ORIGINAL ARTICLES   

International Angiology 2000 June;19(2):147-51

Copyright © 2001 EDIZIONI MINERVA MEDICA

lingua: Inglese

Platelet surface P-selectin molecules increased after exposing platelet to a high shear flow

Goto S., Ichikawa N., Lee M., Goto M., Sakai H., Kim J. J., Yoshida M., Handa M. *, Ikeda Y. **, Handa S.

From the Division of Cardiology, Tokai University School of Medicine, Isehara, Japan * Blood Center and ** Department of Medicine, Keio University School of Medicine, Tokyo, Japan

Background. P-selec­tin is known to play a cru­cial role in leu­co­cyte recruit­ment at sites of vas­cu­lar inju­ry. Although plate­let sur­face expres­sion of P-selec­tin mole­cules are well known to occur after plate­let stim­u­la­tion by chem­i­cal ago­nists such as α-throm­bin, it is still uncer­tain wheth­er P-selec­tin expres­sion ­occurs in the pro­cess of the more phys­io­log­i­cal plate­let acti­va­tion path­way medi­at­ed by inter­ac­tion ­between von Willebrand fac­tor (vWF) and plate­let recep­tor pro­teins, includ­ing gly­co­pro­tein (GP) Ibα and GP IIb/IIIa, occur­ring under high shear rates gen­er­at­ed by blood flow.
Methods. We have devel­oped a meth­od to ­detect P-selec­tin mole­cules ­expressed on plate­let sur­face with flow-cytom­e­ter and mono­clo­nal anti­body, which can bind exclu­sive­ly to P-selec­tin (WGA1), direct­ly con­ju­gat­ed with flu­o­res­ce­in iso­thi­oc­y­nate. This meth­od ­allowed us to meas­ure plate­let sur­face P-selec­tin mole­cules semi-quan­ti­ta­tive­ly.
Results. We dem­on­strat­ed that a sig­nif­i­cant ­increase in plate­let sur­face P-selec­tin mole­cules occurred after expos­ing plate­lets to a rel­a­tive­ly high shear rate of 10,800 s-1. We have also dem­on­strat­ed that shear-­induced sur­face expres­sion of P-selec­tin as well as micro­par­ti­cle ­release from plate­lets depend­ed at least on the inter­ac­tion ­between von Willebrand fac­tor and gly­co­pro­tein Ibα, a plate­let sur­face recep­tor for the for­mer.
Conclusions. Shear-­induced von Willebrand-factor medi­at­ed sur­face expres­sion of P-selec­tin may play a role in leu­co­cyte recruit­ment in plate­let throm­bi at vas­cu­lar inju­ry sites.