PB0399 - The NMDA receptor regulates integrin activation and arterial thrombosis through store-operated Ca2+ entry in platelets

Sunday, June 25, 2023

18:30 – 19:30 ET

Room: Exhibition

Co-Author(s)

FR

Friedrich WB Reusswig

Postdoctoral Research Fellow
Department of Vascular- and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
Duesseldorf, Nordrhein-Westfalen, Germany

Co-Author(s)

MY

Münthea Yilmaz

Masters Student
Clinic for Vascular- and Endovascular Surgery, University Clinic of the Heinrich-Heine- University Düsseldorf, Düsseldorf, Germany
Duesseldorf, Nordrhein-Westfalen, Germany
MB

Marius Brechtenkamp

Masters Student
1Clinic for Vascular- and Endovascular Surgery, University Clinic of the Heinrich-Heine- University Düsseldorf, Düsseldorf, Germany
Duesseldorf, Nordrhein-Westfalen, Germany

Presenting Author(s)

Sevgi C. Cengiz, PhD (she/her/hers)

Postdoctoral Researcher
Institute of Experimantal Vascular Medicine
Düsseldorf, Nordrhein-Westfalen, Germany

Co-Author(s)

IK

Irena Krüger

Vetenerian
1Clinic for Vascular- and Endovascular Surgery, University Clinic of the Heinrich-Heine- University Düsseldorf, Düsseldorf, Germany
Duesseldorf, Nordrhein-Westfalen, Germany
EL

Eckhard Lammert

Professor
Institute of Metabolic Physiology, Heinrich-Heine University, Düsseldorf, Germany
Duesseldorf, Nordrhein-Westfalen, Germany
NK

Nikolaj Klöcker

Professor
Institute of Neural and Sensory Physiology, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
Duesseldorf, Nordrhein-Westfalen, Germany
ME

Margitta Elvers

Professor
Clinic for Vascular- and Endovascular Surgery, University Clinic of the Heinrich-Heine- University Düsseldorf, Düsseldorf, Germany.
Duesseldorf, Nordrhein-Westfalen, Germany

Background: NMDA receptors (NMDA-R) are well-known players in the development and function of neuronal cells. However, little is known about non-neuronal NMDA-R and their functional properties. Especially, the role of NMDA-R in platelets is controversially discussed. Some studies propagate an anti-aggregatory effect of NMDA-R activation, while others reported an amplifying role of NMDA-R in platelet activation and aggregation.

Aims: Deciphering the impact of NMDA-R on platelet activity, thrombus formation and hemostasis by genetic means.

Methods: In vitro and in vivo experiments using platelet specific NMDA-R knockout mice (Grin1fl/fl - PF4-Cre+) as well as the NMDA-R specific inhibitor MK-801 for NMDA-R inhibition in human platelets.

Results: We analyzed Grin1fl/fl-Pf4-Cre+ mice with a platelet-specific knock-out of the essential GluN1 subunit of the NMDAR. We found reduced store-operated Ca2+ entry (SOCE), but unaltered store release in GluN1-deficient platelets. Defective SOCE resulted in reduced Src phosphorylation following stimulation of glycoprotein (GP)VI or the thrombin receptor PAR4 followed by decreased integrin activation but unaltered degranulation. Consequently, thrombus formation on collagen under flow conditions was reduced ex vivo. To analyze thrombus formation in vivo, two different mouse models of arterial thrombosis were used. We induced the injury of the carotid artery and mesenteric artery by FeCl3. While in the mesenteric artery an enhanced occlusion time of the injured vessel was detected, we observed attenuated appearance of the first thrombi in both used models. This suggests that platelet-specific deficiency of GluN1 protects mice against arterial thrombosis. NMDAR blocking in human platelets resulted in impaired SOCE leading to impaired integrin αIIbβ3 activation and thrombus formation, thus confirming the results with murine NMDA-R knock-out platelets

Conclusion(s): NMDAR signaling is important for SOCE in platelets and contributes to platelet activation and arterial thrombosis. Thus, the NMDAR represents a novel target for anti-platelet therapy in cardiovascular disease.