The leech product saratin is a potent inhibitor of platelet integrin alpha2beta1 and von Willebrand factor binding to collagen
Research article published in FEBS J (2007)
Abstract
Subendothelial collagen plays an important role, via both direct and indirect mechanisms, in the initiation of thrombus formation at sites of vascular injury. Collagen binds plasma von Willebrand factor, which mediates platelet recruitment to collagen under high shear. Subsequently, the direct binding of the platelet receptors glycoprotein VI and alpha2beta1 to collagen is critical for platelet activation and stable adhesion. Leeches, have evolved a number of inhibitors directed towards platelet-collagen interactions so as to prevent hemostasis in the host during hematophagy. In this article, we describe the molecular mechanisms underlying the ability of the leech product saratin to inhibit platelet binding to collagen. In the presence of inhibitors of ADP and thromboxane A2, both saratin and 6F1, a blocking alpha2beta1 mAb, abrogated platelet adhesion to fibrillar and soluble collagen. Additionally, saratin eliminated alpha2beta1-dependent platelet adhesion to soluble collagen in the presence of an Src kinase inhibitor. Moreover, saratin prevented platelet-rich plasma adhesion to fibrillar collagen, a process dependent upon both alpha2beta1 and von Willebrand factor binding to collagen. Furthermore, saratin specifically inhibited the binding of the alpha2 integrin subunit I domain to collagen, and prevented platelet adhesion to collagen under flow to the same extent as observed in the presence of a combination of mAbs to glycoprotein Ib and alpha2beta1. These results demonstrate that saratin interferes with integrin alpha2beta1 binding to collagen in addition to inhibiting von Willebrand factor-collagen binding, presumably by binding to an overlapping epitope on collagen. This has significant implications for the use of saratin as a tool to inhibit platelet-collagen interactions.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Subendothelial collagen plays an important role, via both direct and indirect mechanisms, in the initiation of thrombus formation at sites of vascular injury.
Por qué esto importa para la hirudoterapia
Este estudio caracteriza los mecanismos moleculares mediante los cuales la saratina, un producto salival de sanguijuela, inhibe las interacciones plaqueta-colágeno. Mediante ensayos de adhesión plaquetaria, los autores demuestran que la saratina anuló la adhesión plaquetaria dependiente de la integrina alfa2beta1 al colágeno fibrilar y soluble, previno la adhesión del plasma rico en plaquetas al colágeno fibrilar, inhibió específicamente la unión del dominio I de la integrina alfa2 al colágeno y bloqueó la adhesión plaquetaria bajo flujo de forma similar a anticuerpos combinados contra la glucoproteína Ib y alfa2beta1. La saratina también inhibió la unión del factor de von Willebrand al colágeno. Esto es directamente relevante para el dominio de la ASH como estudio mecanístico de un componente definido del secretoma de la sanguijuela. La advertencia es que se trata de investigación preclínica in vitro; no se involucran sanguijuelas vivas, hirudoterapia ni desenlaces clínicos.
Citación
The leech product saratin is a potent inhibitor of platelet integrin alpha2beta1 and von Willebrand factor binding to collagen.
White TC et al. · FEBS J, 2007
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026