Project 11

primary: Dr. Elisabetta Castoldi (CARIM), Prof. Dr. Pierre Morange (C2VN), tertiary: Tim Beissert (TRON)

CARIM (Maastricht, Netherlands), C2VN (Marseille, France), TRON (Mainz, Germany)

Universities of Maastricht and Marseille

Alternative splicing of key coagulation factors has been shown to result in a markedly different activity of these factors and plays a pivotal role in regulating the haemostatic balance. This includes a splicing variant of fibrinogen (fibrinogen γ’) which is associated with an increased risk of venous thrombosis. Thus, we hypothesize that genetic variants and splicing isoforms of coagulation factors are associated with an increased thrombosis risk and their detection in the blood plasma may reveal a procoagulant phenotype.

ESR11 will search for associations between genetic markers in common variants of coagulation-related genes, levels of coagulation factors/inhibitors including their splicing variants, and the risk of thrombosis in existing patient cohorts. The cohorts employed are the SCACORO study (4,000 patients with acute coronary syndrome), the AtheroGene study (2,240 patients with stable angina pectoris or acute coronary syndrome), and MARTHA+MARFAST (2,207 patients with thrombosis or thrombophilia). Subsequently, using cell cultures and biochemical assays in plasma, the molecular mechanisms of the identified associations with a focus on the candidate genes F5 (factor V), TFPI (tissue-factor pathway inhibitor) and FGG (fibrinogen gamma-chain) will be studied. ESR11 will then identify the genetic determinants of factor V-short (FV-short) – a carrier of TFPIα – by genotyping and factor/activity measurements in patient plasma, using minigene models and RT-PCR. ESR11 will investigate the possible mechanisms by which alternatively spliced fibrinogen γ’ affects the risk of thrombosis. Plasma from patients with low fibrinogen γ’ levels and high fibrinogen γ’ levels will be compared by thrombin generation, rotational thromboelastography, and fibrin flow tests. Additional effects of transcriptome 3'-end diversification of the FGG mRNAs will be examined with ESR12. At the non-academic partner TRON, ESR11 will be trained in validation of RNA-based biomarkers.

• Dahlbäck B. Novel insights into the regulation of coagulation by factor V isoforms, tissue factor pathway inhibitor-α, and protein S. J Thromb Haemost 2017; 15: 1241-1250.
• Uitte de Willige S, Standeven KF, Philippou H, Ariëns RA. The pleiotropic role of the fibrinogen gamma' chain in hemostasis. Blood 2009; 114: 3994-4001.