Kinetic analysis of integrin‐dependent cell adhesion on vitronectin

Germer, Matthias; Kanse, Sandip M.; Kirkegaard, Tove; Kjøller, Lars; Felding-Habermann, Brunhilde; Goodman, Simon L.; Preissner, Klaus T.

doi:10.1046/j.1432-1327.1998.2530669.x

Cited by 41 publications

(33 citation statements)

References 5 publications

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“…1A), the inhibition of cell adhesion to vitronectin was not complete, generally reaching a maximum of around 50 -75% inhibition. These data are consistent with earlier studies (26), showing that a 10-fold higher concentration of active PAI-1 is required to inhibit ϳ50% of HEp-2 cells adhesion to vitronectin in comparison to purified integrins. These results demonstrate that PAI-1 inhibition of cellular adhesion to vitronectin conflict with the results using purified integrins.…”

Section: Pai-1 Inhibition Of Cellular Integrin Binding To Vitronectinsupporting

confidence: 93%

The Contributions of Integrin Affinity and Integrin-Cytoskeletal Engagement in Endothelial and Smooth Muscle Cell Adhesion to Vitronectin

Stefansson

Ishigami

et al. 2007

Journal of Biological Chemistry

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The serine proteinase inhibitor, plasminogen activator inhibitor type-1 (PAI-1), binds to the adhesion protein vitronectin with high affinity at a site that is located directly adjacent to the vitronectin RGD integrin binding sequence. The binding of PAI-1 to vitronectin sterically blocks integrin access to this site and completely inhibits the binding of purified integrins to vitronectin; however, its inhibition of endothelial and smooth muscle cell adhesion to vitronectin is at most 50 -75%. Because PAI-1 binds vitronectin with ϳ10 -100-fold higher affinity than purified integrins, we have analyzed the mechanism whereby these cells are able to overcome this obstacle. Our studies exclude proteolytic removal of PAI-1 from vitronectin as the mechanism, and show instead that cell adhesion in the presence of PAI-1 is dependent on integrin-cytoskeleton engagement. Disrupting endothelial or smooth muscle cell actin polymerization and/or focal adhesion assembly reduces cell adhesion to vitronectin in the presence of PAI-1 to levels similar to that observed for the binding of purified integrins to vitronectin. Furthermore, endothelial cell, but not smooth muscle cell adhesion to vitronectin in the presence of PAI-1 requires both polymerized microtubules and actin, further demonstrating the importance of the cytoskeleton for integrin-mediated adhesion. Finally, we show that cell adhesion in the presence of PAI-1 leads to colocalization of PAI-1 with the integrins ␣v␤3 and ␣v␤5 at the cell-matrix interface.Cell adhesion receptors play important roles in maintaining cell anchorage and polarity in addition to promoting migration and differentiation. Many of the known adhesion receptors belong to the integrin family of noncovalent heterodimeric transmembrane proteins that are expressed by most cell types. The integrin family consists of at least 18 ␣-and 8 ␤-subunits that combine to form as many as 24 different ␣␤ dimers (1). The extracellular domains of both integrin subunits are required for binding to adhesion proteins. In addition, integrins need physiological concentrations of divalent cations such as calcium or magnesium. Integrins have relatively short cytoplasmic tails that interact with an intracellular protein complex, termed focal contacts, which include adaptor proteins and kinases. The focal contacts control the linkage between the cytoskeleton and integrins and mediate intracellular signaling. Integrins direct forces generated by the cytoskeleton onto the extracellular matrix (ECM) 2 to produce the traction necessary for cell adhesion and migration (2). Understanding the mechanism and control of integrin-mediated cell adhesion and migration is of special interest because of their importance in processes such as wound healing and angiogenesis as well as pathologies associated with these processes.In general, integrins recognize short linear peptide sequences on adhesion proteins, the most prevalent being arginine-glycine-aspartic acid (RGD), which is found in many ECM proteins such as fibronectin, collagens, ...

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Section: Pai-1 Inhibition Of Cellular Integrin Binding To Vitronectinsupporting

confidence: 93%

The Contributions of Integrin Affinity and Integrin-Cytoskeletal Engagement in Endothelial and Smooth Muscle Cell Adhesion to Vitronectin

Stefansson

Ishigami

et al. 2007

Journal of Biological Chemistry

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“…1 Ligands with the RGD sequence have been shown to interact with endothelial ␣ v ␤ 3 integrin receptors. [2][3][4][5] Integrin receptors are identified on endothelial cell surface and communicate with the cell through cytoplasmic signaling molecules. Activation of ␣ v ␤ 3 receptors is required for vascular development and may be associated with a decrease in endothelial cell apoptosis and with downstream angiogenic signaling through protein kinases.…”

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confidence: 99%

Developmental Endothelial Locus-1 (Del-1), a Novel Angiogenic Protein

Jang

Kaji

et al. 2004

Circulation

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Background-Developmentally regulated endothelial locus-1 (Del-1) is an extracellular matrix protein that is expressed by endothelial cells during embryological vascular development. We speculated that Del-1 may be reexpressed in ischemia and may be involved in endogenous angiogenesis. Methods and Results-Del-1 protein was detected by immunohistochemistry in murine ischemic hindlimb after femoral artery excision. To determine whether exogenous Del-1 would augment angiogenesis in vivo, Del-1 or vehicle was administered for 3 weeks by intramuscular injection of murine ischemic hindlimbs. Angiogenesis was quantified by gadolinium-MRI perfusion and capillary densitometry. We used a disc angiogenesis system (DAS) to characterize the angiogenic response to vehicle (PBS), Del-1, Del-1 mutant (altered RGD domain), Del-1 minor (truncated discoidin-I-like domain), or basic fibroblast growth factor. After 14 days, the discs were extracted and sectioned to quantify vascular growth by morphometry. Endogenous Del-1 protein expression was increased in ischemic hindlimbs. Administration of Del-1 increased hindlimb vascular flow index and capillary density. In the DAS, Del-1 doubled fibrovascular growth, as did basic fibroblast growth factor. However, angiogenesis was not enhanced by the Del-1 mutant or Del-1 minor proteins. Conclusions-Del-1 is expressed in ischemic tissue. Del-1 stimulates angiogenesis, an effect that is dependent on the RGD motif and a second signaling sequence in the discoidin-I-like domain. Exogenous intramuscular administration of Del-1 significantly enhances angiogenesis in the murine ischemic hindlimb. Del-1 may prove to be a novel therapeutic agent for patients with ischemia.

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“…uPA, when bound to the uPA receptor (uPAR), enhances inflammatory cell migration (3,4,7,17,18), cell adhesion mediated by vitronectin (3,19,21), cell invasion through activation of matrix metalloproteinase enzymes (20,22), and the release and activation of growth factors (23). Serpins, inhibit individual steps in these cascades through directed one-to-one stoichiometric inhibition of many of these enzymes (3)(4)(5)(6)(7)(23)(24)(25).…”

mentioning

confidence: 99%

“…Serpins, inhibit individual steps in these cascades through directed one-to-one stoichiometric inhibition of many of these enzymes (3)(4)(5)(6)(7)(23)(24)(25). PAI-1 is a naturally occurring vascular serpin that, like Serp-1, binds to uPA and tPA in the circulating blood, inhibiting plasminogen activator activity, but, in contrast to Serp-1, does not inhibit plasmin activity (8,(21)(22)(23)(24)(25)(26)(27). Plasminogen activator inhibitor-1 (PAI-1)-deficient mice have significantly increased intimal hyperplasia after arterial injury (26 -28).…”

mentioning

confidence: 99%

Serp-1, a Viral Anti-inflammatory Serpin, Regulates Cellular Serine Proteinase and Serpin Responses to Vascular Injury

Dai

Guan

Liu

et al. 2003

Journal of Biological Chemistry

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Complex DNA viruses have tapped into cellular serpin responses that act as key regulatory steps in coagulation and inflammatory cascades. Serp-1 is one such viral serpin that effectively protects virus-infected tissues from host inflammatory responses. When given as purified protein, Serp-1 markedly inhibits vascular monocyte invasion and plaque growth in animal models. We have investigated mechanisms of viral serpin inhibition of vascular inflammatory responses. In vascular injury models, Serp-1 altered early cellular plasminogen activator (tissue plasminogen activator), inhibitor (PAI-1), and receptor (urokinase-type plasminogen activator) expression (p < 0.01). Serp-1, but not a reactive center loop mutant, up-regulated PAI-1 serpin expression in human endothelial cells. Treatment of endothelial cells with antibody to urokinase-type plasminogen activator and vitronectin blocked Serp-1-induced changes. Significantly, Serp-1 blocked intimal hyperplasia (p < 0.0001) after aortic allograft transplant (p < 0.0001) in PAI-1-deficient mice. Serp-1 also blocked plaque growth after aortic isograft transplant and after wire-induced injury (p < 0.05) in PAI-1-deficient mice indicating that increase in PAI-1 expression is not required for Serp-1 to block vasculopathy development. Serp-1 did not inhibit plaque growth in uPAR-deficient mice after aortic allograft transplant. We conclude that the poxviral serpin, Serp-1, attenuates vascular inflammatory responses to injury through a pathway mediated by native uPA receptors and vitronectin.An integrated balance between the thrombotic and thrombolytic cascades, both of which are regulated by serine proteinases, activates arterial clot formation and also mediates inflammatory cell responses at sites of vascular injury (1-7). Serine proteinase inhibitors, termed serpins, in turn regulate these cascades (7). Larger DNA containing viruses have captured host serpins during millions of years of evolution, and adapted them into highly effective shields against host inflammatory responses (8). Serp-1, a secreted anti-inflammatory protein encoded by myxoma virus, is one such poxviral serpin that binds and inhibits, in vitro, the thrombolytic serine proteinases tissue-type and urokinase-type plasminogen activators (tPA 1 and uPA, respectively) and plasmin (9, 10). In vivo, Serp-1 reduces inflammatory leukocyte responses to myxoma viral infection (9, 10). Furthermore, infusion of picogram to nanogram doses of purified Serp-1 protein also profoundly inhibits monocytic cell invasion and subsequent atherosclerotic plaque growth following vascular injury induced by angioplasty (11) or allograft transplant (12,13) 2 in animal models, thus providing a new class of anti-inflammatory drugs.The precise targets and/or receptors, through which viral serpins, specifically Serp-1, inhibit inflammatory cell responses are not yet defined (10 -17). uPA, when bound to the uPA receptor (uPAR), enhances inflammatory cell migration (3, 4, 7, 17, 18), cell adhesion mediated by vitronectin (3, 19, 21), cell ...

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Kinetic analysis of integrin‐dependent cell adhesion on vitronectin

Cited by 41 publications

References 5 publications

The Contributions of Integrin Affinity and Integrin-Cytoskeletal Engagement in Endothelial and Smooth Muscle Cell Adhesion to Vitronectin

The Contributions of Integrin Affinity and Integrin-Cytoskeletal Engagement in Endothelial and Smooth Muscle Cell Adhesion to Vitronectin

Developmental Endothelial Locus-1 (Del-1), a Novel Angiogenic Protein

Serp-1, a Viral Anti-inflammatory Serpin, Regulates Cellular Serine Proteinase and Serpin Responses to Vascular Injury

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