THE ARG-GLY-ASP(SER) SEQUENCE OF FIBRONECTIN, AND THE GLYCOPROTEIN IIB-IIIA COMPLEX ARE NOT INVOLVED IN FIBRONECTIN DEPENDENT PLATELET ADHESION IN FLOW

1987 ◽  
Author(s):  
P F E M Nievelstein ◽  
M Ottenhof-Rovers ◽  
M D Pierschbacher ◽  
J J Sixma

Activated blood platelets interact with fibronectin through it to the glycoprotein IIb-IIIa(GPIIb-IIIa)-complex. The cell attachment site of fibronectin with its crucial arg-gly-asp-(-ser) (RGD(S))sequence is involved in this binding. We have studied the importance of this interaction for the fibronectin dependence of platelet adhesion under flow conditions. An RGDS-containing hexapeptide (GRGDSP) was compared with a non-reactive control peptide (GRGESP). The GRGDSP-peptide inhibited thrombin induced aggregation and adhesion under static conditions at 0.1 mM. This concentration had no effect on platelet adhesion to nonfibrillar collagen type I in flow. GRGDSP at 1 mM had a significant inhibitory effect at 1500 s™1 (8.8 ± 1.4 111In platelets* 105 /cm2, versus 19.8 ± 0.5 for the control). At lower shear rates of 800 and 300 s™1 , where platelet adhesion is also fibronectin dependent, no significant differences were obtained (respectively 11.7 ± 1.1 versus 15.2 ± 2.1, and 11.4 ± 1.0 versus 13.1 ± 0.7).The relation between GPIIb-IIIa and fibronectin dependence was investigated with platelets of a patient with Glanzmann’s thrombasthenia and monoclonal antibodies to GPIIb-IIIa, using endothelial cell matrix (ECM) as a surface. Platelets of normal controls or a patient with Glanzmann’s thrombasthenia showed a inhibition of adhesion in fibronectin free plasma, after the ECM had been preincubated with anti-fibronectin F(ab’)2, of respectively _J5 and 30 percent at 300 s™1 , and 43 and 65 percent at 1300 s™1 . Incubation of platelets with anti GPIIb-IIIa showed inhibition of platelet adhesion at high shear rates. Dependence on fibronectin for platelet adhesion was still observed, even though separate experiments had shown that these anti GPIIb-IIIa antibodies could block binding of radiolabeled fibronectin to thrombin activated platelets. These data suggest the existence of a second binding system from the RGD/GPIIb-IIIa system separate for the interaction of platelets with fibronectin, which may only function when fibronectin is present on a surface.

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 82-88
Author(s):  
PF Nievelstein ◽  
JJ Sixma

Previous studies have indicated that activated blood platelets interact with fibronectin through binding of fibronectin to the glycoprotein IIb- IIIa complex (GPIIb-IIIa). The cell attachment site of fibronectin with its crucial arg-gly-asp(-ser) [RGD(S)]sequence is involved in these bindings. We studied the importance of these interactions for the fibronectin dependence of platelet adhesion under flow conditions. An RGDS-containing hexapeptide (GRGDSP) was compared with a nonreactive control peptide (GRGESP). The GRGDSP-peptide inhibited thrombin-induced aggregation and adhesion under static conditions at 0.1 mmol/L. This concentration had no effect on platelet adhesion to nonfibrillar collagen type I in flow. GRGDSP at 1 mmol/L had a significant inhibitory effect at 1,500 s-1, but not at the lower shear rates of 800 and 300 s-1 where platelet adhesion is also fibronectin dependent. On the matrix of cultured human umbilical vein endothelial cells, 1 mmol/L GRGDSP had no effect on platelet adhesion. The relation between GPIIb- IIIa and fibronectin dependence was investigated with platelets of a patient with Glanzmann's thrombasthenia and monoclonal antibodies to GPIIb-IIIa using endothelial cell matrix (ECM) as a surface. Platelets of normal controls or a patient with Glanzmann's thrombasthenia showed a similar inhibition of adhesion in the presence of fibronectin-free plasma after the ECMs had been preincubated with antifibronectin F(ab')2 fragments. Incubation of platelets with anti-GPIIb-IIIa showed inhibition of platelet adhesion at high shear rates. Dependence on fibronectin for platelet adhesion was still observed even though separate experiments had shown that these anti-GPIIb-IIIa antibodies could block binding of radiolabeled fibronectin to thrombin-activated platelets. These data suggest the existence of another binding system for the interaction of platelets with fibronectin that may only appear when fibronectin is present on a surface.


Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 82-88 ◽  
Author(s):  
PF Nievelstein ◽  
JJ Sixma

Abstract Previous studies have indicated that activated blood platelets interact with fibronectin through binding of fibronectin to the glycoprotein IIb- IIIa complex (GPIIb-IIIa). The cell attachment site of fibronectin with its crucial arg-gly-asp(-ser) [RGD(S)]sequence is involved in these bindings. We studied the importance of these interactions for the fibronectin dependence of platelet adhesion under flow conditions. An RGDS-containing hexapeptide (GRGDSP) was compared with a nonreactive control peptide (GRGESP). The GRGDSP-peptide inhibited thrombin-induced aggregation and adhesion under static conditions at 0.1 mmol/L. This concentration had no effect on platelet adhesion to nonfibrillar collagen type I in flow. GRGDSP at 1 mmol/L had a significant inhibitory effect at 1,500 s-1, but not at the lower shear rates of 800 and 300 s-1 where platelet adhesion is also fibronectin dependent. On the matrix of cultured human umbilical vein endothelial cells, 1 mmol/L GRGDSP had no effect on platelet adhesion. The relation between GPIIb- IIIa and fibronectin dependence was investigated with platelets of a patient with Glanzmann's thrombasthenia and monoclonal antibodies to GPIIb-IIIa using endothelial cell matrix (ECM) as a surface. Platelets of normal controls or a patient with Glanzmann's thrombasthenia showed a similar inhibition of adhesion in the presence of fibronectin-free plasma after the ECMs had been preincubated with antifibronectin F(ab')2 fragments. Incubation of platelets with anti-GPIIb-IIIa showed inhibition of platelet adhesion at high shear rates. Dependence on fibronectin for platelet adhesion was still observed even though separate experiments had shown that these anti-GPIIb-IIIa antibodies could block binding of radiolabeled fibronectin to thrombin-activated platelets. These data suggest the existence of another binding system for the interaction of platelets with fibronectin that may only appear when fibronectin is present on a surface.


1995 ◽  
Vol 73 (05) ◽  
pp. 756-762 ◽  
Author(s):  
Yoshiaki Tomiyama ◽  
Hirokazu Kashiwagi ◽  
Satoru Kosugi ◽  
Masamichi Shiraga ◽  
Yoshio Kanayama ◽  
...  

SummaryWe analyzed the molecular genetic defect responsible for type I Glanzmann’s thrombasthenia in a Japanese patient. In an immunoblot assay using polyclonal anti-GPIIb-IIIa antibodies, some GPIIIa (15% of normal amount) could be detected in the patient’s platelets, whereas GPIIb could not (<2% of normal amount). Nucleotide sequence analysis of platelet GPIIb mRNA-derived polymerase chain reaction (PCR) products revealed that patient’s GPIIb cDNA had a 75-bp deletion in the 3’ boundary of exon 17 resulting in an in-frame deletion of 25 amino acids. DNA analysis and family study revealed that the patient was a compound heterozygote of two GPIIb gene defects. One allele derived from her father was not expressed in platelets, and the other allele derived from her mother had a 9644C → T mutation which was located at the position -3 of the splice donor junction of exon 17 and resulted in a termination codon (TGA). Moreover, quantitative analysis demonstrated that the amount of the abnormal GPIIb transcript in the patient’s platelets was markedly reduced. Thus, the C → T mutation resulting in the abnormal splicing of GPIIb transcript and the reduction in its amount is responsible for Glanzmann’s thrombasthenia.


1983 ◽  
Vol 49 (03) ◽  
pp. 182-186
Author(s):  
G T E Zonneveld ◽  
E F van Leeuwen ◽  
A Sturk ◽  
J W ten Cate

SummaryQuantitative glycoprotein (GP) analysis of whole platelets or platelet membranes was performed by SDS-polyacrylamide gelelectrophoresis (SDS-PAGE) and periodic acid Schiff staining in the families of two unrelated Glanzmann’s thrombasthenia (GT) patients. Each family consisted of two symptom free parents, a symptom free daughter and a GT daughter. All symptom free members had a normal bleeding time, clot retraction and platelet aggregation response to adenosine 5’-diphosphate (ADP), collagen and adrenalin. Platelet Zw* antigen was normally expressed in these subjects. GT patiens, classified as a type I and II subject, showed reduced amounts of GP lib and of GP nia. Analysis of isolated membranes in the non-reduced state, however, showed that the amount of GP Ilia was also reduced in three of the four parents, whereas one parent (of the GT type I patient) and the two unaffected daughters had normal amounts of GP Ilia. Quantitative SDS-PAGE may therefore provide a method for the detection of asymptomatic carriers in GT type I and II.


Blood ◽  
1997 ◽  
Vol 90 (4) ◽  
pp. 1516-1526 ◽  
Author(s):  
Renata Polanowska-Grabowska ◽  
Carl G. Simon ◽  
Rocco Falchetto ◽  
Jeffrey Shabanowitz ◽  
Donald F. Hunt ◽  
...  

Phosphorylation/dephosphorylation events in human blood platelets were investigated during their adhesion to collagen under flow conditions. Using 32P-labeled platelets and one-dimensional gel electrophoresis, we found that adhesion to collagen mediated primarily by the α2β1 integrin resulted in a strong dephosphorylation of several protein bands. Neither adhesion to polylysine nor thrombin-induced aggregation caused similar protein dephosphorylation. In addition, treatment with okadaic acid (OA), an inhibitor of serine/threonine protein phosphatases type 1 (PP1) and 2A (PP2A), caused significant inhibition of adhesion, suggesting that adhesion is regulated by OA-sensitive phosphatases. Recent studies indicate that phosphatases may be associated with the heat-shock proteins. Immunoprecipitations with antibodies against either the heat-shock cognate protein 70 (hsc70) or heat-shock protein 90 (hsp90) showed the presence of a phosphoprotein complex in 32P-labeled, resting human platelets. Antibody probing of this complex detected hsc70, hsp90, two isoforms of the catalytic subunit of PP1, PP1Cα and PP1Cδ, as well as the M regulatory subunit of PP1 (PP1M). OA, at concentrations that markedly blocked platelet adhesion to collagen, caused hyperphosphorylation of the hsc70 complex. In platelets adhering to collagen, hsc70 was completely dephosphorylated and hsp90, PP1α, and PP1M were dissociated from the complex, suggesting involvement of heat-shock proteins and protein phosphatases in platelet adhesion.


1999 ◽  
Vol 105 (2) ◽  
pp. 523-531 ◽  
Author(s):  
Jian Ruan ◽  
Markus Schmugge ◽  
Kenneth J. Clemetson ◽  
Eric Cazes ◽  
Robert Combrie ◽  
...  

Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 669-677 ◽  
Author(s):  
Marie-Christine Morel-Kopp ◽  
Cécile Kaplan ◽  
Valérie Proulle ◽  
Vincent Jallu ◽  
Chantal Melchior ◽  
...  

Abstract Glanzmann's thrombasthenia (GT) is a recessive autosomal bleeding disorder characterized by abnormal platelet aggregation due to a qualitative or quantitative defect of the glycoprotein (GP) IIb-IIIa complex (integrin αIIbβ3). We describe a new mutation in the GPIIIa gene responsible for type I GT in a consanguineous Algerian family. A discordance between phenotyping and genotyping of the GPIIIa-related HPA-1 platelet alloantigen system in three family members heterozygous for the disease suggested a genetic defect in the GPIIIa gene and a normal GPIIb gene. Sequence analysis of amplified genomic DNA fragments showed a 6-bp deletion in exon 7 of the GPIIIa gene resulting in the amino acid deletion/substitution (Ile325Pro326Gly327 → Met) and creating a new BspHI restriction site. Expression of the mutated integrin β3 subunit cDNA in Chinese hamster ovary cells showed that the cDNA gene was transcribed into a full-length β3 protein with an apparent molecular weight identical to wild-type β3 and accumulated as a single-chain molecule in the cell cytoplasm. The absence of heterodimeric complex formation of the mutant β3 protein with endogeneous αv was shown by immunoprecipitation experiments, intracellular immunofluorescent labeling, and a semiquantitative enzyme-linked immunosorbent assay using the αvβ3 complex-specific monoclonal antibodies LM609 and 23C6. Substitution of the methionine residue by a proline, present at position 326 of wild-type β3, did not restore the ability of the recombinant mutant β3 protein to associate with αv, suggesting that the Ile-Pro-Gly motif is located in a β3 domain important for integrin subunit interaction. The association of a BspHI restriction site with this newly identified mutation has allowed allele-specific restriction analysis of Algerian GT individuals and the identification of two new unrelated type I patients exhibiting the same mutation, suggesting that the described mutation might be significant in this population and that BspHI restriction analysis will provide a useful screening assay for antenatal diagnosis and genetic counselling.


1979 ◽  
Author(s):  
E.F. von Leeuwen ◽  
G.T.E. Zonneveld ◽  
L.E. von Riesz ◽  
C.S.P Jenkins ◽  
J.A. van Mourik ◽  
...  

The expression of the platelet-speciftc alloantigens on the platelets from 6 patients with Glanzmann’s Thrombasthenia (G.T.) and their nearest relatives was studied. The alloantigens Zwa (PIAl) and Zwb(PIA2) were found to be completely absent from thrombasthenic platelets while the alloantigens of the Ko-system were found to be normally expressed. The alloantigen Baka(phenotypefrequency 90.2%) was absent on the platelets from 4 studied G.T. patients. The platelets of all the family members reacted positively with anti-Zwa, negatively with antt-Zwb serum. SDS-PA gel electrophoresis of G.T. platelet membranes demonstrated a marked deficiency of the glycoproteins IIb and IIIa. Glycoprotein analysis of the platelet membranes from the family members of 3 of the 6 patients reveoled no apparent abnormalities.Pre-incubation with anti-Zwa containing plasma strongly inhibits ADP-and collagen induced aggregation of platelets from normal Zwa homozygous individuols with a slight inhibition of the aggregation induced by ristocetin. Zwa antibodies did not affect the functions of platelets from ZWb homozygous individuals. Thus binding of Zwa antibodies induces a thrombosthenis-like state.


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