scholarly journals Evidence for the stimulation of dolichol and mannolipid synthesis by glucocorticoids in HeLa cells

1981 ◽  
Vol 198 (1) ◽  
pp. 23-28 ◽  
Author(s):  
C K Ramachandran ◽  
C E Hignite ◽  
S L Gray ◽  
G Melnykovych
Keyword(s):  
Cell Surface ◽  
Hela Cell ◽  
Cell Cultures ◽  
Hela Cells ◽  
Surface Glycoprotein ◽  
Dexamethasone Treatment ◽  
Cell Surface Glycoprotein ◽  
Dolichyl Phosphate ◽  
Stimulation Of

The effects of addition of 1 microM-dexamethasone on the rate of transfer of mannose from GDP-mannose into mannolipid have been studied in HeLa cell cultures. Concurrent with an increase in incorporation of mannose into glycoproteins, the incorporation of mannose from GDP-mannose in vitro into mannolipid and dolichol-linked oligosaccharides was increased after dexamethasone treatment. Stimulation of mannolipid synthesis showed a correlation with the 11 beta, 17 alpha, 21-trihydroxy structure of C21 steroids. Dexamethasone treatment also resulted in an increased incorporation of acetate into dolichol and dolichyl phosphate. The results suggest that the effect of dexamethasone on the cell-surface glycoprotein accumulation is related to increased sugar-linked dolichol synthesis.

scholarly journals Inhibition of ornithine decarboxylase of HeLa cells by diamines and polyamines. Effect on cell proliferation

1980 ◽  
Vol 186 (3) ◽  
pp. 925-931 ◽  
Author(s):  
Andrew A. Branca ◽  
Edward J. Herbst
Keyword(s):  
Hela Cell ◽  
Ornithine Decarboxylase ◽  
Cell Cultures ◽  
Hela Cells ◽  
Horse Serum ◽  
Fresh Medium ◽  
Decarboxylase Activity ◽  
Inhibitory Protein ◽  
Ornithine Decarboxylase Activity ◽  
Stimulation Of

1. Ornithine decarboxylase activity is stimulated in high-density HeLa-cell cultures by dilution of or replacement of spent culture medium with fresh medium containing 10% (v/v) horse serum. 2. After stimulation, ornithine decarboxylase activity reaches a peak at 4–6h, then rapidly declines to the low enzyme activity characteristic of quiescent cultures, where it remains during the remainder of the cell cycle. 3. The stimulation of ornithine decarboxylase is eliminated by the addition of 0.5μm-spermine or -spermidine or 10μm-putrescine to the HeLa-cell cultures at the time of re-feeding with fresh medium. Much higher concentrations (1mm) of the non-physiological diamines, 1,3-diamino-propane or 1,3-diamino-2-hydroxypropane, are required to eliminate the stimulation of ornithine decarboxylase in re-fed HeLa-cell cultures. 4. A heat-labile, non-diffusible inhibitor, comparable with the inhibitory protein ornithine decarboxylase antizyme, is induced in HeLa cells by the addition of exogenous diamines or polyamines. 5. Intracellular putrescine is eliminated, intracellular spermidine and spermine are severely decreased and proliferation of HeLa cells is inhibited when cultures are maintained for 48h in the presence of the non-physiological inducer of ornithine decarboxylase antizyme, 1,3-diamino-2-hydroxypropane. Exogenous putrescine, a physiological inducer of the antizyme, does not decrease intracellular polyamines or interfere with proliferation of HeLa cells.

scholarly journals Cell surface hydrophobicity, adherence to HeLa cell cultures and haemagglutination pattern of pyelonephritogenicEscherichia colistrains

1990 ◽  
Vol 105 (2) ◽  
pp. 255-263 ◽  
Author(s):  
A. Brauner ◽  
M. Katouli ◽  
K. Tullus ◽  
S. H. Jacobson
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Hela Cell ◽  
Cell Cultures ◽  
Hela Cells ◽  
Acute Pyelonephritis ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Hydrophobic Properties ◽  
E Coli

SUMMARYCell surface hydrophobicity, haemagglutination pattern and adherence to HeLa cells were examined in 230 strains ofEscherichia colicollected from women (n= 61 strains) and children (n= 65 strains) with non-obstructive acute pyelonephritis and in 104 faecal control strains ofE. colifrom healthy adults (n= 71 strains) and children (n= 33 strains). PyelonephritogenicE. colistrains showed a significantly increased incidence of hydrophobic properties (90%) and mannose resistant haemagglutination (MRHA) of human erythrocytes (83%) than faecal control strains (64 and 23% respectively,P< 0·001 in both cases). Mannose sensitive haemagglutination (MSHA) was observed in 48% of the pyelonephritogenicE. colistrains and in 50% of the faecal control strains (NS). The incidence of adherence to HeLa cells was low both in pyelonephritogenic and faecal control strains, 6 and 7% respectively (NS). The bacterial phenotypes MRHA + MSHA + and MRHA + MSHA− appeared significantly more often in pyelonephritogenicE. colistrains (35 and 48% respectively) than in faecal control strains (5 and 17% respectively,P< 0·001 in both cases). The phenotype MRHA − MSHA + occurred significantly more often in control strains (45%) than in pyelonephritogenic strains (13%,P< 0·001). Eighty-three per cent of the pyelonephritogenicE. colistrains expressing hydrophobic properties showed MRHA and 50% of the hydrophobic strains showed MSHA. There were no significant correlations between cell surface hydrophobic properties and haemagglutination pattern or adherence to HeLa cells in pyelonephritogenicE. colistrains nor in faecal control strains.

Cell Surface Glycoprotein CD24 Marks Bone Marrow-Derived Human Mesenchymal Stem/Stromal Cells with Reduced Proliferative and Differentiation Capacity In Vitro

2021 ◽  
Vol 30 (6) ◽  
pp. 325-336
Author(s):  
Jeroen van de Peppel ◽  
Gerben J. Schaaf ◽  
Adriana Arruda Matos ◽  
Yuan Guo ◽  
Tanja Strini ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Surface ◽  
Stromal Cells ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein ◽  
Differentiation Capacity

C-CAM (cell-CAM 105) is an adhesive cell surface glycoprotein with homophilic binding properties

1990 ◽  
Vol 96 (1) ◽  
pp. 17-25
Author(s):  
A. Tingstrom ◽  
I. Blikstad ◽  
M. Aurivillius ◽  
B. Obrink
Keyword(s):  
Cell Adhesion ◽  
Cell Surface ◽  
Surface Glycoprotein ◽  
Membrane Glycoproteins ◽  
Binding Properties ◽  
Homophilic Binding ◽  
Cell Surface Glycoprotein ◽  
Fab Fragments ◽  
Cell Cell

C-CAM (Cell-CAM 105) is a cell surface glycoprotein that is involved in cell-cell adhesion of rat hepatocytes in vitro. To elucidate the adhesion mechanism the binding properties of purified C-CAM were investigated. Using proteins immobilized on nitrocellulose it was found that radiolabeled C-CAM bound to C-CAM but not to a variety of other proteins. Partitioning in Triton X-114 showed that C-CAM has hydrophobic properties. In accordance with this, C-CAM was effectively incorporated into phosphatidylcholine liposomes by dialysis from octylglucoside-containing solutions. The C-CAM-containing liposomes bound specifically to isolated hepatocytes. This binding was blocked by Fab fragments of anti-C-CAM antibodies. Furthermore, preincubation of hepatocytes with anti-C-CAM antibodies followed by washing of the cells blocked binding of C-CAM-containing liposomes. At increasing C-CAM contents in the reconstituted liposomes a marked self-aggregation of the liposomes occurred. This aggregation was blocked by Fab fragments of anti-C-CAM antibodies and by alkaline pH. After neutralization a rapid reaggregation occurred. Neither C-CAM binding to C-CAM immobilized on nitrocellulose nor C-CAM-liposome aggregation required calcium ions. Liposomes reconstituted with C-CAM-depleted membrane glycoproteins did not self-aggregate or bind to hepatocytes. Thus, it is concluded that C-CAM can bind specifically to C-CAM in a homophilic binding reaction that does not require calcium. Accordingly, C-CAM has the potential of directly mediating cell-cell adhesion via C-CAM-C-CAM binding between adjacent cells.

scholarly journals Galectin–glycan lattices regulate cell-surface glycoprotein organization and signalling

2008 ◽  
Vol 36 (6) ◽  
pp. 1472-1477 ◽  
Author(s):  
Omai B. Garner ◽  
Linda G. Baum
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Targeted Delivery ◽  
Cell Types ◽  
Surface Glycoprotein ◽  
Membrane Domains ◽  
Cellular Functions ◽  
Cell Surface Glycoprotein

The formation of multivalent complexes of soluble galectins with glycoprotein receptors on the plasma membrane helps to organize glycoprotein assemblies on the surface of the cell. In some cell types, this formation of galectin–glycan lattices or scaffolds is critical for organizing plasma membrane domains, such as lipid rafts, or for targeted delivery of glycoproteins to the apical or basolateral surface. Galectin–glycan lattice formation is also involved in regulating the signalling threshold of some cell-surface glycoproteins, including T-cell receptors and growth factor receptors. Finally, galectin–glycan lattices can determine receptor residency time by inhibiting endocytosis of glycoprotein receptors from the cell surface, thus modulating the magnitude or duration of signalling from the cell surface. This paper reviews recent evidence in vitro and in vivo for critical physiological and cellular functions that are regulated by galectin–glycoprotein interactions.

The major cell surface glycoprotein procyclin is a receptor for induction of a novel form of cell death in African trypanosomes in vitro

2000 ◽  
Vol 111 (2) ◽  
pp. 333-349 ◽  
Author(s):  
Terry W Pearson ◽  
Robert P Beecroft ◽  
Susan C Welburn ◽  
Stefan Ruepp ◽  
Isabel Roditi ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Surface ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein ◽  
African Trypanosomes

scholarly journals A marker for neoplastic progression of human melanocytes is a cell surface ectopeptidase.

1993 ◽  
Vol 177 (4) ◽  
pp. 1135-1143 ◽  
Author(s):  
M E Morrison ◽  
S Vijayasaradhi ◽  
D Engelstein ◽  
A P Albino ◽  
A N Houghton
Keyword(s):  
Cell Surface ◽  
Chromosomal Abnormalities ◽  
Surface Glycoprotein ◽  
Cell Phenotype ◽  
Neoplastic Progression ◽  
Cell Surface Glycoprotein ◽  
Dpp Iv ◽  
Human Melanocytes ◽  
A Cell

Adenosine deaminase binding protein (ADAbp) is a cell surface glycoprotein that is expressed by normal melanocytes but not by melanoma, the malignant counterpart. ADAbp is specifically downregulated during malignant transformation of melanocytes. Recently, we have developed a system that progressively transforms melanocytes in vitro in defined steps. Transduction with v-Ha-ras oncogene followed by long-term culture leads to a cell phenotype and genotype that specifically mimics human melanoma. Loss of ADAbp expression occurred concomitantly with the emergence of growth factor independence and appearance of specific chromosomal abnormalities. The cellular function of ADAbp has not been defined. To characterize ADAbp, the mature 110-kD form was purified from human kidney. Five tryptic peptides from purified human ADAbp revealed 100% homology to a serine protease, human dipeptidyl peptidase IV (DPP IV), also known as CD26. DPP IV activity was detected in lysates from human melanocytes and renal carcinoma cells but not melanoma cells, and DPP IV activity could be specifically isolated from melanocytes by binding to ADA or to S27 monoclonal antibody against ADAbp. These findings show that ADAbp is a cell surface ectopeptidase that is tightly regulated during neoplastic transformation of melanocytes.

scholarly journals Cellular tumorigenicity in nude mice. Test of associations among loss of cell-surface fibronectin, anchorage independence, and tumor-forming ability.

1979 ◽  
Vol 82 (1) ◽  
pp. 1-16 ◽  
Author(s):  
P Kahn ◽  
S I Shin
Keyword(s):  
Cell Surface ◽  
Cell Lines ◽  
Nude Mice ◽  
Diploid Cell ◽  
Tumor Formation ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein ◽  
Chicken Cell

Fibronectin (FN; also called large external transformation-sensitive [LETS] protein or cell-surface protein [CSP]) is a large cell-surface glycoprotein that is frequently observed to be either absent or greatly reduced on the surfaces of malignant cells grown in vitro. Because FN may be a useful molecular marker of cellular malignancy, we have carried out an extensive screening to test the specific association among the degree of expression of FN, anchorage-independent growth, and tumorigenicity in the athymic nude mouse. A variety of diploid cell strains and established cell lines were tested for the expression of surface FN by indirect immunofluorescence using rabbit antisera against human cold insoluble globulin, rodent plasma FN, or chicken cell-surface FN. Concomitantly, the cells were assayed for tumor formation in nude mice and for the ability to form colonies in methylcellulose. Tumorigenic cells often showed very low surface fluorescence, confirming earlier reports. However, many highly tumorigenic fibroblast lines from several species stained strongly with all three antisera. In contrast, the anchorage-independent phenotype was nearly always associated with tumorigenicity in approximately 35 cell lines examined in this study. In another series of experiments, FN-positive but anchorage-independent cells were grown as tumors in nude mice and then reintroduced into culture. In five of the six tumor-derived cell lines, cell-surface FN was not significantly reduced; one such cell line showed very little surface FN. Our data thus indicate that the loss of cell-surface FN is not a necessary step in the process of malignant transformation and that the growth of FN-positive cells as tumors does not require a prior selection in vivo for FN-negative subpopulations.

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