Importance of Platelet Phospholipase Cγ2 Signaling in Arterial Thrombosis as a Function of Lesion Severity

Nonne, Christelle; Lenain, Nadège; Hechler, Béatrice; Mangin, P; Cazenave, Jean‐Pierre; Gachet, Christian; Lanza, François

doi:10.1161/01.atv.0000163184.02484.69

Cited by 81 publications

(94 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This decrease is in accord with the observation that thrombin inhibition similarly decreased platelet accumulation in a related, but not identical laser-induced model of thrombosis in mesenteric arterioles, at least after severe injuries (12). More importantly, it suggests that prevention of platelet activation by thrombin as opposed to simply prevention of thrombin-mediated fibrin deposition might account for the effects of thrombin inhibition in these models.…”

Section: Discussionsupporting

confidence: 82%

Par4 is required for platelet thrombus propagation but not fibrin generation in a mouse model of thrombosis

Vandendries

Hamilton

Coughlin

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

159

168

View full text Add to dashboard Cite

Thrombin, a central mediator of hemostasis and thrombosis, converts fibrinogen to fibrin and is a potent platelet activator. Activated platelets provide a surface for assembly of the tenase and prothrombinase complexes required for thrombin generation. The role of thrombin-induced platelet activation in platelet accumulation and its interplay with fibrin deposition during thrombus assembly has not been fully defined. We studied these processes during laser-induced thrombus formation by using real-time digital fluorescence microscopy in mice lacking protease-activated receptor-4 (Par4), which is necessary for thrombin responsiveness in mouse platelets. Juxtamural platelet accumulation immediately after laser injury was not different in wild-type and Par4 ؊/؊ mice. However, subsequent growth of platelet thrombi was markedly diminished in Par4 ؊/؊ mice. At the time of maximal thrombus size in wild type, platelet accumulation was more than 10-fold higher in wild type than in Par4 ؊/؊ mice. P-selectin expression, a marker of platelet activation, was reduced and delayed in Par4 ؊/؊ thrombi. In contrast to platelet activation and accumulation, the rate and amount of fibrin deposition, predominantly intramural and juxtamural in this model, were indistinguishable in Par4 ؊/؊ and wild-type mice. These results suggest that platelet activation by thrombin is necessary for normal propagation of a platelet thrombus at a distance from the injured vessel wall and hence for normal thrombus growth. However, platelet activation by thrombin is unnecessary for initial and limited accumulation of platelets at or near the vessel wall, and this limited accumulation of platelets and/or platelet-independent mechanism(s) of thrombin generation are sufficient for normal fibrin deposition in this model. blood coagulation ͉ intravital microscopy ͉ P-selectin

show abstract

Section: Discussionsupporting

confidence: 82%

Par4 is required for platelet thrombus propagation but not fibrin generation in a mouse model of thrombosis

Vandendries

Hamilton

Coughlin

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

159

168

View full text Add to dashboard Cite

show abstract

“…Typically 1 or 2 pulses were required to induce vessel wall injury. The magnitude of injury as performed was comparable to the severe laser injury models described by others (32,33), but distinct from the superficial or moderate injuries of the same groups. Multiple thrombi were studied in a single mouse, with new thrombi formed upstream of earlier thrombi to avoid any contribution from thrombi generated earlier in the animal under study.…”

Section: Methodssupporting

confidence: 69%

A critical role for extracellular protein disulfide isomerase during thrombus formation in mice

et al. 2008

View full text Add to dashboard Cite

Thiol isomerases, including protein disulfide isomerase (PDI), catalyze disulfide oxidation, reduction, and isomerization, thereby playing an important role in protein synthesis. To determine whether extracellular PDI mediates thrombus formation in an animal model, PDI expression, platelet accumulation, and fibrin generation were monitored in the blood vessels of mice by intravital fluorescence microscopy following laser-induced arteriolar injury. A time-dependent increase in PDI was observed in murine thrombi following injury. Infusion of the PDI inhibitor bacitracin or a blocking monoclonal antibody against PDI inhibited platelet thrombus formation and fibrin generation. Fibrin deposition is normal in mice lacking the G protein-coupled platelet receptor Par4, although there is no stable accumulation of platelets. Infusion of monoclonal antibodies against PDI into the circulation of Par4 -/-mice prior to vessel wall injury inhibited fibrin generation. These results indicate that PDI is required in vivo in mice for both fibrin generation and platelet thrombus formation.

show abstract

“…37 Platelet behavior was monitored in real time under a fluorescent microscope in which both murine and human platelets were labeled with moAbs against murine GPIb␤ and human GPIIb/IIIa conjugated with Alexa 488 and PE, respectively, before perfusion over the collagen surface. When mixed with NOD/SCID mouse PB, human platelets, representing 5% of the total platelet population, incorporated in the thrombi formed at wall shear rates of 1500 seconds Ϫ1 (supplemental Video 1, available on the Blood website; see the Supplemental Materials link at the top of the online article).…”

Section: Human Platelets Can Incorporate Into Mouse Thrombi During Pementioning

confidence: 99%

Human platelets produced in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice upon transplantation of human cord blood CD34+ cells are functionally active in an ex vivo flow model of thrombosis

Salles¹,

Thijs²,

Brunaud

et al. 2009

Blood

View full text Add to dashboard Cite

Xenotransplantation systems have been used with increasing success to better understand human hematopoiesis and thrombopoiesis. In this study, we demonstrate that production of human platelets in nonobese diabetic/severe combined immunodeficient mice after transplantation of unexpanded cord-blood CD34 ؉ cells was detected within 10 days after transplantation, with the number of circulating human platelets peaking at 2 weeks (up to 87 ؋ 10 3 /L). This rapid human platelet production was followed by a second wave of platelet formation 5 weeks after transplantation, with a population of 5% still detected after 8 weeks, attesting for long-term engraftment. Platelets issued from human hematopoietic stem cell progenitors are functional, as assessed by increased CD62P expression and PAC1 binding in response to collagenrelated peptide and thrombin receptoractivating peptide activation and their ability to incorporate into thrombi formed on a collagen-coated surface in an ex vivo flow model of thrombosis. This interaction was abrogated by addition of inhibitory monoclonal antibodies against human glycoprotein Ib␣ (GPIb␣) and GPIIb/IIIa. Thus, our mouse model with production of human platelets may be further explored to study the function of genetically modified platelets, but also to investigate the effect of stimulators or inhibitors of human thrombopoiesis in vivo. (Blood. 2009;114:5044-5051) IntroductionHuman platelets are anucleated cells that not only play a crucial role in primary hemostasis and wound repair, but are also particularly important in pathologic conditions such as thrombosis, vascular remodeling, and inflammation. Platelets originate from megakaryocytes (MK) in the bone marrow (BM) by fragmentation of pseudopodial elongations called proplatelets in a process that consumes the entire cytoplasmic content and is tightly regulated by thrombopoietin. 1,2 Human megakaryopoiesis has been studied ex vivo by measuring colony-forming units (CFUs; eg, CFU-MK, CFU-granulocyte, erythrocyte, macrophage, megakaryocyte), 3,4 MK polyploidy state, 5,6 expression of MK markers, 7 and novel genes expressed during MK differentiation. [8][9][10] Unraveling molecular mechanisms involved in megakaryopoiesis and thrombopoiesis is particularly relevant in the light of thrombocytopenia and pancytopenia associated with widespread use of high-dose chemotherapy for treatment of most cancers, also occurring after stem cell transplantation. Therefore, there has been an increasing interest in generating human platelets from MK in culture as well as in developing animal models of human hematopoiesis.Human platelet production has been described from differentiation of CD34 ϩ progenitor cells, isolated from mobilized peripheral blood (PB) or umbilical cord blood (CB), cultured in medium with a cytokine mixture containing thrombopoietin. 5,[11][12][13][14][15] Such produced platelets are functional, as demonstrated in aggregation assays and by expression of P-selectin on the platelet surface or by activation of glycosylphosphatidylinosito...

show abstract

Importance of Platelet Phospholipase Cγ2 Signaling in Arterial Thrombosis as a Function of Lesion Severity

Cited by 81 publications

References 37 publications

Par4 is required for platelet thrombus propagation but not fibrin generation in a mouse model of thrombosis

Par4 is required for platelet thrombus propagation but not fibrin generation in a mouse model of thrombosis

A critical role for extracellular protein disulfide isomerase during thrombus formation in mice

Human platelets produced in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice upon transplantation of human cord blood CD34+ cells are functionally active in an ex vivo flow model of thrombosis

Contact Info

Product

Resources

About