Abstract
We have investigated the role of adenosine diphosphate (ADP) receptors in the adhesion, activation, and aggregation of platelets perfused over immobilized von Willebrand factor (VWF) under high shear stress. Blocking P2Y1 prevented stable platelet adhesion and aggregation, indicative of a complete inhibition of αIIbβ3 activation, and decreased the duration of transient arrests from 5.9 seconds ± 2.8 seconds to 1.2 seconds ± 0.8 seconds; in contrast, blocking P2Y12 inhibited only the formation of larger aggregates. Moreover, blocking P2Y1 decreased the proportion of platelets showing early intracytoplasmic Ca ++ elevations (α/β peaks) from 20.6% ± 1.6% to 14.6% ± 1.5% (P <.01), and the corresponding peak ion concentration from 1543 nM ± 312 nM to 1037 nM ± 322 nM (P <.05); it also abolished the Ca++ elevations seen in firmly attached platelets (γ peaks). Blocking P2Y12 had no effect on these parameters, and did not enhance the effect of inhibiting P2Y1. Inhibition of phospholipase C had similar consequences as the blocking of P2Y1, whereas inhibition of Src family kinases abolished both type α/β and γ Ca++ oscillations, although the former effect required a higher inhibitor concentration. Our results demonstrate that, under elevated shear stress conditions, ADP signaling through P2Y1 may contribute to the initial stages of platelet adhesion and activation mediated by immobilized VWF, and through P2Y12 to sustained thrombus formation.
| Original language | English |
|---|---|
| Pages (from-to) | 3221-3227 |
| Number of pages | 7 |
| Journal | Blood |
| Volume | 104 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Nov 15 2004 |
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ASJC Scopus subject areas
- Hematology
Cite this
Distinct roles of ADP receptors in von Willebrand factor-mediated platelet signaling and activation under high flow. / Mazzucato, Mario; Cozzi, Maria Rita; Pradella, Paola; Ruggeri, Zaverio M.; De Marco, Luigi.
In: Blood, Vol. 104, No. 10, 15.11.2004, p. 3221-3227.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Distinct roles of ADP receptors in von Willebrand factor-mediated platelet signaling and activation under high flow
AU - Mazzucato, Mario
AU - Cozzi, Maria Rita
AU - Pradella, Paola
AU - Ruggeri, Zaverio M.
AU - De Marco, Luigi
PY - 2004/11/15
Y1 - 2004/11/15
N2 - We have investigated the role of adenosine diphosphate (ADP) receptors in the adhesion, activation, and aggregation of platelets perfused over immobilized von Willebrand factor (VWF) under high shear stress. Blocking P2Y1 prevented stable platelet adhesion and aggregation, indicative of a complete inhibition of αIIbβ3 activation, and decreased the duration of transient arrests from 5.9 seconds ± 2.8 seconds to 1.2 seconds ± 0.8 seconds; in contrast, blocking P2Y12 inhibited only the formation of larger aggregates. Moreover, blocking P2Y1 decreased the proportion of platelets showing early intracytoplasmic Ca ++ elevations (α/β peaks) from 20.6% ± 1.6% to 14.6% ± 1.5% (P <.01), and the corresponding peak ion concentration from 1543 nM ± 312 nM to 1037 nM ± 322 nM (P <.05); it also abolished the Ca++ elevations seen in firmly attached platelets (γ peaks). Blocking P2Y12 had no effect on these parameters, and did not enhance the effect of inhibiting P2Y1. Inhibition of phospholipase C had similar consequences as the blocking of P2Y1, whereas inhibition of Src family kinases abolished both type α/β and γ Ca++ oscillations, although the former effect required a higher inhibitor concentration. Our results demonstrate that, under elevated shear stress conditions, ADP signaling through P2Y1 may contribute to the initial stages of platelet adhesion and activation mediated by immobilized VWF, and through P2Y12 to sustained thrombus formation.
AB - We have investigated the role of adenosine diphosphate (ADP) receptors in the adhesion, activation, and aggregation of platelets perfused over immobilized von Willebrand factor (VWF) under high shear stress. Blocking P2Y1 prevented stable platelet adhesion and aggregation, indicative of a complete inhibition of αIIbβ3 activation, and decreased the duration of transient arrests from 5.9 seconds ± 2.8 seconds to 1.2 seconds ± 0.8 seconds; in contrast, blocking P2Y12 inhibited only the formation of larger aggregates. Moreover, blocking P2Y1 decreased the proportion of platelets showing early intracytoplasmic Ca ++ elevations (α/β peaks) from 20.6% ± 1.6% to 14.6% ± 1.5% (P <.01), and the corresponding peak ion concentration from 1543 nM ± 312 nM to 1037 nM ± 322 nM (P <.05); it also abolished the Ca++ elevations seen in firmly attached platelets (γ peaks). Blocking P2Y12 had no effect on these parameters, and did not enhance the effect of inhibiting P2Y1. Inhibition of phospholipase C had similar consequences as the blocking of P2Y1, whereas inhibition of Src family kinases abolished both type α/β and γ Ca++ oscillations, although the former effect required a higher inhibitor concentration. Our results demonstrate that, under elevated shear stress conditions, ADP signaling through P2Y1 may contribute to the initial stages of platelet adhesion and activation mediated by immobilized VWF, and through P2Y12 to sustained thrombus formation.
UR - http://www.scopus.com/inward/record.url?scp=8644278154&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=8644278154&partnerID=8YFLogxK
U2 - 10.1182/blood-2004-03-1145
DO - 10.1182/blood-2004-03-1145
M3 - Article
C2 - 15284110
AN - SCOPUS:8644278154
VL - 104
SP - 3221
EP - 3227
JO - Blood
JF - Blood
SN - 0006-4971
IS - 10
ER -