scholarly journals Cell adhesion to fibrillin-1: identification of an Arg-Gly-Asp-dependent synergy region and a heparin-binding site that regulates focal adhesion formation

2007 ◽  
Vol 120 (8) ◽  
pp. 1383-1392 ◽  
Author(s):  
D. V. Bax ◽  
Y. Mahalingam ◽  
S. Cain ◽  
K. Mellody ◽  
L. Freeman ◽  
...  
Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Xiaoqian Fang ◽  
Dong H Kim ◽  
Teresa Santiago-Sim

Introduction: An intracranial aneurysm (IA) is a weak spot in cerebral blood vessel wall that can lead to its abnormal bulging. Previously, we reported that mutations in THSD1 , encoding thrombospondin type-1 domain-containing protein 1, are associated with IA in a subset of patients. THSD1 is a transmembrane molecule with a thrombospondin type-1 repeat (TSR). Proteins with TSR domain have been implicated in a variety of processes including regulation of matrix organization, cell adhesion and migration. We have shown that in mouse brain Thsd1 is expressed in endothelial cells. Hypothesis: THSD1 plays an important role in maintaining the integrity of the endothelium by promoting adhesion of endothelial cells to the underlying basement membrane. Methods: Human umbilical vein endothelial cells are used to investigate the role of THSD1 in vitro . THSD1 expression was knocked-down by RNA interference. Cell adhesion assay was done on collagen I-coated plates and focal adhesion formation was visualized using immunofluorescence by paxillin and phosphorylated focal adhesion kinase (pFAK) staining. THSD1 re-expression is accomplished by transfection with a pCR3.1-THSD1-encoding plasmid. Results: Knockdown of THSD1 caused striking change in cell morphology and size. Compared to control siRNA-treated cells that exhibited typical cobblestone morphology, THSD1 knockdown cells were narrow and elongated, and were significantly smaller ( p <0.01). Cell adherence to collagen I-coated plates was also attenuated in THSD1 knockdown cells ( p <0.01). Consistent with this finding is the observation that the number and size of focal adhesions, based on paxillin and pFAK staining, were significantly reduced after THSD1 knockdown ( p <0.01). These defects in cell adhesion and focal adhesion formation were rescued by re-expression of wild type THSD1 ( p <0.05). In contrast, initial studies indicate that expression of mutated versions of THSD1 as seen in human patients (L5F, R450*, E466G, P639L) could not restore cell adhesion and focal adhesion formation to wild type levels. Conclusions: Our studies provide evidence for a role of THSD1 and THSD1 mutations in endothelial cell adhesion and suggest a possible mechanism underlying THSD1 -mediated aneurysm disease.


FEBS Letters ◽  
2016 ◽  
Vol 590 (14) ◽  
pp. 2138-2145 ◽  
Author(s):  
Rie Miyano ◽  
Takashi Matsumoto ◽  
Hiroyuki Takatsu ◽  
Kazuhisa Nakayama ◽  
Hye-Won Shin

2003 ◽  
Vol 371 (2) ◽  
pp. 565-571 ◽  
Author(s):  
José V. MOYANO ◽  
Alfredo MAQUEDA ◽  
Juan P. ALBAR ◽  
Angeles GARCIA-PARDO

Cell adhesion to fibronectin results in formation of actin stress fibres and focal adhesions. In fibroblasts, this response requires two co-operative signals provided by interactions of the RGD sequence with α5β1 integrin and the heparin-binding domain II (Hep II) domain with syndecan-4. Within Hep II, this activity was mapped to repeat III13 and to the peptide FN-C/H-V(WQPPRARITGY, repeat III14). We previously described that the synthetic heparin-binding peptide/III5 (HBP/III5) (WTPPRAQITGYRLTVGLTRR, repeat III5) binds heparin and mediates cell adhesion via chondroitin sulphate proteoglycans. We have now studied whether HBP/III5 co-operates with α5β1 and drives a full cytoskeletal response in melanoma cells. SKMEL-178 cells attached and spread on the RGD-containing FNIII7–FNIII10 (FNIII7–10) fragment, but did not form stress fibres or focal adhesions. Co-immobilization of HBP/III5 with FNIII7–10 or adding soluble HBP/III5 to cells prespread on FNIII7–10, effectively induced these structures. Cell transfection with dominant-negative N19RhoA, a member of the small GTPase family, abolished the HBP/III5 effect. Both chondroitinase and heparitinase diminished focal adhesions, indicating that both types of proteoglycans bound HBP/III5 in melanoma cells. We have mapped the active sequence of HBP/III5 to YRLTVGLTRR, which is a novel sequence in fibronectin with focal-adhesion-promoting activity. The last two arginine (R) residues of this sequence are required for activity, since their replacement by alanine completely abrogated the HBP/III5 cytoskeletal effect. Moreover, this sequence is also active in the context of large fibronectin fragments. Our results establish that the Hep III region provides co-operative signals to α5β1 for the progression of the cytoskeletal response and that these include activation of RhoA.


2020 ◽  
Vol 19 ◽  
pp. 153473542091894 ◽  
Author(s):  
Aaron A. Jones ◽  
Scott Gehler

Naturally occurring flavonoids, such as acacetin and pinostrobin, disrupt a wide range of processes during tumor progression, such as cell proliferation, apoptosis, and angiogenesis. Although the antiproliferative and antiapoptotic effects of acacetin and pinostrobin have been studied using various cell lines, relatively little is known about the effects of acacetin and pinostrobin on cancer cell migration and metastasis. For instance, it is unclear whether acacetin or pinostrobin have any effect on breast cancer cell migration or adhesion. In this study, we assessed the effects of acacetin and pinostrobin on malignant MDA-MB-231 and T47D breast epithelial cells and non-tumorigenic MCF10A breast epithelial cells. Our results demonstrate that both acacetin and pinostrobin selectively inhibit the migration of both MDA-MB-231 and T47D cells in a dose-dependent manner while exhibiting blunted effects on MCF10A cells. Interestingly, neither compound had an effect on cell proliferation in any of the 3 cell lines. Furthermore, both acacetin and pinostrobin inhibit MDA-MB-231 and T47D cell adhesion, cell spreading, and focal adhesion formation, but have no significant effect on MCF10A cells. Collectively, these results suggest that both acacetin and pinostrobin selectively inhibit malignant breast epithelial cell migration through attenuation of cell adhesion and focal adhesion formation. These findings indicate that both acacetin and pinostrobin may serve as potential therapeutic options to target breast tumor cell migration during late-stage tumor progression.


1994 ◽  
Vol 125 (5) ◽  
pp. 1179-1188 ◽  
Author(s):  
J D San Antonio ◽  
A D Lander ◽  
M J Karnovsky ◽  
H S Slayter

The glycosaminoglycan chains of cell surface heparan sulfate proteoglycans are believed to regulate cell adhesion, proliferation, and extracellular matrix assembly, through their interactions with heparin-binding proteins (for review see Ruoslahti, E. 1988. Annu. Rev. Cell Biol. 4:229-255; and Bernfield, M., R. Kokenyesi, M. Kato, M. T. Hinkes, J. Spring, R. L. Gallo, and E. J. Lose. 1992. Annu. Rev. Cell Biol. 8:365-393). Heparin-binding sites on many extracellular matrix proteins have been described; however, the heparin-binding site on type I collagen, a ubiquitous heparin-binding protein of the extracellular matrix, remains undescribed. Here we used heparin, a structural and functional analogue of heparan sulfate, as a probe to study the nature of the heparan sulfate proteoglycan-binding site on type I collagen. We used affinity coelectrophoresis to study the binding of heparin to various forms of type I collagen, and electron microscopy to visualize the site(s) of interaction of heparin with type I collagen monomers and fibrils. Using affinity coelectrophoresis it was found that heparin has similar affinities for both procollagen and collagen fibrils (Kd's approximately 60-80 nM), suggesting that functionally similar heparin-binding sites exist in type I collagen independent of its aggregation state. Complexes of heparin-albumin-gold particles and procollagen were visualized by rotary shadowing and electron microscopy, and a preferred site of heparin binding was observed near the NH2 terminus of procollagen. Native or reconstituted type I collagen fibrils showed one region of significant heparin-gold binding within each 67-nm period, present near the division between the overlap and gap zones, within the "a" bands region. According to an accepted model of collagen fibril structure, our data are consistent with the presence of a single preferred heparin-binding site near the NH2 terminus of the collagen monomer. Correlating these data with known type I collagen sequences, we suggest that the heparin-binding site in type I collagen may consist of a highly basic triple helical domain, including several amino acids known sometimes to function as disaccharide acceptor sites. We propose that the heparin-binding site of type I collagen may play a key role in cell adhesion and migration within connective tissues, or in the cell-directed assembly or restructuring of the collagenous extracellular matrix.


1989 ◽  
Vol 109 (3) ◽  
pp. 1309-1319 ◽  
Author(s):  
J E Murphy-Ullrich ◽  
M Höök

We examined the effects of thrombospondin (TSP) in the substrate adhesion of bovine aortic endothelial cells. The protein was tested both as a substrate for cell adhesion and as a modulator of the later stages of the cell adhesive process. TSP substrates supported the attachment of some BAE cells, but not cell spreading or the formation of focal adhesion plaques. In contrast, cells seeded on fibrinogen or fibronectin substrates were able to complete the adhesive process, as indicated by the formation of focal adhesion plaques. Incubation of cells in suspension with soluble TSP before or at the time of seeding onto fibronectin substrates resulted in an inhibition of focal adhesion formation. Furthermore, the addition of TSP to fully adherent cells in situ or prespread on fibronectin substrates caused a reduction in the number of cells, which were positive for focal adhesions, although there was no significant effect on cell spreading. In a dose-dependent manner, TSP reduced the number of cells with adhesion plaques to approximately 60% of control levels. The distribution of remaining adhesion plaques in TSP-treated cells was also altered: plaques were primarily limited to the periphery of cells and were not present in the central cell body, as in control cells treated with BSA. The observed effects were specific for TSP and were not observed with platelet factor 4, beta-thromboglobulin, or fibronectin. The TSP-mediated loss of adhesion plaques was neutralized by the addition of heparin, fucoidan, other heparin-binding proteins, and by a monoclonal antibody to the heparin binding domain of TSP, but not by antibodies to the core or carboxy-terminal regions of TSP. The interaction of the heparin-binding domain of TSP with cell-associated heparan sulfate appears to be an important mechanistic component for this activity of TSP. These data indicate that TSP may have a role in destabilizing cell adhesion through prevention of focal adhesion formation and by loss of preformed focal adhesions.


1993 ◽  
Vol 4 (6) ◽  
pp. 605-613 ◽  
Author(s):  
A Woods ◽  
J B McCarthy ◽  
L T Furcht ◽  
J R Couchman

Cell adhesion to extracellular matrix molecules such as fibronectin involves complex transmembrane signaling processes. Attachment and spreading of primary fibroblasts can be promoted by interactions of cell surface integrins with RGD-containing fragments of fibronectin, but the further process of focal adhesion and stress fiber formation requires additional interactions. Heparin-binding fragments of fibronectin can provide this signal. The COOH-terminal heparin-binding domain of fibronectin contains five separate heparin-binding amino acid sequences. We show here that all five sequences, as synthetic peptides coupled to ovalbumin, can support cell attachment. Only three of these sequences can promote focal adhesion formation when presented as multicopy complexes, and only one of these (WQPPRARI) retains this activity as free peptide. The major activity of this peptide resides in the sequence PRARI. The biological response to this peptide and to the COOH-terminal fragment may be mediated through cell surface heparan sulfate proteoglycans because treatment of cells with heparinase II and III, or competition with heparin, reduces the response. Treatment with chondroitinase ABC or competition with chondroitin sulfate does not.


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