Monomeric CRP is prothrombotic and dissociates from circulating pentameric CRP on adhered activated platelets under flow.
2011, Cardiovasc Res. 2011 Aug 22. [Epub ahead of print]
Molins B, Peña E, de la Torre R, Badimon L.
Autors del centre relacionats: Badimon Lina, Peña Esther.
Molins B, Peña E, de la Torre R, Badimon L.
Autors del centre relacionats: Badimon Lina, Peña Esther.
Cardiovascular Research Center, CSIC-ICCC, Institut Investigacions Biomèdiques Sant Pau, Barcelona; Ciber Patofisiologia de la Obesidad y Nutrición, Institute Carlos III.
Abstract - Aims We previously reported that C-reactive protein (CRP) bioactivity on thrombogenesis was based on loss of its pentameric symmetry (pCRP), resulting in formation of monomeric CRP (mCRP). Our purpose was to provide mechanistic information on the direct effects of CRP isoforms on platelet activation and provide a CRP dissociation mechanism in circulating blood. Methods and results CRP-induced platelet activation was evaluated by flow cytometry. Platelet aggregation, clot properties, and coagulation were also measured. Washed platelets were incubated with CRP isoforms and vasodilator-stimulated phosphoprotein (VASP) phosphorylation was analyzed by western blot and immunofluorescence. CRP dissociation under flow was evaluated by confocal microscopy on the surface of adhered platelets after perfusing human blood containing pCRP at different shear rates. Dissociated mCRP thrombogenicity was measured in flow experiments. Platelet aggregation and flow cytometry analysis revealed that mCRP significantly induced platelet aggregation, surface P-selectin and CD63 exposure, and glycoprotein IIb-IIIa activation, whereas pCRP was unable to produce any effect. p38 mitogen-activated protein kinase (MAPK) and Jun N-terminal kinase (JNK) inhibitors, as well as CD36 blocking antibody partially inhibited mCRP-induced platelet activation and aggregation. Additionally, mCRP significantly induced VASP dephosphorylation at serine 239. We found that pCRP dissociated into mCRP on the surface of activated adhered platelets under flow conditions and that this generated mCRP promoted further platelet recruitment. Conclusions These data indicate that whereas serum pCRP may not affect platelet activation, mCRP, which dissociates from pCRP on the surface of activated platelets, could contribute to atherothrombotic complications by promoting thrombosis.
Abstract - Aims We previously reported that C-reactive protein (CRP) bioactivity on thrombogenesis was based on loss of its pentameric symmetry (pCRP), resulting in formation of monomeric CRP (mCRP). Our purpose was to provide mechanistic information on the direct effects of CRP isoforms on platelet activation and provide a CRP dissociation mechanism in circulating blood. Methods and results CRP-induced platelet activation was evaluated by flow cytometry. Platelet aggregation, clot properties, and coagulation were also measured. Washed platelets were incubated with CRP isoforms and vasodilator-stimulated phosphoprotein (VASP) phosphorylation was analyzed by western blot and immunofluorescence. CRP dissociation under flow was evaluated by confocal microscopy on the surface of adhered platelets after perfusing human blood containing pCRP at different shear rates. Dissociated mCRP thrombogenicity was measured in flow experiments. Platelet aggregation and flow cytometry analysis revealed that mCRP significantly induced platelet aggregation, surface P-selectin and CD63 exposure, and glycoprotein IIb-IIIa activation, whereas pCRP was unable to produce any effect. p38 mitogen-activated protein kinase (MAPK) and Jun N-terminal kinase (JNK) inhibitors, as well as CD36 blocking antibody partially inhibited mCRP-induced platelet activation and aggregation. Additionally, mCRP significantly induced VASP dephosphorylation at serine 239. We found that pCRP dissociated into mCRP on the surface of activated adhered platelets under flow conditions and that this generated mCRP promoted further platelet recruitment. Conclusions These data indicate that whereas serum pCRP may not affect platelet activation, mCRP, which dissociates from pCRP on the surface of activated platelets, could contribute to atherothrombotic complications by promoting thrombosis.
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