Novel synthetic collagen fibers, poly(PHG), stimulate platelet aggregation through glycoprotein VI

Abstract

Edited by Veli-Pekka LehtoKeywords: Collagen Synthetic collagen Collagen-related peptide Blood platelet Glycoprotein VI a b s t r a c t Novel synthetic collagen fibers, poly(PHG) made by polycondensation of Pro-Hyp-Gly, spontaneously assume polymeric structure with molecular weights greater than 10 5 . Its application for biomaterials has been explored, but that for a platelet agonist has not been investigated. Poly(PHG)-induced platelet aggregation independently of thromboxane A 2 and integrin a2b1. Poly(PHG)-induced tyrosine phosphorylation of glycoprotein VI (GPVI)-related molecules and failed to activate GPVI/ FcRc-deficient platelets. Binding of GPVI to poly(PHG) was confirmed by a surface plasmon resonance spectroscopy, suggesting that poly(PHG) activates platelets through GPVI. Poly(PHG) is an useful research tool to investigate GPVI-mediated signals and a substitute for collagen in platelet functional assays.

Measurement of soluble C-type lectin-like receptor 2 in human plasma

“…Rhodocytin was purified as described previously [13]. The GPVI agonist poly(PHG) was a generous gift from the JNC Corp. (Yokohama, Japan) [14]. Collagen-related peptide (CRP) was synthesized by Peptide Institute Inc. (Osaka, Japan) and cross-linked with glutaraldehyde as described previously [15].…”

Platelet Activation Receptor CLEC-2 Regulates Blood/Lymphatic Vessel Separation by Inhibiting Proliferation, Migration, and Tube Formation of Lymphatic Endothelial Cells

“…Poly(PHG) is a synthetic collagen fiber made by polycondensation of Pro-HypGly, which spontaneously assumes a polymeric structure with a molecular mass greater than 10 5 . Poly(PHG) has been proven to potently stimulate platelets through GPVI (16). After stimulation with poly(PHG) for 10 min without stirring, platelets were removed by centrifugation, and the resultant supernatant was filtered using a 0.22-m filter to completely remove the platelets from the supernatant.…”

Essential in Vivo Roles of the C-type Lectin Receptor CLEC-2

“…Poly(PHG), a specific GPVI agonist, was generated as described previously (16). 300 l of washed platelets (2.0 ϫ 10 8 /ml) from CLEC-2 or WT chimeras was used for aggregation studies.…”

“…Therefore, we sought to investigate the responses of CLEC-2-deficient platelets to those agonists or extracellular matrices that participate in physiological thrombus formation. CLEC-2-deficient platelets failed to aggregate in response to rhodocytin, a CLEC-2-activating snake venom, but they fully aggregated upon stimulation with other classical agonists, including ADP, U46619, collagen, and poly(PHG) (a GPVI-specific agonist peptide) (16) and thrombin receptor PAR-4-activating peptide (Fig. 4C).…”