PB1397 - Platelet Activating and Fibrin Generating Properties of Distinct Vascular Smooth Muscle Cell Phenotypes

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Constance Baaten, PhD

postdoctoral researcher
Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
Maastricht, Limburg, Netherlands

Co-Author(s)

AV

Alicia Veninga

PhD student
Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
Maastricht, Limburg, Netherlands
AJ

Armand Jaminon

Postdoctoral researcher
Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
Maastricht, Limburg, Netherlands
Fd

Femke de Vries

PhD student
Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
Maastricht, Limburg, Netherlands
LS

Leon J. Schurgers

Professor
Department of BIochemistry, Cardiovascular Research Institute Maastricht, Maastricht University
Maastricht, Limburg, Netherlands
Paola van der Meijden, PhD

Assistant Professor
Department of Biochemistry, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
Maastricht, Limburg, Netherlands

Background: Upon endothelial injury or dysfunction, vascular smooth muscle cells (VSMC) and extracellular matrix can be exposed to the circulation and thereby activate the haemostatic system. VSMCs actively support platelet plug assembly and fibrin formation. Moreover, pathological conditions can drive VSMCs from a quiescent, contractile phenotype towards a proliferative synthetic phenotype, potentially altering their thrombogenicity.

Aims: To study the thrombogenicity of contractile versus synthetic VSMCs and to characterize thrombi formed on these distinct VSMC phenotypes.

Methods: Primary human VSMCs were isolated from healthy aortic tissue, obtained from Maastricht University Medical Centre+. Collection, storage, and use of tissue and human aortic samples agreed with the Dutch Code for Proper Secondary Use of Human Tissue. Upon written informed consent, blood samples were collected from healthy donors free from antithrombotic drugs. VSMCs were cultured on glass coverslips and maintained as contractile VSMCs or differentiated towards synthetic VSMCs using PDGF-BB. To determine VSMC-mediated platelet adhesion and fibrin formation under flow, recalcified citrated whole blood was perfused over VSMCs at 1000 s-1 for 7 min using the Maastricht flow chamber.

Results: Synthetic VSMCs induced the formation of larger thrombi with more fibrin compared to contractile VSMCs. Interestingly, we observed significantly more erythrocytes present in and around thrombi formed on synthetic VSMCs, suggesting upregulated expression of receptors and/or ligands for erythrocyte adhesion by synthetic VSMCs. To determine whether thrombus formation on synthetic VSMCs is more driven by coagulation, whole blood was pre-treated with dabigatran, inhibiting thrombin. Dabigatran strongly suppressed fibrin formation and reduced platelet adhesion and aggregation for both VSMC phenotypes as well, indicating that thrombus growth on synthetic as well as contractile VSMCs is highly dependent on coagulation activation.

Conclusion(s): Collectively, our findings point to a higher thrombogenicity of synthetic VSMCs compared to contractile VSMCs.

Funding: Dutch Heart Foundation 2020T020