Intervesicle Cross-Linking with Integrin α<sub>IIb</sub>β<sub>3</sub>and Cyclic-RGD-Lipopeptide. A Model of Cell-Adhesion Processes

Hu, Bin; Finsinger, Dirk; Peter, K.; Guttenberg, Zeno; Bärmann, M.; Kessler, Ingmar; Escherich, Achim; Moröder, Luis; Böhm, Jochen; Baumeister, Wolfgang; Sui, Sen‐Fang; Sackmann, E.

doi:10.1021/bi000144q

Cited by 53 publications

(46 citation statements)

References 43 publications

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“…Our model (11,13) consists of a giant unilamellar vesicle with mobile RGD-peptide-carrying lipids (14), which interact with a supported bilayer doped with ␣ IIb ␤ 3 integrins (14). Depending on the specific deposition technique used (11,13), the integrins are either fixed (immobile system; Fig.…”

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confidence: 99%

Force-induced growth of adhesion domains is controlled by receptor mobility

Smith

Sengupta

Goennenwein

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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In living cells, adhesion structures have the astonishing ability to grow and strengthen under force. Despite the rising evidence of the importance of this phenomenon, little is known about the underlying mechanism. Here, we show that force-induced adhesion-strengthening can occur purely because of the thermodynamic response to the elastic deformation of the membrane, even in the absence of the actively regulated cytoskeleton of the cell, which was hitherto deemed necessary. We impose pN-forces on two fluid membranes, locally pre-adhered by RGD-integrin binding. One of the binding partners is always mobile whereas the mobility of the other can be switched on or off. Immediate passive strengthening of adhesion structures occurs in both cases. When both binding partners are mobile, strengthening is aided by lateral movement of intact bonds as a transient response to force-induced membrane-deformation. By extending our microinterferometric technique to the suboptical regime, we show that the adhesion, as well as the resistance to force-induced de-adhesion, is greatly enhanced when both, rather than only one, of the binding partners are mobile. We formulate a theory that explains our observations by linking the macroscopic shape deformation with the microscopic formation of bonds, which further elucidates the importance of receptor mobility. We propose this fast passive response to be the first-recognition that triggers signaling events leading to mechanosensing in living cells.cell adhesion under force ͉ dynamic reflection interference contrast microscopy ͉ magnetic tweezers ͉ mobile integrin-RGD bonds ͉ model systems T he formation of adhesion domains is a ubiquitous event in the early stages of cell adhesion. The domains are agglomerates of bonds formed between receptors and counterreceptors (1). For cell-cell contact, before adhesion, both binding partners are mobile, whereas for cells adhering to the extracellular matrix, the counterreceptors are fixed. In the late, actively regulated stage of adhesion, the actin cytoskeleton couples to the adhesion domains (2). Under force, the adhesion domains grow (3) (a phenomenon called mechanoresponse, which is also related to mechanosensing, the ability of cells to sense and respond to rigidity) presumably by applying internal forces that interrogate the substrate (4). Forceinduced strengthening is concomitant with the stiffening of the cytoskeleton (3, 5, 6), leading to the widespread belief that active regulation of the cytoskeleton is solely responsible for mechanoresponse (3, 5-9). However, this actively driven cytoskeletal remodeling due to external mechanical stimulus is expected to occur over time scales of minutes (4). Although it has been mooted previously that, at shorter time scales, the response is dominated by the physical properties of the membrane (1, 10), the force-response of cells over subsecond time scales has rarely been explored. At the same time, several studies have shown that, even in the absence of force, the adhesion is enhanced if both the liga...

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mentioning

confidence: 99%

Force-induced growth of adhesion domains is controlled by receptor mobility

Smith

Sengupta

Goennenwein

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

136

173

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“…Likewise, although no data based on surface plasmon resonance analysis are currently available for the interaction between integrins and disintegrins, the affinities estimated by Scatchard analysis are in the nanomolar range (52). In contrast, integrins were found to bind to cyclic RGD peptides with affinities in the micromolar range or higher (53). The disintegrin-like V2 module exhibited enhanced binding affinities compared with the original EGF-RGD module, especially in the case of ␣ 5 ␤ 1 .…”

Section: Discussionmentioning

confidence: 96%

A Recombinant Chimeric Epidermal Growth Factor-like Module with High Binding Affinity for Integrins

Vella

Thielens

Bersch

et al. 2003

Journal of Biological Chemistry

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Integrins are cell surface receptors involved in numerous pathological processes such as metastasis invasion and abnormal angiogenesis. To target these receptors, the epidermal growth factor (EGF)-like domain of human complement protease C1r was used as a natural scaffold to design chimeric modules containing the RGD motif. Here we report a high yield bacterial expression system and its application to the production of two such modules, EGF-RGD and V2, the latter variant mimicking the RGD-containing domain of disintegrins. These modules were characterized chemically, and their biological activity was investigated by cellular assays using various Chinese hamster ovary cell lines expressing ␤ 1 and ␤ 3 integrins and by surface plasmon resonance spectroscopy. Remarkably, the modifications leading to the V2 variant had differential effects on the interaction with Targeting the appropriate cell type is a major challenge in cancer and cell therapy. Integrins, a family of cell receptors for plasma proteins, extracellular matrix proteins, and cell surface ligands (1-3), are potential targets for this purpose, because they are expressed by all cell types and are involved in many physiological functions including cell adhesion, proliferation, or differentiation, and pathological processes such as metastasis invasion, abnormal angiogenesis and vascularization, or thrombosis (4). In mammals, 18 ␣ and eight ␤ subunits assemble into 24 different non-covalent ␣␤ heterodimers that mediate bidirectional signals through the cell membrane. In response to cell activation, "inside-out" signals control the level of binding affinity for the ligand. In turn, ligand binding induces rearrangements in integrin structure that trigger "outside-in" signaling pathways (5). Extensive cross-talk also takes place between integrin and growth factor receptor signaling pathways (6, 7), influencing most integrin functions.The ␤ 1 integrin subset, comprising the major fibronectin receptor ␣ 5 ␤ 1 , is the most widely expressed. The ␤ 3 subset includes the fibrinogen receptor ␣ IIb ␤ 3 , present on platelets and megakaryocytes, and ␣ v ␤ 3 , originally described as the vitronectin receptor, which also binds a variety of matrix proteins including fibronectin and fibrinogen. Integrin ␣ v ␤ 3 is expressed on vascular cells during angiogenesis (8,9) and is also present in the adult on activated leukocytes, osteoclasts, and macrophages, where it participates in bone resorption and ingestion of apoptotic cells. The expression of various integrins has been shown to be deregulated in a number of cancer cells and invasive tumors and is thought to participate in the malignancy phenotypes (10 -14). Thus, a decreased expression of ␣ 5 ␤ 1 appears to increase the degree of tumorigenicity. In contrast, the level of ␣ v ␤ 3 is correlated with the survival and metastatic activity of tumor cells (10, 15) and has an important role in angiogenesis in tumors (11). Integrins, particularly ␣ v ␤ 3 , are therefore considered as appropriate targets for cancer therapy. Intrac...

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“…[2] Solutions can now flow over the immobilized proteins, so it is possible to add or remove ligands and denaturants easily, and the longer data collection times could be compensated for by designing overnight unfolding-refolding experiments where buffers are exchanged automatically on one fixed protein sample. Combined with the ability to assemble membrane proteins on gold and perform parallel SPR on these surfaces, [3,18] the use of immobilized protein monolayers in CD spectroscopy offers a way to extend the applications of this technique. Methods that increase the surface roughness of the gold [19] could further increase the sensitivity of the procedure.…”

Section: Methodsmentioning

confidence: 99%