Cloning of the human platelet F11 receptor: a cell adhesion molecule member of the immunoglobulin superfamily involved in platelet aggregation

Blood ◽  
2000 ◽  
Vol 95 (8) ◽  
pp. 2600-2609 ◽  
Author(s):  
Malgorzata B. Sobocka ◽  
Tomasz Sobocki ◽  
Probal Banerjee ◽  
Cipora Weiss ◽  
Julie I. Rushbrook ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Platelet Aggregation ◽  
Membrane Protein ◽  
Adhesion Molecule ◽  
Platelet Adhesion ◽  
Human Platelet ◽  
Physiological Role ◽  
Immunoglobulin Superfamily ◽  
Predicted Amino Acid Sequence ◽  
Platelet Surface

Abstract This study demonstrates that the human platelet F11 receptor (F11R) functions as an adhesion molecule, and this finding is confirmed by the structure of the protein as revealed by molecular cloning. The F11R is a 32-/35-kd protein duplex that serves as the binding site through which a stimulatory monoclonal antibody causes platelet aggregation and granule secretion. A physiological role for the F11R protein was demonstrated by its phosphorylation after the stimulation of platelets by thrombin and collagen. A pathophysiological role for the F11R was revealed by demonstrating the presence of F11R-antibodies in patients with thrombocytopenia. Adhesion of platelets through the F11R resulted in events characteristic of the action of cell adhesion molecules (CAMs). To determine the structure of this protein, we cloned the F11R cDNA from human platelets. The predicted amino acid sequence demonstrated that it is an integral membrane protein and an immunoglobulin superfamily member containing 2 extracellular C2-type domains. The structure of the F11R as a member of a CAM family of proteins and its activity in mediating adhesion confirm each another. We conclude that the F11R is a platelet-membrane protein involved in 2 distinct processes initiated on the platelet surface. The first is antibody-induced platelet aggregation and secretion that are dependent on both the FcγRII and the GPIIb/IIIa integrin and that may be involved in pathophysiological processes associated with certain thrombocytopenias. The second is an F11R-mediated platelet adhesion that is not dependent on either the FcγRII or the fibrinogen receptor and that appears to play a role in physiological processes associated with platelet adhesion and aggregation.

Cloning of the human platelet F11 receptor: a cell adhesion molecule member of the immunoglobulin superfamily involved in platelet aggregation

Blood ◽  
2000 ◽  
Vol 95 (8) ◽  
pp. 2600-2609
Author(s):  
Malgorzata B. Sobocka ◽  
Tomasz Sobocki ◽  
Probal Banerjee ◽  
Cipora Weiss ◽  
Julie I. Rushbrook ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Platelet Aggregation ◽  
Membrane Protein ◽  
Adhesion Molecule ◽  
Platelet Adhesion ◽  
Human Platelet ◽  
Physiological Role ◽  
Immunoglobulin Superfamily ◽  
Predicted Amino Acid Sequence ◽  
Platelet Surface

This study demonstrates that the human platelet F11 receptor (F11R) functions as an adhesion molecule, and this finding is confirmed by the structure of the protein as revealed by molecular cloning. The F11R is a 32-/35-kd protein duplex that serves as the binding site through which a stimulatory monoclonal antibody causes platelet aggregation and granule secretion. A physiological role for the F11R protein was demonstrated by its phosphorylation after the stimulation of platelets by thrombin and collagen. A pathophysiological role for the F11R was revealed by demonstrating the presence of F11R-antibodies in patients with thrombocytopenia. Adhesion of platelets through the F11R resulted in events characteristic of the action of cell adhesion molecules (CAMs). To determine the structure of this protein, we cloned the F11R cDNA from human platelets. The predicted amino acid sequence demonstrated that it is an integral membrane protein and an immunoglobulin superfamily member containing 2 extracellular C2-type domains. The structure of the F11R as a member of a CAM family of proteins and its activity in mediating adhesion confirm each another. We conclude that the F11R is a platelet-membrane protein involved in 2 distinct processes initiated on the platelet surface. The first is antibody-induced platelet aggregation and secretion that are dependent on both the FcγRII and the GPIIb/IIIa integrin and that may be involved in pathophysiological processes associated with certain thrombocytopenias. The second is an F11R-mediated platelet adhesion that is not dependent on either the FcγRII or the fibrinogen receptor and that appears to play a role in physiological processes associated with platelet adhesion and aggregation.

Differential Ability of Agonists to Express Distinct Pools of Fibrinogen (Gpllb/llla) Receptors which Can Mediate the Aggregation of Human Platelets

1989 ◽  
Vol 62 (03) ◽  
pp. 955-961 ◽  
Author(s):  
Ian S Watts ◽  
Rebecca J Keery ◽  
Philip Lumley
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Surface Membrane ◽  
Blood Platelet ◽  
Human Platelets ◽  
Membrane Glycoprotein ◽  
Platelet Surface ◽  
Human Platelet Aggregation ◽  
Differential Ability ◽  
Blood Platelet Aggregation

SummaryWe have investigated the effect of two procedures that modify human platelet surface membrane glycoprotein (Gp) IIb and IIIa complexes upon whole blood platelet aggregation to a range of agonists. (A) Irreversible disruption of complexes by temporary (30 min) Ca2+-deprivation with EGTA at 37° C. (B) Binding of a monoclonal antibody M148 to the complex. EGTA exposure abolished aggregation to ADP, adrenaline and PAF. In contrast, full aggregation curves to collagen and U-46619 could still be established. EGTA exposure reduced M148 binding to platelets by 80%. Excess M148 abolished aggregation to ADP, PAF, collagen and U-46619. However, upon removal of unbound antibody from platelets full aggregation curves to collagen and U-46619 but not to ADP and PAF could be re-established. Thus human platelet aggregation to ADP, PAF and adrenaline appears absolutely dependent upon surface membrane GpIIb/IIIa complexes. In contrast, collagen and U-46619 cause expression of an additional distinct pool of Gp complexes inaccessible to EGTA and M148 in unstimulated platelets which is intimately involved in aggregation to these agonists.

ROLE OF PLATELET GLYCOPROTEINS lb AND llb/llla IN TUMOR CELL INDUCED PLATELET AGGREGATION AND TUMOR CELL ADHESION TO EXTRACELLULAR MATRIX. I. Grossi

1987 ◽  
Author(s):  
L Grossi ◽  
K V Honn ◽  
B F Sloane ◽  
J Thomopson ◽  
D Ohannesian ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Adhesion ◽  
Platelet Aggregation ◽  
Tumor Cell ◽  
Platelet Adhesion ◽  
Eicosatetraenoic Acid ◽  
Platelet Glycoprotein ◽  
Dependent Manner ◽  
Tumor Cell Adhesion ◽  
Dose Dependent

Platelet glycoproteins are known to play a role in platelet platelet interactions, platelet activation, and platelet adhesion to extracellular matrix (ECM). Monoclonal antibody to human platelet glycoprotein lb (mAblb) and polyclonal antibodies to the llb/llla complex (pAbllb/llla) were used to evaluate the involvement of these glycoproteins in tumor cellinduced platelet aggregation (TCIPA and tumor cell adhesion to the ECM. We have demonstrated that human cervical carcinoma (MS5I7), human colon carcinoma (Clone A), and rat Walker 256 carcinosarcoma (W256) cells induce aggregation of homologous platelets via thrombin generation. MAblb and pAbllb/llla were shown to inhibit TCIPA by MS517, Clone A, and W256 in a dose dependent manner. MAblb was also shown to inhibit platelet thromboxane B2 production in response to tumor cells in a dose dependent manner. Neither mAblb nor pAbllb/llla had any effect on ADP stimulated platelet aggregation. Concentrations of mAblb and pAbllb/llla which produced half maximal inhibition alone were combined resulting in complete inhibition of TCIPA. Preincubation of MS5I7 and W256 with mAblb also resulted in inhibition of TCIPA, while preincubation of Clone A with mAblb did not, suggesting the presence of this glycoprotein on the cell membranes of MS5I7 and W256, but not on Clone A. Immunofluorescence studies confirmed the presence of this glycoprotein on the cell plasma membrane of the MS5I7 and W256, but not on Clone A. Preincubation of MS5I7 and W256 with both mAblb and pAbllb/llla alone or in combination, also resulted in decreased (12S)-12 -hydroxy -5, 8,10, 14 -eicosatetraenoic acid (12-HETE) production, while platelets preincubated with these antibodies had no effect on the concentration of 12-HETE produced. Isolation of platelet membranes and released platelet contentswere tested separately and in combination on platelet adhesion to ECM. Platelet release factors were ineffective, while isolated platelet membrane ghosts enhanced adhesion. Disruption of the platelet cytoskeleton andinhibition of the formation of the llb/llla complex decreased platelet enhanced tumor cell adhesion. These findings suggest a role for these platelet glycoproteins in TCIPA, platelet enhanced tumor cell adhesion to ECM and subsequent tumor metastasis.

Collagen Coated Gelatine Tubes for the Investigation of Platelet Adhesion and Subsequent Platelet Aggregation Under Controlled flow Conditions

1975 ◽  
Author(s):  
R. Muggli ◽  
H. R. Baumgartner
Keyword(s):  
Platelet Aggregation ◽  
Platelet Adhesion ◽  
Surface Coverage ◽  
Neutral Salt ◽  
Flow Conditions ◽  
Platelet Surface ◽  
Perfusion Chamber ◽  
Artificial Surface ◽  
Platelet Thrombi ◽  
Controlled Flow

Aggregometer studies do not discriminate between platelet adhesion and platelet aggregation. Therefore, we prepared a homogenous collagen surface which could be exposed to whole blood in a perfusion chamber under controlled flow conditions.Artificial “vessel” segments were prepared by dipping glass rods into 20% gelatine and, after air-drying, cross-linking the gelatine in 2.5% glutaraldehyde. Segments of 1 cm length were then drawn on the rod of the perfusion chamber and coated with 300 μl of neutral salt soluble collagen (2.2 mg/ml). Surface coverage with collagen was virtually complete (96%–100%).Uncoated or collagen-coated gelatine segments were exposed to citrated rabbit blood for periods up to 40 min. Platelet-surface interaction was evaluated morphometrically. On uncoated segments surface coverage with platelets amounted to 31% and 50% after 10 min and 40 min (the corresponding ratios of contact/spread platelets were 2.6 and 1.5). Only 0.1% thrombi were found. On collagen-coated segments surface coverage with platelets amounted to 57% and 83% after 10 min and 40 min (the corresponding ratios of contact/ spread platelets were 0.1 and 0.0); platelet thrombi were found on 33% and 42% of the surface after 10 min and 40 min.Platelet adhesion and subsequent aggregation on the collagen-coated artificial surface is similar to that observed on α-chymotrypsin digested subendothelium. The results suggest that fibrillar collagen triggers rapid spreading on a surface, a reaction which is closely associated with the formation of platelet thrombi. The latter phenomenon is thought to be caused by the release of aggregating agents from the spreading platelets.

Axonal cell-adhesion molecule L1 in CNS myelination

2004 ◽  
Vol 1 (1) ◽  
pp. 65-72 ◽  
Author(s):  
G. BARBIN ◽  
M.S. AIGROT ◽  
P. CHARLES ◽  
A. FOUCHER ◽  
M. GRUMET ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Culture Medium ◽  
Immunoglobulin Superfamily ◽  
Map Kinase Pathway ◽  
Cell Adhesion Molecule L1 ◽  
Cns Myelination ◽  
Kinase Pathway

Of the axonal signals influencing myelination, adhesion molecules expressed at the axonal surface are strong candidates to mediate interactions between myelinating cells and axons. The recognition cell-adhesion molecule L1, a member of the immunoglobulin superfamily has been shown to play important roles in neuronal migration and survival, and in PNS myelination. We have investigated the role of axonally expressed L1 in CNS myelination. In co-cultures of myelinating oligodendrocytes and neurons derived from murine brain, we demonstrate that, before myelination, L1 immunoreactivity is confined to neurites. After myelination commences, L1 expression is downregulated on myelinated axons and adjacent, but not yet myelinated, internodes. Interfering with L1 before the onset of myelination, by adding either anti-L1 antibody or L1-Fc fusion proteins to the culture medium, inhibits myelination. In addition, in purified cultures of oligodendrocytes, L1-Fc fusion protein prevents lysophosphatidic acid-induced activation of the mitogen-activated kinase (MAP)-kinase pathway. Together, our data indicate that L1 is involved in the initiation of CNS myelination, and that this effect might involve the dephosphorylation of oligodendroglial phosphoproteins.

Junctional Adhesion Molecule a Helps Maintain Integrin αIIbβ3 in Resting State

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 111-111 ◽  
Author(s):  
Meghna Ulhas Naik ◽  
Timothy J. Stalker ◽  
Lawrence F. Brass ◽  
Ulhas Pandurang Naik
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Adhesion Molecule ◽  
Resting State ◽  
Human Platelets ◽  
Artery Occlusion ◽  
In Vivo Model ◽  
Platelet Surface ◽  
Integrin Αiibβ3

Abstract Under physiological conditions, fibrinogen receptor integrin αIIbβ3 on the circulating platelets is in a low-affinity, or resting state, unable to bind soluble ligands. During platelet activation by agonists, a cascade of signaling events induces a conformational change in the extracellular domain of αIIbβ3, thereby converting it into a high-affinity state capable of binding ligands through a process known as “inside-out signaling”. What maintains this integrin in a low-affinity state is not well understood. We have previously identified JAM-A, junctional adhesion molecule A, on the platelet surface. We have shown that an antibody blockade of JAM-A dose-dependently activates platelets. To understand the molecular mechanism through which JAM-A regulates platelet aggregation, we used Jam-A null mice. Interestingly, the mouse bleeding times were significantly shortened in Jam-A null mice compared to wildtype littermates. Furthermore, the majority of these mice showed a rebleeding phenotype. This phenotype was further confirmed by FeCl3-induced carotid artery occlusion, a well-accepted in vivo model for thrombosis. Platelets derived from Jam-A-null mice were used to evaluate the role of JAM-A in agonist-induced platelet aggregation. We found that Jam-A null platelets showed enhanced aggregation in response to physiological agonists such as PAR4 peptide, collagen, and ADP as compared to platelets from wildtype littermates. JAM-A was found to associate with αIIbβ3 in unactivated human platelets, but this association was disrupted by both agonist-induced platelet aggregation and during outside-in signaling initiated upon platelet spreading on immobilized Fg. We also found that in resting platelets, JAM-A is phosphorylated on a conserved tyrosine 280 in its cytoplasmic domain, which was dephosphorylated upon platelet activation. Furthermore, JAM-A is rapidly and transiently phosphorylated on serine 284 residue during platelet activation by agonists. Interestingly, JAM-A also formed a complex with Csk, a tyrosine kinase known to be inhibitory to Src activation, in resting platelets. This complex was dissociated upon activation of platelets by agonists. These results suggest that tyrosine-phosphorylated JAM-A recruits Csk to αIIbβ3 in resting platelets, thus maintaining a low-affinity state of integrin αIIbβ3. Agonist–induced activation of platelets results in rapid dephosphorylation of JAM-A on Y280 and phosphorylation on S284 residues. This causes dissociation of JAM-A from integrin αIIbβ3 facilitating platelet aggregation.

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