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Quarterly Review of Pediatrics Nov 1958
Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Dermatologic Agents; Ristocetin
PubMed: 13602063
DOI: No ID Found -
Journal of the American Medical... Sep 1958
Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Dermatologic Agents; Ristocetin
PubMed: 13575140
DOI: No ID Found -
International Journal of Molecular... Jun 2023CXCL12, belonging to the CXC chemokine family, is a weak agonist of platelet aggregation. We previously reported that the combination of CXCL12 and collagen at low doses...
CXCL12, belonging to the CXC chemokine family, is a weak agonist of platelet aggregation. We previously reported that the combination of CXCL12 and collagen at low doses synergistically activates platelets via not CXCR7 but CXCR4, a specific receptor for CXCL12 on the plasma membrane. Recently, we reported that not Rho/Rho kinase, but Rac is involved in the platelet aggregation induced by this combination. Ristocetin is an activator of the von Willebrand factor that interacts with glycoprotein (GP) Ib/IX/V, which generates thromboxane A2 via phospholipase A2 activation, resulting in the release of the soluble CD40 ligand (sCD40L) from human platelets. In the present study, we investigated the effects of a combination of ristocetin and CXCL12 at low doses on human platelet activation and its underlying mechanisms. Simultaneous stimulation with ristocetin and CXCL12 at subthreshold doses synergistically induce platelet aggregation. A monoclonal antibody against not CXCR7 but CXCR4 suppressed platelet aggregation induced by the combination of ristocetin and CXCL12 at low doses. This combination induces a transient increase in the levels of both GTP-binding Rho and Rac, followed by an increase in phosphorylated cofilin. The ristocetin and CXCL12-induced platelet aggregation as well as the sCD40L release were remarkably enhanced by Y27362, an inhibitor of Rho-kinase, but reduced by NSC23766, an inhibitor of the Rac-guanine nucleotide exchange factor interaction. These results strongly suggest that the combination of ristocetin and CXCL12 at low doses synergistically induces human platelet activation via Rac and that this activation is negatively regulated by the simultaneous activation of Rho/Rho-kinase.
Topics: Humans; Blood Platelets; CD40 Ligand; Chemokine CXCL12; Phosphorylation; Platelet Activation; Platelet Aggregation; Platelet Glycoprotein GPIb-IX Complex; rho-Associated Kinases; Ristocetin; von Willebrand Factor; rac GTP-Binding Proteins
PubMed: 37298667
DOI: 10.3390/ijms24119716 -
Pediatria Nov 1961
Topics: Anti-Bacterial Agents; Ristocetin
PubMed: 13868485
DOI: No ID Found -
La Clinica Terapeutica Jun 1959
Topics: Anti-Bacterial Agents; Humans; Ristocetin
PubMed: 13671737
DOI: No ID Found -
European Biophysics Journal : EBJ Nov 2010Von Willebrand factor (VWF) is a large multimeric adhesive glycoprotein, with complex roles in thrombosis and hemostasis, present in circulating blood and in secretory...
Von Willebrand factor (VWF) is a large multimeric adhesive glycoprotein, with complex roles in thrombosis and hemostasis, present in circulating blood and in secretory granules of endothelial cells and platelets. High shear stress triggers conformational changes responsible for both binding to the platelet receptor glycoprotein GpIb and its self-association, thus supporting the formation of platelet plug under flow. Ristocetin also promotes the interaction of VWF with GpIb and is able to induce platelet aggregation, and thus is largely used to mimic this effect in vitro. In this research paper, we followed the time course of VWF self-association in solution induced by ristocetin binding by light scattering and at the same time we collected atomic force microscopy images to clarify the nature of the assembly that is formed. In fact, this process evolves initially through the formation of fibrils that subsequently interact to form supramolecular structures whose dimensions would be capable of trapping platelets even in the absence of any degree of shear stress or interaction with external surfaces. This intrinsic property, that is the ability to self-aggregate, may be involved in some pathological settings that have been revealed in clinical practice.
Topics: Anti-Bacterial Agents; Hemostasis; Microscopy, Atomic Force; Platelet Aggregation; Platelet Glycoprotein GPIb-IX Complex; Ristocetin; Scattering, Radiation; Shear Strength; Stress, Mechanical; von Willebrand Factor
PubMed: 20589372
DOI: 10.1007/s00249-010-0617-8 -
British Journal of Haematology Feb 1989
Topics: Humans; Methods; Platelet Aggregation; Ristocetin
PubMed: 2923818
DOI: 10.1111/j.1365-2141.1989.tb04278.x -
Antibiotics Annual
Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Dermatologic Agents; Ristocetin
PubMed: 13425450
DOI: No ID Found -
American Journal of Hematology 1976The absence of ristocetin-induced platelet aggregation appears to correlate with the platelet defect in von Willebrand's disease, suggesting that this reaction mimics a...
The absence of ristocetin-induced platelet aggregation appears to correlate with the platelet defect in von Willebrand's disease, suggesting that this reaction mimics a physiological process. The effect of ristocetin on plasma and on the residual levels of the von Willebrand factor (vWF), Factor VIII procoagulant activity, and Factor VIII-related protein in plasma after aggregation of platelet rich plasma by this agent has been studied in order to further elucidate the mechanism and requirements of this reaction. Ristocetin-induced platelet aggregation causes a consumption of vWF, Factor VIII procoagulant activity, and Factor VIII antigen from the supernatant plasma which is proportional to the number of platelets aggregated. Such a consumption of these factors does not appear to occur after aggregation by other agents. Factor VIII procoagulant activity does not appear necessary for ristocetin-induced platelet aggregation, yet is utilized in this process. These findings support the hypothesis that the molecule associated with Factor VIII procoagulant activity is carried by the molecule necessary for ristocetin-induced platelet aggregation.
Topics: Blood Platelets; Factor VIII; Platelet Aggregation; Ristocetin; von Willebrand Factor
PubMed: 1087117
DOI: 10.1002/ajh.2830010305 -
Seminars in Thrombosis and Hemostasis Oct 1975
Review
Topics: Antigens; Blood Platelets; Factor VIII; Hemostasis; Humans; Ristocetin; von Willebrand Diseases
PubMed: 798270
DOI: 10.1055/s-0028-1086118