TY - JOUR

T1 - Multifaceted effects of arachidonic acid and interaction with cyclic nucleotides in human platelets

AU - Rukoyatkina, Natalia

AU - Shpakova, Valentina

AU - Panteleev, Michael

AU - Kharazova, Alexandra

AU - Gambaryan, Stepan

AU - Geiger, Joerg

PY - 2018/11/1

Y1 - 2018/11/1

N2 - Introduction: Arachidonic acid induced aggregation is a generally accepted test for aspirin resistance. However, doubts have been raised that arachidonic acid stimulated aggregation can be regarded as reliable testing for aspirin resistance. Arachidonic acid, in addition to platelet activation, can induce phosphatidylserine translocation on the outer surface of platelet membrane which could be mediated by apoptosis pathways or transformation of platelets to the procoagulant state. Materials and methods: We explored effects of arachidonic acid over a vast range of concentrations and a wide range of read-outs for human platelet activation, procoagulant activity, and platelet viability. Additionally we tested whether cAMP- or cGMP-dependent protein kinase activation can inhibit procoagulant activity or platelet viability. Results: Arachidonic acid-induced washed platelet activation was detected at low micromolar concentrations during the first 2 min of stimulation. After longer incubation and/or at higher concentrations arachidonic acid triggered platelet procoagulant activity and reduced platelet viability. At the same time, arachidonic acid stimulated adenylate cyclase mediated protein phosphorylation which correlated with reduced platelet activation. Moreover, additional stimulation of cAMP- or cGMP-dependent protein kinase inhibited only platelet activation, but did not prevent pro-coagulant activity and platelet death. Conclusions: While arachidonic acid induces platelet activation at low concentrations and during short incubation time, higher concentrations and lasting incubation evokes adenylate cyclase activation and subsequent protein phosphorylation corresponding to reduced platelet activation, but also enhanced pro-coagulant activity and reduced viability. Our observations provide further proof for the complex fine tuning of platelet responses in a time and agonist concentration dependent manner.

AB - Introduction: Arachidonic acid induced aggregation is a generally accepted test for aspirin resistance. However, doubts have been raised that arachidonic acid stimulated aggregation can be regarded as reliable testing for aspirin resistance. Arachidonic acid, in addition to platelet activation, can induce phosphatidylserine translocation on the outer surface of platelet membrane which could be mediated by apoptosis pathways or transformation of platelets to the procoagulant state. Materials and methods: We explored effects of arachidonic acid over a vast range of concentrations and a wide range of read-outs for human platelet activation, procoagulant activity, and platelet viability. Additionally we tested whether cAMP- or cGMP-dependent protein kinase activation can inhibit procoagulant activity or platelet viability. Results: Arachidonic acid-induced washed platelet activation was detected at low micromolar concentrations during the first 2 min of stimulation. After longer incubation and/or at higher concentrations arachidonic acid triggered platelet procoagulant activity and reduced platelet viability. At the same time, arachidonic acid stimulated adenylate cyclase mediated protein phosphorylation which correlated with reduced platelet activation. Moreover, additional stimulation of cAMP- or cGMP-dependent protein kinase inhibited only platelet activation, but did not prevent pro-coagulant activity and platelet death. Conclusions: While arachidonic acid induces platelet activation at low concentrations and during short incubation time, higher concentrations and lasting incubation evokes adenylate cyclase activation and subsequent protein phosphorylation corresponding to reduced platelet activation, but also enhanced pro-coagulant activity and reduced viability. Our observations provide further proof for the complex fine tuning of platelet responses in a time and agonist concentration dependent manner.

KW - Arachidonic acid

KW - Blood platelets

KW - cAMP dependent protein kinase

KW - Phosphatidylserine

KW - Protein phosphorylation

KW - Vasodilator stimulated phosphoprotein

UR - http://www.scopus.com/inward/record.url?scp=85053385194&partnerID=8YFLogxK

U2 - 10.1016/j.thromres.2018.09.047

DO - 10.1016/j.thromres.2018.09.047

M3 - Article

C2 - 30240944

AN - SCOPUS:85053385194

VL - 171

SP - 22

EP - 30

JO - Thrombosis Research

JF - Thrombosis Research

SN - 0049-3848

ER -