scholarly journals Conditions for fibroblast adhesion without fibronectin

1986 ◽  
Vol 86 (1) ◽  
pp. 25-33
Author(s):  
A.S. Curtis ◽  
H. McMurray
Keyword(s):  
Cell Adhesion ◽  
Low Temperatures ◽  
Cell Attachment ◽  
Culture Conditions ◽  
Cell Binding ◽  
Good Adhesion ◽  
Fibroblast Adhesion ◽  
Fibronectin Binding ◽  
Serum Components

Conditions that permit the adhesion of BHK fibroblasts to a variety of surfaces after inhibition of protein synthesis and competition of any adsorbed fibronectin or vitronectin with the fibronectin cell-binding tetrapeptide, Arg-Gly-Asp-Ser (RGDS), are defined. Exposure of the cells to serum components at any stage in the preparation prevents cell attachment if cycloheximide or fibronectin tetrapeptide is present. If leupeptin is used cell adhesion and spreading occur even when all fibronectin synthesis is suppressed by cycloheximide inhibition, or fibronectin binding by tetrapeptide competition. The adhesions formed under these conditions appear by interference-reflection microscopy and by general properties to be identical to those formed by cells under normal culture conditions. The cell suspensions produced in the presence of leupeptin rather than other trypsin inhibitors show good adhesion at low temperatures, though the cells hardly spread at all. The results suggest that the role of fibronectin in cell adhesion should be reinterpreted in terms of its possible action as an activator rather than as a bonding molecule.

scholarly journals Glycosylation of CD44 is implicated in CD44-mediated cell adhesion to hyaluronan.

1996 ◽  
Vol 132 (6) ◽  
pp. 1199-1208 ◽  
Author(s):  
A Bartolazzi ◽  
A Nocks ◽  
A Aruffo ◽  
F Spring ◽  
I Stamenkovic
Keyword(s):  
Cell Adhesion ◽  
Regulatory Mechanism ◽  
Cell Attachment ◽  
Glycosylation Site ◽  
Side Chain ◽  
Site Specific ◽  
Coated Substrate ◽  
Glycosylation Sites ◽  
Coated Surfaces

CD44-mediated cell adhesion to hyaluronate is controlled by mechanisms which are poorly understood. In the present work we examine the role of N-linked glycosylation and Ser-Gly motifs in regulating CD44-hyaluronate interaction. Our results show that treatment of a panel of human cell lines which constitutively express CD44 with the inhibitor of N-linked glycosylation tunicamycin results in the loss of attachment of these cells to hyaluronate-coated substrate. In contrast, treatment of the same cells with deoxymannojirimycin, which inhibits the conversion of high mannose oligosaccharides to complex N-linked carbohydrates, results in either no change or an increase in CD44-mediated adhesion to hyaluronate, suggesting that complex N-linked oligosaccharides may not be required for and may even inhibit CD44-HA interaction. Using human melanoma cells stably transfected with CD44 N-linked glycosylation site-specific mutants, we show that integrity of five potential N-linked glycosylation sites within the hyaluronate recognition domain of CD44 is critical for hyaluronate binding. Mutation of any one of these potential N-linked glycosylation sites abrogates CD44-mediated melanoma cell attachment to hyaluronate-coated surfaces, suggesting that all five sites are necessary to maintain the HA-recognition domain in the appropriate conformation. We also demonstrate that mutation of serine residues which constitute the four Ser-Gly motifs in the membrane proximal domain, and provide potential sites for glycosaminoglycan side chain attachment, impairs hyaluronate binding. Taken together, these observations indicate that changes in glycosylation of CD44 can have profound effects on its interaction with hyaluronic acid and suggest that glycosylation may provide an important regulatory mechanism of CD44 function.

Comments on the Clinical Application of Fibronectin in Dentistry

1988 ◽  
Vol 67 (2) ◽  
pp. 515-517 ◽  
Author(s):  
B.S. Pearson ◽  
R.J. Klebe ◽  
B.D. Boyan ◽  
D. Moskowicz
Keyword(s):  
Cell Adhesion ◽  
Oral Surgery ◽  
Cell Attachment ◽  
Root Surface ◽  
Tooth Surface ◽  
Tooth Surfaces ◽  
Tissue Attachment ◽  
Cell Adhesion Proteins ◽  
Demineralized Bone

Several studies have demonstrated that citric acid demineralization of the root surface promotes tissue attachment. Since demineralization exposes collagen to which fibronectin binds, the role of fibronectin in the attachment of cells to the tooth surface has been of considerable interest. It is clear that fibronectin and other cell adhesion proteins can promote cell attachment to the tooth surface; therefore, attempts have been made to utilize these findings in a clinical setting. Using a quantitative ELISA procedure to measure the binding of fibronectin to demineralized bone and tooth, we have found that I μg fibronectin can saturate approximately 1 mg of either demineralized bone or demineralized tooth powder. Since serum contains 300 μg fibronectin per mL, the bleeding that occurs during oral surgery should saturate exposed tooth surfaces with amounts of fibronectin adequate for cell adhesion. Thus, exogenous fibronectin would appear to be of little clinical benefit.

scholarly journals Fibronectin glycosylation modulates fibroblast adhesion and spreading.

1986 ◽  
Vol 103 (5) ◽  
pp. 1663-1670 ◽  
Author(s):  
G E Jones ◽  
R G Arumugham ◽  
M L Tanzer
Keyword(s):  
Cell Adhesion ◽  
Biological Functions ◽  
Cell Surfaces ◽  
Fibroblastic Cell ◽  
Cultured Fibroblasts ◽  
Fibroblast Adhesion ◽  
Coated Surfaces ◽  
Composite Data

The role of the carbohydrate residues of fibronectin concerning the specificities of that glycoprotein to interact with fibroblastic cell surfaces, gelatin, and heparin was examined. Tunicamycin was used to produce carbohydrate-depleted fibronectin; it was synthesized by cultured fibroblasts. Unglycosylated and glycosylated fibronectins were analyzed for their ability to bind gelatin and heparin, using affinity columns. Fibronectin-coated surfaces were used to quantitatively measure cell adhesion and spreading. The results showed that the lack of carbohydrates significantly increased the interaction of the protein with gelatin and markedly enhanced its ability to promote adhesion and spreading of fibroblasts. In contrast, the binding of fibronectin to heparin was not influenced by glycosylation. The composite data indicate that the Asn-linked oligosaccharides of fibronectin act as modulators of biological functions of the glycoprotein.

Binding of hexabrachion (tenascin) to the extracellular matrix and substratum and its effect on cell adhesion

1990 ◽  
Vol 95 (2) ◽  
pp. 263-277
Author(s):  
V.A. Lightner ◽  
H.P. Erickson
Keyword(s):  
Extracellular Matrix ◽  
Cell Adhesion ◽  
Cell Attachment ◽  
Solid Phase ◽  
Fluid Phase ◽  
Matrix Proteins ◽  
And Migration ◽  
Cover Up ◽  
Plastic Substratum

Hexabrachion is a large glycoprotein of the extracellular matrix (ECM) that is prominent in embryogenesis, wound healing and tumorigenesis. Because of the role of extracellular matrix proteins in the regulation of cell differentiation and migration, the interaction of hexabrachion with cells as well as with other components of the ECM is of great interest. Early reports suggested that hexabrachion does not bind to fibronectin or gelatin but does bind to chondroitin sulfate proteoglycans. However, more recent reports have suggested that hexabrachion binds to fibronectin and inhibits cell adhesion as well as cell migration on fibronectin. We have found no evidence of strong hexabrachion-fibronectin binding on either a solid-phase ELISA assay or in a fluid-phase sedimentation assay in which the reactants were allowed to dissociate. However, hexabrachion sedimentation was accelerated in a gradient containing fibronectin throughout. This demonstrates an association between hexabrachions and fibronectin, but the complex is apparently weak and readily reversible. The solid-phase ELISA also shows no evidence of hexabrachion binding to gelatin, laminin or types I, III, IV or V collagen. Hexabrachion does not support strong cell attachment of the cell lines tested. Moreover, hexabrachion can inhibit cell attachment to fibronectin. We demonstrate here that this inhibition requires the hexabrachion to be able to bind to the plastic substratum. The results suggest that hexabrachion inhibition is via a steric inhibition. When the hexabrachion molecules bind to the plastic, they cover up a significant fraction of the underlying fibronectin molecules. Antibody studies are presented that show that hexabrachion can nonspecifically block access of immunoglobulin G molecules to the underlying matrix. This steric blocking is not unique to hexabrachion.

scholarly journals A Conserved NXIP Motif Is Required for Cell Adhesion Properties of the Syndecan-4 Ectodomain

2006 ◽  
Vol 281 (43) ◽  
pp. 32156-32163 ◽  
Author(s):  
James R. Whiteford ◽  
John R. Couchman
Keyword(s):  
Cell Adhesion ◽  
Cell Attachment ◽  
Focal Adhesions ◽  
Cell Types ◽  
Binding Activity ◽  
Cytoskeletal Reorganization ◽  
Cell Binding ◽  
Adhesion Properties ◽  
Support Cell ◽  
Β1 Integrins

Syndecans are cell surface proteoglycans involved in cell adhesion and motility. Syndecan-4 is an important component of focal adhesions and is involved in cytoskeletal reorganization. Previous work has shown that the syndecan-4 ectodomain can support cell attachment. Here, three vertebrate syndecan-4 ectodomains were compared, including that of the zebrafish, and we have demonstrated that the cell binding activity of the syndecan-4 ectodomain is conserved. Cell adhesion to the syndecan-4 ectodomain appears to be a characteristic of mesenchymal cells. Comparison of syndecan-4 ectodomain sequences led to the identification of three conserved regions of sequence, of which the NXIP motif is important for cell binding activity. We have shown that cell adhesion to the syndecan-4 ectodomain involves β1 integrins in several cell types.

scholarly journals Murine granulocytic cell adhesion to bone marrow hemonectin is mediated by mannose and galactose

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 135-140 ◽  
Author(s):  
BA Sullenbarger ◽  
MS Petitt ◽  
P Chong ◽  
MW Long ◽  
MS Wicha
Keyword(s):  
Bone Marrow ◽  
Cell Adhesion ◽  
Cell Attachment ◽  
Lectin Binding ◽  
Specific Attachment ◽  
Dependent Inhibition ◽  
Apparent Decrease ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Hemonectin (HN) is a bone marrow (BM) protein that promotes specific attachment of immature granulocytes and their precursors within the BM. We report that HN is a glycoprotein containing both mannose and galactose residues, and provide evidence that these carbohydrates mediate granulocytic cell adhesion to HN. Carbohydrate structure was determined by digoxigenin-conjugated lectin binding to HN and indicated the presence of mannose, galactose, sialic acid, and the absence of fucose-linked oligosaccharides. The role of carbohydrates in mediating cell adhesion was examined by chemical and enzymatic deglycosylation. Deglycosylation of HN with trifluoromethanesulfonic acid, which cleaves N- and O-linked oligosaccharides, inhibits 66% of cell attachment to HN, and results in an apparent decrease in molecular weight from 60 to 50 kD. Enzymatic deglycosylation with endo-B-N-acetylglucosaminidase H, which hydrolyzes specific N-linked mannose residues, inhibits 30% of cell adhesion to HN. Finally, the role of these specific sugars in hemonectin-mediated cell adhesion was confirmed with neoglycoprotein blocking. Preincubation of BM cells with mannosyl- and galactosyl-BSA probes produces a dose-dependent inhibition of cell attachment to HN, whereas fucosyl-BSA does not inhibit cell adhesion to HN. These results show that mannose and galactose partially mediate adhesion of BM granulocytes to HN.

scholarly journals Actin Pedestal Formation by Enterohemorrhagic Escherichia coli Enhances Bacterial Host Cell Attachment and Concomitant Type III Translocation

2014 ◽  
Vol 82 (9) ◽  
pp. 3713-3722 ◽  
Author(s):  
Scott E. Battle ◽  
Michael J. Brady ◽  
Sivapriya Kailasan Vanaja ◽  
John M. Leong ◽  
Gail A. Hecht
Keyword(s):  
Escherichia Coli ◽  
Host Cell ◽  
Mammalian Cells ◽  
Cell Attachment ◽  
Actin Assembly ◽  
Cell Binding ◽  
Type Iii ◽  
Host Cell Attachment ◽  
Pedestal Formation

ABSTRACTAttachment of enterohemorrhagicEscherichia coli(EHEC) to intestinal epithelial cells is critical for colonization and is associated with localized actin assembly beneath bound bacteria. The formation of these actin “pedestals” is dependent on the translocation of effectors into mammalian cells via a type III secretion system (T3SS). Tir, an effector required for pedestal formation, localizes in the host cell plasma membrane and promotes attachment of bacteria to mammalian cells by binding to the EHEC outer surface protein Intimin. Actin pedestal formation has been shown to foster intestinal colonization by EHEC in some animal models, but the mechanisms responsible for this remain undefined. Investigation of the role of Tir-mediated actin assembly promoting host cell binding is complicated by other, potentially redundant EHEC-encoded binding pathways, so we utilized cell binding assays that specifically detect binding mediated by Tir-Intimin interaction. We also assessed the role of Tir-mediated actin assembly in two-step assays that temporally segregated initial translocation of Tir from subsequent Tir-Intimin interaction, thereby permitting the distinction of effects on translocation from effects on cell attachment. In these experimental systems, we compromised Tir-mediated actin assembly by chemically inhibiting actin assembly or by infecting mammalian cells with EHEC mutants that translocate Tir but are specifically defective in Tir-mediated pedestal formation. We found that an inability of Tir to promote actin assembly resulted in a significant and striking decrease in bacterial binding mediated by Tir and Intimin. Bacterial mutants defective for pedestal formation translocated type III effectors to mammalian cells with reduced efficiency, but the decrease in translocation could be entirely accounted for by the decrease in host cell attachment.

scholarly journals Arginylation-dependent regulation of a proteolytic product of talin is essential for cell–cell adhesion

2012 ◽  
Vol 197 (6) ◽  
pp. 819-836 ◽  
Author(s):  
Fangliang Zhang ◽  
Sougata Saha ◽  
Anna Kashina
Keyword(s):  
Cell Adhesion ◽  
Cell Attachment ◽  
Adhesion Formation ◽  
Cell Matrix ◽  
Intracellular Regulation ◽  
Dependent Cell ◽  
Cell Matrix Adhesion ◽  
Proteolytic Product ◽  
Cell Cell

Talin is a large scaffolding molecule that plays a major role in integrin-dependent cell–matrix adhesion. A role for talin in cell–cell attachment through cadherin has never been demonstrated, however. Here, we identify a novel calpain-dependent proteolytic cleavage of talin that results in the release of a 70-kD C-terminal fragment, which serves as a substrate of posttranslational arginylation. The intracellular levels of this fragment closely correlated with the formation of cell–cell adhesions, and this fragment localized to cadherin-containing cell–cell contacts. Moreover, reintroduction of this fragment rescued the cell–cell adhesion defects in arginyltransferase (Ate1) knockout cells, which normally have a very low level of this fragment. Arginylation of this fragment further enhanced its ability to rescue cell–cell adhesion formation. In addition, arginylation facilitated its turnover, suggesting a dual role of arginylation in its intracellular regulation. Thus, our work identifies a novel proteolytic product of talin that is regulated by arginylation and a new role of talin in cadherin-dependent cell–cell adhesion.

Cdk5 regulates cell-matrix and cell-cell adhesion in lens epithelial cells

2002 ◽  
Vol 115 (10) ◽  
pp. 2109-2117 ◽  
Author(s):  
Sewite Negash ◽  
Hwai-Shi Wang ◽  
Chun Gao ◽  
Dolena Ledee ◽  
Peggy Zelenka
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cells ◽  
Cell Attachment ◽  
Dominant Negative ◽  
Lens Epithelial Cells ◽  
Fiber Cells ◽  
Cell Matrix ◽  
Dominant Negative Mutation ◽  
Cell Cell

Cdk5 is a member of the cyclin-dependent kinase family, which is expressed predominantly in terminally differentiated neurons. Lower levels of Cdk5 are also found in a wide variety of cell types, including the lens. Although Cdk5 has been shown to play an important role in neuronal migration and neurite outgrowth, its function in non-neuronal cells is not known. Therefore, this study was undertaken to explore the role of Cdk5 in the lens. Results showed that, within the adult mouse lens, Cdk5 was localized to the cytoplasm,especially along the lateral membranes of differentiating primary fiber cells,which suggests a role in cell-cell adhesion. Staining at the tips of elongating fiber cells was also particularly strong, suggesting a role in cell-matrix adhesion. To examine the possible role of Cdk5 in lens epithelial cell adhesion, we stably transfected N/N1003A rabbit lens epithelial cells with cDNAs for Cdk5 or a dominant-negative mutation, Cdk5-T33. Attachment to a fibronectin matrix, as measured with substrate-coated cell adhesion strips,was increased by Cdk5 overexpression, while an equivalent overexpression of Cdk5-T33 had no effect. Cdk5 also increased the rate of cell attachment and spreading as measured by electric cell-substrate impedance sensing (ECIS). In addition, Cdk5 overexpression decreased cell-cell adhesion as measured by a cell aggregation assay. These findings suggest that Cdk5 plays a role in regulating both cell-matrix and cell-cell interactions in the lens.

scholarly journals Inhibition of fibronectin binding and fibronectin-mediated cell adhesion to collagen by a peptide from the second type I repeat of thrombospondin.

1993 ◽  
Vol 121 (2) ◽  
pp. 469-477 ◽  
Author(s):  
J M Sipes ◽  
N Guo ◽  
E Nègre ◽  
T Vogel ◽  
H C Krutzsch ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Adhesion ◽  
Type I Collagen ◽  
Selective Inhibitor ◽  
Type I ◽  
Surface Receptors ◽  
Extracellular Matrix Components ◽  
Flanking Sequences ◽  
Fibronectin Binding

The platelet and extracellular matrix glycoprotein thrombospondin interacts with various types of cells as both a positive and negative modulator of cell adhesion, motility, and proliferation. These effects may be mediated by binding of thrombospondin to cell surface receptors or indirectly by binding to other extracellular matrix components. The role of peptide sequences from the type I repeats of thrombospondin in its interaction with fibronectin were investigated. Fibronectin bound specifically to the peptide Gly-Gly-Trp-Ser-His-Trp from the second type I repeat of thrombospondin but not to the corresponding peptides from the first or third repeats or flanking sequences from the second repeat. The two Trp residues and the His residue were essential for binding, and the two Gly residues enhanced the affinity of binding. Binding of the peptide and intact thrombospondin to fibronectin were inhibited by the gelatin-binding domain of fibronectin. The peptide specifically inhibited binding of fibronectin to gelatin or type I collagen and inhibited fibronectin-mediated adhesion of breast carcinoma and melanoma cells to gelatin or type I collagen substrates but not direct adhesion of the cells to fibronectin, which was inhibited by the peptide Gly-Arg-Gly-Asp-Ser. Thus, the fibronectin-binding thrombospondin peptide Gly-Gly-Trp-Ser-His-Trp is a selective inhibitor of fibronectin-mediated interactions of cells with collagen in the extracellular matrix.

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