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S L Goodman

Publications and source records attributed to S L Goodman.

At least 37 records · Page 2Linked to original sources
PubMed1998

Transmembrane-truncated alphavbeta3 integrin retains high affinity for ligand binding: evidence for an 'inside-out' suppressor?

The molecular mechanisms of alphavbeta3 integrin affinity regulation have important biological implications in tumour development, wound repair and angiogenesis. We expressed, purified and characterized recombinant forms of human alphavbeta3 (r-alphavbeta3) and compared the activation state of these with alphavbeta3 in its cellular environment. The ligand specificity and selectivity of recombinant full-length and double transmembrane truncations of r-alphavbeta3 cloned in BacPAK6 vectors and expressed in Sf9 and High Five insect cells were compared with those of native placental alphavbeta3 and the receptor in situ on the cell surface. r-alphavbeta3 integrins were purified by affinity chromatography from detergent extracts of cells (full-length), and from the culture medium of cells expressing double-truncated r-alphavbeta3. r-alphavbeta3 had the same epitopes, ligand-binding specificities, bivalent cation requirements and susceptibility to RGD-containing peptides as native alphavbeta3. On M21-L4 melanoma cells, alphavbeta3 mediated binding to vitronectin, but not to fibrinogen unless activated with Mn2+. Non-activated alphaIIbbeta3 integrin as control in M21-L-IIb cells had the opposite profile, mediating binding to fibrinogen, but not to vitronectin unless activated with Mn2+. Thus these receptors had moderate to low ligand affinity. In marked contrast, purified alphavbeta3 receptors, with or without transmembrane and cytoplasmic domains, were constitutively of high affinity and able to bind strongly to vitronectin, fibronectin and fibrinogen under physiological conditions. Our data suggest that, in contrast with the positive regulation of alphaIIbbeta3 in situ, intracellular controls lower the affinity of alphavbeta3, and the cytoplasmic domains may act as a target for negative regulators of alphavbeta3 activity.

Amino Acid Sequence↗
PubMed1998

Design, synthesis and biological evaluation of nonpeptide integrin antagonists.

Recent studies demonstrated that peptide and antibody antagonists of integrin alpha v beta 3 block angiogenesis and tumor growth. In this article, the design, synthesis and biological evaluation of a series of nitroaryl ether-based, nonpeptide mimetics are described. The design of these compounds was based on Merck's arylether/alpha-aminoacid/guanidine framework and incorporates a novel nitroaryl system. The synthesized mimetics were tested against a variety of integrins (alpha v beta 3, alpha IIb beta 3, and alpha v beta 5) in order to determine their binding selectivity and ability to inhibit cell adhesion. Selected compounds were also tested for their ability to inhibit angiogenesis in vivo in the CAM (chick chorioallantoic membrane) assay. From the generated compound library, compounds 16 and 19 proved to be potent and selective inhibitors of alpha IIb beta 3 (IC50 = 14 nM) whereas compound 11 showed excellent in vivo inhibition of angiogenesis (at 30 micrograms/embryo).

Allantois↗
PubMed1998

Chemical modification and photograft polymerization upon expanded poly(tetrafluoroethylene).

Poly(tetrafluoroethylene) (PTFE) films were surface-modified by employing a reaction solution of benzophenone and sodium hydride in anhydrous dimethylformamide at a temperature of 150 degrees C for 12 h. Electron spectroscopy for chemical analysis (ESCA) showed defluorination, oxygen incorporation, and extensive unsaturation within the treated PTFE surfaces. The suitably of these reduced PTFE films as substrates for graft polymerization was initially assessed via photograft polymerization of the sodium salt of styrenesulfonic acid (SS-Na), which permitted unequivocal surface analysis by the introduction of a new atom, as well as poly(ethylene glycol) monoacrylate (PEG-Ac). All photograpt polymerization was performed employing ultraviolet irradiation with 2,2-dimethoxy-2-phenylacetophenone as an initiator. Photograft polymerization of SS-Na was verified by further reduction of fluorine atomic content and the appearance of new sulfur and sodium atomic peaks on ESCA survey spectra, and that of PEG-Ac was verified by further reduction of fluorine atomic content and increase of atomic percent ratio of O/C from ESCA survey spectra as well as appearance of a new ester peak on high resolution ESCA C 1s spectra. Dynamic water contact angles on reduced and PEG-Ac photograft polymerized films were measured and showed that the PTFE film surface became more hydrophilic after reduction (from 120 to 89 deg) and the reduced film became more hydrophilic after photograft polymerization with PEG-Ac (from 89 to 36 deg). Modification of the complete surface of expanded PTFE (ePTFE), i.e. of the lumenal, outside and pore surfaces, was performed by employing the reaction described above, except at 105 degrees C for 1 day, followed by photograft polymerization of PEG-Ac. ESCA was performed on the superficial surfaces (i.e. the lumen and exterior) as well as on cross-sections of the ePTFE to permit analysis of the pore surfaces. This analysis showed that both the initial surface reduction and subsequent photograft polymerization were successful as indicated from F/C and O/C atomic percent ratios from ESCA survey spectra, from overall peaks shapes of high resolution ESCA C 1s spectra and from generation of new ester peaks on high resolution ESCA C 1s spectra of ePTFE graft polymerized with PEG-Ac, which demonstrated an O/C atomic percent ratio close to that of PEG-Ac homopolymer. Low voltage scanning electron microscopy confirmed minimal morphological damage to the ePTFE microstructure after reduction and graft polymerization. The approach explored thus provides a means for modulation of biological interactions at ePTFE surfaces with only minimal modification of material morphology, with some surface texture appearing on a length scale of 50-100 nm.

Benzophenones↗
PubMed1997

Immunohistochemical analysis of integrin alpha vbeta3 expression on tumor-associated vessels of human carcinomas.

Expression of the alpha vbeta3 integrin is upregulated on sprouting endothelia. Systemic application of antibody or peptidic inhibitors of alpha vbeta3 function disrupts tumor angiogenesis and reduces growth and invasiveness of human tumors in animal models. We systematically investigated alpha vbeta3 expression on tumor-associated vessels of 4 different human epithelial tumors and the corresponding normal tissues by means of immunohistochemistry on frozen sections using the alpha vbeta3-complex specific monoclonal antibody LM609. Variable levels of LM609 staining were found in all carcinoma lesions. A considerable number of tumor tissues (35/50) expressed alpha vbeta3 on more than 50% of their vessels. Inflammatory infiltrates and the possibly hypoxic conditions near necrotic areas of tumors were accompanied by an increased alpha vbeta3 expression. Remarkably, the vasculature in apparently normal tissue also stained for alpha vbeta3. However, the percentages of stained vessels and their staining intensity were lower than in neoplastic tissues. Besides the vascular alpha vbeta3 expression, several extravascular cell types stained positive, in both normal and tumor specimens. Taken together, our findings show a considerable number of colon, pancreas, lung and breast carcinoma lesions with many alpha vbeta3-expressing vessels that could be targets for anti-alpha vbeta3-therapy.

Adenocarcinoma↗
PubMed1997

Plasminogen activator inhibitor-1 represses integrin- and vitronectin-mediated cell migration independently of its function as an inhibitor of plasminogen activation.

Cell migration involves the integrins, their extracellular matrix ligands, and pericellular proteolytic enzyme systems. We have studied the role of plasminogen activator inhibitor-1 (PAI-1) in cell migration, using human amnion WISH cells and human epidermoid carcinoma HEp-2 cells in an assay measuring migration from microcarrier beads and a modified Boyden-chamber assay. Active, but not latent or reactive center-cleaved, PAI-1 inhibited migration. A PAI-1 mutant without ability to inhibit plasminogen activation was as active as wild-type PAI-1 as a migration inhibitor, showing that inhibition of plasminogen activation was not involved. PAI-1 specifically interfered with intergrin- and vitronectin-mediated migration: Migration onto vitronectin-coated but not onto fibronectin-coated surfaces was inhibited by PAI-1, a cyclic RGD peptide inhibited migration, and both cell lines expressed vitronectin-binding alpha v-integrins. In addition, active PAI-1, but not latent or reactive center-cleaved PAI-1, inhibited vitronectin binding to integrins in an in vitro binding assay, without affecting binding of fibronectin. Monoclonal antibodies against the urokinase receptor, another vitronectin binding protein, did not affect cell migration in the beads assay, while some inhibitory effect was observed in the Boyden-chamber assay. We conclude that PAI-1, independently of its role as a proteinase inhibitor, inhibits cell migration by competing for vitronectin binding to integrins, while the interference of PAI-1 with binding of vitronectin to the urokinase receptor may play a secondary role. These data define a novel function for the serpin PAI-1, enabling it to regulate cell migration over vitronectin-rich extracellular matrix in the body.

Amnion↗
PubMed1996

Identification and immunolocalization of laminin in cartilage.

In a previous study on the role of integrins in the interaction of human chondrocytes with extracellular collagen and fibronectin (Dürr et al., (1993) Exp. Cell Res. 207, 235) we showed that chondrocytes adhere to laminin-1 (LN-1) in a beta 1-integrin-dependent manner. FACS analysis with various integrin antibodies including the monoclonal antibody GOH3 indicated the presence of the alpha 6 beta 1-laminin receptor on the chondrocyte surface. Anti-alpha 6 antibodies inhibited adhesion to the LN-1/E8 fragment, but not to whole laminin or heat-denatured Laminin-1, indicating that chondrocytes utilize at least two beta 1-integrins for laminin adhesion, one of which is alpha 6 beta 1 recognizing the LN-1/E8 fragment. The presence of alpha 6 beta 1-integrin on the chondrocyte surface also suggested the existence of laminin-like molecules in cartilage. Here we provide immunological and biochemical evidence in support of this possibility. Several polyclonal antibodies raised against laminin-1 or the LN-1/E8 fragment revealed a strong pericellular reaction in sections of human fetal epiphyseal cartilage and adult articular cartilage. In the fetal epiphysis laminin staining was most prominent in mature, large chondrocytes appearing in the secondary ossification zone, in particular, in the vicinity of invading capillary sprouts. Chondrocytes in the proliferating and hypertrophic zone of the growth plate and perichondrium cells were negative. All chondrocytes that stained for alpha 6-integrin also stained for laminin-1. A laminin-1-like molecule was extracted from hyaline cartilage with two bands migrating slightly faster than the alpha 1 and beta 1/gamma 1 subunits of laminin on SDS-gel electrophoresis. The two bands stained with anti-laminin-1 antibodies and could be immunoprecipitated with the same antibodies from metabolically labeled chondrocyte cultures. These findings suggests a role for laminin in developing cartilage and thus additional roles for laminins outside basement membranes.

Adult↗
PubMed1996

Platelet-polymer interactions: morphologic and intracellular free calcium studies of individual human platelets.

Light and electron microscopic methods were used to correlate changes in platelet morphology with levels of internal free calcium in platelets adhering to Formvar, Pellethane, and 14% SO3 Pellethane. Free calcium levels were elevated when platelets initially activated in response to contact with the polymer substrates. With buffer containing 1 mM CA2+, representative of in vivo plasma calcium levels, platelets activating on the sulfonated substrate exhibited significantly higher intracellular free calcium levels compared to those on Formvar and Pellethane. Furthermore, the intracellular free calcium remained elevated in these platelets which failed to spread normally on the sulfonated substrate. In contrast, the platelets adherent on Formvar and Pellethane achieved normal fully spread morphologies with correspondingly low or resting calcium levels. Our results indicate that the addition of the sulfonated group to Pellethane affected internal platelet calcium regulation to cause an abnormal spreading response. The nonviable platelet morphologies observed on sulfonated Pellethane compare to other dead cell morphologies caused by abnormally elevated levels of intracellular free Ca2+.

Biocompatible Materials↗
PubMed1996

Platelet interaction with pyrolytic carbon heart-valve leaflets.

Although the newest generation of mechanical heart-valve prosthetics constructed either partially or wholly of lowtemperature isotropic pyrolytic carbon (LTIC) have significantly reduced thromboembolic complications compared with early-generation mechanical valves (e.g., Starr-Edwards), thromboembolism remains an important clinical complication. In the present study, high-resolution, lowvoltage scanning electron microscopy (HR-LV-SEM) was used to examine the structure and platelet interaction properties of LTIC valve leaflets manufactured by both Carbo Medics, Inc. and by St. Jude Medical, Inc. Valve leaflets from both manufacturers, prepared and polished exactly as used in clinical heart valves, had similar surface energetics and elemental composition. Examination with LV-SEM revealed a rough and complex three-dimensional surface structure with nanometer- to micron-size features. In vitro adhesion of human platelets on the LTIC materials and Formvar were evaluated in the presence of 1 mg/mL albumin. Platelet-surface activation, as evaluated by shape change, spread area, and deposition, was extremely extensive on the LTIC materials compared with the Formvar positive control material. LTIC-adherent platelets were extremely thin, and closely followed the rough LTIC contours, greatly limiting their visibility with conventional SEM. These observations demonstrate that LTIC surfaces can extensively activate platelets even in the presence of albumin, thereby suggesting that platelet interactions with pyrolytic carbon may have a significant role in mechanical-valve thromboembolism.

Biocompatible Materials↗
PubMed1996

Mouse polymorphonuclear granulocyte binding to extracellular matrix molecules involves beta 1 integrins.

The mechanism of adhesion of purified mouse polymorphonuclear granulocytes (PMN) to extracellular matrix proteins characteristic of basement membranes and the interstitium has been investigated and compared with the adhesion of a mouse progranulocytic cell line, 32DC13, and a mouse monocytic cell line, WEHI 78/24. All three cell types bound specifically to fibronectin and vitronectin to different degrees under different cellular activation states. 32DC13 bound to fibronectin and vitronectin strongly, and this binding increased upon cellular activation with phorbol 12-myristate-13-acetate (PMA) but not with formyl-Met-Leu-Phe. Only 32DC13 showed significant binding to laminin-1. By contrast, WEHI 78/24 and PMN bound only fibronectin and vitronectin; this binding was weak and was altered only marginally upon activation with PMA. In the case of WEHI 78/24, a slight increase in adhesion both to fibronectin and to vitronectin was observed after cellular activation with PMA, while PMN adhesion to both substrates was slightly reduced. The mechanism of binding to fibronectin and vitronectin was similar in the three cell types. The integrin alpha5 beta1 mediated fibronectin adhesion, demonstrating for the first time the existence of a functionally active beta1 integrin on mouse PMN. Vitronectin binding was mediated by alpha(v) beta3, as demonstrated by the ability of alpha(v)-specific cyclic L-Arg-L-Gly-L-Asp-D-Phe-L-Val (RGDfV) peptide (EMD66203), and anti-beta3 antibody to inhibit cell adhesion. 32DC13 adhesion to laminin-1 was via the alpha6 beta1 integrin. None of the three cell types tested bound to the basement membrane proteins collagen type IV and perlecan, or to the interstitial stromal constituents tenascin, collagen types I, V and VI. Interestingly, perlecan and collagen type IV were found to repel all three cell types. The relative inability of PMN, WEHI 78/24, and 32DC13 to bind to extracellular matrix proteins characteristic of basement membranes and their ability to bind inflammatory markers of the interstitium is discussed with respect to leukocyte extravasation processes.

Animals↗
PubMed1996

Three-dimensional extracellular matrix textured biomaterials.

Clinical and experimental investigations have reported that manufactured surface topographies have significant effects on cell adhesion and tissue integration. However, essentially all previously examined topographies bear little relation to cell adhesion substrates found in biological tissues. In vivo, many cells are adherent to extracellular matrices (ECM), which have an extremely complex 3-D topography in the micrometre to nanometre range. In addition, many studies indicate that micro- and nano-scale mechanical stresses generated by cell-matrix adhesion have significant effects on cellular phenotypic behaviour. In this report we describe methodology for the fabrication of topographic replicas of the subendothelial ECM topography with a biomedical polyurethane. Using three-dimensional high resolution scanning electron microscopy, accurate replication of subendothelial ECM topography from the macroscopic to the macromolecular scale is demonstrated. Bovine aortic endothelial cells cultured on the ECM replicas spread more rapidly and had a three-dimensional appearance and spread areas at confluence which appeared more like endothelial cells in native arteries, compared with cells cultured on untextured control surfaces. Since the fabrication process may be used with many different types of materials, including polymers of synthetic and biological origin, these biomimetic ECM-textured surfaces may find both research and clinical applications.

Animals↗
PubMed1995

Alpha v beta 1 is a receptor for vitronectin and fibrinogen, and acts with alpha 5 beta 1 to mediate spreading on fibronectin.

We have shown previously that VUP was the only line out of ten human melanoma lines that failed to express the vitronectin receptor alpha v beta 3, but instead expressed alpha v beta 1. Levels of alpha v beta 1 expression were low on parental VUP cells so that iterative sorting by FACS, using an anti-alpha v antibody (13C2), was utilised to derive sublines with 8- to 10-fold higher amounts of cell surface alpha v beta 1. There was little difference between low (V-) and high (V+) alpha v beta 1-expressing sublines with regard to adherence to collagen type I, collagen type IV or laminin substrata. However, adherence to vitronectin and fibrinogen correlated closely with alpha v beta 1 expression (35-42% adhesion for V(+) lines versus 6-8% adhesion for V- lines on vitronectin, for example). Utilising a high alpha v beta 1-expressing subline (V + B2) we have shown that binding to vitronectin and fibrinogen was inhibited specifically by function-blocking antibodies to alpha v (17E6 and 14D9) and beta 1 (A11B2). V(+) sublines spread more compared with V(-) sublines on both vitronectin and fibronectin. However, neither alpha 5- nor alpha v-blocking antibodies had any effect on attachment or spreading of V + B2 on fibronectin whereas the combination of alpha 5 (PID6)- and alpha v(17E6)-blocking antibodies abrogated binding to fibronectin almost completely. This is the first report of an alpha v beta 1 integrin able to recognize vitronectin and fibrinogen, and also cooperate with alpha 5 beta 1 to mediate attachment to and spreading on fibronectin.

Antibodies↗
PubMed1995

An anti-alpha v-integrin antibody that blocks integrin function inhibits the development of a human melanoma in nude mice.

A series of murine monoclonal antibodies were raised against purified human alpha v beta 3 integrin and against M21 human melanoma cells. Five notable hybridomas were identified by ELISA on purified integrins, and the isolated antibodies bound the alpha v-chain. These antibodies, 17E6, 20A9, 23G5, 14D9.F8 and 10G2, recognised the extracellular domains of the integrin, and were shown to be reactive in FACS, immunoprecipitation, ELISA, and ELISA on fixed cells with M21, M21-L4, and UCLA-P3, but not with the alpha v-deficient M21-L or M21-L-IIb (M21-L transfected with GpIIb integrin). One antibody, 17E6, strongly perturbed cell attachment mediated by alpha v integrins, reacting at least with alpha v beta 3, alpha v beta 5, and alpha v beta 1, and strongly inhibiting cell attachment to alpha v-ligands vitronectin and fibronectin with an IC50 of approximately 0.1 microgram ml-1. Furthermore, 17E6 at this concentration could induce cell retraction from the substrate, while LM609 (anti-alpha v beta 3) and control antibody 14E2 (anti-200 kDa melanoma surface protein) at 1,000-fold higher concentrations had minimal effects on cell morphology. The action of 17E6 was reversible and was not due to toxic effects: in vitro 17E6 at 0.1 mg ml-1 did not affect either cell proliferation or DNA synthesis. In two nude-mouse tumour models, subcutaneous tumour development and a lung colonisation ('experimental metastasis') assay, injection of 17E6 strongly inhibited tumour development, while isotype-matched controls had no effect. There was no obvious mechanism of cell or of complement-mediated tumour cytotoxicity; the antibody did not mediate ADCC or AECDC, or complement fixation. The data strongly support previous studies which have indicated the importance of alpha v-integrins, and especially alpha v beta 3, in the tumour progression of human melanoma.

Animals↗
PubMed1993

Integrin receptors and platelet adhesion to synthetic surfaces.

The activation-independent and -dependent integrin receptors--glycoproteins GPIc-IIa (alpha 5-beta 1) and GPIIb-IIIa (alpha IIb-beta 3)--are involved in platelet adhesion and thrombus growth on damaged subendothelium through interactions with fibrinogen, fibronectin, von Willebrand factor, and other adhesive proteins. Because these receptors are used in normal in vivo hemostatic adhesion, they may also have a role for adhesion onto synthetic surfaces in the vasculature. Platelet adhesion in vitro was examined onto Formvar, glass, and four polyurethaneureas with various soft segment chemistries and surface properties. Platelets were pretreated with RGD peptides before and after adhesion. RGD peptide pretreatment inhibited spreading and close contact formation compared to treatment with saline or control RGE peptides, with no observable effect on the number of adherent platelets per area. High-voltage electron microscopy showed abnormally sparse and short microfilament structures with RGD peptide treatment, suggesting an indirect inhibition of actin filament formation. Video-enhanced light microscopy showed a cessation of spreading and a partial reversal of close contacts following RGD peptide application to adherent platelets. Because minimal amounts of plasma proteins are present in column-washed platelet suspensions, and as platelet secretion appeared to be minimal in these experiments, these observations suggest that RGD binding integrin receptors may function in platelet spreading even in the absence of exogenous ligand. As RGD peptides did not affect the numbers of adherent platelets, while producing substantial decreases in the extent of spreading, we suggest that platelet integrins, possibly GPIIb-IIIa, are involved in spreading on synthetic surfaces but not for initial adhesion.

Blood Platelets↗
PubMed1993

Polymerase chain reaction and focal contact formation indicate integrin expression in mesangial cells.

Cultured kidney glomerular mesangial cells (MCs) allow the role of extracellular matrix (ECM) and growth factors in glomerular inflammatory disease to be studied. To investigate the potential of MCs to interact with matrix components, the expression of integrin mRNA in cultured MCs was examined by polymerase chain reaction (PCR), by Northern blotting and by immunofluorescence. In addition, the effect of matrix substrates on mRNA expression was assessed by PCR. Northern blots with cDNA probes to integrin alpha-chains revealed that MCs expressed alpha 1, alpha 3 and alpha 5 integrin mRNA. alpha 1 and alpha 3 were the major messages. No alpha 2, alpha 4 or alpha 6 were detectable. RT-PCR revealed that alpha 2 and alpha 6 were also expressed at low levels. The control cells, HT1080, expressed alpha 2, alpha 3, alpha 4, alpha 5 and alpha 6 mRNA, and Rugli expressed alpha 1, alpha 3 and alpha 5, supporting previous studies. Immunocytochemistry confirmed that alpha 1 beta 1, alpha 2 beta 1, and alpha 5 beta 1 integrins were expressed and that they were concentrated into focal adhesions (alpha 1 beta 1 on type I collagen and laminin; alpha 2 beta 1 on type I collagen; alpha 3 beta 1 on type I collagen, laminin and fibronectin; alpha 5 beta 1 on fibronectin). alpha 6 beta 1 was not detected in focal contacts. Attachment, spreading, and formation of talin and integrin containing focal contacts still occurred when endogenous protein synthesis was blocked with 30 micrograms.ml-1 cycloheximide.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Alpha 3 beta 1 integrin is moved into focal contacts in kidney mesangial cells.

The movement of integrins into focal adhesive structures accompanies cell attachment to extracellular matrix. The kinetics of incorporation of integrins into focal contacts was studied during attachment to matrix of mesangial cells of the kidney glomerulus. On collagen, fibronectin, laminin and vitronectin, the number and intensity of talin-focal contacts increased with time. Talin-containing focal contacts were present in mesangial cells within 2 h of plating and in control cells (HT1080 and Rugli) within 1 h. Integrin alpha-chains colocalized with talin, dependent on the matrix substrate. The attachment, spreading and organization of integrin into focal contacts was not affected when endogenous protein synthesis was suppressed with cycloheximide. In Rugli, alpha 1 beta 1 organized into focal contacts on collagen and laminin, while in HT1080 alpha 2 beta 1 organized on collagen type I, alpha 5 beta 1 on fibronectin, alpha 6 beta 1 on laminin, and alpha 3 beta 1 and alpha 4 beta 1 were diffusely distributed on all substrates. These distributions mirrored the usage and expression patterns previously established for integrins in these cells and was as predicted from the literature. In mesangial cells, however, alpha 3 beta 1 was also organized into prominent focal contact arrays on collagen, fibronectin, EHS and human placental laminins, but not on vitronectin, while alpha 6 beta 1 was not organized. Initial attachment and spreading of mesangial cells was absolutely dependent on divalent cations. Mg2+ and Mn2+ supported attachment on all substrates, while Ca2+ stimulated attachment on laminin (E8), fibronectin and vitronectin. The data suggest that the functional integrins on mesangial cells include alpha 1 beta 1 (on collagen and laminin) alpha 2 beta 1 (on collagen), alpha 5 beta 1 (on fibronectin) and alpha V beta 3 (on vitronectin). However, mesangial cells do not use alpha 6 beta 1 on laminin, and the data support a role for alpha 3 beta 1 as putative receptor for fibronectin, collagen and laminin.

Animals↗