scholarly journals Mucins secreted by a transformed cell line derived from human tracheal gland cells1

1997 ◽  
Vol 326 (2) ◽  
pp. 431-437 ◽  
Author(s):  
Jean-Marc LO-GUIDICE ◽  
Marc D. MERTEN ◽  
Geneviève LAMBLIN ◽  
Nicole PORCHET ◽  
Marie-Christine HOUVENAGHEL ◽  
...  

High-molecular-mass glycoconjugates are secreted by the continuous cell line MM-39, which has been obtained from cultured human tracheal gland cells transformed by simian virus 40. They were purified on Sepharose® CL-4B and then by two steps of density-gradient centrifugation. High-molecular-mass glycoproteins resistant to digestion by hyaluronidase, chondroitin ABC lyase and heparitinase were obtained, in addition to hyaluronic acid and proteoglycans. They were susceptible to β-elimination. They contained polylactosaminoglycan chains as well as carbohydrate chains with a terminal sialic acid in the NeuAc α2-3 sequence. Most of them have a buoyant density of 1.45 g/ml in CsCl-density-gradient centrifugation, except for MUC1. The MM-39 cells were also characterized by a high expression of MUC1 and MUC4 genes, but they did not express MUC2, MUC3, MUC5B and MUC5AC. Therefore the MM-39 cells synthesized mucin-like glycoproteins as well as lysozyme and mucous proteinase inhibitor [Merten, Kammouni, Renaud, Birg, Mattéi and Figarella (1996) Am. J. Respir. Cell. Mol. Biol. 15, 520–528]; they should be considered as having a mixed, both serous and mucous, phenotype.

1984 ◽  
Vol 221 (3) ◽  
pp. 637-644 ◽  
Author(s):  
P J Roughley ◽  
R J White ◽  
A R Poole ◽  
J S Mort

High-buoyant-density proteoglycan aggregates could not be prepared from extracts of adult human cartilage by associative CsCl-density-gradient centrifugation with a starting density of 1.68 g/ml, even though proteoglycan subunits, hyaluronic acid and link proteins were all present. In contrast, aggregates could be prepared when extracts of neonatal human cartilage or bovine nasal cartilage were subjected to the same procedure. This phenomenon did not appear to be due to a defect within the hyaluronic acid-binding region of the adult proteoglycan subunit, but rather to an interference in the stability of the interaction between the proteoglycan subunit and hyaluronic acid towards centrifugation. The factor responsible for this instability was shown to reside within the low-density cartilage protein preparation obtained by direct dissociative CsCl-density-gradient centrifugation of the adult cartilage extract.


1991 ◽  
Vol 277 (3) ◽  
pp. 713-718 ◽  
Author(s):  
R Wu ◽  
C G Plopper ◽  
P W Cheng

We isolated mucin-like glycoproteins from the conditioned medium of primary hamster tracheal epithelial (HTE) cell culture and characterized them biochemically and immunologically. These glycoproteins were purified on Sepharose CL-4B after Streptomyces hyaluronidase treatment and then by CsCl-density-gradient centrifugation in the presence of 4 M-guanidinium chloride. The purified glycoproteins were resistant to digestion by chondroitin AC lyase, heparinase, heparitinase and endo-N-acetylglucosaminidases A, D and H, but susceptible to endo-beta-galactosidase and keratanase. SDS/PAGE demonstrated no contamination by low-molecular-mass proteins. The purified glycoproteins showed a peak buoyant density of 1.56 g/ml in CsCl-density-gradient centrifugation, and contained 10% peptide and 90% carbohydrate by weight. Carbohydrates in these glycoproteins contained N-acetylglucosamine, N-acetylgalactosamine, galactose, fucose, sialic acid and a trace amount of mannose, but no uronic acid. Serine and threonine together accounted for 27% of the total amino acid residues. In addition, the mucin-like glycoproteins exhibited blood-group A and B activities, and very strong inhibitory activity for influenza A virus haemagglutination. With the use of the purified glycoprotein as an antigen, six monoclonal antibodies that stained mucus granules in hamster tracheal epithelium were obtained. We characterized the antibody produced by one of the clones, HM D46. We conclude that HTE cells cultured in the serum-free medium secrete a glycoprotein with physicochemical properties similar to those known in various airways mucins.


1992 ◽  
Vol 283 (3) ◽  
pp. 807-811 ◽  
Author(s):  
E C I Veerman ◽  
P A M van den Keybus ◽  
M Valentijn-Benz ◽  
A V Nieuw Amerongen

By using CsCl-density-gradient ultracentrifugation, two high-Mr mucin species were isolated from human whole saliva, having buoyant densities in 0.2 M-guanidinium chloride of approx. 1.56 g/ml (pool IA) and 1.48 g/ml (pool IIA). Analytical density-gradient centrifugation of submandibular, sublingual, labial and palatal saliva, followed by immunochemical analysis with anti-mucin monoclonal antibodies, indicated immunochemical and physicochemical similarities between the high-density mucins of pool IA and mucins from palatal salivary glands. Chemical analysis indicated that the putative palatal mucin was rich in sulphate, but poor in sialic acid. The lower-density mucins of pool IIA equated with the high-Mr mucins of submandibular-sublingual saliva, both immunochemically and physicochemically (buoyant density).


1996 ◽  
Vol 316 (3) ◽  
pp. 943-951 ◽  
Author(s):  
Lubna H. ABDULLAH ◽  
Shannon W. DAVIS ◽  
Lauranell BURCH ◽  
Mitsuo YAMAUCHI ◽  
Scott H. RANDELL ◽  
...  

The SPOC1 cell, a novel goblet cell line derived from rat trachea, was tested for its ability to exhibit regulated mucin secretion in response to purinergic (P2) agonists. High-molecular-mass glycoconjugates (HMMGs) purified by CsCl-density-gradient centrifugation had a buoyant density of 1.45 g/ml. The purified HMMG material exhibited a single major band with an apparent molecular mass of greater than 1000 kDa in SDS/ polyacrylamide gels stained with silver or blotted and stained with soya-bean agglutinin. [3H]HMMG was resistant to proteoglycan-degrading enzymes, but was susceptible to neuraminidase. The HMMG was approx. 91% carbohydrate by weight, and the glycosides were O-linked. The HMMG amino acid composition was enriched in Ser and Thr (sum 27%). Thus SPOC1-cell HMMG possess the characteristics of mucin. Mucin secretion by SPOC1 cells, grown on permeable supports and perfused luminally, was stimulated by ATP, UTP and adenosine 5′-[γ-thio]triphosphate (100 μM) 4–5-fold over a baseline of 4 ng/min. The three dose–effect relations were nearly identical (K0.5 ~4 μM). SPOC1 cells grown on plastic and rat tracheal epithelial primary cells responded similarly to ATP and/or UTP. SPOC1 cells failed to respond to other purinergic agonists, either luminally or serosally, and consequently seem to possess an apical membrane P2u purinoceptor. SPOC1-cell total RNA was probed for P2u purinoceptor mRNA. Using conserved primers for both reverse transcriptase and PCR, a single band of the predicted size was observed, which had a nucleotide base sequence identical with the rat P2u purinoceptor mRNA. Thus SPOC1 cells secrete mucin under the control of a P2u purinoceptor; they should prove useful in dissecting the associated cellular regulatory pathways.


1978 ◽  
Vol 173 (3) ◽  
pp. 935-939 ◽  
Author(s):  
P Speziale ◽  
M S Speziale ◽  
L Galligani ◽  
C Balduini

Proteoglycans were extracted from bovine cornea with 4M-guanidinium chloride and purified by CsCl-density-gradient centrifugation. Under associative conditions two fractions were found: one capable of forming assemblies of high molecular weight and another lacking this property. The heavier fraction (density 1.59 g/ml) was eluted as a single retarded peak from Sepharose 2B, but on DEAE-Sephadex chromatography, gave two peaks: the first (eluted with 0.75 M-NaCl) contained mainly proteochondroitin sulphate and the second (eluted with 1.25 M-NaCl) mainly proteokeratan sulphate. Each of these proteoglycans was more retarded on Sepharose 2B than was the original sample from density-gradient centrifugation. Re-aggregation was obtained by recombination of the two fractions. The lighter fraction (density 1.44 g/ml), containing predominantly keratan sulphate chains, was eluted from DEAE-Sephadex as a single peak with 1.25 M-NaCl and was retarded on Sepharose 2B: this fraction was not able to form aggregates with proteochondroitin sulphate. Chemical analyses of the carbohydrate and protein moieties of the proteoglycans from DEAE-Sephadex confirmed that, in the cornea, different subunits are present with characteristic aggregation properties and hydrodynamic volumes.


Blood ◽  
1984 ◽  
Vol 63 (2) ◽  
pp. 482-485 ◽  
Author(s):  
BA van Oost ◽  
AP Timmermans ◽  
JJ Sixma

Abstract The relation between platelet buoyant density and beta-thromboglobulin (beta-TG), a marker for platelet alpha-granule content, was assessed by three independent approaches. (1) Platelets were separated on iso- osmolar discontinuous Stractan density gradients into five fractions, ranging in density from 1.061 g/ml to 1.091 g/ml (20 degrees C). The beta-TG content (mean +/- SD, n = 17) increased with the platelet density from 27.8 +/- 8.6 micrograms beta-TG/10(9) cells (20% less- dense platelets) up to 65.6 +/- 15.5 micrograms beta-TG/10(9) cells (15% most-dense platelets). (2) Activation of platelets in platelet- rich plasma with thrombin, adenosine diphosphate, collagen, or epinephrine resulted in a decreased density of the platelets. This was only seen when there was simultaneous secretion of beta-TG. (3) The less-dense and the more-dense platelet fractions, after isolation by density gradient centrifugation, were separately treated with thrombin. After complete degranulation, the density distribution of the originally less-dense and more-dense platelets were identical and were much narrower than the density distribution of resting platelets.


2015 ◽  
Vol 9 ◽  
pp. 194-203 ◽  
Author(s):  
Leyla T. Hathwaik ◽  
Doug Redelman ◽  
Vera Samburova ◽  
Barbara Zielinska ◽  
David K. Shintani ◽  
...  

1992 ◽  
Vol 70 (6) ◽  
pp. 470-474 ◽  
Author(s):  
P. Sindelar ◽  
C. Valtersson

Incubation of small unilamellar vesicles consisting of dioleoyl phosphatidylcholine – dioleoyl phosphatidylethanolamine (3:1) and 2 mol% [3H]dolichol-19 with postheparin plasma from rat resulted in the formation of dolichyl oleate. Normal plasma or heat-treated postheparin plasma contained no activity and, hence, the results indicate the presence of a cell surface associated dolichol acyltransferase that can be released into the blood by heparin. The reaction is strongly stimulated by phosphatidylethanolamine and Ca2+, whereas no stimulation with triglycerides or acyl-CoA was observed. Together with the fact that the only product formed was dolichyl oleate, these results strongly suggest that a transacylation mechanism from the phospholipids to dolichol is operative in the liposomes. Gel chromatography of postheparin plasma yielded a molecular mass of about 350 kilodaltons for the active enzyme and density gradient centrifugation indicated that this high molecular mass complex consists mainly of proteins. Finally, we conclude that this enzyme is not unique to the rat, but is also present in human postheparin plasma.Key words: phospholipids, dolichol, plasma, heparin, acyltransferase(s).


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