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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously demonstrated that human tracheobronchial epithelial (TBE) cells synthesize mucin and form mucous granules in culture when they are maintained on a collagen gel (CG) substratum, but not on a plastic tissue culture surface or a thin collagen-coated surface (Wu et al., Am. J. Respir. Cell Mol. Biol., 3:467-478; 1990). This observation led us to examine the effects of CG thickness on cell growth and differentiation in primary human/monkey TBE cell cultures. Using the same CG preparation, culture dishes with different thicknesses of CG substratum were prepared. In general, equivalent degrees of cell attachment and proliferation were observed in all cultures maintained on a collagen gel, independent of the thicknesses of CG substratum. However, a greater degree of mucin synthesis and secretion by the cells was observed as the thickness of the CG substratum was increased. Cultures maintained on a thick collagen gel (1 mm) exhibited greater apical membrane complexity, more pseudostratification, and more mucous granules than did cultures maintained on a thin CG substratum. The optimal culture surface for airway mucous cell differentiation contains more than 1-mm thickness of collagen gel substratum.
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PMID:Mucin synthesis and secretion by cultured tracheal cells: effects of collagen gel substratum thickness. 833 Oct 31

The effect of the low and high molecular weight salivary mucins on the activity of calcium channel isolated from buccal epithelial cell membranes was investigated. The 45Ca2+ uptake into the vesicle-reconstituted channels, while only moderately (15%) affected by the intact mucin forms, was significantly inhibited (60%) by the acidic mucin fractions. This effect was associated with the sialic acid and sulfate ester groups of the glycoproteins. The channel complex in the presence of epidermal growth factor (EGF) and ATP responded by an increase in protein tyrosine phosphorylation, and the vesicles containing the phosphorylated channels showed a 46% increase in 45Ca2+ uptake. The phosphorylation process was inhibited by the acidic mucins, which also interfered with the binding of EGF to the channel protein. The inhibitory effect was dependent upon the presence of sulfate ester and sialic acid groups, and the loss of the inhibitory capacity occurred following their removal. The results demonstrate the salivary mucins actively participate in the modulation of buccal mucosal calcium channel activity.
Biochem Mol Biol Int 1993 Feb
PMID:Salivary mucin modulation of buccal mucosal calcium channel activity. 838 91

Porphyromonas gingivalis, a bacterium implicated in the pathogenesis of periodontal disease, was found to elaborate an extracellular glycosulfatase enzyme. Upon purification by low temperature acetone fractionation, an active enzyme at 60% acetone was obtained which on SDS-PAGE gave a protein band of 37kDa. The glycosulfatase effectively caused desulfation of galactosyl- and lactosylceramide sulfates (pH 5.0) which contain the sulfate ester groups at C-3 of galactose, a well as proteoglycans (pH 5.7-6.2) of gingival tissue which are rich in N-acetylgalactosamine-4-sulfate, but not the sulfated salivary mucin with the sulfate groups at C-6 of galactose and C-6 of N-acetylglucosamine. The results demonstrate for the first time that P. gingivalis displays glycosulfatase activity and that the disruptive action of this enzyme may be a major factor in the etiology of periodontal disease.
Biochem Mol Biol Int 1993 Apr
PMID:Glycosulfatase activity of Porphyromonas gingivalis a bacterium associated with periodontal disease. 838 37

Hamster tracheal epithelial cells in extended (32 degrees C) primary culture with and without supplemental retinoic acid (RA) were studied during the proliferative (5 days) and differentiation phases (11 days) by correlative transmission electron microscopy (EM) and light microscopic (LM) autoradiography to quantify the relationship between cell proliferation, shape change, and mucin granule expression. In retinyl acetate-containing control medium, cell numerical density was higher and [3H]thymidine labeling index (LI) lower at day 11 compared with day 5. The addition of 10(-7) M RA to the medium caused an increase in cell numerical density at both times. LI was increased by RA at 5 days and decreased at 11 days. Measurements of cell shape in ultrathin sections adjacent to LM autoradiographs made in the vertical plane demonstrated an RA-induced change from flat to cuboidal at 5 days and a more columnar phenotype at 11 days. Cells containing mucin granules were of two main types based on their ultrastructure. One type, seen at 5 and 11 days, contained diminutive mucin granules and had an LI of 50% at 11 days. Its LI and frequency (26%) were unaltered by RA. The other type, less frequent (15%) and present only at 11 days, was more columnar and contained mucous granules similar to those found in vivo. RA doubled the frequency of this cell type but did not affect its LI (11%). Cells of this type with more than five mucin granules in EM profile did not incorporate thymidine. The data indicate that RA accelerates and enhances cell shape change toward a more cuboidal phenotype.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1993 Sep
PMID:Quantitative ultrastructural analysis of the relationship between cell growth, shape change, and mucosecretory differentiation in cultured hamster tracheal epithelial cells exposed to retinoic acid. 839 66

The regulation of mucin secretion by airway goblet cells is poorly understood and the receptor-based regulatory mechanisms have not been described in human airways. In the present study, we report that extracellular triphosphate nucleotides regulate the rate of granule release from goblet cells in both normal and cystic fibrosis (CF) airway epithelial explants. Explants isolated from nasal and tracheobronchial tissues were mounted in perfusion chambers and the secretory activity was assessed by videomicroscopic determination of degranulation in single goblet cells and by ELISA determination of mucins secreted into the mucosal perfusate. Baseline degranulation was measured at 0.05 degranulation events (DE)/min. In normal goblet cells, mucosal ATP (10(-4) M, n = 17) induced a biphasic secretory response comprising 29.1 +/- 4.9 DE during the first 5 min, with an initial rate of 118.2 +/- 10.2 DE/min. Mucosal UTP (10(-4) M, n = 9) induced a similar response to ATP (initial rate: 89.2 +/- 23.9 DE/min, 17.9 +/- 5.1 DE in 5 min), but mucosal 2-MeSATP was not an effective agonist (initial rate: 1.5 +/- 1.4 DE/min, 2.3 +/- 0.5 DE in 5 min). Determination of mucins by ELISA confirmed that both ATP and UTP induced similar secretory responses but that 2-MeSATP was not effective. In CF explants, mucosal UTP (10(-4) M, n = 6) induced similar responses to those observed in normal tissues (initial rate: 82.5 +/- 27.5 DE/min, 18.8 +/- 4.1 DE in 5 min). We conclude that human nasal and tracheobronchial goblet cells are stimulated by mucosal nucleotides, probably via a 5'-nucleotide receptor, and that this response is unaffected by CF.
Am J Respir Cell Mol Biol 1993 Sep
PMID:Nucleotide regulation of goblet cells in human airway epithelial explants: normal exocytosis in cystic fibrosis. 839 69

We compared the chemical composition of salivary mucin glycopeptides from cystic fibrosis (CF) and from non-CF subjects and the adhesion of Pseudomonas aeruginosa to these different salivary glycopeptides. Three pools of CF saliva, four pools of non-CF saliva, one individual CF saliva, and one individual non-CF saliva were studied. The soluble fraction of the saliva was treated with pronase, and gel filtration was performed to obtain high and low molecular mass salivary mucin glycopeptides. The yield of total glycopeptides was significantly higher from CF than from non-CF saliva. Furthermore, the chemical composition revealed a significantly higher sialic acid content in CF than in non-CF mucin glycopeptides, and higher sulfate and fucose content in CF than in non-CF high molecular mass glycopeptides. We studied the adhesion of a nonmucoid strain of P. aeruginosa (1244), its nonpiliated isogenic derivative, and a mucoid strain (M35) to salivary mucin glycopeptides from patients with CF and from non-CF subjects. The three strains bound significantly more to the CF salivary glycopeptides than to the corresponding non-CF salivary glycopeptides. The nonpiliated isogenic mutant of P. aeruginosa 1244 also bound to CF salivary glycopeptides, suggesting that the adhesion of P. aeruginosa could involve nonpilus adhesions. Furthermore, neuraminidase treatment of CF glycopeptides decreased the adhesion of P. aeruginosa 1244. Altogether these results suggested that differences in mucins may in part explain the specificity of P. aeruginosa for CF.
Am J Respir Cell Mol Biol 1993 Sep
PMID:Altered carbohydrate composition of salivary mucins from patients with cystic fibrosis and the adhesion of Pseudomonas aeruginosa. 839 70

Release of mucins from cultured airway surface epithelial cells can be stimulated by extracellular ATP via a P2-purinergic receptor-mediated mechanism (K. C. Kim and B. C. Lee. 1991. Br. J. Pharmacol. 103:1053-1056). In this report, we studied the mechanism by which extracellular ATP induces the mucin release. We found that: (1) ATP increased both mucin release and generation of inositol phosphates in a dose-dependent fashion, and their dose-effect relationships were almost superimposed; (2) the increases in both mucin release and the phosphatidylinositol phosphate (PI) turnover by extracellular ATP were partially, but almost equally, blocked by the pretreatment with pertussis toxin (42% for mucin release and 44% for PI turnover). We conclude that in cultured airway goblet cells extracellular ATP stimulates mucin release by a signal transduction mechanism, which seems to involve coupling of ATP-activated P2 purinoceptors with phospholipase C, at least in part, via pertussis toxin-sensitive GTP-binding proteins. This may be an important finding in understanding the regulation of mucin release by airway goblet cells, since a number of agents present in the airway could influence this signal transduction pathway and subsequently modulate the mucin secretion.
Am J Respir Cell Mol Biol 1993 Feb
PMID:Involvement of a signal transduction mechanism in ATP-induced mucin release from cultured airway goblet cells. 842 4

The equine embryonic capsule replaces the zona pellucida and envelopes the conceptus during the second and third weeks of pregnancy. Although this capsule was described more than 100 years ago, its molecular structure has not been characterized. Here we present evidence that the glycoprotein(s) of the equine capsule resembles those of the mucin glycoprotein family. The resistance of the capsule to chemical and enzymatic solubilization was confirmed, and, as in mucins, protein constituted only 35-40% of its total dry mass. Determination of the sugar composition of the capsule using colorimetric assays and high-performance anion-exchange chromatography also showed it to have mucin-like characteristics. Gal, GalNAc, sulfated sugars, and sialic acid make up a high proportion of the capsular carbohydrate, while GlcNAc, Glc, and Man are minor components. These findings were verified using lectin histochemical staining of frozen sections of conceptuses. The results of amino acid analysis were also consistent with the proposal that the capsular glycoproteins belong to the mucin family. Removal of the covalently bound carbohydrate by beta-elimination under reducing conditions demonstrated that the capsule is O-glycosylated mainly on threonine residues. Affinity chromatography on jacalin-agarose confirmed that, like mucins, the capsular glycoproteins are heavily O-glycosylated. SDS-PAGE analysis revealed a prominent 21-kDa band, specific to the capsule, in preparations solubilized by trypsin but not by other proteases. Characterization of its constituent glycoprotein(s) should be helpful in elucidating the role of the capsule (and analogous blastocyst coverings in other species) during early pregnancy.
Mol Reprod Dev 1993 Mar
PMID:Mucin-like glycoproteins in the equine embryonic capsule. 847 Dec 47

Sulglycotide, a potent antiulcer agent derived from duodenal mucus glycopeptide through sulfation of the carbohydrate moieties, was evaluated with respect to its ability to interfere with H. pylori mucosal attachment. H. pylori cells were incubated with sulglycotide or human gastric mucin and then examined for their inhibitory capacity of H. pylori attachment to erythrocytes. Titration data revealed that the mucin inhibitory activity was confined to its sulfomucin fraction, the titer of which was found to be 16-fold higher than that of intact mucin. The data with sulglycotide showed that the inhibitory titer of this agent against H. pylori attachment was at least 30-fold higher than that of the sulfated gastric mucin fraction. The results point towards the involvement of sulfomucins in the protection of gastric mucosa from H. pylori colonization and demonstrate that sulglycotide, because of structural similarities, is ideally suited to augment the inherent mucosal defenses against this pathogen.
Biochem Mol Biol Int 1993 Apr
PMID:Inhibition of Helicobacter pylori colonization by an antiulcer agent, sulglycotide. 850 47

The goal of our studies was to establish procedures for subculturing normal human tracheobronchial epithelial (NHTBE) cells without compromising their ability to differentiate into mucous and ciliated cells (i.e., differentiation competence) and to study the regulation of airway secretions by epidermal growth factor (EGF) and retinoic acid (RA). Primary NHTBE cells were obtained from a commercial source and subcultured repeatedly in serum-free medium on plastic tissue culture dishes. The subcultured cells were tested after every passage for differentiation competence in air-liquid interface (ALI) cultures. The apical secretions of cultured NHTBE cells were characterized by immunoblotting, Western blotting, or enzyme-linked immunosorbent assay using a variety of antibodies. They contained mucin-like materials as well as lysozyme, lactoferrin, and secretory leukocyte protease inhibitor (SLPI). We found that an EGF concentration of 25 ng/ml, which is commonly used in airway cell cultures, adversely affected growth, mucin production, and morphology of ALI cultures and that RA was essential for mucociliary differentiation. Without RA, the epithelium became squamous and mucin secretions decreased 300- to 900-fold. In contrast, secretion of lysozyme, lactoferrin, and SLPI was significantly increased in RA-depleted cultures. Cells of passage 2 (P-2) through P-4 remained competent to differentiate into mucous and ciliated cells when grown in ALI cultures. However, mucin secretion and ciliagenesis decreased in P-3 and P-4 cell cultures and P-3 but not P-4 cell cultures exhibited bioelectric properties characteristic of airway epithelium. We concluded that P-2 and P-3 NHTBE cell cultures retain many important features of normal airway epithelium. This enables one to conduct many studies of airway cell biology with a greatly expanded (6,000-fold) cell pool.
Am J Respir Cell Mol Biol 1996 Jan
PMID:Mucociliary differentiation of serially passaged normal human tracheobronchial epithelial cells. 853 81


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