Novel thienylacylhydrazone derivatives inhibit platelet aggregation through cyclic nucleotides modulation and thromboxane A2 synthesis inhibition

SummaryDerivatives of cyclic nucleotides were evaluated for their ability to inhibit platelet aggregation and the release reaction. Derivatives substituted in position 8 (mainly 8-Br-cyclic GMP) were more active than 3’-5’ cyclic AMP, and their relative potency in inhibiting platelet aggregation and 14C-serotonin release was comparable to that of N62-0’-dibutyryl-cyclic AMP. Compounds substituted in position 6 or 2’-0 were not effective. The active compounds, which were also tested for their ability to stimulate platelet adenylate cyclase or to inhibit cyclic AMP phosphodiesterase, did not modify the intracellular levels of cyclic AMP. Since previous animal experiments have shown that these derivatives cause less side effects than cyclic AMP and its dibutyryl derivative in animals, it is suggested that modification of the cyclophosphate molecule might make it possible to find compounds active only on platelet function without interfering with other biological systems.

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UPLC-Q-TOF/MS-Based Plasma Metabolomics to Evaluate the Effects of Aspirin Eugenol Ester on Blood Stasis in Rats

Molecules ◽

10.3390/molecules24132380 ◽

2019 ◽

Vol 24 (13) ◽

pp. 2380 ◽

Cited By ~ 3

Author(s):

Dongshuai Shen ◽

Ning Ma ◽

Yajun Yang ◽

Xiwang Liu ◽

Zhe Qin ◽

...

Keyword(s):

Platelet Aggregation ◽

Blood Viscosity ◽

Metabolic Profile ◽

Blood Stasis ◽

Thromboxane A2 ◽

Plasma Viscosity ◽

Inhibit Platelet Aggregation ◽

Underlying Mechanisms ◽

Aspirin Eugenol Ester ◽

Metabolomic Study

Aspirin eugenol ester (AEE) is a novel compound that is formed from the esterification of aspirin (acetylsalicylic acid (ASA)) and eugenol. This study aimed to investigate the effects of AEE on blood stasis in rats and to characterize the underlying mechanisms using a plasma metabolomic study. The results indicate that AEE and ASA could modulate whole blood viscosity (WBV), plasma viscosity (PV), blood coagulation parameters, platelet count, platelet aggregation, lactate dehydrogenase (LDH), creatinine (CR) and the levels of thromboxane A2 (TXA2) and 6-keto prostaglandin F1α (6-keto-PGF1α). The metabolic profiles of the plasma samples from all groups were clearly separated in the score plots. Nineteen potential metabolites were selected and identified, and disordered levels of these metabolites could be regulated by AEE and ASA. Pathway analysis showed that the mechanism of action of AEE on blood stasis might be principally related to the metabolism of amino acid, fatty acid, energy and glycerophospholipid. The above results indicate that AEE protected the rats against blood stasis, and that this effect might have been caused by the anticoagulation activity of AEE and its abilities to maintain a balance between TXA2 and PGI2, reduce blood viscosity, inhibit platelet aggregation and normalize the plasma metabolic profile.

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Novel Peptide Motifs Containing Asp-Glu-Gly Target P2Y12 and Thromboxane A2 Receptors to Inhibit Platelet Aggregation and Thrombus Formation

Journal of Agricultural and Food Chemistry ◽

10.1021/acs.jafc.1c06159 ◽

2022 ◽

Author(s):

Yijie Yang ◽

Bo Li

Keyword(s):

Platelet Aggregation ◽

Thrombus Formation ◽

Thromboxane A2 ◽

Inhibit Platelet Aggregation ◽

Peptide Motifs ◽

A2 Receptors

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Arachidonate Metabolism And Platelet Disaggregation (DA)-Reaggregation (RA)

10.1055/s-0038-1652808 ◽

1981 ◽

Author(s):

Gundu H R Rao ◽

James G White

Keyword(s):

Platelet Aggregation ◽

Adrenergic Receptors ◽

Thromboxane A2 ◽

The Other ◽

Inhibit Platelet Aggregation ◽

Activated Platelets ◽

Arachidonate Metabolism ◽

Thromboxane Synthetase ◽

Platelet Disaggregation ◽

Refractory State

Previous work has shown that platelets irreversibly aggregated by ADP or thrombin (T) can be dissociated by various agents and that the refractory state of disaggregated cells can be reversed immediately by treatment with epinephrine (E). In the present study we have evaluated the influence of drugs which affect different steps in the process of prostaglandin (PG) synthesis on platelet DA-RA. Aspirin and indomethacin did not cause DA of platelets in the process of aggregation nor did they prevent reversal of the refractory state by E and subsequent RA of previously dissociated platelets. Imidazole, which inhibits conversion of endoperoxide to thromboxane A2, also failed to influence DA or restoration of sensitvity and RA of disaggregated platelets. On the other hand, chemicals which interfere with release of AA from the membrane of activated platelets, such as mepacrine, chlorpromazine and trifluoperazine, caused rapid DA. Products of PG synthesis, such as PGE1, PGD2 and PGI2, which usually inhibit platelet aggregation, also caused rapid DA. The refractory state of platelets dissociated from aggregates by most of these agents could be reversed by E treatment. However, trifluoperazine disaggregated platelets could be reaggregated only by the combination of E and AA. Agents which block the a-adrenergic receptors did not cause dissociation of aggregating platelets, but prevented correction of the refractory state of dissociated platelets by E. Thus interference with AA release, even after aggregation, can cause DA of clumped platelets, but blockade of peroxidase, cyclo-oxygenase and thromboxane synthetase do not cause reversal once it is in progress. A membrane linked mechanism associated with AA availability, but not metabolism, regulates DA and restoration of membrane sensitivity for RA.

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GPIb is involved in platelet aggregation induced by mucetin, a snake C-type lectin protein from Chinese habu (Trimeresurus mucrosquamatus) venom

Thrombosis and Haemostasis ◽

10.1160/th03-12-0747 ◽

2004 ◽

Vol 91 (06) ◽

pp. 1168-1176 ◽

Cited By ~ 34

Author(s):

Qiumin Lu ◽

Alexei Navdaev ◽

Jeannine Clemetson ◽

Kenneth Clemetson

Keyword(s):

Platelet Aggregation ◽

Thromboxane A2 ◽

Platelet Glycoprotein ◽

Inhibit Platelet Aggregation ◽

Structural Comparison ◽

Functional Differences ◽

Aggregation Response ◽

Lectin Family ◽

Lectin Protein ◽

Induced Aggregation

SummaryMucetin (Trimeresurus mucrosquamatus venom activator, TMVA) is a potent platelet activator purified from Chinese habu (Trimeresurus mucrosquamatus) venom. It belongs to the snake venom heterodimeric C-type lectin family and exists in several multimeric forms. We now show that binding to platelet glycoprotein (GP) Ib is involved in mucetin-induced platelet aggregation. Antibodies against GPIb as well as the GPIb-blocking C-type lectin echicetin inhibited mucetin-induced platelet aggregation. Binding of GPIb was confirmed by affinity chromatography and Western blotting. Antibodies against GPVI inhibited convulxin- but not mucetin-induced aggregation. Signalling by mucetin involved rapid tyrosine phosphorylation of a number of proteins including Syk, Src, LAT and PLCγ2. Mucetininduced phosphorylation of the Fcγ chain of platelet was greatly promoted by inhibition of αIIbβ3 by the peptidomimetic EMD 132338, suggesting that phosphatases downstream of αIIbβ3 activation are involved in dephosphorylation of Fcγ. Unlike other multimeric snake C-type lectins that act via GPIb and only agglutinate platelets, mucetin activates αIIbβ3. Inhibition of αIIbβ3 strongly reduced the aggregation response to mucetin, indicating that activation of αIIbβ3 and binding of fibrinogen are involved in mucetin-induced platelet aggregation. Apyrase and aspirin also inhibit platelet aggregation induced by mucetin, suggesting that ADP and thromboxane A2 are involved in autocrine feedback. Sequence and structural comparison with closely related members of this protein family point to features that may be responsible for the functional differences.

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Platelet Activation and Aggregation Induced by Recombinant von Willebrand Factors Reproducing Four Type 2B von Willebrand Disease Missense Mutations

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614241 ◽

1998 ◽

Vol 79 (01) ◽

pp. 211-216 ◽

Cited By ~ 13

Author(s):

Lysiane Hilbert ◽

Claudine Mazurier ◽

Christophe de Romeuf

Keyword(s):

Platelet Aggregation ◽

Platelet Activation ◽

Von Willebrand Disease ◽

Platelet Glycoprotein ◽

Missense Mutations ◽

Inhibit Platelet Aggregation ◽

Wild Type ◽

A1 Domain ◽

Von Willebrand ◽

Willebrand Factor

SummaryType 2B of von Willebrand disease (vWD) refers to qualitative variants with increased affinity of von Willebrand factor (vWF) for platelet glycoprotein Ib (GPIb). All the mutations responsible for type 2B vWD have been located in the A1 domain of vWF. In this study, various recombinant von Willebrand factors (rvWF) reproducing four type 2B vWD missense mutations were compared to wild-type rvWF (WT-rvWF) for their spontaneous binding to platelets and their capacity to induce platelet activation and aggregation. Our data show that the multimeric pattern of each mutated rvWF is similar to that of WT-rvWF but the extent of spontaneous binding and the capacity to induce platelet activation and aggregation are more important for the R543Q and V553M mutations than for the L697V and A698V mutations. Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. On the other hand, EDTA and a monoclonal antibody directed against GPIIb/IIIa only inhibit platelet aggregation. Furthermore, the incubation of type 2B rvWFs with platelets, under stirring conditions, results in the decrease in high molecular weight vWF multimers in solution, the extent of which appears correlated with that of plasma vWF from type 2B vWD patients harboring the corresponding missense mutation. This study supports that the binding of different mutated type 2B vWFs onto platelet GPIb induces various degrees of platelet activation and aggregation and thus suggests that the phenotypic heterogeneity of type 2B vWD may be related to the nature and/or location of the causative point mutation.

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Inhibitory Effect of Staphylokinase on Platelet Aggregation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649679 ◽

1993 ◽

Vol 70 (05) ◽

pp. 834-837 ◽

Cited By ~ 6

Author(s):

Akira Suehiro ◽

Yoshio Oura ◽

Motoo Ueda ◽

Eizo Kakishita

Keyword(s):

Platelet Aggregation ◽

Human Platelet ◽

Degradation Products ◽

Platelet Rich Plasma ◽

Inhibitory Effect ◽

Effective Concentration ◽

Inhibit Platelet Aggregation ◽

Platelet Suspension ◽

Washed Platelet ◽

Human Platelet Aggregation

SummaryWe investigated the effect of staphylokinase (SAK), which has specific thrombolytic properties, on human platelet aggregation. Platelet aggregation induced with collagen was observed following preincubation of platelets in platelet-rich plasma (PRP) or washed platelet suspension (WP) with SAK at 37° C for 30 min. SAK inhibited platelet aggregation in PRP only at the highest examined concentration (1 x 10-4 g/ml). Although SAK did not inhibit platelet aggregation in WP which contained fibrinogen, it did when the platelets had been preincubated with SAK and plasminogen. The most effective concentration in WP was 1 x 10-6 g/ml. The effect could be inhibited by adding aprotinin or α2-antiplasmin. The highest generation of plasmin in the same preincubation fluid was detected at 1 x 10-6 g/ml SAK. We concluded that SAK can inhibit platelet aggregation in WP by generating plasmin and/or fibrinogen degradation products, but is only partially effective in PRP because of the existence of α2-antiplasmin.

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In Vitro Incorporation and Metabolism of Icosapentaenoic and Docosahexaenoic Acids in Human Platelets - Effect on Aggregation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661603 ◽

1986 ◽

Vol 56 (01) ◽

pp. 057-062 ◽

Cited By ~ 56

Author(s):

Martine Croset ◽

M Lagarde

Keyword(s):

Arachidonic Acid ◽

Fatty Acid ◽

Platelet Aggregation ◽

Fatty Acid Distribution ◽

Thromboxane A2 ◽

Human Platelets ◽

Aggregation Response ◽

Docosahexaenoic Acids ◽

Membrane Level

SummaryWashed human platelets were pre-loaded with icosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or EPA + DHA and tested for their aggregation response in comparison with control platelets. In fatty acid-rich platelets, an inhibition of the aggregation could be observed when induced by thrombin, collagen or U-46619. The strongest inhibition was observed with DHA-rich platelets and it was reduced when DHA was incorporated in the presence of EPA.Study of fatty acid distribution in cell lipids after loading showed that around 90% of EPA or DHA taken up was acylated into phospholipids and a very small amount (less than 2%) remained in their free and hydroxylated forms. DHA was more efficiently acylated into phosphatidylethanolamine (PE) than into phosphatidylinositol (PI) in contrast to what observed with EPA, and both acids were preferentially incorporated into phosphatidylcholine (PC). EPA inhibited total incorporation of DHA and increased its relative acylation into PE at the expense of PC. In contrast, DHA did not affect the acylation of EPA. Upon stimulation with, thrombin, EPA was liberated from phospholipids and oxygenated (as judged by the formation of its monohydroxy derivative) whereas DHA was much less metabolized, although consistently transferred into PE.It is concluded that EPA and DHA might affect platelet aggregation via different mechanisms when pre-loaded in phospholipids. Whereas EPA is known to alter thromboxane A2 metabolism from endogenous arachidonic acid, by competing with it, DHA might act directly at the membrane level for inhibiting aggregation.

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