclude by examining the influence of mucins on the biophysical properties of CF sputum and discuss existing and novel therapies aimed at removing mucus from the lungs. PMID:24685676

  6. Cystic mucinous adenocarcinoma of the lung: a case report

    PubMed Central

    2011-01-01

    Mucinous cystic tumors of the lung are uncommon, the preoperative pathologic diagnosis is difficult and their biological behavior is still controversial. We report the case of a patient with a clinically benign cystic lesion that post-operatively showed to be consistent with an invasive adenocarcinoma arising in a mucinous cystadenoma of the lung, We underline the difficulty of the clinical pre-operative diagnosis of this cystic neoplasia radiologically mimicking a hydatid cyst, and we report the negative TTF1 immunostaining potentially misleading in the differential diagnosis with metastatic mucinous carcinomas. Finallly, we evidence the presence of a pre-existing mucinous benign lesion suggesting early and complete resection of benign appearing lung cysts because they can undergo malignant transformation if left untreated or they can already harbor foci of invasive carcinoma at the time of the presentation. Even if a good prognosis, better than in other lung carcinomas, with no recurrrence or metastasis after complete surgical exicision, has been reported for cystic mucinous cystoadenocarcinomas, the follow-up showed an aggressive biological behaviour, with the early onset of metastasis, in keeping with P53 positive immunostaining and high Ki-67 proliferation index. PMID:21970610

  7. Biomimetic mucin modified PLGA nanoparticles for enhanced blood compatibility.

    PubMed

    Thasneem, Y M; Rekha, M R; Sajeesh, S; Sharma, Chandra P

    2013-11-01

    Efforts to develop long circulating polymeric nanoparticles have propelled many strategies in nanoparticle surface modification to bypass immune surveillance and systemic clearance. In this context, our present study reports on the preparation and evaluation of mucin functionalized poly lactic-co-glycolic acid (PLGA) nanoparticles as hemocompatible, cell penetrating nanoparticulate drug delivery system. Amino groups of mucin were conjugated to the terminal carboxylic acid groups on PLGA to be followed by nanoparticle synthesis via standard solvent evaporation technique. Detailed in vitro experiments were performed to illustrate the significance of alternating copolymer structured mucin modified PLGA nanoparticles in terms of enhanced hemocompatibility and cellular uptake. Mucylation proved promising in controlling PLGA nanoparticle- interaction with plasma proteins (opsonins) and blood components via hemolysis, thrombogenecity and complement activation. Besides hemocompatibility, the modified and unmodified nanoparticles were also found to be cytocompatible with L929 and C6 cell lines. The fluorescent and confocal image analysis evaluated the extent of cellular uptake of nanoparticles into C6 cells. Specifically the combination of stealth properties and cellular internalization capacity of mucin modified PLGA nanoparticle (PLGA-Mucin) lead us to propose it as a safe, efficient and multifunctional nanoplatform for disease specific intravenous drug delivery applications as far as in vitro experiments are concerned. PMID:23978287

  8. Covalently-crosslinked mucin biopolymer hydrogels for sustained drug delivery.

    PubMed

    Duffy, Connor V; David, Laurent; Crouzier, Thomas

    2015-07-01

    The sustained delivery of both hydrophobic and hydrophilic drugs from hydrogels has remained a challenge requiring the design and scalable production of complex multifunctional synthetic polymers. Here, we demonstrate that mucin glycoproteins, the gel-forming constituents of native mucus, are suitable for assembly into robust hydrogels capable of facilitating the sustained release of hydrophobic and hydrophilic drugs. Covalently-crosslinked mucin hydrogels were generated via exposure of methacrylated mucin to ultraviolet light in the presence of a free radical photoinitiator. The hydrogels exhibited an elastic modulus similar to that of soft mammalian tissue and were sensitive to proteolytic degradation by pronase. Paclitaxel, a hydrophobic anti-cancer drug, and polymyxin B, a positively-charged hydrophilic antibacterial drug, were retained in the hydrogels and released linearly with time over seven days. After four weeks of drug release, the hydrogels continued to release sufficient amounts of active paclitaxel to reduce HeLa cell viability and sufficient amounts of active polymyxin B to prevent bacterial proliferation. Along with previously-established anti-inflammatory, anti-viral, and hydrocarbon-solubilizing properties of mucin, the results of this study establish mucin as a readily-available, chemically-versatile, naturally-biocompatible alternative to complex multifunctional synthetic polymers as building blocks in the design of biomaterials for sustained drug delivery. PMID:25818947

  9. Primary testicular mucinous cystadenoma: Case report and literature review.

    PubMed

    de Lima, Mário Maciel; de Lima, Mário Maciel; Granja, Fabiana

    2015-01-01

    Testicular mucinous cystadenomas are rare in urological practice, and their histogenesis, course and management are debated. We report a primary testicular mucinous cystadenoma in a 54-year old male who presented with left testicular swelling and pain. He denied having a history of cryptorchidism, testicular trauma, infections, urinary complaints, or febrile illnesses. He did not have diabetes, but was on treatment for hypertension. The patient underwent a left inguinal radical orchiectomy, and histological examination of the resected tumour confirmed a primary testicular mucinous cystadenoma. The patient had an uneventful recovery, and is being followed up. Conclusively, urologists need to maintain a high index of suspicion of these tumours and their differentiation from metastatic tumours to ensure optimal therapeutic outcomes. PMID:26600891

  10. [A case of mucinous cystic neoplasm of the liver].

    PubMed

    Tatsumi, Ryoji; Amizuka, Hisato; Matsubara, Yu; Yoshizaki, Koji; Sakamoto, Jun; Sato, Ryu; Kimura, Keisuke; Nishimori, Hiroyuki; Ohta, Tomoyuki

    2015-07-01

    We present a case of resected mucinous cystic neoplasm of the liver in a 71-year-old woman admitted to our hospital with epigastric discomfort. Abdominal ultrasonography and computed tomography revealed a multi-locular cystic tumor measuring 35 mm in diameter in segment IV of the liver. Left hepatic lobectomy was performed based on the diagnosis of mucinous cystic neoplasm of the liver; subsequent histology revealed that the tumor was multi-locular, cystic, and lined with a single layer of columnar epithelium with low-grade atypia and was associated with a typical ovarian-like stroma. There was no evidence (imaging or histological) to support communication of the cyst with the intrahepatic bile duct, despite modest bile deposition being observed in the cystic wall. The definitive diagnosis was mucinous cystic neoplasm with low-grade intrahepatic epithelial neoplasia. PMID:26155869

  11. Gelation of mucin: Protecting the stomach from autodigestion

    NASA Astrophysics Data System (ADS)

    Bansil, Rama

    2011-03-01

    In this talk I will describe the molecular mechanisms involved in the remarkable ability of the mucus lining of the stomach for protecting the stomach from being digested by the acidic gastric juices that it secretes. These physical properties can be attributed to the presence of a high molecular weight glycoprotein found in mucus, called mucin. Rheology and other measurements show that gastric mucin forms a gel under acidic pH. A model of gelation based on the interplay of hydrophobic and electrostatic interactions will be discussed. Molecular Dynamics simulation studies of folding and aggregation of mucin domains provide further support for this model. The relevance of gelation to the motion of the ulcer causing bacterium H. pylori will be discussed.

  12. Mucin biopolymers as broad-spectrum antiviral agents

    PubMed Central

    Lieleg, Oliver; Lieleg, Corinna; Bloom, Jesse; Buck, Christopher B.; Ribbeck, Katharina

    2012-01-01

    Mucus is a porous biopolymer matrix that coats all wet epithelia in the human body and serves as the first line of defense against many pathogenic bacteria and viruses. However, under certain conditions viruses are able to penetrate this infection barrier, which compromises the protective function of native mucus. Here, we find that isolated porcine gastric mucin polymers, key structural components of native mucus, can protect an underlying cell layer from infection by small viruses such as human papillomavirus (HPV), Merkel cell polyomavirus (MCV), or a strain of influenza A virus. Single particle analysis of virus mobility inside the mucin barrier reveals that this shielding effect is in part based on a retardation of virus diffusion inside the biopolymer matrix. Our findings suggest that purified mucins may be used as a broad-range antiviral supplement to personal hygiene products, baby formula or lubricants to support our immune system. PMID:22475261

  13. Divergent Mechanisms of Interaction of Helicobacter pylori and Campylobacter jejuni with Mucus and Mucins

    PubMed Central

    Naughton, Julie Ann; Mariño, Karina; Dolan, Brendan; Reid, Colm; Gough, Ronan; Gallagher, Mary E.; Kilcoyne, Michelle; Gerlach, Jared Q.; Joshi, Lokesh; Rudd, Pauline; Carrington, Stephen; Bourke, Billy

    2013-01-01

    Helicobacter pylori and Campylobacter jejuni colonize the stomach and intestinal mucus, respectively. Using a combination of mucus-secreting cells, purified mucins, and a novel mucin microarray platform, we examined the interactions of these two organisms with mucus and mucins. H. pylori and C. jejuni bound to distinctly different mucins. C. jejuni displayed a striking tropism for chicken gastrointestinal mucins compared to mucins from other animals and preferentially bound mucins from specific avian intestinal sites (in order of descending preference: the large intestine, proximal small intestine, and cecum). H. pylori bound to a number of animal mucins, including porcine stomach mucin, but with less avidity than that of C. jejuni for chicken mucin. The strengths of interaction of various wild-type strains of H. pylori with different animal mucins were comparable, even though they did not all express the same adhesins. The production of mucus by HT29-MTX-E12 cells promoted higher levels of infection by C. jejuni and H. pylori than those for the non-mucus-producing parental cell lines. Both C. jejuni and H. pylori bound to HT29-MTX-E12 mucus, and while both organisms bound to glycosylated epitopes in the glycolipid fraction of the mucus, only C. jejuni bound to purified mucin. This study highlights the role of mucus in promoting bacterial infection and emphasizes the potential for even closely related bacteria to interact with mucus in different ways to establish successful infections. PMID:23716616

  14. Genome wide analysis of the bovine mucin genes and their gastrointestinal transcription profile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mucins are large glycoproteins implicated in protection of all mucosal surfaces. In humans and rodents, the mucin gene family has been well described and previous studies have investigated the distribution and function of mucins in the respiratory, urogenital and gastrointestinal (GI) tracts. In con...

  15. GABA selectively increases mucin-1 expression in isolated pig jejunum.

    PubMed

    Braun, Hannah-Sophie; Sponder, Gerhard; Pieper, Robert; Aschenbach, Jörg R; Deiner, Carolin

    2015-11-01

    The inhibitory neurotransmitter GABA (γ-aminobutyric acid) is synthesized by glutamic acid decarboxylase, which is expressed in the central nervous system and in various other tissues including the intestine. Moreover, GABA can be ingested in vegetarian diets or produced by bacterial commensals in the gastrointestinal tract. As previous studies in lung have suggested a link between locally increased GABA availability and mucin 5AC production, the present study sought to test whether the presence or lack of GABA (and its precursor glutamine) has an effect on intestinal mucin expression. Porcine jejunum epithelial preparations were incubated with two different amounts of GABA or glutamine on the mucosal side for 4 h, and changes in the relative gene expression of seven different mucins, enzymes involved in mucin shedding, GABA B receptor, enzymes involved in glutamine/GABA metabolism, glutathione peroxidase 2, and interleukin 10 were examined by quantitative PCR (TaqMan(®) assays). Protein expression of mucin-1 (MUC1) was analyzed by Western blot. On the RNA level, only MUC1 was significantly up-regulated by both GABA concentrations compared with the control. Glutamine-treated groups showed the same trend. On the protein level, all treatment groups showed a significantly higher MUC1 expression than the control group. We conclude that GABA selectively increases the expression of MUC1, a cell surface mucin that prevents the adhesion of microorganisms, because of its size and negative charge, and therefore propose that the well-described positive effects of glutamine on enterocytes and intestinal integrity are partly attributable to effects of its metabolite GABA. PMID:26471792

  16. Mucinous Borderline Ovarian Tumor in Very Old Aged Postmenopausal Woman

    PubMed Central

    Lee, Seung-Hee; Lee, Hae-Hyeog; Lee, Arum; Kim, Yeon-Suk; Jeon, Dong-Su; Kwak, Jeong Ja; Yang, Yo-Sep

    2015-01-01

    Mucinous borderline ovarian tumors (BOTs) occur most often in women between the ages of 20 and 30. Early-stage detection of the condition has a more favorable prognosis. In this case report, the authors present an elderly 93-year old woman who visited our hospital due to severe abdominal pain after being diagnosed with a pelvic mass 2 years ago and not undergoing any treatment since the diagnosis was made. She underwent emergency left salpingo-oophorectomy and was diagnosed with mucinous BOT according to biopsy results. PMID:26793682

  17. Frequent KRAS mutation in complex mucinous epithelial lesions of the endometrium.

    PubMed

    Alomari, Ahmed; Abi-Raad, Rita; Buza, Natalia; Hui, Pei

    2014-05-01

    KRAS mutation correlates with mucinous differentiation in various human cancers, and recently, was found in a high proportion of a small cohort of papillary mucinous lesions of the endometrium. In this study, a large number of endometrial mucinous lesions were analyzed for the presence of KRAS mutation along with clinical progression. A total of 45 endometrial biopsy/curettage cases were included in the study and classified into the following categories: simple mucinous change (5 cases), complex mucinous change (33 cases) and mucinous adenocarcinoma (7 cases). Follow-up hysterectomy specimens were available in 14 of 33 patients (42%) with complex mucinous lesions, of which 9 cases (64%) showed atypical complex hyperplasia with an average interval of 21 weeks. None of the 5 cases of simple mucinous change showed KRAS mutation. KRAS mutation was observed in 18 of 33 patients with complex mucinous lesions (55%) and in 6 of 7 cases of mucinous adenocarcinoma (86%). Overall, KRAS mutation has a positive predictive value (PPV) of 88% (7/8 cases) for complex atypical hyperplasia or adenocarcinoma in the follow-up hysterectomy. In conclusion, the current data further emphasizes the architectural complexity as an important prognostic indicator for patients with mucinous endometrial lesions. The presence of KRAS mutation in both mucinous adenocarcinoma and complex mucinous changes indicates that KRAS mutational activation is implicated in the pathogenesis of a significant subset of endometrial mucinous carcinoma. With a high PPV, KRAS mutation analysis may offer an additional discriminatory power to refine risk stratification algorithm for patients with endometrial mucinous lesions. PMID:24186144

  18. Intraductal Papillary Mucinous Neoplasm of Pancreas

    PubMed Central

    Machado, Norman Oneil; al Qadhi, Hani; al Wahibi, Khalifa

    2015-01-01

    Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are neoplasms that are characterized by ductal dilation, intraductal papillary growth, and thick mucus secretion. This relatively recently defined pathology is evolving in terms of its etiopathogenesis, clinical features, diagnosis, management, and treatment guidelines. A PubMed database search was performed. All the relevant abstracts in English language were reviewed and the articles in which cases of IPMN could be identified were further scrutinized. Information of IPMN was derived, and duplication of information in several articles and those with areas of persisting uncertainties were excluded. The recent consensus guidelines were examined. The reported incidence of malignancy varies from 57% to 92% in the main duct-IPMN (MD-IPMN) and from 6% to 46% in the branch duct-IPMN (BD-IPMN). The features of high-risk malignant lesions that raise concern include obstructive jaundice in a patient with a cystic lesion in the pancreatic head, the findings on radiological imaging of a mass lesion of >30 mm, enhanced solid component, and the main pancreatic duct (MPD) of size ≥10 mm; while duct size 5-9 mm and cyst size <3 mm are considered as “worrisome features.” Magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) are primary investigations in diagnosing and following up on these patients. The role of pancreatoscopy and the analysis of aspirated cystic fluid for cytology and DNA analysis is still to be established. In general, resection is recommended for most MD-IPMN, mixed variant, and symptomatic BD-IPMN. The 5-year survival of patients after surgical resection for noninvasive IPMN is reported to be at 77-100%, while for those with invasive carcinoma, it is significantly lower at 27-60%. The follow-up of these patients could vary from 6 months to 1 year and would depend on the risk stratification for invasive malignancy and the pathology of the resected specimen. The understanding of

  19. Colonic mucin synthesis is increased by sodium butyrate.

    PubMed

    Finnie, I A; Dwarakanath, A D; Taylor, B A; Rhodes, J M

    1995-01-01

    The effects of sodium butyrate and sodium bromo-octanoate (an inhibitor of beta oxidation) on colonic mucus glycoprotein (mucin) synthesis have been assessed using tissue from colonic resection samples. Epithelial biopsy specimens were incubated for 16 hours in RPMI 1640 with glutamine, supplemented with 10% fetal calf serum and N-acetyl-[3H]-glucosamine ([3H]-Glc NAc), and differing concentrations of sodium butyrate. Incorporation of [3H] Glc NAc into mucin by normal epithelium at least 10 cm distant from colonic cancer was increased in the presence of sodium butyrate in a dose dependent manner, with maximum effect (476%) at a concentration of 0.1 mM (number of specimens = 24 from six patients, p < 0.001). The increase in response to butyrate was not seen when specimens were incubated in the presence of the beta oxidation inhibitor sodium bromo-octanoate 0.05 M. The striking increase in mucin synthesis that results when butyrate is added to standard nutrient medium suggests that this may be an important mechanism affecting the rate of mucin synthesis in vivo and may also explain the therapeutic effect of butyrate in colitis. PMID:7890244

  20. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.

    PubMed

    Pechar, Radko; Rada, Vojtech; Parafati, Lucia; Musilova, Sarka; Bunesova, Vera; Vlkova, Eva; Killer, Jiri; Mrazek, Jakub; Kmet, Vladimir; Svejstil, Roman

    2014-11-17

    Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples. PMID:25217723

  1. Mucins and Cytokeratins as Serum Tumor Markers in Breast Cancer.

    PubMed

    Nicolini, Andrea; Ferrari, Paola; Rossi, Giuseppe

    2015-01-01

    Structural and functional characteristics of mucins and cytokeratins are shortly described. Thereafter, those commonly used in breast cancer as serum tumor markers are considered. First CA15.3, MCA, CA549, CA27.29 mucins and CYFRA21.1, TPA, TPS cytokeratins alone or in association have been examined in different stages and conditions. Then their usefulness in monitoring disease-free breast cancer patients is evaluated. The central role of the established cut-off and critical change, the "early" treatment of recurrent disease and the potential benefit in survival are other issues that have been highlighted and discussed. The successive sections and subsections deal with the monitoring of advanced disease. In them, the current recommendations and the principal findings on using the above mentioned mucins and cytokeratins have been reported. A computer program for interpreting consecutive measurements of serum tumor markers also has been illustrated. The final part of the chapter is devoted to mucins and cytokeratins as markers of circulating and disseminated tumor cells and their usefulness for prognosis. PMID:26530368

  2. Physical Properties of Human Whole Salivary Mucin:A Dynamic Light Scattering Study

    NASA Astrophysics Data System (ADS)

    Mahajan, Manish; Kumar, Vijay; Saraswat, Mayank; Yadav, Savita; Shukla, N. K.; Singh, T. P.

    2008-04-01

    Human salivary mucin, a primary mucous membrane coating glycoprotein forms the first line of defense against adverse environments, attributed to the complex formation between mucin subunits and non mucin species. Aim of the study was to emphasize the effect of pH, denaturants (guanidinum hydrochloride, urea) and detergents (CHAPS, TRITON X -100, SDS on human whole salivary mucin. Hydrodynamic size distribution was measured using DLS. It was observed that aggregation was due to increase in hydrophobic interactions, believed to be accomplished by unfolding of the protein core. Whereas, the detergents which solubilize the proteins by decreasing hydrophobicity lead to disaggregation of mucin into smaller fragments. Mucin subjected to tobacco extract and upon subsequent addition of nicotine was found to have a disaggregating effect on it, suggesting nicotine may be one of the factors responsible for the disaggregating effect of tobacco on mucin, an important carcinogenetic mechanism.

  3. ALK-rearranged adenocarcinoma with extensive mucin production can mimic mucinous adenocarcinoma: clinicopathological analysis and comprehensive histological comparison with KRAS-mutated mucinous adenocarcinoma.

    PubMed

    Cha, Yoon Jin; Han, Joungho; Hwang, Soo Hyun; Lee, Tae Bum; Kim, Hojoong; Zo, Jea Ill

    2016-06-01

    We aimed to investigate clinicopathological features and histology of ALK-rearranged adenocarcinomas with extensive mucin production (AEM) that mimic mucinous adenocarcinoma (MA). Retrospectively, 12 cases of AEM and 25 cases of MA harbouring KRAS mutation were retrieved. The clinicopathological profile and detailed histological features were analysed and compared based on the ALK and KRAS status. AEMs occurred in younger patients (p = 0.044) and were characterised by floating tubulopapillary pattern (p < 0.001), prominent nucleolus (p < 0.001), and apical cytoplasmic snouts (p < 0.001). In contrast, KRAS-mutated MAs lacked ALK-specific histological patterns (p < 0.05). Instead, tumour-infiltrating leukocytes (p = 0.018) and smooth cytoplasmic borders (p < 0.001) with vesicular nuclei (p = 0.004) were prominent in KRAS-mutated MAs. AEMs demonstrated characteristic tubulopapillary pattern and apical snouts, which were distinguishing features from MAs with KRAS mutation. Apical snouts can be a useful histological surrogate for ALK rearrangement in the pulmonary adenocarcinomas showing extensive mucin that mimic MA. PMID:27114375

  4. Streptavidin Modified ZnO Film Bulk Acoustic Resonator for Detection of Tumor Marker Mucin 1.

    PubMed

    Zheng, Dan; Guo, Peng; Xiong, Juan; Wang, Shengfu

    2016-12-01

    A ZnO-based film bulk acoustic resonator has been fabricated using a magnetron sputtering technology, which was employed as a biosensor for detection of mucin 1. The resonant frequency of the thin-film bulk acoustic resonator was located near at 1503.3 MHz. The average electromechanical coupling factor [Formula: see text] and quality factor Q were 2.39 % and 224, respectively. Using the specific binding system of avidin-biotin, the streptavidin was self-assembled on the top gold electrode as the sensitive layer to indirectly test the MUC1 molecules. The resonant frequency of the biosensor decreases in response to the mass loading in range of 20-500 nM. The sensor modified with the streptavidin exhibits a high sensitivity of 4642.6 Hz/nM and a good selectivity. PMID:27624339

  5. O-glycosylation sites identified from mucin core-1 type glycopeptides from human serum.

    PubMed

    Darula, Zsuzsanna; Sarnyai, Farkas; Medzihradszky, Katalin F

    2016-06-01

    In this work O-linked glycopeptides bearing mucin core-1 type structures were enriched from human serum. Since about 70 % of the O-glycans in human serum bind to the plant lectin Jacalin, we tested a previously successful protocol that combined Jacalin affinity enrichment on the protein- and peptide-level with ERLIC chromatography as a further enrichment step in between, to eliminate the high background of unmodified peptides. In parallel, we developed a simpler and significantly faster new workflow that used two lectins sequentially: wheat germ agglutinin and then Jacalin. The first lectin provides general glycopeptide enrichment, while the second specifically enriches O-linked glycopeptides with Galβ1-3GalNAcα structures. Mass spectrometric analysis of enriched samples showed that the new sample preparation method is more selective and sensitive than the former. Altogether, 52 unique glycosylation sites in 20 proteins were identified in this study. PMID:26729242

  6. Effect of dexamethasone and ACC on bacteria-induced mucin expression in human airway mucosa.

    PubMed

    Hauber, Hans-Peter; Goldmann, Torsten; Vollmer, Ekkehard; Wollenberg, Barbara; Zabel, Peter

    2007-11-01

    Gram-negative bacteria can stimulate mucin production, but excessive mucus supports bacterial infection and consequently leads to airway obstruction. Therefore, the effect of dexamethasone (DEX) and the antioxidant acetyl-cysteine (ACC) on bacteria-induced mucus expression was investigated. Explanted human airway mucosa and mucoepidermoid cells (Calu-3) were stimulated with lipopolysaccharide (LPS) or PAM3 (a synthetic lipoprotein). DEX or ACC were added to either LPS- or PAM3-stimulated airway mucosa or Calu-3 cells. Mucin mRNA expression (MUC5AC) and total mucus glycoconjugates (mucin protein) were quantified using real-time PCR and periodic acid Schiff staining. LPS and PAM3 significantly increased mucin expression in airway mucosa and Calu-3 cells (P < 0.05). DEX alone had no significant effect on mucin expression in airway mucosa or Calu-3 cells (P > 0.05). In contrast, DEX significantly reduced LPS- and PAM3-induced mucin expression in explanted mucosal tissue and mucin expression in Calu-3 cells (P < 0.05). In explanted human airway mucosa ACC alone significantly increased mucin expression (P < 0.05). In contrast, ACC significantly decreased LPS- and PAM3-induced mucin expression (P < 0.05). In Calu-3 cells ACC alone had no significant effect on mucin expression (P > 0.05). ACC decreased LPS- and PAM3-induced mucin expression, but this effect was not significant (P > 0.05). These data suggest that DEX can effectively reduce bacteria-induced mucin expression in the airways. ACC alone may increase mucin expression in noninfected mucosa, but it decreased bacteria-induced mucin expression. Further studies are warranted to evaluate whether the effect of DEX or ACC is clinically relevant. PMID:17600317

  7. Pathology of Mucinous Appendiceal Tumors and Pseudomyxoma Peritonei.

    PubMed

    Ramaswamy, Veena

    2016-06-01

    Neoplasms of the appendix are rare, but because of their unusual presentation and unpredictable biologic behavior, it is important to diagnose them correctly. Mucinous tumors account for 58 % of malignant tumors of appendix in SEER database and the remaining are carcinoids. The mucinous appendiceal tumors have a potential to spread to the peritoneum and viscera in the form of gelatinous material with or without neoplastic cells resulting in Pseudomyxoma peritonei. (PMP) PMP is a clinical entity that has a unique biological behavior and can arise from seemingly benign tumors to frankly malignant ones. Several classifications exist for PMP of which Ronnet's classification has been the most popular. In 2010, the WHO proposed a 2 tier classification that classified PMP as either low grade or high grade based on the presence of mucin, cytological and architectural features. According to this classification when the underlying cause for PMP is an appendiceal tumor it is always a mucinous adenocarcinoma rather than a mucocoele or adenoma and these terms should no longer be used. This system of classification helps in predicting the behavior of the tumor and proper treatment strategies. The understanding of the pathogenesis of the disease has also improved with identification of newer biomarkers and molecular genetic alterations. IHC markers CK 20, CDX2 and MUC2 are found to be positive in these tumors in addition to KRAS mutation and loss of heterozygosity in some gene loci. Proper histopathologic classification and predicting the tumor behavior requires a close interaction between the pathologist and the surgeon. The use of the combined modality treatment of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has led to a 5-year survival ranging from 62.5 % to 100 % for low grade, and 0 %-65 % for high grade disease. This article focuses on the etiopathogenesis, clinical behavior, diagnosis and classification of mucinous tumors of the

  8. Identification of a Novel Mucin Gene HCG22 Associated With Steroid-Induced Ocular Hypertension

    PubMed Central

    Jeong, Shinwu; Patel, Nitin; Edlund, Christopher K.; Hartiala, Jaana; Hazelett, Dennis J.; Itakura, Tatsuo; Wu, Pei-Chang; Avery, Robert L.; Davis, Janet L.; Flynn, Harry W.; Lalwani, Geeta; Puliafito, Carmen A.; Wafapoor, Hussein; Hijikata, Minako; Keicho, Naoto; Gao, Xiaoyi; Argüeso, Pablo; Allayee, Hooman; Coetzee, Gerhard A.; Pletcher, Mathew T.; Conti, David V.; Schwartz, Stephen G.; Eaton, Alexander M.; Fini, M. Elizabeth

    2015-01-01

    Purpose. The pathophysiology of ocular hypertension (OH) leading to primary open-angle glaucoma shares many features with a secondary form of OH caused by treatment with glucocorticoids, but also exhibits distinct differences. In this study, a pharmacogenomics approach was taken to discover candidate genes for this disorder. Methods. A genome-wide association study was performed, followed by an independent candidate gene study, using a cohort enrolled from patients treated with off-label intravitreal triamcinolone, and handling change in IOP as a quantitative trait. Results. An intergenic quantitative trait locus (QTL) was identified at chromosome 6p21.33 near the 5′ end of HCG22 that attained the accepted statistical threshold for genome-level significance. The HCG22 transcript, encoding a novel mucin protein, was expressed in trabecular meshwork cells, and expression was stimulated by IL-1, and inhibited by triamcinolone acetate and TGF-β. Bioinformatic analysis defined the QTL as an approximately 4 kilobase (kb) linkage disequilibrium block containing 10 common single nucleotide polymorphisms (SNPs). Four of these SNPs were identified in the National Center for Biotechnology Information (NCBI) GTEx eQTL browser as modifiers of HCG22 expression. Most are predicted to disrupt or improve motifs for transcription factor binding, the most relevant being disruption of the glucocorticoid receptor binding motif. A second QTL was identified within the predicted signal peptide of the HCG22 encoded protein that could affect its secretion. Translation, O-glycosylation, and secretion of the predicted HCG22 protein was verified in cultured trabecular meshwork cells. Conclusions. Identification of two independent QTLs that could affect expression of the HCG22 mucin gene product via two different mechanisms (transcription or secretion) is highly suggestive of a role in steroid-induced OH. PMID:25813999

  9. The O-Linked Glycome and Blood Group Antigens ABO on Mucin-Type Glycoproteins in Mucinous and Serous Epithelial Ovarian Tumors

    PubMed Central

    Vitiazeva, Varvara; Kattla, Jayesh J.; Flowers, Sarah A.; Lindén, Sara K.; Premaratne, Pushpa; Weijdegård, Birgitta; Sundfeldt, Karin; Karlsson, Niclas G.

    2015-01-01

    Background Mucins are heavily O-glycosylated proteins where the glycosylation has been shown to play an important role in cancer. Normal epithelial ovarian cells do not express secreted mucins, but their abnormal expression has previously been described in epithelial ovarian cancer and may relate to tumor formation and progression. The cyst fluids were shown to be a rich source for acidic glycoproteins. The study of these proteins can potentially lead to the identification of more effective biomarkers for ovarian cancer. Methods In this study, we analyzed the expression of the MUC5AC and the O-glycosylation of acidic glycoproteins secreted into ovarian cyst fluids. The samples were obtained from patients with serous and mucinous ovarian tumors of different stages (benign, borderline, malignant) and grades. The O-linked oligosaccharides were released and analyzed by negative-ion graphitized carbon Liquid Chromatography (LC) coupled to Electrospray Ionization tandem Mass Spectrometry (ESI-MSn). The LC-ESI-MSn of the oligosaccharides from ovarian cyst fluids displayed differences in expression of fucose containing structures such as blood group ABO antigens and Lewis-type epitopes. Results The obtained data showed that serous and mucinous benign adenomas, mucinous low malignant potential carcinomas (LMPs, borderline) and mucinous low-grade carcinomas have a high level of blood groups and Lewis type epitopes. In contrast, this type of fucosylated structures were low abundant in the high-grade mucinous carcinomas or in serous carcinomas. In addition, the ovarian tumors that showed a high level of expression of blood group antigens also revealed a strong reactivity towards the MUC5AC antibody. To visualize the differences between serous and mucinous ovarian tumors based on the O-glycosylation, a hierarchical cluster analysis was performed using mass spectrometry average compositions (MSAC). Conclusion Mucinous benign and LMPs along with mucinous low-grade carcinomas

  10. A procedure for Alcian blue staining of mucins on polyvinylidene difluoride membranes.

    PubMed

    Dong, Weijie; Matsuno, Yu-ki; Kameyama, Akihiko

    2012-10-16

    The isolation and characterization of mucins are critically important for obtaining insight into the molecular pathology of various diseases, including cancers and cystic fibrosis. Recently, we developed a novel membrane electrophoretic method, supported molecular matrix electrophoresis (SMME), which separates mucins on a polyvinylidene difluoride (PVDF) membrane impregnated with a hydrophilic polymer. Alcian blue staining is widely used to visualize mucopolysaccharides and acidic mucins on both blotted membranes and SMME membranes; however, this method cannot be used to stain mucins with a low acidic glycan content. Meanwhile, periodic acid-Schiff staining can selectively visualize glycoproteins, including mucins, but is incompatible with glycan analysis, which is indispensable for mucin characterizations. Here we describe a novel staining method, designated succinylation-Alcian blue staining, for visualizing mucins on a PVDF membrane. This method can visualize mucins regardless of the acidic residue content and shows a sensitivity 2-fold higher than that of Pro-Q Emerald 488, a fluorescent periodate Schiff-base stain. Furthermore, we demonstrate the compatibility of this novel staining procedure with glycan analysis using porcine gastric mucin as a model mucin. PMID:22950532

  11. Structural investigation of porcine stomach mucin by X-ray fiber diffraction and homology modeling

    SciTech Connect

    Veluraja, K.; Vennila, K.N.; Umamakeshvari, K.; Jasmine, A.; Velmurugan, D.

    2011-03-25

    Research highlights: {yields} Techniques to get oriented mucin fibre. {yields} X-ray fibre diffraction pattern for mucin. {yields} Molecular modeling of mucin based on X-ray fibre diffraction pattern. -- Abstract: The basic understanding of the three dimensional structure of mucin is essential to understand its physiological function. Technology has been developed to achieve orientated porcine stomach mucin molecules. X-ray fiber diffraction of partially orientated porcine stomach mucin molecules show d-spacing signals at 2.99, 4.06, 4.22, 4.7, 5.37 and 6.5 A. The high intense d-spacing signal at 4.22 A is attributed to the antiparallel {beta}-sheet structure identified in the fraction of the homology modeled mucin molecule (amino acid residues 800-980) using Nidogen-Laminin complex structure as a template. The X-ray fiber diffraction signal at 6.5 A reveals partial organization of oligosaccharides in porcine stomach mucin. This partial structure of mucin will be helpful in establishing a three dimensional structure for the whole mucin molecule.

  12. VAMP8 is a vesicle SNARE that regulates mucin secretion in airway goblet cells.

    PubMed

    Jones, Lisa C; Moussa, Lama; Fulcher, M Leslie; Zhu, Yunxiang; Hudson, Elizabeth J; O'Neal, Wanda K; Randell, Scott H; Lazarowski, Eduardo R; Boucher, Richard C; Kreda, Silvia M

    2012-02-01

    Mucin secretion is an innate defence mechanism, which is noxiously upregulated in obstructive lung diseases (e.g. chronic obstructive pulmonary disease (COPD), cystic fibrosis and asthma). Mucin granule exocytosis is regulated by specific protein complexes, but the SNARE exocytotic core has not been defined in airway goblet cells. In this study, we identify VAMP8 as one of the SNAREs regulating mucin granule exocytosis. VAMP8 mRNA was present in human airway and lung epithelial cells, and deep-sequencing and expression analyses of airway epithelial cells revealed that VAMP8 transcripts were expressed at 10 times higher levels than other VAMP mRNAs. In human airway epithelial cell cultures and freshly excised tissues, VAMP8 immunolocalised mainly to goblet cell mucin granules. The function of VAMP8 in airway mucin secretion was tested by RNA interference techniques. Both VAMP8 short interfering RNAs (siRNAs) and short hairpin RNAs (shRNAs) reduced mucin secretion induced by PAR agonists, neutrophil elastase and ATP in two airway epithelial cell culture models. Notably, basal (non-agonist elicited) mucin secretion was also reduced in these experiments. VAMP8 knockdown was also effective in decreasing mucin secretion in airway epithelial cell cultures with induced mucous metaplasia/mucin hypersecretion. Unlike VAMP8 silencing, knockdown of VAMP2 or VAMP3 did not affect mucin secretion. Importantly, in VAMP8 knock-out (KO) mice with IL-13-induced mucous metaplasia, mucin content in the bronchoalveolar lavage (BAL) and ATP-stimulated mucin secretion in the trachea were reduced compared to WT-matched littermates. Our data indicate that VAMP8 is an essential SNARE in airway mucin granule exocytosis. Reduction of VAMP8 activity/expression may provide a novel therapeutic target to ameliorate airway mucus obstruction in lung diseases. PMID:22144578

  13. An evaluation of the morphologic features of low-grade mucinous neoplasms of the appendix metastatic in the ovary, and comparison with primary ovarian mucinous tumors.

    PubMed

    Stewart, Colin J R; Ardakani, Nima M; Doherty, Dorota A; Young, Robert H

    2014-01-01

    It may be difficult to distinguish ovarian involvement by a low-grade appendiceal mucinous neoplasm (LAMN) from a primary gastrointestinal-type primary borderline (proliferative) ovarian tumor (IBMT) or an ovarian mucinous tumor arising within a teratoma, particularly when the latter is associated with mucinous ascites/pseudomyxoma peritonei. We noted that LAMNs involving the ovaries show 2 distinctive histologic features, "scalloped" glands and subepthelial stromal clefts, whereas IBMTs more often are associated with reactive cellular stroma and histiocyte aggregates (mucin granulomas). The frequency of these features was investigated in 18 LAMNs (16 with pseudomyxoma peritonei), 18 primary IBMTs, and 6 teratoma-associated mucinous tumors (selected on the basis of associated pseudomyxoma peritonei). Scalloped glands and subepithelial clefts were identified in 17 and 16 LAMNs, respectively, and in 3 and 7 IBMTs, respectively. Conversely, reactive stroma and histiocyte aggregates were present in 2 and 0 LAMNs, respectively, and in 11 and 10 IBMTs, respectively. LAMNs were often bilateral (12/18 cases) and they more frequently showed mucin dissection of the ovarian stroma and tall mucin-rich (hypermucinous) epithelial cells compared with IBMTs. Our findings suggest that scalloped glands, subepithelial clefts, cellular stroma, and histiocyte aggregates may be useful additional morphologic parameters to help distinguish these tumor types. However, teratoma-associated mucinous neoplasms can show identical histologic features to those of LAMNs involving the ovary, and therefore accurate diagnosis of such cases requires careful macroscopic and microscopic examinations of the ovaries together with complete histologic assessment of the appendix. PMID:24300528

  14. [Microbiocenosis of parietal mucin in the gastrointestinal tract of rats].

    PubMed

    Vorob'ev, A A; Nesvizhskiĭ, Iu V; Bogdanova, E A; Korneev, L M

    2005-01-01

    The qualitative and quantitative composition of the microbial community in parietal mucin at different areas of the gastrointestinal tract (GIT) of rats was revealed. The pronounced variability in the quantitative and qualitative characteristics of microbiocenosis in parietal mucin of rats at different sections was revealed. The differences were most pronounced in the passage from upper to lower GIT sections, the large intestine found to be the richest biocenosis. The microbial composition of rat feces was faintly associated with the GIT parietal microbiocenosis. The individual areas of GIT mucosa were unique of their microbial characteristics and organization. This makes it possible to regard them as relatively independent biotopes and indicates that it is impossible to evaluate the microbial community by one of the colonic mucosal sifes. PMID:16438365

  15. Enzymatically active biomimetic micropropellers for the penetration of mucin gels

    PubMed Central

    Walker, Debora; Käsdorf, Benjamin T.; Jeong, Hyeon-Ho; Lieleg, Oliver; Fischer, Peer

    2015-01-01

    In the body, mucus provides an important defense mechanism by limiting the penetration of pathogens. It is therefore also a major obstacle for the efficient delivery of particle-based drug carriers. The acidic stomach lining in particular is difficult to overcome because mucin glycoproteins form viscoelastic gels under acidic conditions. The bacterium Helicobacter pylori has developed a strategy to overcome the mucus barrier by producing the enzyme urease, which locally raises the pH and consequently liquefies the mucus. This allows the bacteria to swim through mucus and to reach the epithelial surface. We present an artificial system of reactive magnetic micropropellers that mimic this strategy to move through gastric mucin gels by making use of surface-immobilized urease. The results demonstrate the validity of this biomimetic approach to penetrate biological gels, and show that externally propelled microstructures can actively and reversibly manipulate the physical state of their surroundings, suggesting that such particles could potentially penetrate native mucus. PMID:26824056

  16. Synthetic Oral Mucin Mimic from Polymer Micelle Networks

    PubMed Central

    2015-01-01

    Mucin networks are formed in the oral cavity by complexation of glycoproteins with other salivary proteins, yielding a hydrated lubricating barrier. The function of these networks is linked to their structural, chemical, and mechanical properties. Yet, as these properties are interdependent, it is difficult to tease out their relative importance. Here, we demonstrate the ability to recreate the fibrous like network through a series of complementary rinses of polymeric worm-like micelles, resulting in a 3-dimensional (3D) porous network that can be deposited layer-by-layer onto any surface. In this work, stability, structure, and microbial capture capabilities were evaluated as a function of network properties. It was found that network structure alone was sufficient for bacterial capture, even with networks composed of the adhesion-resistant polymer, poly(ethylene glycol). The synthetic networks provide an excellent, yet simple, means of independently characterizing mucin network properties (e.g., surface chemistry, stiffness, and pore size). PMID:24992241

  17. CFTR, Mucins, and Mucus Obstruction in Cystic Fibrosis

    PubMed Central

    Kreda, Silvia M.; Davis, C. William; Rose, Mary Callaghan

    2012-01-01

    Mucus pathology in cystic fibrosis (CF) has been known for as long as the disease has been recognized and is sometimes called mucoviscidosis. The disease is marked by mucus hyperproduction and plugging in many organs, which are usually most fatal in the airways of CF patients, once the problem of meconium ileus at birth is resolved. After the CF gene, CFTR, was cloned and its protein product identified as a cAMP-regulated Cl− channel, causal mechanisms underlying the strong mucus phenotype of the disease became obscure. Here we focus on mucin genes and polymeric mucin glycoproteins, examining their regulation and potential relationships to a dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR). Detailed examination of CFTR expression in organs and different cell types indicates that changes in CFTR expression do not always correlate with the severity of CF disease or mucus accumulation. Thus, the mucus hyperproduction that typifies CF does not appear to be a direct cause of a defective CFTR but, rather, to be a downstream consequence. In organs like the lung, up-regulation of mucin gene expression by inflammation results from chronic infection; however, in other instances and organs, the inflammation may have a non-infectious origin. The mucus plugging phenotype of the β-subunit of the epithelial Na+ channel (βENaC)-overexpressing mouse is proving to be an archetypal example of this kind of inflammation, with a dehydrated airway surface/concentrated mucus gel apparently providing the inflammatory stimulus. Data indicate that the luminal HCO3 − deficiency recently described for CF epithelia may also provide such a stimulus, perhaps by causing a mal-maturation of mucins as they are released onto luminal surfaces. In any event, the path between CFTR dysfunction and mucus hyperproduction has proven tortuous, and its unraveling continues to offer its own twists and turns, along with fascinating glimpses into biology. PMID:22951447

  18. S100P is a useful marker for differentiation of ovarian mucinous tumors.

    PubMed

    Umezaki, Y; Ito, M; Nakashima, M; Mihara, Y; Naruke, Y; Kurohama, H; Yatsunami, N; Yasuhi, I

    2015-01-01

    The S100P protein stimulates cell proliferation and survival, thereby contributing to tumor progression. The purpose of this study was to evaluate S100P expression in the three subtypes of mucinous cystic tumors, cystadenomas, borderline tumors, and adenocarcinomas. The authors examined nuclear S100P expression in 60 mucinous ovarian tumor specimens, including 24 specimens of mucinous cystadenoma, 15 of borderline tumors, and 21 of adenocarcinomas. Immunohistochemistry revealed S100P expression followed one of three patterns: (1) Expressed in most nuclei of mucinous epithelial cells, (2) sporadic (spotted or patchy) expression, or (3) absent or rarely expressed in the nuclei of mucinous epithelial cells. Most adenomas showed the first expression pattern, and borderline tumors often showed a patchy expression pattern. Adenocarcinomas generally demonstrated absence of S100P expression. These data suggest that S100P is a useful histological marker to differentiate between benign, borderline, and malignant mucinous tumors of the ovary. PMID:26050349

  19. A distinct molecular profile associated with mucinous epithelial ovarian cancer

    PubMed Central

    Heinzelmann-Schwarz, V A; Gardiner-Garden, M; Henshall, S M; Scurry, J P; Scolyer, R A; Smith, A N; Bali, A; Bergh, P Vanden; Baron-Hay, S; Scott, C; Fink, D; Hacker, N F; Sutherland, R L; O'Brien, P M

    2006-01-01

    Mucinous epithelial ovarian cancers (MOC) are clinically and morphologically distinct from the other histological subtypes of ovarian cancer. To determine the genetic basis of MOC and to identify potential tumour markers, gene expression profiling of 49 primary ovarian cancers of different histological subtypes was performed using a customised oligonucleotide microarray containing >59 000 probesets. The results show that MOC express a genetic profile that both differs and overlaps with other subtypes of epithelial ovarian cancer. Concordant with its histological phenotype, MOC express genes characteristic of mucinous carcinomas of varying epithelial origin, including intestinal carcinomas. Differences in gene expression between MOC and other histological subtypes of ovarian cancer were confirmed by RT–PCR and/or immunohistochemistry. In particular, galectin 4 (LGALS4) was highly and specifically expressed in MOC, but expressed at lower levels in benign mucinous cysts and borderline (atypical proliferative) tumours, supporting a malignant progression model of MOC. Hence LGALS4 may have application as an early and differential diagnostic marker of MOC. PMID:16508639

  20. Mucins help to avoid alloreactivity at the maternal fetal interface.

    PubMed

    Redzovic, Arnela; Laskarin, Gordana; Dominovic, Marin; Haller, Herman; Rukavina, Daniel

    2013-01-01

    During gestation, many different mechanisms act to render the maternal immune system tolerant to semi-allogeneic trophoblast cells of foetal origin, including those mediated via mucins that are expressed during the peri-implantation period in the uterus. Tumour- associated glycoprotein-72 (TAG-72) enhances the already established tolerogenic features of decidual dendritic cells with the inability to progress towards Th1 immune orientation due to lowered interferon (IFN)- γ and interleukin (IL)-15 expression. Mucine 1 (Muc 1) supports alternative activation of decidual macrophages, restricts the proliferation of decidual regulatory CD56(+) bright natural killer (NK) cells, and downregulates their cytotoxic potential, including cytotoxic mediator protein expression. Removing TAG-72 and Muc 1 from the eutopic implantation site likely contributes to better control of trophoblast invasion by T cells and NK cells and appears to have important immunologic advantages for successful implantation, in addition to mechanical advantages. However, these processes may lead to uncontrolled trophoblast growth after implantation, inefficient defence against infection or tumours, and elimination of unwanted immunocompetent cells at the maternal-foetal interface. The use of mucins by tumour cells to affect the local microenvironment in order to avoid the host immune response and to promote local tumour growth, invasion, and metastasis confirms this postulation. PMID:23864879

  1. Tea derived galloylated polyphenols cross-link purified gastrointestinal mucins.

    PubMed

    Georgiades, Pantelis; Pudney, Paul D A; Rogers, Sarah; Thornton, David J; Waigh, Thomas A

    2014-01-01

    Polyphenols derived from tea are thought to be important for human health. We show using a combination of particle tracking microrheology and small-angle neutron scattering that polyphenols acts as cross-linkers for purified gastrointestinal mucin, derived from the stomach and the duodenum. Both naturally derived purified polyphenols, and green and black tea extracts are shown to act as cross-linkers. The main active cross-linking component is found to be the galloylated forms of catechins. The viscosity, elasticity and relaxation time of the mucin solutions experience an order of magnitude change in value upon addition of the polyphenol cross-linkers. Similarly small-angle neutron scattering experiments demonstrate a sol-gel transition with the addition of polyphenols, with a large increase in the scattering at low angles, which is attributed to the formation of large scale (>10 nm) heterogeneities during gelation. Cross-linking of mucins by polyphenols is thus expected to have an impact on the physicochemical environment of both the stomach and duodenum; polyphenols are expected to modulate the barrier properties of mucus, nutrient absorption through mucus and the viscoelastic microenvironments of intestinal bacteria. PMID:25162539

  2. [Intraductal papillary mucinous neoplasia: which findings support observation?].

    PubMed

    Mayerle, J; Kraft, M; Menges, P; Simon, P; Ringel, J; Partecke, L I; Heidecke, C D; Lerch, M M

    2012-02-01

    On abdominal CT scans asymptomatic cystic lesions of the pancreas are accidentally detected in 1-2% of patients. Congenital cysts and pancreatic pseudocysts account for two thirds of these lesions. Pancreatic pseudocysts are a frequent complication of acute and chronic pancreatitis. Among resected cystic neoplasms serous cystic adenoma accounts for 30%, mucinous cystic neoplasms for 45% and intraductal papillary mucinous neoplasms for 25%. The diagnosis of a cystic pancreatic lesion is usually made by diagnostic imaging. Symptomatic lesions require definitive therapeutic treatment after appropriate diagnostic work-up. In the diagnosis of asymptomatic cystic lesions several factors are important, among them whether the cyst is connected to the pancreatic duct (as in IPMN and pseudocysts), the size of lesion (for treatment indications) and whether nodules form in the wall of the cyst (a sign of potential malignancy). EUS-guided fine needle aspiration of the cyst fluid adds to the discrimination between benign, premalignant and malignant cystic lesions. Measuring lipase activity, CEA, viscosity and mucin as well as cytology can help in differentiating cystic lesions. An algorithm is discussed for the differential diagnosis and for selection of the appropriate treatment for pancreatic cystic lesions, most of which never require surgery. PMID:22271054

  3. Diffusion through Pig Gastric Mucin: Effect of Relative Humidity

    PubMed Central

    Runnsjö, Anna; Dabkowska, Aleksandra P.; Sparr, Emma; Kocherbitov, Vitaly; Arnebrant, Thomas; Engblom, Johan

    2016-01-01

    Mucus covers the epithelium found in all intestinal tracts, where it serves as an important protecting barrier, and pharmaceutical drugs administrated by the oral, rectal, vaginal, ocular, or nasal route need to penetrate the mucus in order to reach their targets. Furthermore, the diffusion in mucus as well as the viscosity of mucus in the eyes, nose and throat can change depending on the relative humidity of the surrounding air. In this study we have investigated how diffusion through gels of mucin, the main protein in mucus, is affected by changes in ambient relative humidity (i.e. water activity). Already a small decrease in water activity was found to give rise to a significant decrease in penetration rate through the mucin gel of the antibacterial drug metronidazole. We also show that a decrease in water activity leads to decreased diffusion rate in the mucin gel for the fluorophore fluorescein. This study shows that it is possible to alter transport rates of molecules through mucus by changing the water activity in the gel. It furthermore illustrates the importance of considering effects of the water activity in the mucosa during development of potential pharmaceuticals. PMID:27336158

  4. Polymorphisms in mucin genes in the development of gastric cancer

    PubMed Central

    Wen, Rong; Gao, Fang; Zhou, Cheng-Jiang; Jia, Yan-Bin

    2015-01-01

    Gastric cancer (GC) is the third leading cause of cancer-related death worldwide. In areas of high prevalence, such as Japan, South Korea and China, most cases of GC are related to Helicobacter pylori (H. pylori), which involves well-characterized sequential stages, including infection, atrophic gastritis, intestinal metaplasia, dysplasia, and GC. Mucins are the most abundant high-molecular-weight glycoproteins in mucus, which is the first line of defense and plays a major role in blocking pathogenic factors. Normal gastric mucosa shows expression of MUC1, MUC5AC and MUC6 that is specific to cell type. However, the specific pattern of MUC1, MUC5AC and MUC6 expression is changed in gastric carcinogenesis, accompanied by de novo expression of secreted MUC2. Recent studies have provided evidence that variations in these mucin genes affect many steps of GC development, such as H. pylori infection, and gastric precancerous lesions. In this review, we focus on studies of the association between polymorphisms in mucin genes and development of GC. This information should be helpful for the early detection, surveillance, and treatment of GC. PMID:26600932

  5. Salivary Mucins Protect Surfaces from Colonization by Cariogenic Bacteria

    PubMed Central

    Frenkel, Erica Shapiro

    2014-01-01

    Understanding how the body's natural defenses function to protect the oral cavity from the myriad of bacteria that colonize its surfaces is an ongoing topic of research that can lead to breakthroughs in treatment and prevention. One key defense mechanism on all moist epithelial linings, such as the mouth, gastrointestinal tract, and lungs, is a layer of thick, well-hydrated mucus. The main gel-forming components of mucus are mucins, large glycoproteins that play a key role in host defense. This study focuses on elucidating the connection between MUC5B salivary mucins and dental caries, one of the most common oral diseases. Dental caries is predominantly caused by Streptococcus mutans attachment and biofilm formation on the tooth surface. Once S. mutans attaches to the tooth, it produces organic acids as metabolic by-products that dissolve tooth enamel, leading to cavity formation. We utilize CFU counts and fluorescence microscopy to quantitatively show that S. mutans attachment and biofilm formation are most robust in the presence of sucrose and that aqueous solutions of purified human MUC5B protect surfaces by acting as an antibiofouling agent in the presence of sucrose. In addition, we find that MUC5B does not alter S. mutans growth and decreases surface attachment and biofilm formation by maintaining S. mutans in the planktonic form. These insights point to the importance of salivary mucins in oral health and lead to a better understanding of how MUC5B could play a role in cavity prevention or diagnosis. PMID:25344244

  6. Palliative Surgical Approach in Advanced Nonresponsive Mucinous Ovarian Cancer: A Rare Case Report

    PubMed Central

    Agarwal, Manika; Kumar, Ritesh; Topno, Noor; Mishra, Shweta; Dhirasaria, Ashish; Singh, A Santa

    2016-01-01

    Advanced mucinous ovarian cancer is a separate entity and has different biological behaviour. There is a wide range of therapeutic challenges and dilemmas in the management of these patients. The authors present a case of advanced ovarian mucinous cystadenocarcinoma with pseudomyxoma peritonei who had poor response to standard neoadjuvant chemotherapy. This case is highlighted to emphasize the challenges in the decision making for the management of advanced mucinous ovarian cancer. PMID:27162429

  7. Mucin Agarose Gel Electrophoresis: Western Blotting for High-molecular-weight Glycoproteins.

    PubMed

    Ramsey, Kathryn A; Rushton, Zachary L; Ehre, Camille

    2016-01-01

    Mucins, the heavily-glycosylated proteins lining mucosal surfaces, have evolved as a key component of innate defense by protecting the epithelium against invading pathogens. The main role of these macromolecules is to facilitate particle trapping and clearance while promoting lubrication of the mucosa. During protein synthesis, mucins undergo intense O-glycosylation and multimerization, which dramatically increase the mass and size of these molecules. These post-translational modifications are critical for the viscoelastic properties of mucus. As a result of the complex biochemical and biophysical nature of these molecules, working with mucins provides many challenges that cannot be overcome by conventional protein analysis methods. For instance, their high-molecular-weight prevents electrophoretic migration via regular polyacrylamide gels and their sticky nature causes adhesion to experimental tubing. However, investigating the role of mucins in health (e.g., maintaining mucosal integrity) and disease (e.g., hyperconcentration, mucostasis, cancer) has recently gained interest and mucins are being investigated as a therapeutic target. A better understanding of the production and function of mucin macromolecules may lead to novel pharmaceutical approaches, e.g., inhibitors of mucin granule exocytosis and/or mucolytic agents. Therefore, consistent and reliable protocols to investigate mucin biology are critical for scientific advancement. Here, we describe conventional methods to separate mucin macromolecules by electrophoresis using an agarose gel, transfer protein into nitrocellulose membrane, and detect signal with mucin-specific antibodies as well as infrared fluorescent gel reader. These techniques are widely applicable to determine mucin quantitation, multimerization and to test the effects of pharmacological compounds on mucins. PMID:27341489

  8. Cysteamine and prostaglandin F2 beta stimulate rat gastric mucin release

    SciTech Connect

    Lamont, J.T.; Ventola, A.S.; Maull, E.A.; Szabo, S.

    1983-02-01

    Gastric mucin glycoproteins form an adherent gel over the surface epithelium that is thought to protect the stomach against chemical and physical damage. The purpose of this study was to measure the release of mucin glycoproteins from rat stomach after treatment with cysteamine and prostaglandin F2 beta, two structurally unrelated drugs that have been shown to protect the stomach against the noxious effects of alcohol and other damaging agents. Gastric mucin was separated into soluble (washout) and insoluble (adherent) phases before colorimetric quantitation of total mucin, protein-bound hexose, and sialic acid. Cysteamine produced a dose-dependent increase in release of soluble and gel mucin. Prostaglandin F2 beta caused a dose-dependent release of hexose-containing mucin but had no effect on sialic acid-containing glycoproteins. Sepharose 4B chromatography of both the soluble and adherent mucus revealed that greater than 90% was a high molecular weight glycoprotein fraction. N-Ethylmaleimide, a known inhibitor of cytoprotection by cysteamine, had no effect on mucin secretion. Similarly, indomethacin inhibited mucin secretion by cysteamine but did not significantly influence cytoprotection. Thus the secretion of mucin by cytoprotective agents is unlikely by itself to explain the ability of the stomach to resist chemical or physical damage.

  9. Molecular analysis of ovarian mucinous carcinoma reveals different cell of origins.

    PubMed

    Wang, Yihong; Shwartz, Lauren Ende; Anderson, Derek; Lin, Ming-Tseh; Haley, Lisa; Wu, Ren-Chin; Vang, Russell; Shih, Ie-Ming; Kurman, Robert J

    2015-09-01

    It is believed that a subset of primary ovarian mucinous tumors is derived from mature teratomas [1-5]. To confirm this, we performed microsatellite genotyping using a variety of short tandem repeat makers and analyzed allelotypes of 8 mucinous tumors (4 mucinous carcinomas, 3 atypical proliferative mucinous tumors and 1 mucinous cystadenoma) associated with a teratoma to determine whether they were clonally related. 7 of the 8 mucinous tumors showed complete or a high degree of homozygosity. Among the 6 pairs of tumors with teratoma tissue available for comparison, 5 of 6 showed a high or complete degree of allelotypes matching, which differed from the somatic allelotypes of the normal control tissue. A discrepancy was detected between carcinoma and teratoma in one pair at several loci, with different X-chromosome inactivation patterns revealed by the HUMARA clonality assay. We also investigated the allelotypes of 16 ovarian mucinous carcinomas without a teratoma in young patients (range 13-30) and in 6 older patients (range 40-67) using the same method. None of these tumors showed pure homozygosity. The number of homozygous loci in this cohort was significantly lower than that in the first. Our results suggest first, that most mucinous tumors associated with a teratoma are derived from the teratoma but occasionally they could be collision tumors and second that the majority of pure mucinous tumors in young women in whom a teratoma is not present are not derived from a teratoma. PMID:26355245

  10. Benign mucinous metaplasia of the penis. A lesion resembling extramammary Paget's disease.

    PubMed

    Val-Bernal, J F; Hernández-Nieto, E

    2000-02-01

    Benign mucinous metaplasia in the surface epithelium of the genital area is rare and has only been reported once in the vulva. A unique case of benign mucinous metaplasia of the prepuce in a 65-year-old man is reported here. The lesion measured 0.6 cm, was located in the mucous surface of the foreskin, and showed acid mucin containing cells. We regard benign mucinous metaplasia as a reactive rather than a neoplastic process. The main lesions to be considered in the differential diagnosis are mucinous syringometaplasia, extramammary Paget's disease, cutaneous squamous cell carcinoma in situ with mucinous metaplasia, superficial spreading malignant melanoma, and epidermotropic metastasis. The confinement of mucin-containing cells to the epidermis, the absence of nuclear atypia, the basal orientation of the nuclei, the predominant location of the cells in the upper layers of the epithelium, and the fact that the mucinous cells are replacing the squamous epithelium rather that infiltrating it, all assist in recognizing mucinous metaplasia of the penis as a specific and benign entity. PMID:10678702

  11. Emerging Potential of Natural Products for Targeting Mucins for Therapy Against Inflammation and Cancer

    PubMed Central

    Macha, Muzafar A.; Krishn, Shiv Ram; Jahan, Rahat; Banerjee, Kasturi; Batra, Surinder K.; Jain, Maneesh

    2015-01-01

    Deregulated mucin expression is a hallmark of several inflammatory and malignant pathologies. Emerging evidence suggests that, apart from biomarkers, these deregulated mucins are functional contributors to pathogenesis in inflammation and cancer. Both overexpression and downregulation of mucins in various organ systems is associated with pathobiology of inflammation and cancer. Restoration of mucin homeostasis has become an important goal for therapy and management of such disorders and has fueled the quest for selective mucomodulators. With improved understanding of mucin regulation and mechanistic insights into their pathobiological roles, there is optimism to find selective non-toxic agents capable of modulating mucin expression and function. Recently, natural compounds derived from dietary sources have drawn attention due to their anti-inflammatory and anti-oxidant properties and low toxicity. Considerable efforts have been directed towards evaluating dietary natural products as chemopreventive and therapeutic agents; identification, characterization and synthesis of their active compounds; and improving their delivery and bioavailability. We describe the current understanding of mucin regulation, rationale for targeting mucins with natural products and discuss some natural products that modulate mucin expression and functions. We further discuss the approaches and parameters that should guide future research to identify and evaluate selective natural mucomodulators for therapy. PMID:25624117

  12. The effect of the space flight environment on mucin production in the mouse uterine tube

    NASA Astrophysics Data System (ADS)

    Svalina, Gorica; Forsman, Allan D.

    2013-06-01

    Numerous studies have indicated that the microgravity environment of space has harmful effects on several tissues throughout the body. Although this phenomenon is well documented, research in this area is still in its relative infancy. This study investigates the effects of space flight on mucin production of the uterine tubes of mice. This study examined the epithelium of the uterine tubes from female mice that were flown on the space shuttle Endeavour for 13 days in August, 2007 and their concomitant controls. The tissue was qualitatively analyzed for the type of mucin produced, i.e., acidic, neutral, acidic/neutral mixture. Further, the tissue was quantitatively analyzed for the amounts of mucins produced by measuring the thickness of the mucin layer for each region of the uterine tube: isthmus, ampulla, and infundibulum. One way ANOVA tests were used to compare mucin thickness between all three sets of animals. Results indicate similar but not identical results between the three regions of the uterine tube. The Baseline tissue had the thickest mucin layer regardless of treatment group. In the ampulla the mucin layer was the thinnest in the Flight tissue, followed by the Ground Control, with the Baseline being the thickest. Analysis of the mucin layer of the infundibulum of the three treatment groups indicated no difference in its thickness between the three regions of the uterine tube. These results indicate a trend toward thinning of the mucin layer of the uterine tube in space flight, but also indicate an influence by the housing environment.

  13. Emerging potential of natural products for targeting mucins for therapy against inflammation and cancer.

    PubMed

    Macha, Muzafar A; Krishn, Shiv Ram; Jahan, Rahat; Banerjee, Kasturi; Batra, Surinder K; Jain, Maneesh

    2015-03-01

    Deregulated mucin expression is a hallmark of several inflammatory and malignant pathologies. Emerging evidence suggests that, apart from biomarkers, these deregulated mucins are functional contributors to the pathogenesis in inflammation and cancer. Both overexpression and downregulation of mucins in various organ systems is associated with pathobiology of inflammation and cancer. Restoration of mucin homeostasis has become an important goal for therapy and management of such disorders has fueled the quest for selective mucomodulators. With improved understanding of mucin regulation and mechanistic insights into their pathobiological roles, there is optimism to find selective non-toxic agents capable of modulating mucin expression and function. Recently, natural compounds derived from dietary sources have drawn attention due to their anti-inflammatory and anti-oxidant properties and low toxicity. Considerable efforts have been directed towards evaluating dietary natural products as chemopreventive and therapeutic agents; identification, characterization and synthesis of their active compounds; and improving their delivery and bioavailability. We describe the current understanding of mucin regulation, rationale for targeting mucins with natural products and discuss some natural products that modulate mucin expression and functions. We further discuss the approaches and parameters that should guide future research to identify and evaluate selective natural mucomodulators for therapy. PMID:25624117

  14. Ocular surface mucins and local inflammation-studies in genetically modified mouse lines.

    PubMed

    Shirai, Kumi; Saika, Shizuya

    2015-01-01

    Mucins locate to the apical surfaces of all wet-surfaced epithelia including ocular surface. The functions of the mucins include anti-adhesive, lubrication, water retention, allergens and pathogen barrier function. Ocular surface pathologies, i.e. dry eye syndrome or allergic conjunctivitis, are reportedly associated with alteration of expression pattern of mucin components. Recent investigations indicated anti-bacterial adhesion or anti-inflammatory effects of members of mucins in non-ocular tissues, i.e., gastrointestinal tracts or airway tissues, by using genetically modified mouse lines that lacks an expression of a mucin member. However, examination of ocular phenotypes of each of mucin gene-ablated mouse lines has not yet fully performed. Muc16-dficient mouse is associated with spontaneous subclinical inflammation in conjunctiva. The article reviews the roles of mucin members in modulation of local inflammation in mucous membrane tissues and phenotype of mouse lines with the loss of a mucin gene. Analysis of ocular surface of mucin-gene related mutant mouse lines are to be further performed. PMID:26818460

  15. Cystic fibrosis airway secretions exhibit mucin hyperconcentration and increased osmotic pressure

    PubMed Central

    Henderson, Ashley G.; Ehre, Camille; Button, Brian; Abdullah, Lubna H.; Cai, Li-Heng; Leigh, Margaret W.; DeMaria, Genevieve C.; Matsui, Hiro; Donaldson, Scott H.; Davis, C. William; Sheehan, John K.; Boucher, Richard C.; Kesimer, Mehmet

    2014-01-01

    The pathogenesis of mucoinfective lung disease in cystic fibrosis (CF) patients likely involves poor mucus clearance. A recent model of mucus clearance predicts that mucus flow depends on the relative mucin concentration of the mucus layer compared with that of the periciliary layer; however, mucin concentrations have been difficult to measure in CF secretions. Here, we have shown that the concentration of mucin in CF sputum is low when measured by immunologically based techniques, and mass spectrometric analyses of CF mucins revealed mucin cleavage at antibody recognition sites. Using physical size exclusion chromatography/differential refractometry (SEC/dRI) techniques, we determined that mucin concentrations in CF secretions were higher than those in normal secretions. Measurements of partial osmotic pressures revealed that the partial osmotic pressure of CF sputum and the retained mucus in excised CF lungs were substantially greater than the partial osmotic pressure of normal secretions. Our data reveal that mucin concentration cannot be accurately measured immunologically in proteolytically active CF secretions; mucins are hyperconcentrated in CF secretions; and CF secretion osmotic pressures predict mucus layer–dependent osmotic compression of the periciliary liquid layer in CF lungs. Consequently, mucin hypersecretion likely produces mucus stasis, which contributes to key infectious and inflammatory components of CF lung disease. PMID:24892808

  16. Efficacy of a novel mucolytic agent on pseudomyxoma peritonei mucin, with potential for treatment through peritoneal catheters.

    PubMed

    Akhter, Javed; Pillai, Krishna; Chua, Terence C; Alzarin, Naeef; Morris, David Lawson

    2014-01-01

    Compared to current treatment for pseudomyxoma peritonei (PMP), the extraction of solubilised mucin through peritoneal catheter can be minimally invasive. However, mucin has variable appearance that may influence mucolysis. Hence, we investigated the mucolysis of 36 mucin samples with a novel agent. Using visual inspection and hardness index, PMP mucin was classified into three grades. The mucin pathological category was identified from patient record. Subsequently, the dissolution of the samples was tested. For in vitro, 1 g of mucin was treated to the mucolytic agent in 10 ml TRIS buffer at 37 deg. Celsius for 3 hours, with weighing of residual mucin. Control treatment was similar but received TRIS buffer. For in vivo, 2 g of implanted intra-peritoneal mucin in nude rats was treated to mucolytic (2 X 500 ul/24 hr, over 48 hours, plus another treatment before sacrifice at 56 hours, with weighing of residual mucin. Controls were treated but only with TRIS buffer. Six animals were used for each mucin grade (3 mucolytic treated & and 3 controls). Grades of mucin were soft mucin (62%), semi hard (20%) and hard mucin (18%). Diffuse peritoneal adenomucinosis had 50% of soft mucin and peritoneal mucinous carcinoma had 11% (P = 0.0382). In vitro and in vivo absolute disintegration was 100% for soft, 57.38% and 48.67% for semi hard, 50% and 28.67% for hard mucin. Majority of mucin were soft with complete disintegration, the rest showed variable disintegration, suggesting that the mucolytic has potential for treating PMP. PMID:25232491

  17. Efficacy of a novel mucolytic agent on pseudomyxoma peritonei mucin, with potential for treatment through peritoneal catheters

    PubMed Central

    Akhter, Javed; Pillai, Krishna; Chua, Terence C; Alzarin, Naeef; Morris, David Lawson

    2014-01-01

    Compared to current treatment for pseudomyxoma peritonei (PMP), the extraction of solubilised mucin through peritoneal catheter can be minimally invasive. However, mucin has variable appearance that may influence mucolysis. Hence, we investigated the mucolysis of 36 mucin samples with a novel agent. Using visual inspection and hardness index, PMP mucin was classified into three grades. The mucin pathological category was identified from patient record. Subsequently, the dissolution of the samples was tested. For in vitro, 1 g of mucin was treated to the mucolytic agent in 10 ml TRIS buffer at 37 deg. Celsius for 3 hours, with weighing of residual mucin. Control treatment was similar but received TRIS buffer. For in vivo, 2 g of implanted intra-peritoneal mucin in nude rats was treated to mucolytic (2 X 500 ul/24 hr, over 48 hours, plus another treatment before sacrifice at 56 hours, with weighing of residual mucin. Controls were treated but only with TRIS buffer. Six animals were used for each mucin grade (3 mucolytic treated & and 3 controls). Grades of mucin were soft mucin (62%), semi hard (20%) and hard mucin (18%). Diffuse peritoneal adenomucinosis had 50% of soft mucin and peritoneal mucinous carcinoma had 11% (P = 0.0382). In vitro and in vivo absolute disintegration was 100% for soft, 57.38% and 48.67% for semi hard, 50% and 28.67% for hard mucin. Majority of mucin were soft with complete disintegration, the rest showed variable disintegration, suggesting that the mucolytic has potential for treating PMP. PMID:25232491

  18. PAX2, PAX8 and CDX2 Expression in Metastatic Mucinous, Primary Ovarian Mucinous and Seromucinous Tumors and Review of the Literature.

    PubMed

    Ates Ozdemir, D; Usubutun, A

    2016-07-01

    Ovarian cancer is the most common cause of gynecologic cancer death. Both morphologically and immunohistochemically, metastatic mucinous tumors are the best mimickers of mucinous ovarian tumors; its pathogenesis still remains a mystery. PAX2 and PAX8 immunohisyochemistries are useful for differentiating numerous primary tumour types from metastatic ones. There are few studies in literature about PAX expressions in mucinous and seromucinous tumors. None of these are takes into account the histologic type (whether it is seromucinous or mucinous) or the metastatic origin. With this purpose hematoxylin and eosine slides of ovarian mucinous and seromucinous tumors were re-evaluated and one block was chosen for each case. The study included 76 ovarian mucinous and seromucinous tumors of the ovary reported in Hacettepe University department of pathology between 2000 and 2013. Tissue microarray (TMA) was designed from the chosen blocks, PAX2, PAX8, CDX2 immunostains was preformed to the TMA slides. As a result, most of the metastatic cases were negative for PAX2 (91.2 %) and PAX8 (86.3 %), many were diffusely and strongly positive for CDX2 (68.2 %). Seromucinous tumors were devoid of CDX2 expression; but all cases (except one) displayed strong and diffuse positivity with PAX8. In other words differing from mucinous tumors, seromucinous tumors show strong PAX8 positivity-similar to serous tumors. This study shows that PAX8 and CDX2 could be useful in differentiating primary mucinous from metastatic tumor. Furthermore unlike the homogeneity in seromucinous tumors for PAX8 and CDX2 mucinous tumors shows heterogeneity with different expression patterns. PMID:26797858

  19. Depletion of mucin in mucin-producing human gastrointestinal carcinoma: Results from in vitro and in vivo studies with bromelain and N-acetylcysteine

    PubMed Central

    Amini, Afshin; Masoumi-Moghaddam, Samar; Ehteda, Anahid; Liauw, Winston; Morris, David L.

    2015-01-01

    Aberrant expression of membrane-associated and secreted mucins, as evident in epithelial tumors, is known to facilitate tumor growth, progression and metastasis, and to provide protection against adverse growth conditions, chemotherapy and immune surveillance. Emerging evidence provides support for the oncogenic role of MUC1 in gastrointestinal carcinomas and relates its expression to an invasive phenotype. Similarly, mucinous differentiation of gastrointestinal tumors, in particular increased or de novo expression of MUC2 and/or MUC5AC, is widely believed to imply an adverse clinicopathological feature. Through formation of viscous gels, too, MUC2 and MUC5AC significantly contribute to the biology and pathogenesis of mucin-secreting gastrointestinal tumors. Here, we investigated the mucin-depleting effects of bromelain (BR) and N-acetylcysteine (NAC), in nine different regimens as single or combination therapy, in in vitro (MKN45, KATOIII and LS174T cell lines) and in vivo (female nude mice bearing intraperitoneal MKN45 and LS174T) settings. The inhibitory effects of the treatment on cancer cell growth and proliferation were also evaluated in vivo. Our results suggest that a combination of BR and NAC with dual effects on growth and mucin products of mucin-expressing tumor cells is a promising candidate towards the development of novel approaches to gastrointestinal malignancies with the involvement of mucin pathology. This capability supports the use of this combination formulation in locoregional approaches for reducing the adverse effects of the aberrantly secreted gel-forming mucins, as in pseudomyxoma peritonei and similar pathologies with ectopic production of mucin. PMID:26436698

  20. Depletion of mucin in mucin-producing human gastrointestinal carcinoma: Results from in vitro and in vivo studies with bromelain and N-acetylcysteine.

    PubMed

    Amini, Afshin; Masoumi-Moghaddam, Samar; Ehteda, Anahid; Liauw, Winston; Morris, David L

    2015-10-20

    Aberrant expression of membrane-associated and secreted mucins, as evident in epithelial tumors, is known to facilitate tumor growth, progression and metastasis, and to provide protection against adverse growth conditions, chemotherapy and immune surveillance. Emerging evidence provides support for the oncogenic role of MUC1 in gastrointestinal carcinomas and relates its expression to an invasive phenotype. Similarly, mucinous differentiation of gastrointestinal tumors, in particular increased or de novo expression of MUC2 and/or MUC5AC, is widely believed to imply an adverse clinicopathological feature. Through formation of viscous gels, too, MUC2 and MUC5AC significantly contribute to the biology and pathogenesis of mucin-secreting gastrointestinal tumors. Here, we investigated the mucin-depleting effects of bromelain (BR) and N-acetylcysteine (NAC), in nine different regimens as single or combination therapy, in in vitro (MKN45, KATOIII and LS174T cell lines) and in vivo (female nude mice bearing intraperitoneal MKN45 and LS174T) settings. The inhibitory effects of the treatment on cancer cell growth and proliferation were also evaluated in vivo. Our results suggest that a combination of BR and NAC with dual effects on growth and mucin products of mucin-expressing tumor cells is a promising candidate towards the development of novel approaches to gastrointestinal malignancies with the involvement of mucin pathology. This capability supports the use of this combination formulation in locoregional approaches for reducing the adverse effects of the aberrantly secreted gel-forming mucins, as in pseudomyxoma peritonei and similar pathologies with ectopic production of mucin. PMID:26436698

  1. Baseline Goblet Cell Mucin Secretion in the Airways Exceeds Stimulated Secretion over Extended Time Periods, and Is Sensitive to Shear Stress and Intracellular Mucin Stores.

    PubMed

    Zhu, Yunxiang; Abdullah, Lubna H; Doyle, Sean P; Nguyen, Kristine; Ribeiro, Carla M P; Vasquez, Paula A; Forest, M Gregory; Lethem, Michael I; Dickey, Burton F; Davis, C William

    2015-01-01

    Airway mucin secretion studies have focused on goblet cell responses to exogenous agonists almost to the exclusion of baseline mucin secretion (BLMS). In human bronchial epithelial cell cultures (HBECCs), maximal agonist-stimulated secretion exceeds baseline by ~3-fold as measured over hour-long periods, but mucin stores are discharged completely and require 24 h for full restoration. Hence, over 24 h, total baseline exceeds agonist-induced secretion by several-fold. Studies with HBECCs and mouse tracheas showed that BLMS is highly sensitive to mechanical stresses. Harvesting three consecutive 1 h baseline luminal incubations with HBECCs yielded equal rates of BLMS; however, lengthening the middle period to 72 h decreased the respective rate significantly, suggesting a stimulation of BLMS by the gentle washes of HBECC luminal surfaces. BLMS declined exponentially after washing HBECCs (t1/2 = 2.75 h), to rates approaching zero. HBECCs exposed to low perfusion rates exhibited spike-like increases in BLMS when flow was jumped 5-fold: BLMS increased >4 fold, then decreased within 5 min to a stable plateau at 1.5-2-fold over control. Higher flow jumps induced proportionally higher BLMS increases. Inducing mucous hyperplasia in HBECCs increased mucin production, BLMS and agonist-induced secretion. Mouse tracheal BLMS was ~6-fold higher during perfusion, than when flow was stopped. Munc13-2 null mouse tracheas, with their defect of accumulated cellular mucins, exhibited similar BLMS as WT, contrary to predictions of lower values. Graded mucous metaplasia induced in WT and Munc13-2 null tracheas with IL-13, caused proportional increases in BLMS, suggesting that naïve Munc13-2 mouse BLMS is elevated by increased mucin stores. We conclude that BLMS is, [i] a major component of mucin secretion in the lung, [ii] sustained by the mechanical activity of a dynamic lung, [iii] proportional to levels of mucin stores, and [iv] regulated differentially from agonist-induced mucin

  2. Baseline Goblet Cell Mucin Secretion in the Airways Exceeds Stimulated Secretion over Extended Time Periods, and Is Sensitive to Shear Stress and Intracellular Mucin Stores

    PubMed Central

    Doyle, Sean P.; Nguyen, Kristine; Ribeiro, Carla M. P.; Vasquez, Paula A.; Forest, M. Gregory; Lethem, Michael I.; Dickey, Burton F.; Davis, C. William

    2015-01-01

    Airway mucin secretion studies have focused on goblet cell responses to exogenous agonists almost to the exclusion of baseline mucin secretion (BLMS). In human bronchial epithelial cell cultures (HBECCs), maximal agonist-stimulated secretion exceeds baseline by ~3-fold as measured over hour-long periods, but mucin stores are discharged completely and require 24 h for full restoration. Hence, over 24 h, total baseline exceeds agonist-induced secretion by several-fold. Studies with HBECCs and mouse tracheas showed that BLMS is highly sensitive to mechanical stresses. Harvesting three consecutive 1 h baseline luminal incubations with HBECCs yielded equal rates of BLMS; however, lengthening the middle period to 72 h decreased the respective rate significantly, suggesting a stimulation of BLMS by the gentle washes of HBECC luminal surfaces. BLMS declined exponentially after washing HBECCs (t1/2 = 2.75 h), to rates approaching zero. HBECCs exposed to low perfusion rates exhibited spike-like increases in BLMS when flow was jumped 5-fold: BLMS increased >4 fold, then decreased within 5 min to a stable plateau at 1.5–2-fold over control. Higher flow jumps induced proportionally higher BLMS increases. Inducing mucous hyperplasia in HBECCs increased mucin production, BLMS and agonist-induced secretion. Mouse tracheal BLMS was ~6-fold higher during perfusion, than when flow was stopped. Munc13-2 null mouse tracheas, with their defect of accumulated cellular mucins, exhibited similar BLMS as WT, contrary to predictions of lower values. Graded mucous metaplasia induced in WT and Munc13-2 null tracheas with IL-13, caused proportional increases in BLMS, suggesting that naïve Munc13-2 mouse BLMS is elevated by increased mucin stores. We conclude that BLMS is, [i] a major component of mucin secretion in the lung, [ii] sustained by the mechanical activity of a dynamic lung, [iii] proportional to levels of mucin stores, and [iv] regulated differentially from agonist-induced mucin

  3. Mucins as Diagnostic and Prognostic Biomarkers in a Fish-Parasite Model: Transcriptional and Functional Analysis

    PubMed Central

    Pérez-Sánchez, Jaume; Estensoro, Itziar; Redondo, María José; Calduch-Giner, Josep Alvar; Kaushik, Sadasivam; Sitjà-Bobadilla, Ariadna

    2013-01-01

    Mucins are O-glycosylated glycoproteins present on the apex of all wet-surfaced epithelia with a well-defined expression pattern, which is disrupted in response to a wide range of injuries or challenges. The aim of this study was to identify mucin gene sequences of gilthead sea bream (GSB), to determine its pattern of distribution in fish tissues and to analyse their transcriptional regulation by dietary and pathogenic factors. Exhaustive search of fish mucins was done in GSB after de novo assembly of next-generation sequencing data hosted in the IATS transcriptome database (www.nutrigroup-iats.org/seabreamdb). Six sequences, three categorized as putative membrane-bound mucins and three putative secreted-gel forming mucins, were identified. The transcriptional tissue screening revealed that Muc18 was the predominant mucin in skin, gills and stomach of GSB. In contrast, Muc19 was mostly found in the oesophagus and Muc13 was along the entire intestinal tract, although the posterior intestine exhibited a differential pattern with a high expression of an isoform that does not share a clear orthologous in mammals. This mucin was annotated as intestinal mucin (I-Muc). Its RNA expression was highly regulated by the nutritional background, whereas the other mucins, including Muc2 and Muc2-like, were expressed more constitutively and did not respond to high replacement of fish oil (FO) by vegetable oils (VO) in plant protein-based diets. After challenge with the intestinal parasite Enteromyxum leei, the expression of a number of mucins was decreased mainly in the posterior intestine of infected fish. But, interestingly, the highest down-regulation was observed for the I-Muc. Overall, the magnitude of the changes reflected the intensity and progression of the infection, making mucins and I-Muc, in particular, reliable markers of prognostic and diagnostic value of fish intestinal health. PMID:23776483

  4. Prognostic comparison between mucinous and nonmucinous adenocarcinoma in colorectal cancer.

    PubMed

    Park, Jong Seob; Huh, Jung Wook; Park, Yoon Ah; Cho, Yong Beom; Yun, Seong Hyeon; Kim, Hee Cheol; Lee, Woo Yong; Chun, Ho-Kyung

    2015-04-01

    Mucinous adenocarcinoma (MAC) is a histological subtype of colorectal cancer. The oncologic behavior of MAC differs from nonmucinous adenocarcinoma (non-MAC). Our aim in this study was to characterize patients with colorectal MAC through evaluation of a large, institutional-based cohort with long-term follow-up. A total of 6475 patients with stages I to III colorectal cancer who underwent radical surgery were enrolled from January 2000 to December 2010. Prognostic comparison between MAC (n = 274, 4.2%) and non-MAC was performed. The median follow-up period was 48.0 months. Patients with MAC were younger than those without MAC (P = 0.012) and had larger tumor size (P < 0.001), higher preoperative carcinoembryonic antigen (P < 0.001), higher pathologic T stage (P < 0.001), more right-sided colon cancer (49.3%, P < 0.001), and more frequent high-frequency microsatellite instability (10.2%, P < 0.001). Five-year disease-free survival (DFS) was 76.5% in the MAC group and 83.2% in the non-MAC group (P = 0.008), and 5-year overall survival was 81.4% versus 87.4%, respectively (P = 0.005). Mucinous histology (MAC vs non-MAC) in the entire cohort was not an independent prognostic factor of DFS but had a statistical tendency (P = 0.071). In subgroup analysis of colon cancer without rectal cancer, mucinous histology was an independent prognostic factor (P = 0.026). MAC was found at more advanced stage, located mainly at the right side and was an independent factor of survival in colon cancer. Because of the unique biological behavior of MAC, patients with MAC require special consideration during follow-up. PMID:25881840

  5. Novel bifidobacterial glycosidases acting on sugar chains of mucin glycoproteins.

    PubMed

    Katayama, Takane; Fujita, Kiyotaka; Yamamoto, Kenji

    2005-05-01

    Bifidobacterium bifidum was found to produce a specific 1,2-alpha-L-fucosidase. Its gene (afc A) has been cloned and the DNA sequence was determined. The Afc A protein consisting of 1959 amino acid residues with a predicted molecular mass of 205 kDa can be divided into three domains; the N-terminal function-unknown domain (576 aa), the catalytic domain (898 aa), and the C-terminal bacterial Ig-like domain (485 aa). The recombinant catalytic domain specifically hydrolyzed the terminal alpha-(1-->2)-fucosidic linkages of various oligosaccharides and sugar chains of glycoproteins. The primary structure of the catalytic domain exhibited no similarity to those of any glycoside hydrolases but showed similarity to those of several hypothetical proteins in a database, which resulted in establishment of a novel glycoside hydrolase family (GH family 95). Several bifidobacteria were found to produce a specific endo-alpha-N-acetylgalactosaminidase, which is the endoglycosidase liberating the O-glycosidically linked galactosyl beta1-->3 N-acetylgalactosamine disaccharide from mucin glycoprotein. The molecular cloning of endo-alpha-N-acetylgalactosaminidase was carried out on Bifidobacterium longum based on the information in the database. The gene was found to comprise 1966 amino acid residues with a predicted molecular mass of 210 kDa. The recombinant protein released galactosyl beta1-->3 N-acetylgalactosamine disaccharide from natural glycoproteins. This enzyme of B. longum is believed to be involved in the catabolism of oligosaccharide of intestinal mucin glycoproteins. Both 1,2-alpha-L-fucosidase and endo-alpha-N-acetylgalactosaminidase are novel and specific enzymes acting on oligosaccharides that exist mainly in mucin glycoproteins. Thus, it is reasonable to conclude that bifidobacteria produce these enzymes to preferentially utilize the oligosaccharides present in the intestinal ecosystem. PMID:16233817

  6. Antigenic and structural features of goblet-cell mucin of human small intestine.

    PubMed Central

    Mantle, M; Forstner, G G; Forstner, J F

    1984-01-01

    With the use of a newly developed solid-phase radioimmunoassay method, the major antigenic determinants of human small-intestinal goblet-cell mucin were investigated and related to the overall tertiary structure of the mucin. Preliminary hapten inhibition studies with various oligosaccharides of known sequence and structure suggested that the determinants did not reside in carbohydrate. Exhaustive thiol reduction, however, almost abolished antigenicity, caused breakdown of the mucin into small heterogeneous glycopeptides, and liberated a 'link' peptide of Mr 118000. Western 'blots' of reduced mucin from polyacrylamide gels on to nitrocellulose sheets showed that a small amount of residual antigenicity remained in large-Mr glycopeptides (Mr greater than 200000). The 'link' peptide was not antigenic. Timed Pronase digestion of native mucin resulted in a progressive loss of antigenic determinants. Gel electrophoresis revealed that after 8h of digestion the 118000-Mr peptide had disappeared, whereas antigenicity, which was confined to large-Mr glycopeptides, was destroyed much more slowly with time (70% by 24h, 100% by 72h). Despite the loss of antigenicity, 72h-Pronase-digested glycopeptides retained all of the carbohydrate of the native mucin. Therefore the antibody to human small-intestinal mucin appears to recognize a 'naked' (non-glycosylated and Pronase-susceptible) peptide region(s) of mucin glycopeptides. For full antigenicity, however, disulphide bonds are required to stabilize a specific three-dimensional configuration of the 'naked' region. Images Fig. 4. Fig. 6. PMID:6199017

  7. Incidental Finding of a Rare Urachal Pathology: Urachal Mucinous Cystic Tumour of Low Malignant Potential

    PubMed Central

    Wang, Luke L.; Liddell, Heath; Tanny, Sharman Tan; Norris, Briony; Appu, Sree; Pan, David

    2016-01-01

    Urachal mucinous cystic tumours are rare pathological findings with only 23 previously reported cases in the literature. We present the case of a 54-year-old man with an incidentally found urachal mucinous cystic tumour laparoscopically excised. With its known potential to cause pseudomyxoma peritonei, complete surgical excision is important. Long-term cystoscopic and radiological surveillance is also required. PMID:26881171

  8. Different staining patterns of ovarian Brenner tumor and the associated mucinous tumor.

    PubMed

    Roma, Andres A; Masand, Ramya P

    2015-02-01

    The association of ovarian Brenner tumors and adjacent mucinous tumors is well known but not completely understood. In this study, we analyzed immunohistochemical markers on Brenner tumors and their associated mucinous tumor to explore Mullerian as well as Wolffian and germ cell derivation and determine if the mucinous component is independent or related to the Brenner tumor. Of 32 consecutive cases of Brenner tumors, 8 were identified with significant mucinous component, and 7 additional cases included foci of mucinous epithelium within the Brenner transitional nests. All Brenner tumors were diffusely positive for GATA3 and negative for Paired box gene 8, PAX2, and Sal-like protein 4. Interestingly, the areas of mucinous epithelium as well as mucinous tumors, intermixed and adjacent to the Brenner tumor, were negative for all 4 markers; however, occasional basal-like cells retained expression of GATA3. The immunoprofile of mucinous tumors associated with Brenner tumors shares the lack of Mullerian markers PAX2 and Paired box gene 8 with the Brenner tumor but differs in the expression of GATA3 only in the Brenner tumor component. PMID:25596159

  9. Mucin aggregation from a rod-like meso-scale model

    NASA Astrophysics Data System (ADS)

    Moreno, Nicolas; Perilla, Jairo E.; Colina, Coray M.; Lísal, Martin

    2015-05-01

    Dissipative particle dynamics, a meso-scale particle-based model, was used to study the aggregation of mucins in aqueous solutions. Concentration, strength of the mucin-water interactions, as well as the effects of size, shape, and composition of the model molecules were studied. Model proteins were represented as rod-like objects formed by coarse-grained beads. In the first model, only one type of beads formed the mucin. It was found that all the surfaces were available to form aggregates and the conformation of the aggregates was a function of the strength of the mucin-water interaction. With this model, the number of aggregates was unaffected by the initial position of the mucins in the simulation box, except for the lowest mucin concentration. In a more refined mucin model, two kinds of beads were used in the molecule in order to represent the existence of cysteine-like terminal groups in the actual molecule. With this new scheme, aggregation took place by the interaction of the terminal groups between model molecules. The kinetic analysis of the evolution of the number of aggregates with time was also studied for both mucin models.

  10. Effect of reserpine on the histochemical and biochemical properties of rat intestinal mucin

    SciTech Connect

    Forstner, J.; Roomi, N.; Khorasani, R.; Kuhns, W.; Forstner, G. )

    1991-04-01

    Biochemical and histochemical parameters of intestinal mucins were examined in control and reserpine-treated rats. An assay for intestinal mucin sulfotransferase was developed and the activity shown to increase 3.4 times over control levels in rats given intraperitonal reserpine (0.5 mg/kg body wt) daily for 7 days. Histochemical staining of intestinal sections revealed an increase in sulfomucins in goblet cells of reserpine-treated rats. The effects were prominent as early as 1 day following injection, particularly in the distal third of the small intestine, and during the next 6 days these changes spread progressively to the middle and proximal thirds. After 3 days of treatment mucins were purified from each intestinal segment and compared to control mucins with respect to composition and (35S)NaSO{sub 4} incorporation. Although individual amino acid and carbohydrate molar ratios were unchanged, the total carbohydrate and sulfate content of mucins in treated animals was elevated (two to three times above control) in the middle and distal thirds of the intestine. In vivo ({sup 35}S)SO{sub 4} incorporation into these mucins was also proportionaltely elevated, and was targetted to O-linked oligosaccharide side chains. These findings are consistent with an action of reserpine causing an increased production of mucin which is enriched in glycoprotein components bearing sulfated oligosaccharide chains. The relevance of these findings to the production of hypersulfated and hyperglycosylated mucins in cystic fibrosis is discussed.

  11. Mechanophysical Stimulations of Mucin Secretion in Cultures of Nasal Epithelial Cells

    PubMed Central

    Even-Tzur Davidovich, Nurit; Kloog, Yoel; Wolf, Michael; Elad, David

    2011-01-01

    Nasal epithelial cells secret mucins and are exposed in vivo to airflow-induced mechanophysical stresses, including wall shear stress (WSS), temperature, and humidity. In this work, human nasal epithelial cells cultured under air-liquid interface conditions were subjected to fields of airflow-induced oscillatory WSS at different temperature and humidity conditions. Changes in mucin secretion due to WSS were measured and the role of the cytoskeleton in mucin secretion was explored. Mucin secretion significantly increased in response to WSS in a magnitude-dependent manner with respect to static cultures and independently of the airflow temperature and humidity. In static cultures, mucin secretion decreased at high humidity with or without elevation of the temperature with respect to cultures at a comfortable climate. In cultures exposed to WSS, mucin secretion increased at high temperature with respect to cultures at comfortable climate conditions. The polymerization of actin microfilaments was shown to increase mucin secretion under WSS, whereas the dynamics of microtubule polymerization did not affect secretion. In conclusion, the data in this study show that mucin secretion is sensitive to oscillatory WSS as well as high temperature and humidity conditions. PMID:21689518

  12. [Mucinous adenocarcinoma of the appendix. Report of a case].

    PubMed

    Wolniczak, Isabella; Cáceres Del Águila, Alonso; Santillana Callirgos, Juan Alberto

    2016-01-01

    Mucinous adenocarcinoma of the appendix is a rare neoplasm with an incidence rate of 0.08% of all malignancies. The diagnosis is usually made by biopsy because its clinical presentation may mimic other diseases of structures located in the right lower quadrant. Currently, the treatment is still controversial, being surgery the best option. This report describes a patient with a history of appendectomy 27 years ago that is hospitalized for a painful mass in the lower abdomen associated with carcinoembryonic antigen of 138 ng/dl. PMID:27409095

  13. An abundantly expressed mucin-like protein from Toxocara canis infective larvae: the precursor of the larval surface coat glycoproteins.

    PubMed Central

    Gems, D; Maizels, R M

    1996-01-01

    Evasion of host immunity by Toxocara canis infective larvae is mediated by the nematode surface coat, which is shed in response to binding by host antibody molecules or effector cells. The major constituent of the coat is the TES-120 glycoprotein series. We have isolated a 730-bp cDNA from the gene encoding the apoprotein precursor of TES-120. The mRNA is absent from T. canis adults but hyperabundant in larvae, making up approximately 10% of total mRNA, and is trans-spliced with the nematode 5' leader sequence SL1. It encodes a 15.8-kDa protein (after signal peptide removal) containing a typical mucin domain: 86 amino acid residues, 72.1% of which are Ser or Thr, organized into an array of heptameric repeats, interspersed with proline residues. At the C-terminal end of the putative protein are two 36-amino acid repeats containing six Cys residues, in a motif that can also be identified in several genes in Caenorhabditis elegans. Although TES-120 displays size and charge heterogeneity, there is a single copy gene and a homogeneous size of mRNA. The association of overexpression of some membrane-associated mucins with immunosuppression and tumor metastasis suggests a possible model for the role of the surface coat in immune evasion by parasitic nematodes. Images Fig. 1 Fig. 4 PMID:8643687

  14. Colonic mucin composition in primates. Selective alterations associated with spontaneous colitis in the cotton-top tamarin.

    PubMed

    Podolsky, D K; Madara, J L; King, N; Sehgal, P; Moore, R; Winter, H S

    1985-01-01

    Heterogeneity of colonic mucin glycoprotein was examined in rectal mucosal biopsy specimens from a variety of primate species (Saguinus oedipus, n = 18; Macaca mulatta, n = 2; Macaca fascicularis, n = 2; Aotus trivirgatus, n = 2; Saimiri sciureus, n = 2; and Callithrix jacchus, n = 2). After initial separation of radiolabeled mucin and nonmucin glycoproteins solubilized from mucosal biopsy specimens, at least five labeled mucin components were found in monkey rectal mucosa in contrast to the six mucin fractions observed in the human colon. Although primates consistently lacked the earliest eluting component present in human colonic mucin, other mucin components cochromatographed with comparable fractions previously identified in human colonic biopsy specimens. The relative proportions of each fraction were consistent throughout all species except the cotton-top tamarin (S. oedipus), an animal that develops a chronic colitis. The cotton-top tamarin was found to have a markedly reduced amount of one mucin component (IV) in a manner analogous to the reduction in a human mucin fraction previously noted in patients with ulcerative colitis. Sequential evaluation of mucin profiles in cotton-top tamarins (n = 12) treated with sulfasalazine (50 mg/kg X day) or placebo in a 10-wk double-blind crossover study demonstrated the persistence of the selective reduction in tamarin species IV unrelated to disease activity. In contrast, the relative amount of tamarin mucin III was greater in association with increased disease activity than that observed in association with reduced disease activity (46% +/- 11% total mucin vs. 19% +/- 7% total mucin posttreatment). PMID:3917260

  15. Mucin-1 and its relation to grade, stage and survival in ovarian carcinoma patients

    PubMed Central

    2012-01-01

    Background Mucin-1 is known to be over-expressed by various human carcinomas and is shed into the circulation where it can be detected in patient’s serum by specific anti-Mucin-1 antibodies, such as the tumour marker assays CA 15–3 and CA 27.29. The prognostic value of Mucin-1 expression in ovarian carcinoma remains uncertain. One aim of this study was to compare the concentrations of Mucin-1 in a cohort of patients with either benign or malignant ovarian tumours detected by CA 15–3 and CA 27.29. Another aim of this study was to evaluate Mucin-1 expression by immunohistochemistry in a different cohort of ovarian carcinoma patients with respect to grade, stage and survival. Methods Patients diagnosed with and treated for ovarian tumours were included in the study. Patient characteristics, histology including histological subtype, tumour stage, grading and follow-up data were available from patient records. Serum Mucin-1 concentrations were measured with ELISA technology detecting CA 15–3 and CA 27.29, Mucin-1 tissue expression was determined by immunohistochemistry using the VU4H5 and VU3C6 anti-Mucin-1 antibodies. Statistical analysis was performed by using SPSS 18.0. Results Serum samples of 118 patients with ovarian tumours were obtained to determine levels of Mucin-1. Median CA 15–3 and CA 27.29 concentrations were significantly higher in patients with malignant disease (p< 0.001) than in patients with benign disease. Paraffin-embedded tissue of 154 patients with ovarian carcinoma was available to determine Mucin-1 expression. The majority of patients presented with advanced stage disease at primary diagnosis. Median follow-up time was 11.39 years. Immunohistochemistry results for VU4H5 showed significant differences with respect to tumour grade, FIGO stage and overall survival. Patients with negative expression had a mean overall survival of 9.33 years compared to 6.27 years for patients with positive Mucin-1 expression. Conclusions This study found

  16. Mucinous tumors of the ovary: current thoughts on diagnosis and management.

    PubMed

    Brown, Jubilee; Frumovitz, Michael

    2014-06-01

    Mucinous tumors of the ovary represent a spectrum of neoplastic disorders, including benign mucinous cystadenoma, pseudomyxoma peritonei, mucinous tumors of low malignant potential (borderline), and invasive mucinous ovarian carcinoma. These tumors are related closely to each other and are distinct from other histologic subtypes of epithelial ovarian neoplasms from a clinical, histologic, and molecular standpoint. A continuum appears to be present from benign to borderline to malignant, which is different from other types of epithelial ovarian cancer. Mutational profiles are also distinct, as KRAS mutations are common, but p53 and BRCA mutations are infrequent. These characteristics lead to specific biologic behavior and guide both clinical management and research efforts in patients with mucinous ovarian tumors. PMID:24777667

  17. Residual mucin and response after neoadjuvant chemotherapy (NAC) in breast cancer.

    PubMed

    Jove, Maria; Verghese, Eldo; Sharma, Nisha; Lane, Sally

    2016-01-01

    Neoadjuvant chemotherapy (NAC) is the standard of care for patients with breast cancer with inoperable disease or smaller tumours who might benefit from a conservative surgery after downstaging of their disease. Nevertheless, evidence shows that preoperative and postoperative chemotherapy are equivalent in terms of long-term survival. Response and histological changes after NAC have been widely studied in invasive ductal carcinoma not otherwise specified, but there is a paucity of characterisation of patterns of response to chemotherapy in less frequent histological types. We report extensive residual mucin deposits after chemotherapy in a woman with locally advanced breast cancer and a prominent mucinous component at diagnosis. Interestingly, residual mucin was co-located with the initial tumour, in the breast as well as in the axillary lymph nodes. The distribution of mucin may be a valuable marker of the extent of mucinous carcinomas prior to NAC. PMID:27154986

  18. Transforming Growth Factor-β2 Induces Bronchial Epithelial Mucin Expression in Asthma

    PubMed Central

    Chu, Hong Wei; Balzar, Silvana; Seedorf, Gregory J.; Westcott, Jay Y.; Trudeau, John B.; Silkoff, Phil; Wenzel, Sally E.

    2004-01-01

    The transforming growth factor (TGF)-β family is important for tissue repair in pathological conditions including asthma. However, little is known about the impact of either TGF-β1 or TGF-β2 on asthmatic airway epithelial mucin expression. We evaluated bronchial epithelial TGF-β1 and TGF-β2 expression and their effects on mucin expression, and the role of TGF-β1 or TGF-β2 in interleukin (IL)-13-induced mucin expression. Epithelial TGF-β1, TGF-β2, and mucin expression were evaluated in endobronchial biopsies from asthmatics and normal subjects. The effects of TGF-β1 or TGF-β2 on mucin MUC5AC protein and mRNA expression, and the impact of IL-13 on epithelial TGF-β1, TGF-β2, and MUC5AC were determined in cultured bronchial epithelial cells from endobronchial brushings of both subject groups. In biopsy tissue, epithelial TGF-β2 expression levels were higher than TGF-β1 in both asthmatics and normals. TGF-β2, but not TGF-β1, was increased in asthmatics compared with normals, and significantly correlated with mucin expression. TGF-β2, but not TGF-β1, increased mucin expression in cultured epithelial cells from both subject groups. IL-13 increased the release of TGF-β2, but not TGF-β1, from epithelial cells. A neutralizing TGF-β2 antibody partially inhibited IL-13-induced mucin expression. These data suggest that TGF-β2 production by asthmatic bronchial epithelial cells may increase airway mucin expression. IL-13-induced mucin expression may occur in part through TGF-β2 up-regulation. PMID:15466377

  19. Transforming growth factor-beta2 induces bronchial epithelial mucin expression in asthma.

    PubMed

    Chu, Hong Wei; Balzar, Silvana; Seedorf, Gregory J; Westcott, Jay Y; Trudeau, John B; Silkoff, Phil; Wenzel, Sally E

    2004-10-01

    The transforming growth factor (TGF)-beta family is important for tissue repair in pathological conditions including asthma. However, little is known about the impact of either TGF-beta1 or TGF-beta2 on asthmatic airway epithelial mucin expression. We evaluated bronchial epithelial TGF-beta1 and TGF-beta2 expression and their effects on mucin expression, and the role of TGF-beta1 or TGF-beta2 in interleukin (IL)-13-induced mucin expression. Epithelial TGF-beta1, TGF-beta2, and mucin expression were evaluated in endobronchial biopsies from asthmatics and normal subjects. The effects of TGF-beta1 or TGF-beta2 on mucin MUC5AC protein and mRNA expression, and the impact of IL-13 on epithelial TGF-beta1, TGF-beta2, and MUC5AC were determined in cultured bronchial epithelial cells from endobronchial brushings of both subject groups. In biopsy tissue, epithelial TGF-beta2 expression levels were higher than TGF-beta1 in both asthmatics and normals. TGF-beta2, but not TGF-beta1, was increased in asthmatics compared with normals, and significantly correlated with mucin expression. TGF-beta2, but not TGF-beta1, increased mucin expression in cultured epithelial cells from both subject groups. IL-13 increased the release of TGF-beta2, but not TGF-beta1, from epithelial cells. A neutralizing TGF-beta2 antibody partially inhibited IL-13-induced mucin expression. These data suggest that TGF-beta2 production by asthmatic bronchial epithelial cells may increase airway mucin expression. IL-13-induced mucin expression may occur in part through TGF-beta2 up-regulation. PMID:15466377

  20. Cytopathological Analysis of Cyst Fluid Enhances Diagnostic Accuracy of Mucinous Pancreatic Cystic Neoplasms

    PubMed Central

    Utomo, Wesley K.; Braat, Henri; Bruno, Marco J.; van Eijck, Casper H.J.; Koerkamp, Bas Groot; Krak, Nanda C.; van de Vreede, Adriaan; Fuhler, Gwenny M.; Peppelenbosch, Maikel P.; Biermann, Katharina

    2015-01-01

    Abstract Widespread use of cross-sectional imaging and increasing age of the general population has increased the number of detected pancreatic cystic lesions. However, several pathological entities with a variety in malignant potential have to be discriminated to allow clinical decision making. Discrimination between mucinous pancreatic cystic neoplasms (PCNs) and nonmucinous pancreatic lesions is the primary step in the clinical work-up, as malignant transformation is mostly associated with mucinous PCN. We performed a retrospective analysis of all resected PCN in our tertiary center from 2000 to 2014, to evaluate preoperative diagnostic performance and the results of implementation of the consensus guidelines over time. This was followed by a prospective cohort study of patients with an undefined pancreatic cyst, where the added value of cytopathological mucin evaluation to carcinoembryonic antigen (CEA) in cyst fluid for the discrimination of mucinous PCN and nonmucinous cysts was investigated. Retrospective analysis showed 115 patients operated for a PCN, with a correct preoperative classification in 96.2% of the patients. High-grade dysplasia or invasive carcinoma was observed in only 32.3% of mucinous PCN. In our prospective cohort (n = 71), 57.7% of patients were classified as having a mucinous PCN. CEA ≥192 ng/mL had an accuracy of 63.4%, and cytopathological mucin evaluation an accuracy of 73.0%. Combining these 2 tests further improved diagnostic accuracy of a mucinous PCN to 76.8%. CEA level and mucin evaluation were not predictive of the degree of dysplasia. These findings show that adding cytopathology to cyst fluid biochemistry improves discrimination between mucinous PCN and nonmucinous cysts.

  1. Rectal Cancer: Mucinous Carcinoma on Magnetic Resonance Imaging Indicates Poor Response to Neoadjuvant Chemoradiation

    SciTech Connect

    Oberholzer, Katja; Menig, Matthias; Kreft, Andreas; Schneider, Astrid; Junginger, Theodor; Heintz, Achim; Kreitner, Karl-Friedrich; Hoetker, Andreas M.; Hansen, Torsten; Dueber, Christoph; Schmidberger, Heinz

    2012-02-01

    Purpose: To assess response of locally advanced rectal carcinoma to chemoradiation with regard to mucinous status and local tumor invasion found at pretherapeutic magnetic resonance imaging (MRI). Methods and Materials: A total of 88 patients were included in this prospective study of patients with advanced mrT3 and mrT4 carcinomas. Carcinomas were categorized by MRI as mucinous (mucin proportion >50% within the tumor volume), and as nonmucinous. Patients received neoadjuvant chemoradiation consisting of 50.4 Gy (1.8 Gy/fraction) and 5-fluorouracil on Days 1 to 5 and Days 29 to 33. Therapy response was assessed by comparing pretherapeutic MRI with histopathology of surgical specimens (minimum distance between outer tumor edge and circumferential resection margin = CRM, T, and N category). Results: A mucinous carcinoma was found in 21 of 88 patients. Pretherapeutic mrCRM was 0 mm (median) in the mucinous and nonmucinous group. Of the 88 patients, 83 underwent surgery with tumor resection. The ypCRM (mm) at histopathology was significantly lower in mucinous carcinomas than in nonmucinous carcinomas (p {<=} 0.001). Positive resection margins (ypCRM {<=} 1 mm) were found more frequently in mucinous carcinomas than in nonmucinous ones (p {<=} 0.001). Treatment had less effect on local tumor stage in mucinous carcinomas than in nonmucinous carcinomas (for T downsizing, p = 0.012; for N downstaging, p = 0.007). Disease progression was observed only in patients with mucinous carcinomas (n = 5). Conclusion: Mucinous status at pretherapeutic MRI was associated with a noticeably worse response to chemoradiation and should be assessed by MRI in addition to local tumor staging to estimate response to treatment before it is initiated.

  2. Cryptococcus neoformans Infection in Mice Lacking Type I Interferon Signaling Leads to Increased Fungal Clearance and IL-4-Dependent Mucin Production in the Lungs

    PubMed Central

    Sato, Ko; Yamamoto, Hideki; Nomura, Toshiki; Matsumoto, Ikumi; Miyasaka, Tomomitsu; Zong, Tong; Kanno, Emi; Uno, Kazuko; Ishii, Keiko; Kawakami, Kazuyoshi

    2015-01-01

    Type I interferons (IFNs) are secreted by many cell types upon stimulation via pattern recognition receptors and bind to IFN-α/β receptor (IFNAR), which is composed of IFNAR1 and IFNAR2. Although type I IFNs are well known as anti-viral cytokines, limited information is available on their role during fungal infection. In the present study, we addressed this issue by examining the effect of IFNAR1 defects on the host defense response to Cryptococcus neoformans. In IFNAR1KO mice, the number of live colonies was lower and the host immune response mediated not only by Th1 but also by Th2 and Th17-related cytokines was more accelerated in the infected lungs than in WT mice. In addition, mucin production by bronchoepithelial cells and expression of MUC5AC, a major core protein of mucin in the lungs, were significantly higher in IFNAR1KO mice than in WT mice. This increase in mucin and MUC5AC production was significantly inhibited by treatment with neutralizing anti-IL-4 mAb. In contrast, administration of recombinant IFN-αA/D significantly suppressed the production of IL-4, but not of IFN-γ and IL-17A, in the lungs of WT mice after cryptococcal infection. These results indicate that defects of IFNAR1 led to improved clearance of infection with C. neoformans and enhanced synthesis of IFN-γ and the IL-4-dependent production of mucin. They also suggest that type I IFNs may be involved in the negative regulation of early host defense to this infection. PMID:26384031

  3. Intraductal Papillary Mucinous Neoplasm of the Pancreas: An Update

    PubMed Central

    Xiao, Shu-Yuan

    2012-01-01

    Intraductal papillary mucinous neoplasm (IPMN) is a cystic tumor of the pancreas. The etiology is unknown, but increasing evidence suggests the involvement of several tumorigenesis pathways, including an association with hereditary syndromes. IPMN occurs more commonly in men, with the mean age at diagnosis between 64 and 67 years old. At the time of diagnosis, it may be benign, with or without dysplasia, or frankly malignant with an invasive carcinoma. Tumors arising from the main pancreatic duct are termed main-duct IPMNs, those involving the branch ducts, branch-duct IPMNs. In general, small branch-duct IPMNs are benign, particularly in asymptomatic patients, and can be safely followed. In contrast, main-duct tumors should be surgically resected and examined carefully for an invasive component. In the absence of invasion, patient's survival is excellent, from 94 to 100%. For patients with an IPMN-associated invasive carcinoma, the prognosis overall is better than those with a de novo pancreatic ductal adenocarcinoma, with a 5-year survival of 40% to 60% in some series. However, no survival advantage can be demonstrated if the invasive component in an IPMN patient is that of the conventional tubular type (versus mucinous carcinoma). Several histomorphologic variants are recognized, although the clinical significance of this “subtyping” is not well defined. PMID:24278753

  4. Molecular pathology of intraductal papillary mucinous neoplasms of the pancreas

    PubMed Central

    Paini, Marina; Crippa, Stefano; Partelli, Stefano; Scopelliti, Filippo; Tamburrino, Domenico; Baldoni, Andrea; Falconi, Massimo

    2014-01-01

    Since the first description of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas in the eighties, their identification has dramatically increased in the last decades, hand to hand with the improvements in diagnostic imaging and sampling techniques for the study of pancreatic diseases. However, the heterogeneity of IPMNs and their malignant potential make difficult the management of these lesions. The objective of this review is to identify the molecular characteristics of IPMNs in order to recognize potential markers for the discrimination of more aggressive IPMNs requiring surgical resection from benign IPMNs that could be observed. We briefly summarize recent research findings on the genetics and epigenetics of intraductal papillary mucinous neoplasms, identifying some genes, molecular mechanisms and cellular signaling pathways correlated to the pathogenesis of IPMNs and their progression to malignancy. The knowledge of molecular biology of IPMNs has impressively developed over the last few years. A great amount of genes functioning as oncogenes or tumor suppressor genes have been identified, in pancreatic juice or in blood or in the samples from the pancreatic resections, but further researches are required to use these informations for clinical intent, in order to better define the natural history of these diseases and to improve their management. PMID:25110429

  5. Muc5ac Mucin Expression During Rat Skin Development

    PubMed Central

    Ferretti, V.; Segal-Eiras, A.; Barbeito, C.G.; Croce, M.V.

    2015-01-01

    Some mucin genes have been detected during human embryonic and fetal organ development; however, little is known about mucin expression in epidermal development, neither in humans nor in other species. The present research was developed to explore Muc5ac skin expression during pre- and post-natal rat development. Immunohistochemistry (IHC), Western blotting (WB) and RT-PCR were employed. By IHC, Muc5ac protein was found early in embryonic epidermis from day 13 of gestation until seven days after birth when the surface epidermis became negative and the reaction was restricted to secreting sebum cells. In coincidence with IHC findings, WB analysis showed a band at approximately 200KDa at the same periods of development. Results were also confirmed by RT-PCR. Muc5ac expression in rat embryonic epidermis suggests that Muc5ac may play a protective role in embryonic skin previous to birth which may be replaced by pile covering. To our knowledge, this is the first report that confirmed Muc5ac expression during skin development. PMID:25820562

  6. Human MUC5AC mucin dimerizes in the rough endoplasmic reticulum, similarly to the MUC2 mucin.

    PubMed Central

    Asker, N; Axelsson, M A; Olofsson, S O; Hansson, G C

    1998-01-01

    Biosynthetic studies on the human MUC5AC mucin were performed by immunoprecipitations with antisera recognizing only the non-O-glycosylated apomucin in the colon adenocarcinoma cell line LS 174T. Pulse-chase studies and subcellular fractionations showed that MUC5AC formed dimers in the rough endoplasmic reticulum within 15 min of the initiation of biosynthesis. No non-O-glycosylated species larger than dimers were identified. The dimerization was N-glycosylation-dependent, because tunicamycin treatment significantly lowered the rate of dimerization. When the biosynthesis of MUC5AC apomucin was compared with that of MUC2 apomucin, also produced in the LS 174T cell line, both apomucins were assembled in similar ways with respect to their rates of dimerization with and without inhibition of N-glycosylation. No heterodimerization was observed between the human MUC5AC and the MUC2 apomucins despite the extensive sequence similarities in the positions of the cysteine residues in the C-termini proposed to be involved in mucin dimerization. PMID:9761738

  7. Mucin production by human colonic carcinoma cells correlates with their metastatic potential in animal models of colon cancer metastasis.

    PubMed Central

    Bresalier, R S; Niv, Y; Byrd, J C; Duh, Q Y; Toribara, N W; Rockwell, R W; Dahiya, R; Kim, Y S

    1991-01-01

    Patients with mucinous colorectal cancers characteristically present with advanced disease, however, the relationship between mucin production by colon cancer cells and their metastatic potential remains unclear. We therefore sought to define the relationship between mucin production by human colon cancer cells and metastatic ability by employing animal models of colon cancer metastasis. LS LiM 6, a colon carcinoma cell line with high liver metastasizing ability during cecal growth in nude mice produced twofold more metabolically labeled intracellular mucin and secreted four- to fivefold more mucin into the culture medium compared to poorly metastatic parental line LS174T. This was accompanied by a similar elevation in poly(A)+ RNA detected by blot hybridization with a human intestinal mucin cDNA probe, and increases in mucin core carbohydrate antigens determined immunohistochemically. Variants of LS174T selected for high (HM 7) or low (LM 12) mucin synthesizing capacity also yielded metastases after cecal growth and colonized the liver after splenic-portal injection in proportion to their ability to produce mucin. Inhibition of mucin glycosylation by the arylglycoside benzyl-alpha-N-acetyl-galactosamine greatly reduced liver colonization after splenic-portal injection of the tumor cells. These data suggest that mucin production by human colon cancer cells correlates with their metastatic potential and affects their ability to colonize the liver in experimental model systems. Images PMID:1999484

  8. A case of Krukenberg carcinoma metastasized from colon cancer resembling mucinous cystadenocarcinoma of the ovary.

    PubMed

    Shiono, Saori; Saito, Tsuyoshi; Fujii, Hiroaki; Arakawa, Atsushi; Nakamura, Takanori; Yao, Takashi

    2014-01-01

    We report a case of a 44-year-old woman with bilateral ovarian carcinoma that had metastasized from the colon and mimicked primary mucinous cystadenocarcinoma. Macroscopically, both ovarian tumors were large, multiloculated cystic masses with abundant mucinous content. Histologically, they were lined with mucinous epithelium with mild to moderate nuclear atypia and showed stromal invasion and surface involvement. At first, the tumors were diagnosed as bilateral primary ovarian mucinous cystadenocarcinomas. However, three months after surgery, a large villous tumor was discovered in the ascending colon by colonoscopic examination and was surgically resected. Histologically, the colonic tumor was a villous adenomatous tumor with invasive components of mucinous adenocarcinoma composed of well-differentiated adenocarcinoma and exhibited abundant extracellular mucin production. As a villous adenomatous component was present in the mucosal area, the colonic tumor was considered a primary tumor. Therefore, the original diagnosis of bilateral ovarian tumors was revised for consistent with metastasis from the colon carcinoma, in line with the findings of immunohistochemistry and loss of heterozygosity analysis. This case highlights the importance of considering the possibility of metastatic tumors from the gastrointestinal tract in the diagnosis of mucinous ovarian tumors. PMID:24427362

  9. Regulation of particulate matter-induced mucin secretion by transient receptor potential vanilloid 1 receptors.

    PubMed

    Yu, Hongmei; Li, Qi; Kolosov, Victor P; Perelman, Juliy M; Zhou, Xiangdong

    2012-12-01

    Exposure to airborne particulate matter (PM) is a worldwide health problem. Previous studies have reported that PMs induced depolarizing currents and increased intracellular Ca(2+) in human bronchial epithelial cells. Ca(2+) plays important role in the regulation of mucus exocytosis, and mucin hypersecretion is a key pathological feature of inflammatory respiratory diseases. To explore more mechanisms underlying PM toxicity, we measured PM-induced mucin secretion in human bronchial epithelial (16HBE) cells. MUC5AC secretion and cyclic adenosine monophosphate (cAMP) level were detected by ELISA. Transient receptor potential vanilloid (TRPV)1 inward currents were examined by electrophysiology. Ca(2+) concentration was assessed by laser scanning confocal microscope. Exposure of PMs to 16HBE cells was found to induce mucin secretion, as a consequence of sustained Ca(2+) influx and cAMP increase through TRPV1 receptors. Mucin secretion was completely inhibited by TRPV1 receptor antagonist capsazepine. Removal of Ca(2+) by Ca(2+) chelator BAPTA or inhibition of protein kinase A (PKA) by the PKA inhibitors H-89 each partially reduced PC(2)s-induced mucin secretion. The combination of BAPTA and H-89 completely prevented mucin secretion mediated by PMs. These results suggest that PM induces mucin secretion through Ca(2+) influx and cAMP/PKA pathway by TRPV1 receptors in human bronchial epithelial cells, thereby providing a potential mechanism to reduce PM toxicity. PMID:22829138

  10. Comparison of the Transmembrane Mucins MUC1 and MUC16 in Epithelial Barrier Function

    PubMed Central

    Gipson, Ilene K.; Spurr-Michaud, Sandra; Tisdale, Ann; Menon, Balaraj B.

    2014-01-01

    Membrane-anchored mucins are present in the apical surface glycocalyx of mucosal epithelial cells, each mucosal epithelium having at least two of the mucins. The mucins have been ascribed barrier functions, but direct comparisons of their functions within the same epithelium have not been done. In an epithelial cell line that expresses the membrane-anchored mucins, MUC1 and MUC16, the mucins were independently and stably knocked down using shRNA. Barrier functions tested included dye penetrance, bacterial adherence and invasion, transepithelial resistance, tight junction formation, and apical surface size. Knockdown of MUC16 decreased all barrier functions tested, causing increased dye penetrance and bacterial invasion, decreased transepithelial resistance, surprisingly, disruption of tight junctions, and greater apical surface cell area. Knockdown of MUC1 did not decrease barrier function, in fact, barrier to dye penetrance and bacterial invasion increased significantly. These data suggest that barrier functions of membrane-anchored mucins vary in the context of other membrane mucins, and MUC16 provides a major barrier when present. PMID:24968021

  11. Candida albicans Shed Msb2 and Host Mucins Affect the Candidacidal Activity of Salivary Hst 5

    PubMed Central

    Puri, Sumant; Friedman, Justin; Saraswat, Darpan; Kumar, Rohitashw; Li, Rui; Ruszaj, Donna; Edgerton, Mira

    2015-01-01

    Salivary Histatin 5 (Hst 5) is an antimicrobial peptide that exhibits potent antifungal activity towards Candida albicans, the causative agent of oral candidiasis. However, it exhibits limited activity in vivo, largely due to inactivation by salivary components of both host and pathogen origin. Proteins secreted by C. albicans during infection such as secreted aspartyl proteases (Saps) and shed mucin Msb2 can reduce Hst 5 activity; and human salivary mucins, while suggested to protect Hst 5 from proteolytic degradation, can entrap peptides into mucin gels, thereby reducing bioavailability. We show here that Sap6 that is secreted during hyphal growth reduces Hst 5 activity, most likely a result of proteolytic degradation of Hst 5 since this effect is abrogated with heat inactivated Sap 6. We further show that just like C. albicans shedding Msb2, mammalian mucins, fetuin and porcine gut mucin (that is related to salivary mucins), also reduce Hst 5 activity. However, we identify mucin-like protein-induced changes in C. albicans cell morphology and aggregation patterns, suggesting that the effect of such proteins on Hst 5 cannot be interpreted independently of their effect on yeast cells. PMID:26529023

  12. Clonality analysis of combined Brenner and mucinous tumours of the ovary reveals their monoclonal origin.

    PubMed

    Wang, Yihong; Wu, Ren-chin; Shwartz, Lauren Ende; Haley, Lisa; Lin, Ming-tse; Shih, Ie-ming; Kurman, Robert J

    2015-10-01

    The derivation of ovarian intestinal-type mucinous tumours is not well established. Some are derived from teratomas but the origin of the majority is not clear. It has been recently proposed that the non-germ cell group may be derived from Brenner tumours, as the association of a mucinous tumour with a Brenner tumour is frequently observed. In order to explore the histogenesis of these neoplasms, we undertook a clonality analysis of the two components of ten combined Brenner and mucinous tumours using a human androgen receptor gene (HUMARA) assay. All eight informative cases of ten showed a concordant X-chromosome inactivation pattern between the two tumour components, indicative of a shared clonal origin (p = 0.0039). Microsatellite genotyping in five of the combined tumours displayed an identical heterozygous pattern with paired Fallopian tube tissue, indicative of a somatic cell origin. In addition, paired box protein 8, a highly sensitive Müllerian epithelial marker, was not detected by immunohistochemistry in either tumour component in any of the ten tumours, suggesting that this subset of mucinous tumours does not originate from Müllerian-derived epithelium. In conclusion, this study demonstrates that in combined mucinous and Brenner tumours, there is a shared clonal relationship between the two different tumour components and suggests that some pure mucinous tumours may develop from a Brenner tumour in which the Brenner tumour component becomes compressed and obliterated by an expanding mucinous neoplasm. PMID:26095692

  13. Induction of cyclooxygenase-2 in monocyte/macrophage by mucins secreted from colon cancer cells

    PubMed Central

    Inaba, Takaaki; Sano, Hajime; Kawahito, Yutaka; Hla, Timothy; Akita, Kaoru; Toda, Munetoyo; Yamashina, Ikuo; Inoue, Mizue; Nakada, Hiroshi

    2003-01-01

    Up-regulation of cyclooxygenase-2 (COX-2) and overproduction of prostaglandins have been implicated in the initiation and/or progression of colon cancer. However, it is uncertain in which cells and how COX-2 is induced initially in the tumor microenvironment. We found that a conditioned medium of the colon cancer cell line, LS 180, contained a factor to induce COX-2 in human peripheral blood mononuclear cells. This factor was purified biochemically and revealed to be mucins. A small amount of mucins (≈100 ng of protein per ml) could elevate prostaglandin E2 production by monocytes. The mucins induced COX-2 mRNA and protein levels of monocytes in a dose- and time-dependent manner, indicating a COX-2-mediated pathway. We also have examined immunohistochemically the localization of COX-2 protein and mucins in human colorectal cancer tissues. It is noteworthy that COX-2-expressing macrophages were located around the region in which mucins were detectable, suggesting that COX-2 also was induced by mucins in vivo. These results suggest that mucins produced by colon cancer cells play a critical role in the initial induction of COX-2 in the tumor microenvironment. PMID:12598658

  14. Differential expression of matrix metalloproteinase-13 in mucinous and nonmucinous colorectal carcinomas.

    PubMed

    Foda, Abd Al-Rahman Mohammad; El-Hawary, Amira K; Abdel-Aziz, Azza

    2013-08-01

    Colorectal carcinoma (CRC) is a major health problem all over the world. Mucinous CRCs are known to have a peculiar behavior and genetic derangements. This study aimed to investigate matrix metalloproteinase (MMP)-13 expression in mucinous and nonmucinous CRCs. We studied tumor tissue specimens from 150 patients with mucinous and nonmucinous CRC who underwent radical surgery from January 2007 to January 2012. High-density manual tissue microarrays were constructed using a modified mechanical pencil tip technique, and paraffin sections were submitted for immunohistochemistry using MMP-13. Statistical analysis was performed for clinical and pathological data of all studied cases together with MMP-13 expression in mucinous and nonmucinous groups. Mucinous carcinoma was significantly associated with young age, more depth of invasion, lymph node metastasis, and less peritumoral and intratumoral neutrophils. Nonmucinous carcinomas showed higher MMP-13 expression compared with mucinous carcinomas. Despite the negative or low expression of MMP-13, mucinous carcinomas had more depth of invasion and more frequency of lymph node metastasis than did nonmucinous carcinomas. PMID:23665089

  15. Differential expression of mucins in Middle Eastern patients with colorectal cancer

    PubMed Central

    AL-KHAYAL, KHAYAL; ABDULLA, MAHA; AL-OBAID, OMAR; ZUBAIDI, AHMAD; VAALI-MOHAMMED, MANSOOR-ALI; ALSHEIKH, ABDULMALIK; AHMAD, REHAN

    2016-01-01

    Mucin overexpression has been implicated in the tumorigenesis and progression of colorectal carcinoma (CRC). However, data obtained on the prognostic importance of mucin expression in CRC is inconsistent. Due to lack of data on mucin expression and the increase in CRC incidence in Saudi Arabia, the aim of the present study was to analyze the mucin expression profile in patients with CRC in this ethnic group. The present study consisted of 22 patients that underwent surgery for CRC. Histopathological and immunohistochemical staining was performed on CRC tumor and adjacent normal tissues. A tissue microarray was prepared from the tumor and normal adjacent samples to investigate the mucin expression profile using immunohistochemistry. Formalin-fixed paraffin-embedded human colorectal cancer tissues were immunostained with mucin 1 (MUC1), mucin 2 (MUC2) and mucin 5AC (MUC5AC) antibodies. Associations between mucin expression and histopathological variables were evaluated. The present study indicated that MUC1 was highly expressed in early (stage I and II; P=0.0016) and late (stage III and IV; P<0.0001) stage CRC tissues compared to normal adjacent tissues. However, MUC2 expression was observed to be downregulated in early and late stage CRC tissues compared to normal and adjacent tissues. Furthermore, serum MUC1 levels were observed to be increased in early and late stage CRC. The present findings indicate that MUC1 expression was significantly higher in early and late stage CRC tissues and MUC2 was downregulated in CRC tissues compared with normal adjacent tissues, and serum MUC1 protein was significantly higher in CRC patients compared to control serum. In conclusion, during colorectal tumorigenesis the pattern of MUC1 and MUC2 expression is altered in Saudi Arabian patients with CRC compared with normal. A higher expression of MUC1 may be used as an independent biomarker in various stages of CRC tumors, which would aid in the early detection of CRC. PMID:27347157

  16. Evidence and Role for Bacterial Mucin Degradation in Cystic Fibrosis Airway Disease

    PubMed Central

    Flynn, Jeffrey M.; Niccum, David; Dunitz, Jordan M.

    2016-01-01

    Chronic lung infections in cystic fibrosis (CF) patients are composed of complex microbial communities that incite persistent inflammation and airway damage. Despite the high density of bacteria that colonize the lower airways, nutrient sources that sustain bacterial growth in vivo, and how those nutrients are derived, are not well characterized. In this study, we examined the possibility that mucins serve as an important carbon reservoir for the CF lung microbiota. While Pseudomonas aeruginosa was unable to efficiently utilize mucins in isolation, we found that anaerobic, mucin-fermenting bacteria could stimulate the robust growth of CF pathogens when provided intact mucins as a sole carbon source. 16S rRNA sequencing and enrichment culturing of sputum also identified that mucin-degrading anaerobes are ubiquitous in the airways of CF patients. The collective fermentative metabolism of these mucin-degrading communities in vitro generated amino acids and short chain fatty acids (propionate and acetate) during growth on mucin, and the same metabolites were also found in abundance within expectorated sputum. The significance of these findings was supported by in vivo P. aeruginosa gene expression, which revealed a heightened expression of genes required for the catabolism of propionate. Given that propionate is exclusively derived from bacterial fermentation, these data provide evidence for an important role of mucin fermenting bacteria in the carbon flux of the lower airways. More specifically, microorganisms typically defined as commensals may contribute to airway disease by degrading mucins, in turn providing nutrients for pathogens otherwise unable to efficiently obtain carbon in the lung. PMID:27548479

  17. Evidence and Role for Bacterial Mucin Degradation in Cystic Fibrosis Airway Disease.

    PubMed

    Flynn, Jeffrey M; Niccum, David; Dunitz, Jordan M; Hunter, Ryan C

    2016-08-01

    Chronic lung infections in cystic fibrosis (CF) patients are composed of complex microbial communities that incite persistent inflammation and airway damage. Despite the high density of bacteria that colonize the lower airways, nutrient sources that sustain bacterial growth in vivo, and how those nutrients are derived, are not well characterized. In this study, we examined the possibility that mucins serve as an important carbon reservoir for the CF lung microbiota. While Pseudomonas aeruginosa was unable to efficiently utilize mucins in isolation, we found that anaerobic, mucin-fermenting bacteria could stimulate the robust growth of CF pathogens when provided intact mucins as a sole carbon source. 16S rRNA sequencing and enrichment culturing of sputum also identified that mucin-degrading anaerobes are ubiquitous in the airways of CF patients. The collective fermentative metabolism of these mucin-degrading communities in vitro generated amino acids and short chain fatty acids (propionate and acetate) during growth on mucin, and the same metabolites were also found in abundance within expectorated sputum. The significance of these findings was supported by in vivo P. aeruginosa gene expression, which revealed a heightened expression of genes required for the catabolism of propionate. Given that propionate is exclusively derived from bacterial fermentation, these data provide evidence for an important role of mucin fermenting bacteria in the carbon flux of the lower airways. More specifically, microorganisms typically defined as commensals may contribute to airway disease by degrading mucins, in turn providing nutrients for pathogens otherwise unable to efficiently obtain carbon in the lung. PMID:27548479

  18. Refractory Jaundice From Intraductal Papillary Mucinous Neoplasm Treated With Cholangioscopy-Guided Radiofrequency Ablation

    PubMed Central

    Brown, Nicholas G.; Camilo, Joel; McCarter, Martin

    2016-01-01

    Intraductal papillary mucinous neoplasms (IPMNs) are epithelial neoplasms treated with surgical resection when appropriate. We present a 79-year-old man with jandice refractory to endoscopic stenting. Biliary radiofrequency ablation (RFA) with cholangioscopy was used as palliation of obstructive jaundice due to a mucin-producing pancreatic IPMN with fistulous biliary communication. Clinical improvement permitted surgery, and he returned to pre-illness status at 17 months. The use of cholangioscopy in the setting of mucinous filling defects can guide over-the-wire RFA for palliation and may be a bridge to surgery. PMID:27144205

  19. Mucinous Pleural Effusion in a Dog with a Pulmonary Adenocarcinoma and Carcinomatosis.

    PubMed

    Tropf, Melissa; Sellon, Rance; Paulson, Kathleen; Nelson, Danielle

    2015-01-01

    An 11 yr old castrated male greyhound presented to the Washington State University's Veterinary Teaching Hospital (WSU VTH) for evaluation of a 4 day history of pleural effusion. The pleural effusion had a gelatinous appearance, suggestive of mucus, and was characterized cytologically as a pyogranulomatous exudate with some features suggestive of a carcinoma. Postmortem examination identified a pulmonary mass with evidence of carcinomatosis. Pulmonary papillary adenocarcinoma with carcinomatosis was the histologic diagnosis. Abundant mucin production was present, consistent with a mucinous pulmonary adenocarcinoma. To the authors' knowledge, this is the first report of a mucinous pulmonary adenocarcinoma with mucus pleural effusion in a dog. PMID:26355581

  20. Refractory Jaundice From Intraductal Papillary Mucinous Neoplasm Treated With Cholangioscopy-Guided Radiofrequency Ablation.

    PubMed

    Brown, Nicholas G; Camilo, Joel; McCarter, Martin; Shah, Raj J

    2016-04-01

    Intraductal papillary mucinous neoplasms (IPMNs) are epithelial neoplasms treated with surgical resection when appropriate. We present a 79-year-old man with jandice refractory to endoscopic stenting. Biliary radiofrequency ablation (RFA) with cholangioscopy was used as palliation of obstructive jaundice due to a mucin-producing pancreatic IPMN with fistulous biliary communication. Clinical improvement permitted surgery, and he returned to pre-illness status at 17 months. The use of cholangioscopy in the setting of mucinous filling defects can guide over-the-wire RFA for palliation and may be a bridge to surgery. PMID:27144205

  1. Mucin in the dermis: a case of tender tumors.

    PubMed

    Ferris, Gina J; Spohn, Gina P; Gru, Alejandro; Kaffenberger, Jessica

    2016-01-01

    We present an original case report of a 45-year-old woman with a five-month history of sporadic, tender, nodules present on the right upper abdomen, bilateral dorsal wrists, right upper arm, and left flank. Biopsy revealed a mild perivascular infiltrate, increased dermal mucin, and no significant increase in fibroblasts. Presentation and histology were most consistent with nodular lichen myxedematosus (NLM), a rare primary mucinosis. Only four previous cases are reported in the literature to our knowledge. Management of NLM and other subtypes of lichen myxedematosus is not well described. Our patient failed systemic steroids and was unable to tolerate hydroxychloroquine, but subsequently improved with oral methotrexate. This suggests that methotrexate may be of benefit for NLM. PMID:27617942

  2. Androgen-Dependent Regulation of Human MUC1 Mucin Expression

    PubMed Central

    Mitchell, Stephen; Abel, Paul; Madaan, Sanjeev; Jeffs, James; Chaudhary, Khurram; Stamp, Gordon; Lalani, El-Nasir

    2002-01-01

    Abstract MUC1 mucin is transcriptionally regulated by estrogen, progesterone, and glucocorticoids. Our objective was to determine whether androgen receptor (AR) activation regulates expression of MUC1. The following breast and prostatic cell lines were phenotyped and grouped according to AR and MUC1 protein expression: 1) AR+MUC1+ [DAR17+19 (AR transfectants of DU-145), ZR-75-1, MDA-MB-453, and T47D]; 2) AR-MUC1+ [DZeo1 (AR-vector control), DU-145, BT20,MDA-MB-231, and MCF7]; 3) AR+MUC1- (LNCaP and LNCaP-r). Cell proliferation was determined using the MTT assay in the presence of synthetic androgen R1881, 0.1 pM to 1 µM. Cell surface MUC1 expression was determined by flow cytometry in the presence or absence of oestradiol, medroxy progesterone acetate or R1881, with and without 4 hydroxy-flutamide (4-OH), a nonsteroidal AR antagonist. The functional significance of MUC1 expression was investigated with a cell-cell aggregation assay. Only AR+ MUC1+ cell lines showed a significant increase in MUC1 expression with AR activation (P (range) =.01 to.0001), reversed in the presence of 4-OHF. Cell proliferation was unaffected. Increased expression of MUC1 was associated with a significant (P (range) =.002 to.001) reduction in cell-cell adhesion. To our knowledge, this is the first description of androgen-dependent regulation of MUC1 mucin. This is also functionally associated with decreased cell-cell adhesion, a recognised feature of progressive malignancy. These findings have important implications for physiological and pathological processes. PMID:11922395

  3. Structural analysis of O-glycans of mucin from jellyfish (Aurelia aurita) containing 2-aminoethylphosphonate.

    PubMed

    Urai, Makoto; Nakamura, Takemichi; Uzawa, Jun; Baba, Takayuki; Taniguchi, Kayoko; Seki, Hiroko; Ushida, Kiminori

    2009-11-01

    The structure of O-glycan in qniumucin (Q-mucin), which is a novel mucin extracted from jellyfish, was analyzed by a combination of NMR and ESI-MS/MS. A previously unidentified monosaccharide involved in the glycan chains was determined to be N-acetylgalactosamine (GalNAc) substituted by 2-aminoethylphosphonate (AEP) at the C-6. The O-glycans in Q-mucin from Aurelia aurita were proved to be mainly composed of three monosaccharides: GalNAc, AEP-(O-->6)-GalNAc, and P-6-GalNAc. To the best of our knowledge, this is the first example of an O-glycan structure of glycoproteins containing AEP. This exceptionally simple structure of Q-mucin and its potential use in material science and technology are revealed. PMID:19732869

  4. Expression of c-myc and mutation of the KRAS gene in patients with ovarian mucinous tumors.

    PubMed

    Li, X S; Sun, J; He, X L

    2015-01-01

    We examined the expression of c-myc and mutations in the KRAS gene in ovarian mucinous tumors to explore the pathogenesis of these tumors and the feasibility of targeted gene therapy. Expression of c-myc protein and mutations in the KRAS gene in 24 cases of ovarian mucinous cystadenoma, 46 cases of ovarian borderline mucinous cystadenoma, and 46 cases of ovarian mucinous cystadenocarcinoma were detected using the immunohistochemistry PV-9000 2-step method and polymerase chain reaction-restriction fragment length polymorphism. The positive expression rates of c-myc in ovarian mucinous cystadenoma, borderline mucinous cystadenoma, and cystadenocarcinoma were 0, 39.1, and 65.2%, respectively (P < 0.01), while the mutation rates in KRAS were 0, 39.1 and 13.0%, respectively. The mutation rate of the borderline group was significantly higher, while rates in the other 2 groups were similar (P > 0.05). c-myc was not correlated with clinical stage, pathological grade, or age of patients with ovarian mucinous cystadenocarcinoma or borderline mucinous cystadenoma (P > 0.05), but was correlated with tumor size (P < 0.05). Mutations in KRAS were not correlated with clinical stage or tumor size in patients with borderline mucinous cystadenoma (P > 0.05), whereas it was correlated with age (P < 0.05). In borderline mucinous cystadenoma, c-myc expression and KRAS mutations were not correlated (P > 0.05). c-myc is involved in the formation of ovarian borderline mucinous cystadenoma and mucinous cystadenocarcinoma, and the KRAS gene may contribute to the formation of borderline mucinous cystadenoma. PMID:26400304

  5. Helicobacter pylori and gastric mucin expression: A systematic review and meta-analysis

    PubMed Central

    Niv, Yaron

    2015-01-01

    AIM: To investigate the relationship between Helicobacter pylori (H. pylori) and mucin expression in gastric mucosa. METHODS: English Medical literature searches were conducted for gastric mucin expression in H. pylori infected people vs uninfected people. Searches were performed up to December 31th 2014, using MEDLINE, PubMed, EMBASE, Scopus, and CENTRAL. Studies comparing mucin expression in the gastric mucosa in patients positive and negative for H. pylori infection, were included. Meta-analysis was performed by using Comprehensive meta-analysis software (Version 3, Biostat Inc., Englewood, NJ, United States). Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated compared mucin expression in individual studies by using the random effects model. Heterogeneity between studies was evaluated using the Cochran Q-test, and it was considered to be present if the Q-test P value was less than 0.10. I2 statistic was used to measure the proportion of inconsistency in individual studies, with I2 > 50% representing substantial heterogeneity. We also calculated a potential publication bias. RESULTS: Eleven studies, which represent 53 sub-studies of 15 different kinds of mucin expression, were selected according to the inclusion criteria. Every kind of mucin has been considered as one study. When a specific mucin has been studied in more than one paper, we combined the results in a nested meta-analysis of this particular mucin: MUC2, MUC6, STn, Paradoxical con A, Tn, T, Type 1 chain mucin, LeA, SLeA, LeB, AB-PAS, MUC1, and MUC5AC. The odds ratio of mucin expression in random analysis was 2.33, 95%CI: 1.230-4.411, P = 0.009, higher expression in H. pylori infected patients. Odds ratio for mucin expression in H. pylori positive patients was higher for MUC6 (9.244, 95%CI: 1.567-54.515, P = 0.014), and significantly lower for MUC5AC (0.447, 95%CI: 0.211-0.949, P = 0.036). Thus, H. pylori infection may increase MUC6 expression and decrease MUC5AC expression by

  6. REG4 Is Highly Expressed in Mucinous Ovarian Cancer: A Potential Novel Serum Biomarker

    PubMed Central

    Lehtinen, Laura; Vesterkvist, Pia; Roering, Pia; Korpela, Taina; Hattara, Liisa; Kaipio, Katja; Mpindi, John-Patrick; Hynninen, Johanna; Auranen, Annika; Davidson, Ben; Haglund, Caj; Iljin, Kristiina; Grenman, Seija; Siitari, Harri; Carpen, Olli

    2016-01-01

    Preoperative diagnostics of ovarian neoplasms rely on ultrasound imaging and the serum biomarkers CA125 and HE4. However, these markers may be elevated in non-neoplastic conditions and may fail to identify most non-serous epithelial cancer subtypes. The objective of this study was to identify histotype-specific serum biomarkers for mucinous ovarian cancer. The candidate genes with mucinous histotype specific expression profile were identified from publicly available gene-expression databases and further in silico data mining was performed utilizing the MediSapiens database. Candidate biomarker validation was done using qRT-PCR, western blotting and immunohistochemical staining of tumor tissue microarrays. The expression level of the candidate gene in serum was compared to the serum CA125 and HE4 levels in a patient cohort of prospectively collected advanced ovarian cancer. Database searches identified REG4 as a potential biomarker with specificity for the mucinous ovarian cancer subtype. The specific expression within epithelial ovarian tumors was further confirmed by mRNA analysis. Immunohistochemical staining of ovarian tumor tissue arrays showed distinctive cytoplasmic expression pattern only in mucinous carcinomas and suggested differential expression between benign and malignant mucinous neoplasms. Finally, an ELISA based serum biomarker assay demonstrated increased expression only in patients with mucinous ovarian cancer. This study identifies REG4 as a potential serum biomarker for histotype-specific detection of mucinous ovarian cancer and suggests serum REG4 measurement as a non-invasive diagnostic tool for postoperative follow-up of patients with mucinous ovarian cancer. PMID:26981633

  7. REG4 Is Highly Expressed in Mucinous Ovarian Cancer: A Potential Novel Serum Biomarker.

    PubMed

    Lehtinen, Laura; Vesterkvist, Pia; Roering, Pia; Korpela, Taina; Hattara, Liisa; Kaipio, Katja; Mpindi, John-Patrick; Hynninen, Johanna; Auranen, Annika; Davidson, Ben; Haglund, Caj; Iljin, Kristiina; Grenman, Seija; Siitari, Harri; Carpen, Olli

    2016-01-01

    Preoperative diagnostics of ovarian neoplasms rely on ultrasound imaging and the serum biomarkers CA125 and HE4. However, these markers may be elevated in non-neoplastic conditions and may fail to identify most non-serous epithelial cancer subtypes. The objective of this study was to identify histotype-specific serum biomarkers for mucinous ovarian cancer. The candidate genes with mucinous histotype specific expression profile were identified from publicly available gene-expression databases and further in silico data mining was performed utilizing the MediSapiens database. Candidate biomarker validation was done using qRT-PCR, western blotting and immunohistochemical staining of tumor tissue microarrays. The expression level of the candidate gene in serum was compared to the serum CA125 and HE4 levels in a patient cohort of prospectively collected advanced ovarian cancer. Database searches identified REG4 as a potential biomarker with specificity for the mucinous ovarian cancer subtype. The specific expression within epithelial ovarian tumors was further confirmed by mRNA analysis. Immunohistochemical staining of ovarian tumor tissue arrays showed distinctive cytoplasmic expression pattern only in mucinous carcinomas and suggested differential expression between benign and malignant mucinous neoplasms. Finally, an ELISA based serum biomarker assay demonstrated increased expression only in patients with mucinous ovarian cancer. This study identifies REG4 as a potential serum biomarker for histotype-specific detection of mucinous ovarian cancer and suggests serum REG4 measurement as a non-invasive diagnostic tool for postoperative follow-up of patients with mucinous ovarian cancer. PMID:26981633

  8. [Mucinous ovarian neoplasms. Prognostically mostly excellent, infrequently a wolf in sheep's clothing].

    PubMed

    Lax, S; Staebler, A

    2014-07-01

    Mucinous ovarian neoplasms represent the second largest group of epithelial ovarian tumors after serous neoplasms, of which benign cystadenomas constitute more than 80 %. Mucinous cystadenomas and carcinomas cannot be distinguished by the clinical features or the mean age of onset of the disease. They typically occur unilaterally, are confined to the adnexae (FIGO stage I) and clinically present with non-specific abdominal symptoms or are diagnosed by chance. The mean age of disease onset is around 50 years old. The prognosis is excellent. Implants, peritoneal metastases and bilateral occurrence of ovarian mucinous neoplasms should lead to the suspicion of metastasis particularly from a gastrointestinal tumor. Neither microinvasion defined as a maximum extent of invasion of 5 mm, nor intraepithelial carcinoma characterized by high grade atypia without invasion, affect the prognosis of mucinous borderline tumors. Mucinous carcinomas typically show confluent glandular, expansile growth that leads to a labyrinth-like pattern. A destructive infiltrative or nodular growth pattern, however, should lead to the consideration of metastasis. Mural nodules that may reveal a spindle cell sarcomatous or anaplastic carcinomatous pattern occur infrequently in mucinous and do not affect the prognosis. Pax8 positivity is indicative of a primary ovarian neoplasm. In this case, however, mucinous tumors associated with teratomas may show the colonic immunoreaction pattern (CK7-/CK20+/CDX2+). The rare mucinous tumors with endocervical differentiation are now designated as seromucinous tumors and consist of two or more distinct cell types, are frequently associated with endometriosis and seem to show a molecular genetic relationship to endometrioid neoplasms. PMID:24962632

  9. Mucin degradation by Bifidobacterium strains isolated from the human intestinal microbiota.

    PubMed

    Ruas-Madiedo, Patricia; Gueimonde, Miguel; Fernández-García, María; de los Reyes-Gavilán, Clara G; Margolles, Abelardo

    2008-03-01

    The presence of the genes engBF (endo-alpha-N-acetylgalactosaminidase) and afcA (1,2-alpha-L-fucosidase) was detected in several intestinal Bifidobacterium isolates. Two strains of Bifidobacterium bifidum contained both genes, and they were able to degrade high-molecular weight porcine mucin in vitro. The expression of both genes was highly induced in the presence of mucin. PMID:18223105

  10. A huge ovarian mucinous cystadenoma causing virilization, preterm labor, and persistent supine hypotensive syndrome during pregnancy

    PubMed Central

    Acar, Canan; Temizkan, Osman; Ozagari, Aysim; Gozukara, Ilay; Akyol, Atif

    2016-01-01

    Mucinous cystadenoma (MC) of the ovary is an unilateral, multilocular cystic benign epithelial tumor. Supposed to be hormone responsive, MC reaches huge sizes during pregnancy. Aortocaval compression is common during pregnancy, especially when the pregnant woman is in the supine position. However, the compression recovers with a change in position. The authors report the first case of a huge mucinous cystadenoma of the ovary complicating pregnancy and causing virilization, premature labor, and persistent supine hypotensive syndrome. PMID:27547742

  11. Mucinous Adenocarcinoma Involving the Ovary: Comparative Evaluation of the Classification Algorithms using Tumor Size and Laterality

    PubMed Central

    Jung, Eun Sun; Bae, Jeong Hoon; Choi, Yeong Jin; Park, Jong-Sup; Lee, Kyo-Young

    2010-01-01

    For intraoperative consultation of mucinous adenocarcinoma involving the ovary, it would be useful to have approaching methods in addition to the traditional limited microscopic findings in order to determine the nature of the tumors. Mucinous adenocarcinomas involving the ovaries were evaluated in 91 cases of metastatic mucinous adenocarcinomas and 19 cases of primary mucinous adenocarcinomas using both an original algorithm (unilateral ≥10 cm tumors were considered primary and unilateral <10 cm tumors or bilateral tumors were considered metastatic) and a modified cut-off size algorithm. With 10 cm, 13 cm, and 15 cm size cut-offs, the algorithm correctly classified primary and metastatic tumors in 82.7%, 87.3%, and 89.1% of cases and in 80.6%, 84.9%, and 87.1% of signet ring cell carcinoma (SRC) excluded cases. In total cases and SRC excluded cases, 98.0% and 97.2% of bilateral tumors were metastatic and 100% and 100% of unilateral tumors <10 cm were metastatic, respectively. In total cases and SRC excluded cases, 68.4% and 68.4% of unilateral tumors ≥15 cm were primary, respectively. The diagnostic algorithm using size and laterality, in addition to clinical history, preoperative image findings, and operative findings, is a useful adjunct tool for differentiation of metastatic mucinous adenocarcinomas from primary mucinous adenocarcinomas of the ovary. PMID:20119573

  12. Interfacial Interaction between Transmembrane Ocular Mucins and Adhesive Polymers and Dendrimers Analyzed by Surface Plasmon Resonance

    PubMed Central

    Noiray, M.; Briand, E.; Woodward, A. M.; Argüeso, P.; Molina Martínez, I. T.; Herrero-Vanrell, R.; Ponchel, G.

    2013-01-01

    Purpose Development of the first in vitro method based on biosensor chip technology designed for probing the interfacial interaction phenomena between transmembrane ocular mucins and adhesive polymers and dendrimers intended for ophthalmic administration. Methods The surface plasmon resonance (SPR) technique was used. A transmembrane ocular mucin surface was prepared on the chip surface and characterized by QCM-D (Quartz Crystal Microbalance with Dissipation) and XPS (X-ray photoelectron spectroscopy). The mucoadhesive molecules tested were: hyaluronic acid (HA), carboxymethyl cellulose (CMC), hydroxypropylmethyl cellulose (HPMC), chitosan (Ch) and polyamidoamine dendrimers (PAMAM). Results While Ch originated interfacial interaction with ocular transmembrane mucins, for HA, CMC and HPMC, chain interdiffusion seemed to be mandatory for bioadherence at the concentrations used in ophthalmic clinical practise. Interestingly, PAMAM dendrimers developed permanent interfacial interactions with transmembrane ocular mucins whatever their surface chemical groups, showing a relevant importance of co-operative effect of these multivalent systems. Polymers developed interfacial interactions with ocular membrane-associated mucins in the following order: Ch(1 %) > G4PAMAM-NH2(2 %) = G4PAMAM-OH(2 %) > G3.5PAMAM-COOH(2 %)≫ CMC(0.5 %) = HA(0.2 %) = HPMC(0.3 %). Conclusions The method proposed is useful to discern between the mucin-polymer chemical interactions at molecular scale. Results reinforce the usefulness of chitosan and den-drimers as polymers able to increase the retention time of drugs on the ocular surface and hence their bioavailability. PMID:22565639

  13. Molecular structure and rheological properties of short-side-chain heavily glycosylated porcine stomach mucin.

    PubMed

    Yakubov, Gleb E; Papagiannopoulos, Aristeidis; Rat, Elodie; Easton, Richard L; Waigh, Thomas A

    2007-11-01

    The current accepted model for high-molecular-weight gastric mucins of the MUC family is that they adopt a polydisperse coil conformation in bulk solutions. We develop this model using well-characterized highly purified porcine gastric mucin Orthana that is genetically close to the human MUC6 type. It has short side chains and low levels of sialic acid residues and includes minute amounts of cysteine residues that, if abundant, can be responsible for the self-polymerization of mucin. We have established that the mucin structure in bulk solutions corresponds to a daisy-chain random coil. Dynamic light scattering experiments probe the internal dynamics of globular subunits (individual daisies) at the approximately 9 nm length scale, whereas viscosity and light scattering measurements indicate that the size of the whole mucin chains is much larger, approximately 50 nm. The bulk viscosity (eta) scales with mucin concentration (c) in a manner similar to that found for short-side-chain synthetic comb polyelectrolytes and is characterized by a transition between semidilute (eta approximately c1/2) and entangled (eta approximately c3/2) regimes. PMID:17910495

  14. Non-pancreatic retroperitoneal mucinous neoplasms and a discussion of the differential diagnosis

    PubMed Central

    Cobb, Camilla; Raza, Anwar Sultana

    2016-01-01

    Retroperitoneal mucinous neoplasms are common and have a wide range of differential diagnoses to consider. It is of utmost importance to maintain a multidisciplinary approach when evaluating these lesions. Clinical history, surgical impression and radiographic studies should be obtained and used in conjunction with morphology and immunohistochemistry to help guide the pathologist to the correct diagnosis. We recently encountered a case of a 51-year-old man who presented with an 11.5 cm left-sided retroperitoneal mucinous neoplasm. This lesion was initially diagnosed as a low-grade mucinous carcinoma of probable pancreatic origin at an outside facility, and he was subsequently treated with chemotherapy. One year later he presented to our institution and underwent retroperitoneal en bloc resection of the 7-cm residual multiloculated mucinous neoplasm. When discussed at tumor board additional medical history was obtained, and review of the patient’s chart revealed a remote history of left orchiectomy for a mixed malignant germ cell tumor and metastatic embryonal carcinoma in 2 of 34 retroperitoneal/para-aortic lymph nodes. With no clinical evidence of tumor in the pancreas or extension from it, the predominately para-aortic location of the tumor favors a mucinous carcinoma arising from a rest of mature metastatic/proliferating teratoma that persisted after chemotherapy. This case illustrates the importance of a thorough history, however remote, and correlation with imaging in the development of differential diagnoses, as well as, the need to consider non-pancreaticobiliary sources of retroperitoneal mucinous tumors. PMID:27034817

  15. Analysis of the Distribution of Mucins in Adult Human Gastric Mucosa and Its Functional Significance

    PubMed Central

    2016-01-01

    Introduction Mucins are complex composition of carbohydrates seen in the epithelial cells lining the gastrointestinal tract (GIT). Normal distribution of such mucins in different part of the GIT and its alteration in various inflammatory, benign and malignant lesions of GIT has aroused interest in the field of histochemistry. Aim By applying variety of histochemical techniques an attempt has been made to draw a map of mucin secretion by the different epithelial cell types in different parts of the stomach. Materials and Methods Fifty samples were taken each from different parts of the stomach like fundus, body and pylorus, from dissected fresh specimens (total of 150 specimens). Tissue samples were subjected for routine process and studied for histological and different histochemical staining. Results Mucin pattern in adult predominantly secretes neutral mucosubstances. Surface epithelium shows predominant neutral mucin while cardiac and gastric glands with foveolar cells show moderate amount. Sialomucin is present in a few cells of the surface epithelium, foveolar cells and in most of the mucous neck cells. Small amount of sialomucin and sulphomucin are found in surface epithelial foveolar cells while traces of sulphomucin are found in deep foveolar cells. Mucous neck cells secrete both sulphomucin and sialomucin. Conclusion Normal gastric mucosa adjacent to gastric ulcers and malignant tumours of stomach secretes mucins which differ histochemically and biochemically from that of normal. Early recognition of such changes could be useful in recognizing the different type of carcinomas and their prognosis. PMID:27042436

  16. Mucinous cystadenoma of the appendix presenting as an umbilical hernia: A case report

    PubMed Central

    REN, BINGBING; MENG, XIANGCHAO; CAO, ZI; GUO, CHUNLI; ZHANG, ZILI

    2016-01-01

    Mucinous cystadenoma of the appendix is a rare condition that develops as a result of proliferation of mucin-secreting cells in an occluded appendix. Mucinous cystadenoma of the appendix presenting as an umbilical hernia is a rare clinical entity. The most common causes of this condition are known to be ascites, hepatitis and cirrhosis; however, the patient in the present study, was diagnosed as hepatitis- and cirrhosis-negative, with no history of chronic coughing or constipation. The aim of the present study was to report a rare case of mucinous cystadenoma of the appendix presenting as an umbilical hernia in a 66-year-old female patient. The patient had a 6-month history of a reducible mass in the umbilical region and was diagnosed with umbilical hernia. Computed tomography and ultrasonography were performed and revealed massive ascites. Ultimately, a laparoscopic appendectomy was performed and borderline mucinous appendiceal cystadenoma of low malignant potential was confirmed. In addition, the present study discussed the association between mucinous cystadenoma of the appendix and umbilical hernia, as well as the diagnostic process and treatment strategies. PMID:27313766

  17. The effect of divalent vs. monovalent ions on the swelling of Mucin-like polyelectrolyte gels: Governing equations and equilibrium analysis

    NASA Astrophysics Data System (ADS)

    Sircar, S.; Keener, J. P.; Fogelson, A. L.

    2013-01-01

    We introduce a comprehensive model of a mucin-like polyelectrolyte gel swelling-deswelling which includes the ion-mediated crosslinking of polymer strands and the exchange of divalent and monovalent ions in the gel. The gel is modeled as a multi-phase mixture which accounts for the polymer and solvent volume fractions and velocities as well as ionic species concentrations. Motion is determined by force balances involving viscous, drag, and chemical forces. The chemical forces are derived from a free energy which includes entropic contributions as well as the chemical and electrostatic interactions among the crosslinked polymer, uncrosslinked polymer, and the ionic solvent. The unified derivation produces all the classical effects (van't Hoff osmotic pressure, Donnan equilibrium potential, Nernst-Planck motion of ions) as well as expressions for Flory interaction parameter and the standard free energy parameters that explicitly depend on the gel chemistry and crosslink structure. For this model, we show how the interplay between ionic bath concentrations, ionic binding, and transient divalent crosslinking leads to a variety of swelled and deswelled phases/phase transitions. In particular, we show how the absorption of divalent ions can lead to a massive deswelling of the gel. We conclude that the unique properties of mucin-like gels can be explained by their ionic binding affinities and transient divalent crosslinking.

  18. Structure of a SusD Homologue, BT1043, Involved in Mucin O-Glycan Utilization in a Prominent Human Gut Symbiont

    SciTech Connect

    Koropatkin, Nicole; Martens, Eric C.; Gordon, Jeffrey I.; Smith, Thomas J.

    2009-05-21

    Mammalian distal gut bacteria have an expanded capacity to utilize glycans. In the absence of dietary sources, some species rely on host-derived mucosal glycans. The ability of Bacteroides thetaiotaomicron, a prominent human gut symbiont, to forage host glycans contributes to both its ability to persist within an individual host and its ability to be transmitted naturally to new hosts at birth. The molecular basis of host glycan recognition by this species is still unknown but likely occurs through an expanded suite of outermembrane glycan-binding proteins that are the primary interface between B. thetaiotaomicron and its environment. Presented here is the atomic structure of the B. thetaiotaomicron protein BT1043, an outer membrane lipoprotein involved in host glycan metabolism. Despite a lack of detectable amino acid sequence similarity, BT1043 is a structural homologue of the B. thetaiotaomicron starch-binding protein SusD. Both structures are dominated by tetratrico peptide repeats that may facilitate association with outer membrane {beta}-barrel transporters required for glycan uptake. The structure of BT1043 complexed with N-acetyllactosamine reveals that recognition is mediated via hydrogen bonding interactions with the reducing end of {beta}-N-acetylglucosamine, suggesting a role in binding glycans liberated from the mucin polypeptide. This is in contrast to CBM 32 family members that target the terminal nonreducing galactose residue of mucin glycans. The highly articulated glycan-binding pocket of BT1043 suggests that binding of ligands to BT1043 relies more upon interactions with the composite sugar residues than upon overall ligand conformation as previously observed for SusD. The diversity in amino acid sequence level likely reflects early divergence from a common ancestor, while the unique and conserved {alpha}-helical fold the SusD family suggests a similar function in glycan uptake.

  19. Secreted mucins in pseudomyxoma peritonei: pathophysiological significance and potential therapeutic prospects

    PubMed Central

    2014-01-01

    Pseudomyxoma peritonei (PMP, ORPHA26790) is a clinical syndrome characterized by progressive dissemination of mucinous tumors and mucinous ascites in the abdomen and pelvis. PMP is a rare disease with an estimated incidence of 1–2 out of a million. Clinically, PMP usually presents with a variety of unspecific signs and symptoms, including abdominal pain and distention, ascites or even bowel obstruction. It is also diagnosed incidentally at surgical or non-surgical investigations of the abdominopelvic viscera. PMP is a neoplastic disease originating from a primary mucinous tumor of the appendix with a distinctive pattern of the peritoneal spread. Computed tomography and histopathology are the most reliable diagnostic modalities. The differential diagnosis of the disease includes secondary peritoneal carcinomatoses and some rare peritoneal conditions. Optimal elimination of mucin and the mucin-secreting tumor comprises the current standard of care for PMP offered in specialized centers as visceral resections and peritonectomy combined with intraperitoneal chemotherapy. This multidisciplinary approach has reportedly provided a median survival rate of 16.3 years, a median progression-free survival rate of 8.2 years and 10- and 15-year survival rates of 63% and 59%, respectively. Despite its indolent, bland nature as a neoplasm, PMP is a debilitating condition that severely impacts quality of life. It tends to be diagnosed at advanced stages and frequently recurs after treatment. Being ignored in research, however, PMP remains a challenging, enigmatic entity. Clinicopathological features of the PMP syndrome and its morbid complications closely correspond with the multifocal distribution of the secreted mucin collections and mucin-secreting implants. Novel strategies are thus required to facilitate macroscopic, as well as microscopic, elimination of mucin and its source as the key components of the disease. In this regard, MUC2, MUC5AC and MUC5B have been found as

  20. Virulent Shigella flexneri Affects Secretion, Expression, and Glycosylation of Gel-Forming Mucins in Mucus-Producing Cells

    PubMed Central

    Sperandio, Brice; Fischer, Natalie; Chevalier-Curt, Marie Joncquel; Rossez, Yannick; Roux, Pascal; Robbe Masselot, Catherine

    2013-01-01

    Mucin glycoproteins are secreted in large amounts by the intestinal epithelium and constitute an efficient component of innate immune defenses to promote homeostasis and protect against enteric pathogens. In this study, our objective was to investigate how the bacterial enteropathogen Shigella flexneri, which causes bacillary dysentery, copes with the mucin defense barrier. We report that upon in vitro infection of mucin-producing polarized human intestinal epithelial cells, virulent S. flexneri manipulates the secretion of gel-forming mucins. This phenomenon, which is triggered only by virulent strains, results in accumulation of mucins at the cell apical surface, leading to the appearance of a gel-like structure that favors access of bacteria to the cell surface and the subsequent invasion process. We identify MUC5AC, a gel-forming mucin, as a component of this structure. Formation of this gel does not depend on modifications of electrolyte concentrations, induction of trefoil factor expression, endoplasmic reticulum stress, or response to unfolded proteins. In addition, transcriptional and biochemical analyses of infected cells reveal modulations of mucin gene expression and modifications of mucin glycosylation patterns, both of which are induced by virulent bacteria in a type III secretion system-dependent manner. Thus, S. flexneri has developed a dedicated strategy to alter the mucus barrier by targeting key elements of the gel-forming capacity of mucins: gene transcription, protein glycosylation, and secretion. PMID:23876800

  1. Effect of copper sulfate upon gill secretory cell nature, mucin production and mucin composition in Mytilus edulis with notes on Modiolus modiolus

    SciTech Connect

    Clements, J.R.

    1983-01-01

    Mussels secrete increased amounts of mucin upon exposure to copper sulfate concentrations equal to or greater than 3 ppm. The threshold level of copper necessary to elicit this response is higher if the animals are exposed to copper sulfate in filtered rather than in unfiltered seawater. At high levels of copper sulfate there is an increase in the relative hydration of the gill tissue.

  2. Excess Secretion of Gel-Forming Mucins and Associated Innate Defense Proteins with Defective Mucin Un-Packaging Underpin Gallbladder Mucocele Formation in Dogs.

    PubMed

    Kesimer, Mehmet; Cullen, John; Cao, Rui; Radicioni, Giorgia; Mathews, Kyle G; Seiler, Gabriela; Gookin, Jody L

    2015-01-01

    Mucosal protection of the gallbladder is vital yet we know very little about the mechanisms involved. In domestic dogs, an emergent syndrome referred to as gallbladder mucocele formation is characterized by excessive secretion of abnormal mucus that results in obstruction and rupture of the gallbladder. The cause of gallbladder mucocele formation is unknown. In these first mechanistic studies of this disease, we investigated normal and mucocele-forming dog gallbladders to determine the source, identity, biophysical properties, and protein associates of the culprit mucins with aim to identify causes for abnormal mucus behavior. We established that mucocele formation involves an adoptive excess secretion of gel forming mucins with abnormal properties by the gallbladder epithelium. The mucus is characterized by a disproportionally significant increase in Muc5ac relative to Muc5b, defective mucin un-packaging, and mucin-interacting innate defense proteins that are capable of dramatically altering the physical and functional properties of mucus. These findings provide an explanation for abnormal mucus behavior and based on similarity to mucus observed in the airways of people with cystic fibrosis, suggest that abnormal mechanisms for maintenance of gallbladder epithelial hydration may be an instigating factor for mucocele formation in dogs. PMID:26414376

  3. Excess Secretion of Gel-Forming Mucins and Associated Innate Defense Proteins with Defective Mucin Un-Packaging Underpin Gallbladder Mucocele Formation in Dogs

    PubMed Central

    Kesimer, Mehmet; Cullen, John; Cao, Rui; Radicioni, Giorgia; Mathews, Kyle G.; Seiler, Gabriela; Gookin, Jody L.

    2015-01-01

    Mucosal protection of the gallbladder is vital yet we know very little about the mechanisms involved. In domestic dogs, an emergent syndrome referred to as gallbladder mucocele formation is characterized by excessive secretion of abnormal mucus that results in obstruction and rupture of the gallbladder. The cause of gallbladder mucocele formation is unknown. In these first mechanistic studies of this disease, we investigated normal and mucocele-forming dog gallbladders to determine the source, identity, biophysical properties, and protein associates of the culprit mucins with aim to identify causes for abnormal mucus behavior. We established that mucocele formation involves an adoptive excess secretion of gel forming mucins with abnormal properties by the gallbladder epithelium. The mucus is characterized by a disproportionally significant increase in Muc5ac relative to Muc5b, defective mucin un-packaging, and mucin-interacting innate defense proteins that are capable of dramatically altering the physical and functional properties of mucus. These findings provide an explanation for abnormal mucus behavior and based on similarity to mucus observed in the airways of people with cystic fibrosis, suggest that abnormal mechanisms for maintenance of gallbladder epithelial hydration may be an instigating factor for mucocele formation in dogs. PMID:26414376

  4. Searching the Evolutionary Origin of Epithelial Mucus Protein Components-Mucins and FCGBP.

    PubMed

    Lang, Tiange; Klasson, Sofia; Larsson, Erik; Johansson, Malin E V; Hansson, Gunnar C; Samuelsson, Tore

    2016-08-01

    The gel-forming mucins are large glycosylated proteins that are essential components of the mucus layers covering epithelial cells. Using novel methods of identifying mucins based on profile hidden Markov models, we have found a large number of such proteins in Metazoa, aiding in their classification and allowing evolutionary studies. Most vertebrates have 5-6 gel-forming mucin genes and the genomic arrangement of these genes is well conserved throughout vertebrates. An exception is the frog Xenopus tropicalis with an expanded repertoire of at least 26 mucins of this type. Furthermore, we found that the ovomucin protein, originally identified in chicken, is characteristic of reptiles, birds, and amphibians. Muc6 is absent in teleost fish, but we now show that it is present in animals such as ghost sharks, demonstrating an early origin in vertebrate evolution. Public RNA-Seq data were analyzed with respect to mucins in zebrafish, frog, and chicken, thus allowing comparison in regard of tissue and developmental specificity. Analyses of invertebrate proteins reveal that gel-forming-mucin type of proteins is widely distributed also in this group. Their presence in Cnidaria, Porifera, and in Ctenophora (comb jellies) shows that these proteins were present early in metazoan evolution. Finally, we examined the evolution of the FCGBP protein, abundant in mucus and related to gel-forming mucins in terms of structure and localization. We demonstrate that FCGBP, ubiquitous in vertebrates, has a conserved N-terminal domain. Interestingly, this domain is also present as an N-terminal sequence in a number of bacterial proteins. PMID:27189557

  5. Searching the Evolutionary Origin of Epithelial Mucus Protein Components—Mucins and FCGBP

    PubMed Central

    Lang, Tiange; Klasson, Sofia; Larsson, Erik; Johansson, Malin E. V.; Hansson, Gunnar C.; Samuelsson, Tore

    2016-01-01

    The gel-forming mucins are large glycosylated proteins that are essential components of the mucus layers covering epithelial cells. Using novel methods of identifying mucins based on profile hidden Markov models, we have found a large number of such proteins in Metazoa, aiding in their classification and allowing evolutionary studies. Most vertebrates have 5–6 gel-forming mucin genes and the genomic arrangement of these genes is well conserved throughout vertebrates. An exception is the frog Xenopus tropicalis with an expanded repertoire of at least 26 mucins of this type. Furthermore, we found that the ovomucin protein, originally identified in chicken, is characteristic of reptiles, birds, and amphibians. Muc6 is absent in teleost fish, but we now show that it is present in animals such as ghost sharks, demonstrating an early origin in vertebrate evolution. Public RNA-Seq data were analyzed with respect to mucins in zebrafish, frog, and chicken, thus allowing comparison in regard of tissue and developmental specificity. Analyses of invertebrate proteins reveal that gel-forming-mucin type of proteins is widely distributed also in this group. Their presence in Cnidaria, Porifera, and in Ctenophora (comb jellies) shows that these proteins were present early in metazoan evolution. Finally, we examined the evolution of the FCGBP protein, abundant in mucus and related to gel-forming mucins in terms of structure and localization. We demonstrate that FCGBP, ubiquitous in vertebrates, has a conserved N-terminal domain. Interestingly, this domain is also present as an N-terminal sequence in a number of bacterial proteins. PMID:27189557

  6. The tyrosine phosphatase, SHP-1, is involved in bronchial mucin production during oxidative stress.

    PubMed

    Jang, Min Kyoung; Kim, Sae-Hoon; Lee, Ki-Young; Kim, Tae-Bum; Moon, Keun Ae; Park, Chan Sun; Bae, Yun Jeong; Zhu, Zhou; Moon, Hee-Bom; Cho, You Sook

    2010-02-26

    Mucus hypersecretion is a clinically important manifestation of chronic inflammatory airway diseases, such as asthma and Chronic obstructive pulmonary disease (COPD). Mucin production in airway epithelia is increased under conditions of oxidative stress. Src homology 2 domain-containing protein tyrosine phosphatase (SHP)-1 suppression is related to the development of airway inflammation and increased ROS levels. In this study, we investigated the role of SHP-1 in mucin secretion triggered by oxidative stress. Human lung mucoepidermoid H292 carcinoma cells were transfected with specific siRNA to eliminate SHP-1 gene expression. Cultured cells were treated with hydrogen peroxide (H(2)O(2)), and Mucin 5AC(MUC5AC) gene expression and mucin production were determined. Activation of p38 mitogen activated protein kinase (MAPK) in association with MUC5AC production was evaluated. N-acetylcysteine (NAC) was employed to determine whether antioxidants could block MUC5AC production. To establish the precise role of p38, mucin expression was observed after pre-treatment of SHP-1-depleted H292 cells with the p38 chemical blocker. We investigated the in vivo effects of oxidative stress on airway mucus production in SHP-1-deficient heterozygous (mev/+) mice. MUC5AC expression was enhanced in SHP-1 knockdown H292 cells exposed to H(2)O(2), compared to that in control cells. The ratio between phosphorylated and total p38 was significantly increased in SHP-1-deficient cells under oxidative stress. Pre-treatment with NAC suppressed both MUC5AC production and p38 activation. Blockage of p38 MAPK led to suppression of MUC5AC mRNA expression. Notably, mucin production was enhanced in the airway epithelia of mev/+ mice exposed to oxidative stress. Our results clearly indicate that SHP-1 plays an important role in airway mucin production through regulating oxidative stress. PMID:20117097

  7. Biosynthesis of mucins in bovine trachea: identification of the major radiolabelled species.

    PubMed Central

    Svitacheva, N; Hovenberg, H W; Davies, J R

    1998-01-01

    Bovine trachea in organ culture secretes mucus containing a 'high-density' (1.46 g/ml) and a 'low-density' (1.37 g/ml) mucin similar to those identified previously in bovine respiratory secretions [Hovenberg, Carlstedt and Davies (1997) Biochem. J. 321, 117-123]. After pulse-labelling, autoradiography showed uptake of [35S]sulphate by both epithelial goblet cells and submucosal glands, while [3H]proline was mainly incorporated into the ciliated surface epithelial cells. After 24 h of radiolabelling, neither the high- nor the low-density mucin in the secreted mucus gel was heavily radiolabelled with the precursors. In contrast, a population of molecules banding at 1.50 g/ml was heavily radiolabelled with [35S]sulphate. This component was smaller than the high-density mucin from the mucus gel and was insensitive to reduction or digestion with chondroitin ABC lyase or heparan sulphate lyase. The molecules yielded two populations of high-Mr glycopeptides upon trypsin digestion, were sensitive to keratanase and endo-beta-galactosidase digestion and contained O-linked glycans. Extracts of the surface epithelium and submucosal tissue after radiolabelling showed that the high- and low-density mucins in the tissue were also poorly radiolabelled. Thus, under these conditions, the radiolabelled precursors were not effectively incorporated into the large oligomeric mucins but into a high-Mr monomeric species. This study suggests that data obtained in investigations where mucins are radiolabelled and studied without further separation into distinct components may rather reflect the turnover of this 'novel' monomeric species than the large oligomeric mucins. PMID:9657987

  8. Gallbladder inflammation is associated with increase in mucin expression and pigmented stone formation.

    PubMed

    Vilkin, Alexander; Nudelman, Israel; Morgenstern, Sara; Geller, Alex; Bar Dayan, Yosefa; Levi, Zohar; Rodionov, Galina; Hardy, Britta; Konikoff, Fred; Gobbic, Diana; Niv, Yaron

    2007-07-01

    Mucin is a high molecular weight glycoprotein that plays an important role in protecting the gallbladder epithelium from the detergent effect of bile. However, it also participates in gallstone formation. There is little information about a possible relationship between gallbladder inflammation and mucin expression or gallbladder stones' characteristics. The aims of this study were to investigate stone characteristics and patterns of mucin expression in the gallbladder epithelium and bile of gallstone patients, in relation to inflammation. Gallbladder bile and tissue samples from 21 patients were obtained at surgery. Mucin content was evaluated by gel filtration on a Sepharose CL-4B column. Dot blot for bile mucin apoproteins and immunohistochemistry staining for gallbladder mucosal mucin apoproteins were performed with antibodies to MUC2, MUC3, MUC5AC, MUC5B and MUC6. Staining intensity score (0-3) was used for assessment of antigen expression and the level of inflammation. Gallstone cholesterol content was determined in 16 patients. MUC 5AC and MUC 5B were demonstrated in 95.4 and 100% of gallbladder bile samples, respectively. Immunohistochemistry staining with antibodies to MUC 2, MUC 3, MUC 5AC, MUC 5B and MUC 6 were positive in 0, 100, 85.7, 100 and 95.4% of the gallbladder mucosal samples, respectively. Pigmented brown stones were associated with a higher level of gallbladder inflammation. Mucin species expressed in gallbladder epithelium are MUC3, MUC5AC, MUC5B and MUC6. MUC5AC and MUC5B are secreted into bile. Inflammation of the gallbladder is accompanied by a higher level of MUC5AC expression and is associated with pigmented brown stones. PMID:17385041

  9. Advances in the care of patients with mucinous colorectal cancer.

    PubMed

    Hugen, Niek; Brown, Gina; Glynne-Jones, Robert; de Wilt, Johannes H W; Nagtegaal, Iris D

    2016-06-01

    The majority of colorectal cancers (CRCs) are classified as adenocarcinoma not otherwise specified (AC). Mucinous carcinoma (MC) is a distinct form of CRC and is found in 10-15% of patients with CRC. MC differs from AC in terms of both clinical and histopathological characteristics, and has long been associated with an inferior response to treatment compared with AC. The debate concerning the prognostic implications of MC in patients with CRC is ongoing and MC is still considered an unfavourable and unfamiliar subtype of the disease. Nevertheless, in the past few years epidemiological and clinical studies have shed new light on the treatment and management of patients with MC. Use of a multidisciplinary approach, including input from surgeons, pathologists, oncologists and radiologists, is beginning to lead to more-tailored approaches to patient management, on an individualized basis. In this Review, the authors provide insight into advances that have been made in the care of patients with MC. The prognostic implications for patients with colon or rectal MC are described separately; moreover, the predictive implications of MC regarding responses to commonly used therapies for CRC, such as chemotherapy, radiotherapy and chemoradiotherapy, and the potential for, and severity of, metastasis are also described. PMID:26323388

  10. Genome-wide significant risk associations for mucinous ovarian carcinoma

    PubMed Central

    Kelemen, Linda E.; Lawrenson, Kate; Tyrer, Jonathan; Li, Qiyuan; M. Lee, Janet; Seo, Ji-Heui; Phelan, Catherine M.; Beesley, Jonathan; Chen, Xiaoqin; Spindler, Tassja J.; Aben, Katja K.H.; Anton-Culver, Hoda; Antonenkova, Natalia; Baker, Helen; Bandera, Elisa V.; Bean, Yukie; Beckmann, Matthias W.; Bisogna, Maria; Bjorge, Line; Bogdanova, Natalia; Brinton, Louise A.; Brooks-Wilson, Angela; Bruinsma, Fiona; Butzow, Ralf; Campbell, Ian G.; Carty, Karen; Chang-Claude, Jenny; Chen, Y. Ann; Chen, Zhihua; Cook, Linda S.; Cramer, Daniel W.; Cunningham, Julie M.; Cybulski, Cezary; Dansonka-Mieszkowska, Agnieszka; Dennis, Joe; Dicks, Ed; Doherty, Jennifer A.; Dörk, Thilo; du Bois, Andreas; Dürst, Matthias; Eccles, Diana; Easton, Douglas T.; Edwards, Robert P.; Eilber, Ursula; Ekici, Arif B.; Engelholm, Svend Aage; Fasching, Peter A.; Fridley, Brooke L.; Gao, Yu-Tang; Gentry-Maharaj, Aleksandra; Giles, Graham G.; Glasspool, Rosalind; Goode, Ellen L.; Goodman, Marc T.; Grownwald, Jacek; Harrington, Patricia; Harter, Philipp; Hasmad, Hanis Nazihah; Hein, Alexander; Heitz, Florian; Hildebrandt, Michelle A.T.; Hillemanns, Peter; Hogdall, Estrid; Hogdall, Claus; Hosono, Satoyo; Iversen, Edwin S.; Jakubowska, Anna; Jensen, Allan; Ji, Bu-Tian; Karlan, Beth Y; Kellar, Melissa; Kelley, Joseph L.; Kiemeney, Lambertus A.; Krakstad, Camilla; Kjaer, Susanne K.; Kupryjanczyk, Jolanta; Lambrechts, Diether; Lambrechts, Sandrina; Le, Nhu D.; Lee, Alice W.; Lele, Shashi; Leminen, Arto; Lester, Jenny; Levine, Douglas A.; Liang, Dong; Lissowska, Jolanta; Lu, Karen; Lubinski, Jan; Lundvall, Lene; Massuger, Leon F.A.G.; Matsuo, Keitaro; McGuire, Valerie; McLaughlin, John R.; McNeish, Iain; Menon, Usha; Modugno, Francesmary; Moes-Sosnowska, Joanna; Moysich, Kirsten B.; Narod, Steven A.; Nedergaard, Lotte; Ness, Roberta B.; Nevanlinna, Heli; Azmi, Mat Adenan Noor; Odunsi, Kunle; Olson, Sara H.; Orlow, Irene; Orsulic, Sandra; Weber, Rachel Palmieri; Paul, James; Pearce, Celeste Leigh; Pejovic, Tanja; Pelttari, Liisa M.; Permuth-Wey, Jennifer; Pike, Malcolm C.; Poole, Elizabeth M.; Ramus, Susan J.; Risch, Harvey A.; Rosen, Barry; Rossing, Mary Anne; Rothstein, Joseph H.; Rudolph, Anja; Runnebaum, Ingo B.; Rzepecka, Iwona K.; Salvesen, Helga B.; Schildkraut, Joellen M.; Schwaab, Ira; Shu, Xiao-Ou; Shvetsov, Yurii B; Siddiqui, Nadeem; Sieh, Weiva; Song, Honglin; Southey, Melissa C.; Sucheston, Lara; Tangen, Ingvild L.; Teo, Soo-Hwang; Terry, Kathryn L.; Thompson, Pamela J; Tworoger, Shelley S.; van Altena, Anne M.; Van Nieuwenhuysen, Els; Vergote, Ignace; Vierkant, Robert A.; Wang-Gohrke, Shan; Walsh, Christine; Wentzensen, Nicolas; Whittemore, Alice S.; Wicklund, Kristine G.; Wilkens, Lynne R.; Wlodzimierz, Sawicki; Woo, Yin-Ling; Wu, Xifeng; Wu, Anna H.; Yang, Hannah; Zheng, Wei; Ziogas, Argyrios; Sellers, Thomas A.; Freedman, Matthew L.; Chenevix-Trench, Georgia; Pharoah, Paul D.; Gayther, Simon A.; Berchuck, Andrew

    2015-01-01

    Genome-wide association studies have identified several risk associations for ovarian carcinomas (OC) but not for mucinous ovarian carcinomas (MOC). Genotypes from OC cases and controls were imputed into the 1000 Genomes Project reference panel. Analysis of 1,644 MOC cases and 21,693 controls identified three novel risk associations: rs752590 at 2q13 (P = 3.3 × 10−8), rs711830 at 2q31.1 (P = 7.5 × 10−12) and rs688187 at 19q13.2 (P = 6.8 × 10−13). Expression Quantitative Trait Locus (eQTL) analysis in ovarian and colorectal tumors (which are histologically similar to MOC) identified significant eQTL associations for HOXD9 at 2q31.1 in ovarian (P = 4.95 × 10−4, FDR = 0.003) and colorectal (P = 0.01, FDR = 0.09) tumors, and for PAX8 at 2q13 in colorectal tumors (P = 0.03, FDR = 0.09). Chromosome conformation capture analysis identified interactions between the HOXD9 promoter and risk SNPs at 2q31.1. Overexpressing HOXD9 in MOC cells augmented the neoplastic phenotype. These findings provide the first evidence for MOC susceptibility variants and insights into the underlying biology of the disease. PMID:26075790