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Query: UMLS:C0001511 (
Adhesion
)
5,955
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The vascular cell adhesion molecule-1 (VCAM-1) plays an important role in diverse physiological and pathological processes. The homologous first and fourth immunoglobulin-like domains of the seven domain form of VCAM-1 present binding motifs for alpha 4
beta 1
integrin. Using a panel of VCAM-1 domain deletion mutants we show that alpha 4 beta 7 integrin interacts with both domains 1 and 4. In contrast to their identical domain usage, alpha 4
beta 1
and alpha 4 beta 7 integrins differ in the activation states required for binding to domains 1 and 4 of VCAM-1. We show that integrin alpha 4
beta 1
required significantly higher concentrations of Mn2+ than integrin alpha 4 beta 7 to support half-maximal adhesion to domain 4. Moreover, a clear difference in the capacity of integrins alpha 4
beta 1
and alpha 4 beta 7 to interact with domain 4 was detected in the presence of Ca2+ and Mg2+ cations.
Adhesion
to domain 1 of VCAM-1, however, was not affected by integrin heterodimer composition. Instead, the activity level of integrin alpha 4
beta 1
for domain 1 binding was regulated by CD24 expression. Binding to seven domain VCAM-1 was not altered significantly by
beta 1
and beta 7 subunits or CD24. These data indicate that integrin heterodimer composition and CD24 expression differentially modulate integrin binding to domains 1 and 4 of VCAM-1. Mechanisms that alter integrin binding specificity or monovalent versus divalent interactions may affect the strength of adhesion as well as signal transmission in adherent cells and may therefore be critical to controlling the cellular response to integrin occupancy.
...
PMID:Differential regulation of alpha 4 integrin-dependent binding to domains 1 and 4 of vascular cell adhesion molecule-1. 753 4
Regulation of
beta 1
integrins in neurite outgrowth following N6,2'-O-dibutyryladenosine 3':5'-cyclic monophosphate (dBcAMP) treatment was investigated using the human neuroblastoma cell line TR 14. Three
beta 1
integrins were identified: the alpha 1
beta 1
receptor bound collagen type I, collagen type IV and probably laminin; the alpha 2
beta 1
integrin bound collagen type I; and the alpha v beta i receptor bound fibronectin. Neurite extension was detectable as early as 30 minutes following dBcAMP treatment, was maximal after 24 hours and remained constant during treatment for 4 days.
Adhesion
-perturbing
beta 1
subunit-specific antibodies, added together with dBcAMP, prevented the outgrowth of new neurites. During the first 24 hours of neurite outgrowth, no change was observed in the amount of
beta 1
integrins nor in their topographic distribution. However, dBcAMP treatment increased the binding of alpha 1
beta 1
receptors to collagen type IV-Sepharose by a factor 2.3 +/- 0.6 (P < 0.02), while no alteration in the binding to collagen type I was detected. Moreover, neurites and growth cones were immunoreactive for collagen type IV but not for collagen type I. Consistently dBcAMP-induced neurite outgrowth was inhibited by adhesion-perturbing alpha 1 subunit-specific antibodies. Following maximal neurite outgrowth, the amount of
beta 1
integrins determined by immunoprecipitation and by confocal microscopy decreased to 58.3 +/- 11.2% (P < 0.001) and to 55.4 +/- 17.5% (P < 0.001) of untreated levels, respectively, without any change in the level of
beta 1
mRNA or de novo synthesized
beta 1
precursor. However, pulse-chase experiments showed an increased turnover of the
beta 1
subunit: the amount of
beta 1
precursor that was degraded after 1 hour chase was 50.5 +/- 8.4% in cells treated for 4 days and 34.2 +/- 3.9% in untreated cells (P < 0.02); the amount of mature
beta 1
after 24 hours chase was smaller in cells treated for 4 days compared to untreated cells. In conclusion, during neurite outgrowth, alpha 1
beta 1
integrins are required and acquire an enhanced binding activity for collagen type IV; but following maximal neurite outgrowth, expression of
beta 1
integrins is reduced.
...
PMID:Selective increase in the binding of the alpha 1 beta 1 integrin for collagen type IV during neurite outgrowth of human neuroblastoma TR 14 cells. 753 84
Interactions between tumour cells and the endothelium are vital to the formation of haematogenous metastases. Binding to model endothelium of one oestrogen receptor positive breast carcinoma cell line (MCF-7) and one receptor negative line (HS578T) was examined in vitro together with endothelial retraction induced by these tumour cells.
Adhesion
was inhibited by monoclonal antibodies specific for the VLA integrins and by peptides containing the RGD motif which is commonly recognised as a ligand by the VLA adhesion molecules. However, binding of the two tumour cell lines was inhibited by monoclonal antibodies specific for different VLA molecules; anti-alpha 6
beta 1
inhibited MCF-7 adhesion but anti-alpha 5
beta 1
inhibited Hs578T. These results were consistent with flow cytometric quantification of the expression of these VLA integrins on the surfaces of the two tumour cell lines. Enzyme-linked immunosorbent assays (ELISA) demonstrated that laminin was present on the endothelial cell surface but collagen IV was absent. ELISA failed to detect increased exposure of the subendothelial matrix during the first hour after addition of either cancer cell type. This was supported by assays which demonstrated maintenance of the endothelial permeability barrier during this period. Slight endothelial retraction was detected within 2 hours of the addition of tumour cells. It is concluded that binding between tumour cells and confluent endothelium is inhibited by the blockade of adhesion molecules which are normally associated with interactions between the cell and the subendothelial matrix. Tumour cell to matrix interactions rather than direct tumour to endothelial cell adhesion may be the limiting step in tumour cell binding to the endothelium.
...
PMID:The role of beta 1 integrins in adhesion of two breast carcinoma cell lines to a model endothelium. 753 54
Adhesion
molecules play a role in the migration of hematopoietic progenitor cells and regulation of hematopoiesis. To study whether the mobilization process is associated with changes in expression of adhesion molecules, the expression of CD31, CD44, L-selectin, sialyl Lewisx,
beta 1
integrins very late antigen 4 (VLA-4) and VLA-5, and beta 2 integrins lymphocyte function-associated 1 and Mac-1 was measured on either bone marrow (BM) CD34+ cells or on peripheral blood CD34+ cells mobilized with a combination of granulocyte colony-stimulating factor (G-CSF) and chemotherapy.
beta 1
integrin VLA-4 was expressed at a significantly lower concentration on peripheral blood progenitor cells than on BM CD34+ cells, procured either during steady-state hematopoiesis or at the time of leukocytapheresis. No differences in the level of expression were found for the other adhesion molecules. To obtain insight in which adhesion molecules may participate in the homing of peripheral blood stem cells (PBSCs), the number of CD34+ cells expressing these adhesion molecules present in leukocytapheresis material was quantified and correlated with hematopoietic recovery after intensive chemotherapy in 27 patients. The number of CD34+ cells in the subset defined by L-selectin expression correlated significantly better with time to platelet recovery after PBSC transplantation (r = -.86) than did the total number of CD34+ cells (r = -.55). Statistical analysis of the relationship between the number of CD34+L-selectin+ cells and platelet recovery resulted in a threshold value for rapid platelet recovery of 2.1 x 10(6) CD34+ L-selectin+ cells/kg. A rapid platelet recovery (< or = 14 days) was observed in 13 of 15 patients who received > or = 2.1 x 10(6) CD34+ L-selectin+ cells/kg (median, 11 days; range, 7 to 16 days), whereas 10 of 12 patients who received less double positive cells had a relative slow platelet recovery (median, 20 days; range, 13 to 37 days). The L-selectin+ subpopulation of CD34+ cells also correlated better with time to neutrophil recovery (r = -.70) than did the total number of reinfused CD34+ cells (r = -.51). However, this latter difference failed to reach statistical significance. This study suggests that L-selectin is involved in the homing of CD34+ cells after PBSC transplantation.
...
PMID:Expression of adhesion molecules on CD34+ cells: CD34+ L-selectin+ cells predict a rapid platelet recovery after peripheral blood stem cell transplantation. 753 23
Mammalian osteoclasts express three integrin receptors--alpha v beta 3 (vitronectin receptor), alpha 2
beta 1
and alpha v
beta 1
. The vitronectin receptor recognizes bone matrix proteins, including bone sialoproteins, in an RGD-dependent manner, whereas adhesion to collagen involves
beta 1
integrins. Interference with integrin function, by anti-receptor antibodies or RGD-peptides, blocks bone resorption. Data on the mechanism of osteoclast adhesion to sialoproteins and the differential synthesis of osteopontin and bone sialoprotein by osteoclasts is presented. Thus, osteoclasts adhere to both osteopontin and bone sialoprotein with a characteristic irregular morphology with numerous, peripherally placed, actin-rich podosomes.
Adhesion
is predominantly RGD and beta 3 dependent, though alpha v
beta 1
may also be involved in adhesion to bone sialoprotein. KQAGD and AGDV, but not H12, fibrinogen peptides induce osteoclast 'rounding' on osteopontin suggesting there is an alternative anti-adhesive signal to 'RGD.' However, adhesion is not completely inhibited and is not specific for osteopontin as equivalent effects are seen with adhesion to serum. The role of sialoproteins in osteoclast adhesion in situ in the skeleton is complicated by the finding of endogenous synthesis of osteopontin, but not bone sialoprotein, by osteoclasts. The disposition of osteoclast integrins during resorption and the role of integrins and sialoprotein-derived peptides in osteoclast adhesion and function is also reviewed.
...
PMID:Interaction of osteopontin with osteoclast integrins. 754 Mar 73
Human fetal livers contain progenitor cells that become mast cells after 4 weeks of culture with recombinant human stem cell factor. Expression of cell surface CD29 (
beta 1
), CD18 (beta 2), CD61 (beta 3), and beta 5 integrins was investigated on such cells by flow cytometry and adhesion measurements. High surface expression of CD49e, CD51, and CD61 along with kit was apparent by 4 weeks of culture, whereas expression of each at day 0 was low to undetectable. CD29 and CD49d were detected on cells from day 0 to 4 weeks of culture; CD49b, CD49c, CD49f, CD18, and CD54 expression was negligible. The fetal liver-derived mast cells spontaneously adhered to vitronectin. No evidence for degranulation was found during vitronectin-dependent adhesion.
Adhesion
occurred in part through the CD61/CD51 receptor. No evidence for adhesion to vitronectin through CD29 and beta 5 integrins was obtained. Almost all of the vitronectin-adherent cells expressed CD51, CD61, kit, and tryptase, and exhibited metachromasia with toluidine blue. Thus, among the fetal liver-derived cells, developing mast cells were selectively adherent to vitronectin. These mast cells and the other cell types present also adhere spontaneously to fibronectin and to laminin, this adhesion being partially inhibited by antibodies against CD61 and CD29 integrins. In conclusion, human mast cells acquire functional vitronectin receptors as they develop from fetal liver progenitors under the influence of rhSCF. This may be important for the recruitment, localization, and retention of developing mast cells.
...
PMID:Human mast cells derived from fetal liver cells cultured with stem cell factor express a functional CD51/CD61 (alpha v beta 3) integrin. 754 4
The integrins are a class of adhesion molecules which have been implicated in the homing of hemopoietic stem cells and in their restriction within the bone marrow. Integrins function as mediators of cell-extracellular matrix (ECM) interactions amd also of cell-cell interactions. They are unique membrane receptors which are capable of activation, change in affinity, and change in expression. Because of their broad potential for modulation we examined the effect of a cytokine growth factor which is present constitutively in the marrow, interleukin 3 (IL3), on integrin-mediated adherence of hemopoietic progenitor cells to the matrix component fibronectin (FN). The multipotential murine cell line B6Sut and the committed granulocyte progenitor cell line FDCP-1 were used. Both of these cell lines have been shown to bind to FN-coated dishes and to dishes coated with the 120 kDa and 40 kDa chymotryptic fragments of FN. It was found that after a brief withdrawal of IL3 the cells lost 80% adherence to the 120 kDa FN fragment containing the RGD cell binding site. This loss of binding was not related to a loss of viability, appeared unrelated to the growth/survival activity of IL3, and was quickly reversible by readdition of the growth factor.
Adhesion
of these cells to the RGD site was likely mediated by alpha 5
beta 1
integrin which was identified in the cell membrane of both cell lines, but present in low copy number in B6Sut cells. Two antibodies against the external and internal domains of alpha 5 and one antibody against
beta 1
were used to study expression of the integrin. By flow cytometry the expression of alpha 5 was found to decrease in both cell lines by 4 h in the absence of IL3. The relative mean fluorescence intensity for B6Sut cells decreased from 1.0 (control cells always in the presence of IL3) to 0.6 over 4 h, and for FDCP-1 cells the decrement was from 1.0 to 0.8. The loss of RGD-mediated adhesion in the absence of IL3 appeared to proceed through this decrement in expression of the integrin; a loss of affinity of the receptor for its substrate was not detected. The general modulation of integrin activity by growth factors is of great interest because of its potential negative impact on the endothelium in cytokine-treated patients, and also because of its potential positive impact on engraftment during clinical bone marrow transplantation.
...
PMID:Modulation of the adhesion of hemopoietic progenitor cells to the RGD site of fibronectin by interleukin 3. 754 62
In summary, adhesion molecules are likely to play a prominent role in scleroderma pathogenesis and evolution. Endothelial adhesion molecules required for leukocyte extravasation are upregulated in affected tissue, though the mechanism is unclear. Certainly, endothelial adhesion molecule expression is seen in the context of other diseases not characterized by fibrosis.
Adhesion
molecules on the fibroblast, particularly those that play a role in fibroblast collagen interactions, may be very important. The ability of fibroblasts to organize collagen fibrils, and to exert forces across collagenous tissue, is likely to involve a prominent role of alpha 2
beta 1
integrin. Enhanced organization and contraction of newly formed collagen, as well as unregulated procollagen production, may be intimately linked in this disease process. At least two factors that strongly enhance fibroblast force generation could potentially influence other aspects of scleroderma. TGF beta is a potent stimulus for collagen production and has been found to be elevated in lesional scleroderma. Endothelin 1 is also a potent vasoconstrictor and is elevated in scleroderma patient serum as well [60,62-65]. Its apparent role in other fibrocontractive diseases suggests that its potential role in the pathogenesis of scleroderma deserves additional attention.
...
PMID:Adhesion molecules in scleroderma: collagen binding integrins. 754 87
The effect of transformation on the expression and the functions of
beta 1
integrins was studied using an in vitro cell transformation model. S115 mammary epithelial tumor cells undergo transformation into tumorigenic fibroblastoid cells in the presence of steroids. Transformation was found to reduce the attachment and the spreading of S115 cells on laminin-1 but not fibronectin.
Adhesion
of S115 cells to laminin-1 was inhibited in the presence of an antibody against the
beta 1
integrin subunit. Both nontreated and transformed S115 cells expressed at least two putative laminin-1-binding
beta 1
integrins at the same level. In transformed cells, however, the mature integrin subunits appeared to be structurally altered, showing a slower electrophoretic mobility. Treatment with N-glycosidase-F and tunicamycin abolished this mobility difference, suggesting that the presence of complex-type N-linked oligosaccharides was responsible. Detailed enzymatic analysis of the oligosaccharides present on the
beta 1
subunits revealed that the difference in glycosylation is, at least partially, due to poly-N-lactosaminoglycan chains on
beta 1
integrin from transformed cells. Removal of this difference in glycosylation by either cleavage of the polylactosaminoglycan chains with endo-beta-galactosidase or inhibiton of complex-type glycan formation with swainsonine repeatedly enhanced the spreading of transformed cells on laminin-1. Thus, the increased size of complex-type oligosaccharides on
beta 1
integrin may affect cell-laminin-1 interactions. Similar changes may contribute to the altered adhesion of cancer cells during the invasion and metastasis.
...
PMID:Increased glycosylation of beta 1 integrins affects the interaction of transformed S115 mammary epithelial cells with laminin-1. 754 7
Four disintegrins, eristostatin, albolabrin, barbourin and echistatin, injected IV into C57BL/6 mice in combination with B16F10 murine melanoma cells, inhibited formation of experimental lung metastases with ID50s of 0.05, 1.0, 0.9, and 3.7 mumoles per mouse, respectively. When injected 1 h after tumor cells, albolabrin, echistatin and barbourin had the same antimetastatic activity, while eristostatin was not active. Eristostatin (IC50 7-8 nM) was more potent than echistatin (IC50 74-75 nM), barbourin (IC50 46-60 nM), and albolabrin (IC50 130-165 nM) as an inhibitor of murine platelet aggregation induced by ADP or tumor cells. Fibronectin was the best substrate for melanoma cell adhesion (95%), followed by laminin (47%) and vitronectin (24%). Albolabrin was the strongest and eristostatin the weakest inhibitor of cell adhesion to all substrata.
Adhesion
of melanoma cells to albolabrin, echistatin, and barbourin was partially inhibited by monoclonal antibody against mouse alpha v subunit. This antibody bound to B16F10 melanoma cells in suspension and inhibited binding of fluorescein isothiocyanate (FITC)-labeled disintegrins to these cells, being the most effective with FITC-labeled albolabrin. Our study suggests that a major contribution of eristostatin to inhibition of lung colonization is via preferential binding to platelet alpha IIb beta 3 integrin and blocking tumor cells interaction with platelets. A major contribution of albolabrin, barbourin and echistatin appears to be by interference with other integrin receptors on the tumor cell surface. Albolabrin appeared to inhibit RGD-dependent integrins containing alpha v subunit, such as alpha v beta 3 and alpha v
beta 1
.
...
PMID:Effect of four disintegrins on the adhesive and metastatic properties of B16F10 melanoma cells in a murine model. 754 46
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