PB0867 - Development of an endothelialized in vitro thrombosis model with a disease relevant extracellular matrix

Background: Acute coronary syndrome (ACS) occurs following the rupture or erosion of an atherosclerotic plaque. The exposed extracellular matrix (ECM), a dynamic, complex network of glycoproteins, collagens and growth factors, activates circulating platelets, initiating thrombosis. Antiplatelet drugs represent the cornerstone treatment for ACS, however there is a need for safer more efficacious therapies, the development of which are dependent on disease relevant models.

Aims: The aim of this study was to develop an in vitro thrombosis model with an endothelial phenotype and ECM relevant to ruptured or eroded plaques, to enable the development of a more stratified antithrombotic approach.

Methods: The composition of the ECM produced by endothelial cells (ECs) and smooth muscle cells (SMCs) under healthy conditions and following disease related stimuli was identified using mass spectrometry. Thrombus formation under arterial flow conditions was measured using fluorescent microscopy on the cell-derived matrices, and on recombinant ‘erosion’ and ‘rupture’ composites designed from ECM characterization in the literature.

Results: Methods were successfully developed to remove ECs and SMCs, leaving an intact ECM for thrombus formation, and to retrieve the cell-derived ECM in sufficient quantities for mass spectrometry. The extracellular matrix generated by ECs and SMCs varied considerably between the different cell treatments and this was reflected in the thrombogenicity of the different cell-derived matrices, with significant differences in the size of the thrombi produced (P < 0.05). Differences were also observed in the thrombogenicity of the composite matrices, with larger thrombi formed under ‘rupture’ conditions.

Conclusion(s): Developing disease-relevant in vitro thrombosis models will facilitate the stratification of antithrombotic treatment based on plaque phenotype and will contribute towards reducing the use of animals in cardiovascular research.